diff --git a/src/tools/clippy/.cargo/config b/src/tools/clippy/.cargo/config
new file mode 100644
index 00000000000..2bad3b9c57f
--- /dev/null
+++ b/src/tools/clippy/.cargo/config
@@ -0,0 +1,6 @@
+[alias]
+uitest = "test --test compile-test"
+dev = "run --package clippy_dev --bin clippy_dev --manifest-path clippy_dev/Cargo.toml --"
+
+[build]
+rustflags = ["-Zunstable-options"]
diff --git a/src/tools/clippy/.editorconfig b/src/tools/clippy/.editorconfig
new file mode 100644
index 00000000000..a13173544d8
--- /dev/null
+++ b/src/tools/clippy/.editorconfig
@@ -0,0 +1,19 @@
+# EditorConfig helps developers define and maintain consistent
+# coding styles between different editors and IDEs
+# editorconfig.org
+
+root = true
+
+[*]
+end_of_line = lf
+charset = utf-8
+trim_trailing_whitespace = true
+insert_final_newline = true
+indent_style = space
+indent_size = 4
+
+[*.md]
+trim_trailing_whitespace = false
+
+[*.yml]
+indent_size = 2
diff --git a/src/tools/clippy/.gitattributes b/src/tools/clippy/.gitattributes
new file mode 100644
index 00000000000..90cf33053c7
--- /dev/null
+++ b/src/tools/clippy/.gitattributes
@@ -0,0 +1,3 @@
+* text=auto eol=lf
+*.rs text eol=lf whitespace=tab-in-indent,trailing-space,tabwidth=4
+*.fixed linguist-language=Rust
diff --git a/src/tools/clippy/.github/ISSUE_TEMPLATE.md b/src/tools/clippy/.github/ISSUE_TEMPLATE.md
new file mode 100644
index 00000000000..15006a07b44
--- /dev/null
+++ b/src/tools/clippy/.github/ISSUE_TEMPLATE.md
@@ -0,0 +1,8 @@
+
diff --git a/src/tools/clippy/.github/PULL_REQUEST_TEMPLATE.md b/src/tools/clippy/.github/PULL_REQUEST_TEMPLATE.md
new file mode 100644
index 00000000000..97aa220afea
--- /dev/null
+++ b/src/tools/clippy/.github/PULL_REQUEST_TEMPLATE.md
@@ -0,0 +1,31 @@
+Thank you for making Clippy better!
+
+We're collecting our changelog from pull request descriptions.
+If your PR only updates to the latest nightly, you can leave the
+`changelog` entry as `none`. Otherwise, please write a short comment
+explaining your change.
+
+If your PR fixes an issue, you can add "fixes #issue_number" into this
+PR description. This way the issue will be automatically closed when
+your PR is merged.
+
+If you added a new lint, here's a checklist for things that will be
+checked during review or continuous integration.
+
+- [ ] Followed [lint naming conventions][lint_naming]
+- [ ] Added passing UI tests (including committed `.stderr` file)
+- [ ] `cargo test` passes locally
+- [ ] Executed `cargo dev update_lints`
+- [ ] Added lint documentation
+- [ ] Run `cargo dev fmt`
+
+[lint_naming]: https://rust-lang.github.io/rfcs/0344-conventions-galore.html#lints
+
+Note that you can skip the above if you are just opening a WIP PR in
+order to get feedback.
+
+Delete this line and everything above before opening your PR.
+
+---
+
+changelog: none
diff --git a/src/tools/clippy/.github/deploy.sh b/src/tools/clippy/.github/deploy.sh
new file mode 100644
index 00000000000..3f425e5b725
--- /dev/null
+++ b/src/tools/clippy/.github/deploy.sh
@@ -0,0 +1,57 @@
+#!/bin/bash
+
+set -ex
+
+echo "Removing the current docs for master"
+rm -rf out/master/ || exit 0
+
+echo "Making the docs for master"
+mkdir out/master/
+cp util/gh-pages/index.html out/master
+python3 ./util/export.py out/master/lints.json
+
+if [[ -n $TAG_NAME ]]; then
+ echo "Save the doc for the current tag ($TAG_NAME) and point stable/ to it"
+ cp -r out/master "out/$TAG_NAME"
+ rm -f out/stable
+ ln -s "$TAG_NAME" out/stable
+fi
+
+if [[ $BETA = "true" ]]; then
+ echo "Update documentation for the beta release"
+ cp -r out/master out/beta
+fi
+
+# Generate version index that is shown as root index page
+cp util/gh-pages/versions.html out/index.html
+
+echo "Making the versions.json file"
+python3 ./util/versions.py out
+
+cd out
+# Now let's go have some fun with the cloned repo
+git config user.name "GHA CI"
+git config user.email "gha@ci.invalid"
+
+if git diff --exit-code --quiet; then
+ echo "No changes to the output on this push; exiting."
+ exit 0
+fi
+
+if [[ -n $TAG_NAME ]]; then
+ # Add the new dir
+ git add "$TAG_NAME"
+ # Update the symlink
+ git add stable
+ # Update versions file
+ git add versions.json
+ git commit -m "Add documentation for ${TAG_NAME} release: ${SHA}"
+elif [[ $BETA = "true" ]]; then
+ git add beta
+ git commit -m "Automatic deploy to GitHub Pages (beta): ${SHA}"
+else
+ git add .
+ git commit -m "Automatic deploy to GitHub Pages: ${SHA}"
+fi
+
+git push "$SSH_REPO" "$TARGET_BRANCH"
diff --git a/src/tools/clippy/.github/driver.sh b/src/tools/clippy/.github/driver.sh
new file mode 100644
index 00000000000..a2e87f5eb37
--- /dev/null
+++ b/src/tools/clippy/.github/driver.sh
@@ -0,0 +1,29 @@
+#!/bin/bash
+
+set -ex
+
+# Check sysroot handling
+sysroot=$(./target/debug/clippy-driver --print sysroot)
+test "$sysroot" = "$(rustc --print sysroot)"
+
+if [[ ${OS} == "Windows" ]]; then
+ desired_sysroot=C:/tmp
+else
+ desired_sysroot=/tmp
+fi
+sysroot=$(./target/debug/clippy-driver --sysroot $desired_sysroot --print sysroot)
+test "$sysroot" = $desired_sysroot
+
+sysroot=$(SYSROOT=$desired_sysroot ./target/debug/clippy-driver --print sysroot)
+test "$sysroot" = $desired_sysroot
+
+# Make sure this isn't set - clippy-driver should cope without it
+unset CARGO_MANIFEST_DIR
+
+# Run a lint and make sure it produces the expected output. It's also expected to exit with code 1
+# FIXME: How to match the clippy invocation in compile-test.rs?
+./target/debug/clippy-driver -Dwarnings -Aunused -Zui-testing --emit metadata --crate-type bin tests/ui/cstring.rs 2> cstring.stderr && exit 1
+sed -e "s,tests/ui,\$DIR," -e "/= help/d" cstring.stderr > normalized.stderr
+diff normalized.stderr tests/ui/cstring.stderr
+
+# TODO: CLIPPY_CONF_DIR / CARGO_MANIFEST_DIR
diff --git a/src/tools/clippy/.github/workflows/clippy.yml b/src/tools/clippy/.github/workflows/clippy.yml
new file mode 100644
index 00000000000..8edf0c23860
--- /dev/null
+++ b/src/tools/clippy/.github/workflows/clippy.yml
@@ -0,0 +1,99 @@
+name: Clippy Test
+
+on:
+ push:
+ # Ignore bors branches, since they are covered by `clippy_bors.yml`
+ branches-ignore:
+ - auto
+ - try
+ # Don't run Clippy tests, when only textfiles were modified
+ paths-ignore:
+ - 'COPYRIGHT'
+ - 'LICENSE-*'
+ - '**.md'
+ - '**.txt'
+ pull_request:
+ # Don't run Clippy tests, when only textfiles were modified
+ paths-ignore:
+ - 'COPYRIGHT'
+ - 'LICENSE-*'
+ - '**.md'
+ - '**.txt'
+
+env:
+ RUST_BACKTRACE: 1
+ CARGO_TARGET_DIR: '${{ github.workspace }}/target'
+ NO_FMT_TEST: 1
+
+jobs:
+ base:
+ runs-on: ubuntu-latest
+
+ steps:
+ # Setup
+ - uses: rust-lang/simpleinfra/github-actions/cancel-outdated-builds@master
+ with:
+ github_token: "${{ secrets.github_token }}"
+
+ - name: rust-toolchain
+ uses: actions-rs/toolchain@v1.0.3
+ with:
+ toolchain: nightly
+ target: x86_64-unknown-linux-gnu
+ profile: minimal
+
+ - name: Checkout
+ uses: actions/checkout@v2.0.0
+
+ - name: Run cargo update
+ run: cargo update
+
+ - name: Cache cargo dir
+ uses: actions/cache@v1
+ with:
+ path: ~/.cargo
+ key: ${{ runner.os }}-x86_64-unknown-linux-gnu-${{ hashFiles('Cargo.lock') }}
+ restore-keys: |
+ ${{ runner.os }}-x86_64-unknown-linux-gnu
+
+ - name: Master Toolchain Setup
+ run: bash setup-toolchain.sh
+
+ # Run
+ - name: Set LD_LIBRARY_PATH (Linux)
+ run: |
+ SYSROOT=$(rustc --print sysroot)
+ echo "::set-env name=LD_LIBRARY_PATH::${SYSROOT}/lib${LD_LIBRARY_PATH+:${LD_LIBRARY_PATH}}"
+
+ - name: Build
+ run: cargo build --features deny-warnings
+
+ - name: Test
+ run: cargo test --features deny-warnings
+
+ - name: Test clippy_lints
+ run: cargo test --features deny-warnings
+ working-directory: clippy_lints
+
+ - name: Test rustc_tools_util
+ run: cargo test --features deny-warnings
+ working-directory: rustc_tools_util
+
+ - name: Test clippy_dev
+ run: cargo test --features deny-warnings
+ working-directory: clippy_dev
+
+ - name: Test cargo-clippy
+ run: ../target/debug/cargo-clippy
+ working-directory: clippy_workspace_tests
+
+ - name: Test clippy-driver
+ run: bash .github/driver.sh
+ env:
+ OS: ${{ runner.os }}
+
+ # Cleanup
+ - name: Run cargo-cache --autoclean
+ run: |
+ cargo +nightly install cargo-cache --no-default-features --features ci-autoclean cargo-cache
+ cargo cache
diff --git a/src/tools/clippy/.github/workflows/clippy_bors.yml b/src/tools/clippy/.github/workflows/clippy_bors.yml
new file mode 100644
index 00000000000..6675a1029bb
--- /dev/null
+++ b/src/tools/clippy/.github/workflows/clippy_bors.yml
@@ -0,0 +1,329 @@
+name: Clippy Test (bors)
+
+on:
+ push:
+ branches:
+ - auto
+ - try
+
+env:
+ RUST_BACKTRACE: 1
+ CARGO_TARGET_DIR: '${{ github.workspace }}/target'
+ NO_FMT_TEST: 1
+
+jobs:
+ changelog:
+ runs-on: ubuntu-latest
+
+ steps:
+ - uses: rust-lang/simpleinfra/github-actions/cancel-outdated-builds@master
+ with:
+ github_token: "${{ secrets.github_token }}"
+ - name: Checkout
+ uses: actions/checkout@v2.0.0
+ with:
+ ref: ${{ github.ref }}
+
+ # Run
+ - name: Check Changelog
+ run: |
+ MESSAGE=$(git log --format=%B -n 1)
+ PR=$(echo "$MESSAGE" | grep -o "#[0-9]*" | head -1 | sed -e 's/^#//')
+ output=$(curl -H "Authorization: token ${{ secrets.GITHUB_TOKEN }}" -s "https://api.github.com/repos/rust-lang/rust-clippy/pulls/$PR" | \
+ python -c "import sys, json; print(json.load(sys.stdin)['body'])" | \
+ grep "^changelog: " | \
+ sed "s/changelog: //g")
+ if [[ -z "$output" ]]; then
+ echo "ERROR: PR body must contain 'changelog: ...'"
+ exit 1
+ elif [[ "$output" = "none" ]]; then
+ echo "WARNING: changelog is 'none'"
+ fi
+ env:
+ PYTHONIOENCODING: 'utf-8'
+ base:
+ needs: changelog
+ strategy:
+ matrix:
+ os: [ubuntu-latest, windows-latest, macos-latest]
+ host: [x86_64-unknown-linux-gnu, i686-unknown-linux-gnu, x86_64-apple-darwin, x86_64-pc-windows-msvc]
+ exclude:
+ - os: ubuntu-latest
+ host: x86_64-apple-darwin
+ - os: ubuntu-latest
+ host: x86_64-pc-windows-msvc
+ - os: macos-latest
+ host: x86_64-unknown-linux-gnu
+ - os: macos-latest
+ host: i686-unknown-linux-gnu
+ - os: macos-latest
+ host: x86_64-pc-windows-msvc
+ - os: windows-latest
+ host: x86_64-unknown-linux-gnu
+ - os: windows-latest
+ host: i686-unknown-linux-gnu
+ - os: windows-latest
+ host: x86_64-apple-darwin
+
+ runs-on: ${{ matrix.os }}
+
+ steps:
+ # Setup
+ - uses: rust-lang/simpleinfra/github-actions/cancel-outdated-builds@master
+ with:
+ github_token: "${{ secrets.github_token }}"
+
+ - name: Install dependencies (Linux-i686)
+ run: |
+ sudo dpkg --add-architecture i386
+ sudo apt-get update
+ sudo apt-get install gcc-multilib libssl-dev:i386 libgit2-dev:i386
+ if: matrix.host == 'i686-unknown-linux-gnu'
+
+ - name: rust-toolchain
+ uses: actions-rs/toolchain@v1.0.3
+ with:
+ toolchain: nightly
+ target: ${{ matrix.host }}
+ profile: minimal
+
+ - name: Checkout
+ uses: actions/checkout@v2.0.0
+
+ - name: Run cargo update
+ run: cargo update
+
+ - name: Cache cargo dir
+ uses: actions/cache@v1
+ with:
+ path: ~/.cargo
+ key: ${{ runner.os }}-${{ matrix.host }}-${{ hashFiles('Cargo.lock') }}
+ restore-keys: |
+ ${{ runner.os }}-${{ matrix.host }}
+
+ - name: Master Toolchain Setup
+ run: bash setup-toolchain.sh
+ env:
+ HOST_TOOLCHAIN: ${{ matrix.host }}
+ shell: bash
+
+ # Run
+ - name: Set LD_LIBRARY_PATH (Linux)
+ if: runner.os == 'Linux'
+ run: |
+ SYSROOT=$(rustc --print sysroot)
+ echo "::set-env name=LD_LIBRARY_PATH::${SYSROOT}/lib${LD_LIBRARY_PATH+:${LD_LIBRARY_PATH}}"
+ - name: Link rustc dylib (MacOS)
+ if: runner.os == 'macOS'
+ run: |
+ SYSROOT=$(rustc --print sysroot)
+ sudo mkdir -p /usr/local/lib
+ sudo find "${SYSROOT}/lib" -maxdepth 1 -name '*dylib' -exec ln -s {} /usr/local/lib \;
+ - name: Set PATH (Windows)
+ if: runner.os == 'Windows'
+ run: |
+ $sysroot = rustc --print sysroot
+ $env:PATH += ';' + $sysroot + '\bin'
+ echo "::set-env name=PATH::$env:PATH"
+
+ - name: Build
+ run: cargo build --features deny-warnings
+ shell: bash
+
+ - name: Test
+ run: cargo test --features deny-warnings
+ shell: bash
+
+ - name: Test clippy_lints
+ run: cargo test --features deny-warnings
+ shell: bash
+ working-directory: clippy_lints
+
+ - name: Test rustc_tools_util
+ run: cargo test --features deny-warnings
+ shell: bash
+ working-directory: rustc_tools_util
+
+ - name: Test clippy_dev
+ run: cargo test --features deny-warnings
+ shell: bash
+ working-directory: clippy_dev
+
+ - name: Test cargo-clippy
+ run: ../target/debug/cargo-clippy
+ shell: bash
+ working-directory: clippy_workspace_tests
+
+ - name: Test clippy-driver
+ run: bash .github/driver.sh
+ shell: bash
+ env:
+ OS: ${{ runner.os }}
+
+ # Cleanup
+ - name: Run cargo-cache --autoclean
+ run: |
+ cargo +nightly install cargo-cache --no-default-features --features ci-autoclean cargo-cache
+ cargo cache
+ shell: bash
+ integration_build:
+ needs: changelog
+ runs-on: ubuntu-latest
+
+ steps:
+ # Setup
+ - uses: rust-lang/simpleinfra/github-actions/cancel-outdated-builds@master
+ with:
+ github_token: "${{ secrets.github_token }}"
+
+ - name: rust-toolchain
+ uses: actions-rs/toolchain@v1.0.3
+ with:
+ toolchain: nightly
+ target: x86_64-unknown-linux-gnu
+ profile: minimal
+
+ - name: Checkout
+ uses: actions/checkout@v2.0.0
+
+ - name: Run cargo update
+ run: cargo update
+
+ - name: Cache cargo dir
+ uses: actions/cache@v1
+ with:
+ path: ~/.cargo
+ key: ${{ runner.os }}-x86_64-unknown-linux-gnu-${{ hashFiles('Cargo.lock') }}
+ restore-keys: |
+ ${{ runner.os }}-x86_64-unknown-linux-gnu
+
+ - name: Master Toolchain Setup
+ run: bash setup-toolchain.sh
+
+ # Run
+ - name: Build Integration Test
+ run: cargo test --test integration --features integration --no-run
+
+ # Upload
+ - name: Extract Binaries
+ run: |
+ DIR=$CARGO_TARGET_DIR/debug
+ rm $DIR/deps/integration-*.d
+ mv $DIR/deps/integration-* $DIR/integration
+ find $DIR ! -executable -o -type d ! -path $DIR | xargs rm -rf
+ rm -rf $CARGO_TARGET_DIR/release
+
+ - name: Upload Binaries
+ uses: actions/upload-artifact@v1
+ with:
+ name: target
+ path: target
+
+ # Cleanup
+ - name: Run cargo-cache --autoclean
+ run: |
+ cargo +nightly install cargo-cache --no-default-features --features ci-autoclean cargo-cache
+ cargo cache
+ integration:
+ needs: integration_build
+ strategy:
+ fail-fast: false
+ max-parallel: 6
+ matrix:
+ integration:
+ - 'rust-lang/cargo'
+ - 'rust-lang/rls'
+ - 'rust-lang/chalk'
+ - 'rust-lang/rustfmt'
+ - 'Marwes/combine'
+ - 'Geal/nom'
+ - 'rust-lang/stdarch'
+ - 'serde-rs/serde'
+ - 'chronotope/chrono'
+ - 'hyperium/hyper'
+ - 'rust-random/rand'
+ - 'rust-lang/futures-rs'
+ - 'rust-itertools/itertools'
+ - 'rust-lang-nursery/failure'
+ - 'rust-lang/log'
+
+ runs-on: ubuntu-latest
+
+ steps:
+ # Setup
+ - uses: rust-lang/simpleinfra/github-actions/cancel-outdated-builds@master
+ with:
+ github_token: "${{ secrets.github_token }}"
+
+ - name: rust-toolchain
+ uses: actions-rs/toolchain@v1.0.3
+ with:
+ toolchain: nightly
+ target: x86_64-unknown-linux-gnu
+ profile: minimal
+
+ - name: Checkout
+ uses: actions/checkout@v2.0.0
+
+ - name: Run cargo update
+ run: cargo update
+
+ - name: Cache cargo dir
+ uses: actions/cache@v1
+ with:
+ path: ~/.cargo
+ key: ${{ runner.os }}-x86_64-unknown-linux-gnu-${{ hashFiles('Cargo.lock') }}
+ restore-keys: |
+ ${{ runner.os }}-x86_64-unknown-linux-gnu
+
+ - name: Master Toolchain Setup
+ run: bash setup-toolchain.sh
+
+ # Download
+ - name: Download target dir
+ uses: actions/download-artifact@v1
+ with:
+ name: target
+ path: target
+
+ - name: Make Binaries Executable
+ run: chmod +x $CARGO_TARGET_DIR/debug/*
+
+ # Run
+ - name: Test ${{ matrix.integration }}
+ run: $CARGO_TARGET_DIR/debug/integration
+ env:
+ INTEGRATION: ${{ matrix.integration }}
+ RUSTUP_TOOLCHAIN: master
+
+ # Cleanup
+ - name: Run cargo-cache --autoclean
+ run: |
+ cargo +nightly install cargo-cache --no-default-features --features ci-autoclean cargo-cache
+ cargo cache
+
+ # These jobs doesn't actually test anything, but they're only used to tell
+ # bors the build completed, as there is no practical way to detect when a
+ # workflow is successful listening to webhooks only.
+ #
+ # ALL THE PREVIOUS JOBS NEED TO BE ADDED TO THE `needs` SECTION OF THIS JOB!
+
+ end-success:
+ name: bors test finished
+ if: github.event.pusher.name == 'bors' && success()
+ runs-on: ubuntu-latest
+ needs: [base, integration]
+
+ steps:
+ - name: Mark the job as successful
+ run: exit 0
+
+ end-failure:
+ name: bors test finished
+ if: github.event.pusher.name == 'bors' && (failure() || cancelled())
+ runs-on: ubuntu-latest
+ needs: [base, integration]
+
+ steps:
+ - name: Mark the job as a failure
+ run: exit 1
diff --git a/src/tools/clippy/.github/workflows/clippy_dev.yml b/src/tools/clippy/.github/workflows/clippy_dev.yml
new file mode 100644
index 00000000000..ec3b43c2f43
--- /dev/null
+++ b/src/tools/clippy/.github/workflows/clippy_dev.yml
@@ -0,0 +1,74 @@
+name: Clippy Dev Test
+
+on:
+ push:
+ branches:
+ - auto
+ - try
+ pull_request:
+ # Only run on paths, that get checked by the clippy_dev tool
+ paths:
+ - 'CHANGELOG.md'
+ - 'README.md'
+ - '**.stderr'
+ - '**.rs'
+
+env:
+ RUST_BACKTRACE: 1
+
+jobs:
+ clippy_dev:
+ runs-on: ubuntu-latest
+
+ steps:
+ # Setup
+ - name: rust-toolchain
+ uses: actions-rs/toolchain@v1.0.3
+ with:
+ toolchain: nightly
+ target: x86_64-unknown-linux-gnu
+ profile: minimal
+ components: rustfmt
+
+ - name: Checkout
+ uses: actions/checkout@v2.0.0
+
+ # Run
+ - name: Build
+ run: cargo build --features deny-warnings
+ working-directory: clippy_dev
+
+ - name: Test limit_stderr_length
+ run: cargo dev limit_stderr_length
+
+ - name: Test update_lints
+ run: cargo dev update_lints --check
+
+ - name: Test fmt
+ run: cargo dev fmt --check
+
+ # These jobs doesn't actually test anything, but they're only used to tell
+ # bors the build completed, as there is no practical way to detect when a
+ # workflow is successful listening to webhooks only.
+ #
+ # ALL THE PREVIOUS JOBS NEED TO BE ADDED TO THE `needs` SECTION OF THIS JOB!
+
+ end-success:
+ name: bors dev test finished
+ if: github.event.pusher.name == 'bors' && success()
+ runs-on: ubuntu-latest
+ needs: [clippy_dev]
+
+ steps:
+ - name: Mark the job as successful
+ run: exit 0
+
+ end-failure:
+ name: bors dev test finished
+ if: github.event.pusher.name == 'bors' && (failure() || cancelled())
+ runs-on: ubuntu-latest
+ needs: [clippy_dev]
+
+ steps:
+ - name: Mark the job as a failure
+ run: exit 1
diff --git a/src/tools/clippy/.github/workflows/deploy.yml b/src/tools/clippy/.github/workflows/deploy.yml
new file mode 100644
index 00000000000..f542f9b02c1
--- /dev/null
+++ b/src/tools/clippy/.github/workflows/deploy.yml
@@ -0,0 +1,51 @@
+name: Deploy
+
+on:
+ push:
+ branches:
+ - master
+ - beta
+ tags:
+ - rust-1.**
+
+env:
+ TARGET_BRANCH: 'gh-pages'
+ SHA: '${{ github.sha }}'
+ SSH_REPO: 'git@github.com:${{ github.repository }}.git'
+
+jobs:
+ deploy:
+ runs-on: ubuntu-latest
+ if: github.repository == 'rust-lang/rust-clippy'
+
+ steps:
+ # Setup
+ - name: Checkout
+ uses: actions/checkout@v2.0.0
+
+ - name: Checkout
+ uses: actions/checkout@v2.0.0
+ with:
+ ref: ${{ env.TARGET_BRANCH }}
+ path: 'out'
+
+ # Run
+ - name: Set tag name
+ if: startswith(github.ref, 'refs/tags/')
+ run: |
+ TAG=$(basename ${{ github.ref }})
+ echo "::set-env name=TAG_NAME::$TAG"
+ - name: Set beta to true
+ if: github.ref == 'refs/heads/beta'
+ run: echo "::set-env name=BETA::true"
+
+ - name: Use scripts and templates from master branch
+ run: |
+ git fetch --no-tags --prune --depth=1 origin master
+ git checkout origin/master -- .github/deploy.sh util/gh-pages/ util/*.py
+
+ - name: Deploy
+ run: |
+ eval "$(ssh-agent -s)"
+ ssh-add - <<< "${{ secrets.DEPLOY_KEY }}"
+ bash .github/deploy.sh
diff --git a/src/tools/clippy/.github/workflows/remark.yml b/src/tools/clippy/.github/workflows/remark.yml
new file mode 100644
index 00000000000..cc175e8bf24
--- /dev/null
+++ b/src/tools/clippy/.github/workflows/remark.yml
@@ -0,0 +1,55 @@
+name: Remark
+
+on:
+ push:
+ branches:
+ - auto
+ - try
+ pull_request:
+ paths:
+ - '**.md'
+
+jobs:
+ remark:
+ runs-on: ubuntu-latest
+
+ steps:
+ # Setup
+ - name: Checkout
+ uses: actions/checkout@v2.0.0
+
+ - name: Setup Node.js
+ uses: actions/setup-node@v1.1.0
+
+ - name: Install remark
+ run: npm install remark-cli remark-lint remark-lint-maximum-line-length remark-preset-lint-recommended
+
+ # Run
+ - name: Check *.md files
+ run: git ls-files -z '*.md' | xargs -0 -n 1 -I {} ./node_modules/.bin/remark {} -u lint -f > /dev/null
+
+ # These jobs doesn't actually test anything, but they're only used to tell
+ # bors the build completed, as there is no practical way to detect when a
+ # workflow is successful listening to webhooks only.
+ #
+ # ALL THE PREVIOUS JOBS NEED TO BE ADDED TO THE `needs` SECTION OF THIS JOB!
+
+ end-success:
+ name: bors remark test finished
+ if: github.event.pusher.name == 'bors' && success()
+ runs-on: ubuntu-latest
+ needs: [remark]
+
+ steps:
+ - name: Mark the job as successful
+ run: exit 0
+
+ end-failure:
+ name: bors remark test finished
+ if: github.event.pusher.name == 'bors' && (failure() || cancelled())
+ runs-on: ubuntu-latest
+ needs: [remark]
+
+ steps:
+ - name: Mark the job as a failure
+ run: exit 1
diff --git a/src/tools/clippy/.gitignore b/src/tools/clippy/.gitignore
new file mode 100644
index 00000000000..adf5e8feddf
--- /dev/null
+++ b/src/tools/clippy/.gitignore
@@ -0,0 +1,37 @@
+# Used by CI to be able to push:
+/.github/deploy_key
+out
+
+# Compiled files
+*.o
+*.d
+*.so
+*.rlib
+*.dll
+*.pyc
+*.rmeta
+
+# Executables
+*.exe
+
+# Generated by Cargo
+*Cargo.lock
+/target
+/clippy_lints/target
+/clippy_workspace_tests/target
+/clippy_dev/target
+/rustc_tools_util/target
+
+# Generated by dogfood
+/target_recur/
+
+# gh pages docs
+util/gh-pages/lints.json
+
+# rustfmt backups
+*.rs.bk
+
+helper.txt
+*.iml
+.vscode
+.idea
diff --git a/src/tools/clippy/.remarkrc b/src/tools/clippy/.remarkrc
new file mode 100644
index 00000000000..0ede7ac75cb
--- /dev/null
+++ b/src/tools/clippy/.remarkrc
@@ -0,0 +1,12 @@
+{
+ "plugins": [
+ "remark-preset-lint-recommended",
+ ["remark-lint-list-item-indent", false],
+ ["remark-lint-no-literal-urls", false],
+ ["remark-lint-no-shortcut-reference-link", false],
+ ["remark-lint-maximum-line-length", 120]
+ ],
+ "settings": {
+ "commonmark": true
+ }
+}
diff --git a/src/tools/clippy/CHANGELOG.md b/src/tools/clippy/CHANGELOG.md
new file mode 100644
index 00000000000..575773580c0
--- /dev/null
+++ b/src/tools/clippy/CHANGELOG.md
@@ -0,0 +1,1657 @@
+# Change Log
+
+All notable changes to this project will be documented in this file.
+See [Changelog Update](doc/changelog_update.md) if you want to update this
+document.
+
+## Unreleased / In Rust Nightly
+
+[891e1a8...master](https://github.com/rust-lang/rust-clippy/compare/891e1a8...master)
+
+## Rust 1.44
+
+Current beta, release 2020-06-04
+
+[204bb9b...891e1a8](https://github.com/rust-lang/rust-clippy/compare/204bb9b...891e1a8)
+
+### New lints
+
+* [`explicit_deref_methods`] [#5226](https://github.com/rust-lang/rust-clippy/pull/5226)
+* [`implicit_saturating_sub`] [#5427](https://github.com/rust-lang/rust-clippy/pull/5427)
+* [`macro_use_imports`] [#5230](https://github.com/rust-lang/rust-clippy/pull/5230)
+* [`verbose_file_reads`] [#5272](https://github.com/rust-lang/rust-clippy/pull/5272)
+* [`future_not_send`] [#5423](https://github.com/rust-lang/rust-clippy/pull/5423)
+* [`redundant_pub_crate`] [#5319](https://github.com/rust-lang/rust-clippy/pull/5319)
+* [`large_const_arrays`] [#5248](https://github.com/rust-lang/rust-clippy/pull/5248)
+* [`result_map_or_into_option`] [#5415](https://github.com/rust-lang/rust-clippy/pull/5415)
+* [`redundant_allocation`] [#5349](https://github.com/rust-lang/rust-clippy/pull/5349)
+* [`fn_address_comparisons`] [#5294](https://github.com/rust-lang/rust-clippy/pull/5294)
+* [`vtable_address_comparisons`] [#5294](https://github.com/rust-lang/rust-clippy/pull/5294)
+
+
+### Moves and Deprecations
+
+* Deprecate [`replace_consts`] lint [#5380](https://github.com/rust-lang/rust-clippy/pull/5380)
+* Move [`cognitive_complexity`] to nursery [#5428](https://github.com/rust-lang/rust-clippy/pull/5428)
+* Move [`useless_transmute`] to nursery [#5364](https://github.com/rust-lang/rust-clippy/pull/5364)
+* Downgrade [`inefficient_to_string`] to pedantic [#5412](https://github.com/rust-lang/rust-clippy/pull/5412)
+* Downgrade [`option_option`] to pedantic [#5401](https://github.com/rust-lang/rust-clippy/pull/5401)
+* Downgrade [`unreadable_literal`] to pedantic [#5419](https://github.com/rust-lang/rust-clippy/pull/5419)
+* Downgrade [`let_unit_value`] to pedantic [#5409](https://github.com/rust-lang/rust-clippy/pull/5409)
+* Downgrade [`trivially_copy_pass_by_ref`] to pedantic [#5410](https://github.com/rust-lang/rust-clippy/pull/5410)
+* Downgrade [`implicit_hasher`] to pedantic [#5411](https://github.com/rust-lang/rust-clippy/pull/5411)
+
+### Enhancements
+
+* On _nightly_ you can now use `cargo clippy --fix -Z unstable-options` to
+ auto-fix lints that support this [#5363](https://github.com/rust-lang/rust-clippy/pull/5363)
+* Make [`redundant_clone`] also trigger on cases where the cloned value is not
+ consumed. [#5304](https://github.com/rust-lang/rust-clippy/pull/5304)
+* Expand [`integer_arithmetic`] to also disallow bit-shifting [#5430](https://github.com/rust-lang/rust-clippy/pull/5430)
+* [`option_as_ref_deref`] now detects more deref cases [#5425](https://github.com/rust-lang/rust-clippy/pull/5425)
+* [`large_enum_variant`] now report the sizes of the largest and second-largest variants [#5466](https://github.com/rust-lang/rust-clippy/pull/5466)
+* [`bool_comparison`] now also checks for inequality comparisons that can be
+ written more concisely [#5365](https://github.com/rust-lang/rust-clippy/pull/5365)
+* Expand [`clone_on_copy`] to work in method call arguments as well [#5441](https://github.com/rust-lang/rust-clippy/pull/5441)
+* [`redundant_pattern_matching`] now also handles `while let` [#5483](https://github.com/rust-lang/rust-clippy/pull/5483)
+* [`integer_arithmetic`] now also lints references of integers [#5329](https://github.com/rust-lang/rust-clippy/pull/5329)
+* Expand [`float_cmp_const`] to also work on arrays [#5345](https://github.com/rust-lang/rust-clippy/pull/5345)
+* Trigger [`map_flatten`] when map is called on an `Option` [#5473](https://github.com/rust-lang/rust-clippy/pull/5473)
+
+### False Positive Fixes
+
+* [`many_single_char_names`] [#5468](https://github.com/rust-lang/rust-clippy/pull/5468)
+* [`should_implement_trait`] [#5437](https://github.com/rust-lang/rust-clippy/pull/5437)
+* [`unused_self`] [#5387](https://github.com/rust-lang/rust-clippy/pull/5387)
+* [`redundant_clone`] [#5453](https://github.com/rust-lang/rust-clippy/pull/5453)
+* [`precedence`] [#5445](https://github.com/rust-lang/rust-clippy/pull/5445)
+* [`suspicious_op_assign_impl`] [#5424](https://github.com/rust-lang/rust-clippy/pull/5424)
+* [`needless_lifetimes`] [#5293](https://github.com/rust-lang/rust-clippy/pull/5293)
+* [`redundant_pattern`] [#5287](https://github.com/rust-lang/rust-clippy/pull/5287)
+* [`inconsistent_digit_grouping`] [#5451](https://github.com/rust-lang/rust-clippy/pull/5451)
+
+
+### Suggestion Improvements
+
+* Improved [`question_mark`] lint suggestion so that it doesn't add redundant `as_ref()` [#5481](https://github.com/rust-lang/rust-clippy/pull/5481)
+* Improve the suggested placeholder in [`option_map_unit_fn`] [#5292](https://github.com/rust-lang/rust-clippy/pull/5292)
+* Improve suggestion for [`match_single_binding`] when triggered inside a closure [#5350](https://github.com/rust-lang/rust-clippy/pull/5350)
+
+### ICE Fixes
+
+* Handle the unstable `trivial_bounds` feature [#5296](https://github.com/rust-lang/rust-clippy/pull/5296)
+* `shadow_*` lints [#5297](https://github.com/rust-lang/rust-clippy/pull/5297)
+
+### Documentation
+
+* Fix documentation generation for configurable lints [#5353](https://github.com/rust-lang/rust-clippy/pull/5353)
+* Update documentation for [`new_ret_no_self`] [#5448](https://github.com/rust-lang/rust-clippy/pull/5448)
+* The documentation for [`option_option`] now suggest using a tri-state enum [#5403](https://github.com/rust-lang/rust-clippy/pull/5403)
+* Fix bit mask example in [`verbose_bit_mask`] documentation [#5454](https://github.com/rust-lang/rust-clippy/pull/5454)
+* [`wildcard_imports`] documentation now mentions that `use ...::prelude::*` is
+ not linted [#5312](https://github.com/rust-lang/rust-clippy/pull/5312)
+
+## Rust 1.43
+
+Current stable, released 2020-04-23
+
+[4ee1206...204bb9b](https://github.com/rust-lang/rust-clippy/compare/4ee1206...204bb9b)
+
+### New lints
+
+* [`imprecise_flops`] [#4897](https://github.com/rust-lang/rust-clippy/pull/4897)
+* [`suboptimal_flops`] [#4897](https://github.com/rust-lang/rust-clippy/pull/4897)
+* [`wildcard_imports`] [#5029](https://github.com/rust-lang/rust-clippy/pull/5029)
+* [`single_component_path_imports`] [#5058](https://github.com/rust-lang/rust-clippy/pull/5058)
+* [`match_single_binding`] [#5061](https://github.com/rust-lang/rust-clippy/pull/5061)
+* [`let_underscore_lock`] [#5101](https://github.com/rust-lang/rust-clippy/pull/5101)
+* [`struct_excessive_bools`] [#5125](https://github.com/rust-lang/rust-clippy/pull/5125)
+* [`fn_params_excessive_bools`] [#5125](https://github.com/rust-lang/rust-clippy/pull/5125)
+* [`option_env_unwrap`] [#5148](https://github.com/rust-lang/rust-clippy/pull/5148)
+* [`lossy_float_literal`] [#5202](https://github.com/rust-lang/rust-clippy/pull/5202)
+* [`rest_pat_in_fully_bound_structs`] [#5258](https://github.com/rust-lang/rust-clippy/pull/5258)
+
+### Moves and Deprecations
+
+* Move [`unneeded_field_pattern`] to pedantic group [#5200](https://github.com/rust-lang/rust-clippy/pull/5200)
+
+### Enhancements
+
+* Make [`missing_errors_doc`] lint also trigger on `async` functions
+ [#5181](https://github.com/rust-lang/rust-clippy/pull/5181)
+* Add more constants to [`approx_constant`] [#5193](https://github.com/rust-lang/rust-clippy/pull/5193)
+* Extend [`question_mark`] lint [#5266](https://github.com/rust-lang/rust-clippy/pull/5266)
+
+### False Positive Fixes
+
+* [`use_debug`] [#5047](https://github.com/rust-lang/rust-clippy/pull/5047)
+* [`unnecessary_unwrap`] [#5132](https://github.com/rust-lang/rust-clippy/pull/5132)
+* [`zero_prefixed_literal`] [#5170](https://github.com/rust-lang/rust-clippy/pull/5170)
+* [`missing_const_for_fn`] [#5216](https://github.com/rust-lang/rust-clippy/pull/5216)
+
+### Suggestion Improvements
+
+* Improve suggestion when blocks of code are suggested [#5134](https://github.com/rust-lang/rust-clippy/pull/5134)
+
+### ICE Fixes
+
+* `misc_early` lints [#5129](https://github.com/rust-lang/rust-clippy/pull/5129)
+* [`missing_errors_doc`] [#5213](https://github.com/rust-lang/rust-clippy/pull/5213)
+* Fix ICE when evaluating `usize`s [#5256](https://github.com/rust-lang/rust-clippy/pull/5256)
+
+### Documentation
+
+* Improve documentation of [`iter_nth_zero`]
+* Add documentation pages for stable releases [#5171](https://github.com/rust-lang/rust-clippy/pull/5171)
+
+### Others
+
+* Clippy now completely runs on GitHub Actions [#5190](https://github.com/rust-lang/rust-clippy/pull/5190)
+
+
+## Rust 1.42
+
+Released 2020-03-12
+
+[69f99e7...4ee1206](https://github.com/rust-lang/rust-clippy/compare/69f99e7...4ee1206)
+
+### New lints
+
+* [`filetype_is_file`] [#4543](https://github.com/rust-lang/rust-clippy/pull/4543)
+* [`let_underscore_must_use`] [#4823](https://github.com/rust-lang/rust-clippy/pull/4823)
+* [`modulo_arithmetic`] [#4867](https://github.com/rust-lang/rust-clippy/pull/4867)
+* [`mem_replace_with_default`] [#4881](https://github.com/rust-lang/rust-clippy/pull/4881)
+* [`mutable_key_type`] [#4885](https://github.com/rust-lang/rust-clippy/pull/4885)
+* [`option_as_ref_deref`] [#4945](https://github.com/rust-lang/rust-clippy/pull/4945)
+* [`wildcard_in_or_patterns`] [#4960](https://github.com/rust-lang/rust-clippy/pull/4960)
+* [`iter_nth_zero`] [#4966](https://github.com/rust-lang/rust-clippy/pull/4966)
+* [`invalid_atomic_ordering`] [#4999](https://github.com/rust-lang/rust-clippy/pull/4999)
+* [`skip_while_next`] [#5067](https://github.com/rust-lang/rust-clippy/pull/5067)
+
+### Moves and Deprecations
+
+* Move [`transmute_float_to_int`] from nursery to complexity group
+ [#5015](https://github.com/rust-lang/rust-clippy/pull/5015)
+* Move [`range_plus_one`] to pedantic group [#5057](https://github.com/rust-lang/rust-clippy/pull/5057)
+* Move [`debug_assert_with_mut_call`] to nursery group [#5106](https://github.com/rust-lang/rust-clippy/pull/5106)
+* Deprecate [`unused_label`] [#4930](https://github.com/rust-lang/rust-clippy/pull/4930)
+
+### Enhancements
+
+* Lint vectored IO in [`unused_io_amount`] [#5027](https://github.com/rust-lang/rust-clippy/pull/5027)
+* Make [`vec_box`] configurable by adding a size threshold [#5081](https://github.com/rust-lang/rust-clippy/pull/5081)
+* Also lint constants in [`cmp_nan`] [#4910](https://github.com/rust-lang/rust-clippy/pull/4910)
+* Fix false negative in [`expect_fun_call`] [#4915](https://github.com/rust-lang/rust-clippy/pull/4915)
+* Fix false negative in [`redundant_clone`] [#5017](https://github.com/rust-lang/rust-clippy/pull/5017)
+
+### False Positive Fixes
+
+* [`map_clone`] [#4937](https://github.com/rust-lang/rust-clippy/pull/4937)
+* [`replace_consts`] [#4977](https://github.com/rust-lang/rust-clippy/pull/4977)
+* [`let_and_return`] [#5008](https://github.com/rust-lang/rust-clippy/pull/5008)
+* [`eq_op`] [#5079](https://github.com/rust-lang/rust-clippy/pull/5079)
+* [`possible_missing_comma`] [#5083](https://github.com/rust-lang/rust-clippy/pull/5083)
+* [`debug_assert_with_mut_call`] [#5106](https://github.com/rust-lang/rust-clippy/pull/5106)
+* Don't trigger [`let_underscore_must_use`] in external macros
+ [#5082](https://github.com/rust-lang/rust-clippy/pull/5082)
+* Don't trigger [`empty_loop`] in `no_std` crates [#5086](https://github.com/rust-lang/rust-clippy/pull/5086)
+
+### Suggestion Improvements
+
+* [`option_map_unwrap_or`] [#4634](https://github.com/rust-lang/rust-clippy/pull/4634)
+* [`wildcard_enum_match_arm`] [#4934](https://github.com/rust-lang/rust-clippy/pull/4934)
+* [`cognitive_complexity`] [#4935](https://github.com/rust-lang/rust-clippy/pull/4935)
+* [`decimal_literal_representation`] [#4956](https://github.com/rust-lang/rust-clippy/pull/4956)
+* [`unknown_clippy_lints`] [#4963](https://github.com/rust-lang/rust-clippy/pull/4963)
+* [`explicit_into_iter_loop`] [#4978](https://github.com/rust-lang/rust-clippy/pull/4978)
+* [`useless_attribute`] [#5022](https://github.com/rust-lang/rust-clippy/pull/5022)
+* [`if_let_some_result`] [#5032](https://github.com/rust-lang/rust-clippy/pull/5032)
+
+### ICE fixes
+
+* [`unsound_collection_transmute`] [#4975](https://github.com/rust-lang/rust-clippy/pull/4975)
+
+### Documentation
+
+* Improve documentation of [`empty_enum`], [`replace_consts`], [`redundant_clone`], and [`iterator_step_by_zero`]
+
+
+## Rust 1.41
+
+Released 2020-01-30
+
+[c8e3cfb...69f99e7](https://github.com/rust-lang/rust-clippy/compare/c8e3cfb...69f99e7)
+
+* New Lints:
+ * [`exit`] [#4697](https://github.com/rust-lang/rust-clippy/pull/4697)
+ * [`to_digit_is_some`] [#4801](https://github.com/rust-lang/rust-clippy/pull/4801)
+ * [`tabs_in_doc_comments`] [#4806](https://github.com/rust-lang/rust-clippy/pull/4806)
+ * [`large_stack_arrays`] [#4807](https://github.com/rust-lang/rust-clippy/pull/4807)
+ * [`same_functions_in_if_condition`] [#4814](https://github.com/rust-lang/rust-clippy/pull/4814)
+ * [`zst_offset`] [#4816](https://github.com/rust-lang/rust-clippy/pull/4816)
+ * [`as_conversions`] [#4821](https://github.com/rust-lang/rust-clippy/pull/4821)
+ * [`missing_errors_doc`] [#4884](https://github.com/rust-lang/rust-clippy/pull/4884)
+ * [`transmute_float_to_int`] [#4889](https://github.com/rust-lang/rust-clippy/pull/4889)
+* Remove plugin interface, see
+ [Inside Rust Blog](https://blog.rust-lang.org/inside-rust/2019/11/04/Clippy-removes-plugin-interface.html) for
+ details [#4714](https://github.com/rust-lang/rust-clippy/pull/4714)
+* Move [`use_self`] to nursery group [#4863](https://github.com/rust-lang/rust-clippy/pull/4863)
+* Deprecate [`into_iter_on_array`] [#4788](https://github.com/rust-lang/rust-clippy/pull/4788)
+* Expand [`string_lit_as_bytes`] to also trigger when literal has escapes
+ [#4808](https://github.com/rust-lang/rust-clippy/pull/4808)
+* Fix false positive in `comparison_chain` [#4842](https://github.com/rust-lang/rust-clippy/pull/4842)
+* Fix false positive in `while_immutable_condition` [#4730](https://github.com/rust-lang/rust-clippy/pull/4730)
+* Fix false positive in `explicit_counter_loop` [#4803](https://github.com/rust-lang/rust-clippy/pull/4803)
+* Fix false positive in `must_use_candidate` [#4794](https://github.com/rust-lang/rust-clippy/pull/4794)
+* Fix false positive in `print_with_newline` and `write_with_newline`
+ [#4769](https://github.com/rust-lang/rust-clippy/pull/4769)
+* Fix false positive in `derive_hash_xor_eq` [#4766](https://github.com/rust-lang/rust-clippy/pull/4766)
+* Fix false positive in `missing_inline_in_public_items` [#4870](https://github.com/rust-lang/rust-clippy/pull/4870)
+* Fix false positive in `string_add` [#4880](https://github.com/rust-lang/rust-clippy/pull/4880)
+* Fix false positive in `float_arithmetic` [#4851](https://github.com/rust-lang/rust-clippy/pull/4851)
+* Fix false positive in `cast_sign_loss` [#4883](https://github.com/rust-lang/rust-clippy/pull/4883)
+* Fix false positive in `manual_swap` [#4877](https://github.com/rust-lang/rust-clippy/pull/4877)
+* Fix ICEs occurring while checking some block expressions [#4772](https://github.com/rust-lang/rust-clippy/pull/4772)
+* Fix ICE in `use_self` [#4776](https://github.com/rust-lang/rust-clippy/pull/4776)
+* Fix ICEs related to `const_generics` [#4780](https://github.com/rust-lang/rust-clippy/pull/4780)
+* Display help when running `clippy-driver` without arguments, instead of ICEing
+ [#4810](https://github.com/rust-lang/rust-clippy/pull/4810)
+* Clippy has its own ICE message now [#4588](https://github.com/rust-lang/rust-clippy/pull/4588)
+* Show deprecated lints in the documentation again [#4757](https://github.com/rust-lang/rust-clippy/pull/4757)
+* Improve Documentation by adding positive examples to some lints
+ [#4832](https://github.com/rust-lang/rust-clippy/pull/4832)
+
+## Rust 1.40
+
+Released 2019-12-19
+
+[4e7e71b...c8e3cfb](https://github.com/rust-lang/rust-clippy/compare/4e7e71b...c8e3cfb)
+
+* New Lints:
+ * [`unneeded_wildcard_pattern`] [#4537](https://github.com/rust-lang/rust-clippy/pull/4537)
+ * [`needless_doctest_main`] [#4603](https://github.com/rust-lang/rust-clippy/pull/4603)
+ * [`suspicious_unary_op_formatting`] [#4615](https://github.com/rust-lang/rust-clippy/pull/4615)
+ * [`debug_assert_with_mut_call`] [#4680](https://github.com/rust-lang/rust-clippy/pull/4680)
+ * [`unused_self`] [#4619](https://github.com/rust-lang/rust-clippy/pull/4619)
+ * [`inefficient_to_string`] [#4683](https://github.com/rust-lang/rust-clippy/pull/4683)
+ * [`must_use_unit`] [#4560](https://github.com/rust-lang/rust-clippy/pull/4560)
+ * [`must_use_candidate`] [#4560](https://github.com/rust-lang/rust-clippy/pull/4560)
+ * [`double_must_use`] [#4560](https://github.com/rust-lang/rust-clippy/pull/4560)
+ * [`comparison_chain`] [#4569](https://github.com/rust-lang/rust-clippy/pull/4569)
+ * [`unsound_collection_transmute`] [#4592](https://github.com/rust-lang/rust-clippy/pull/4592)
+ * [`panic`] [#4657](https://github.com/rust-lang/rust-clippy/pull/4657)
+ * [`unreachable`] [#4657](https://github.com/rust-lang/rust-clippy/pull/4657)
+ * [`todo`] [#4657](https://github.com/rust-lang/rust-clippy/pull/4657)
+ * [`option_expect_used`] [#4657](https://github.com/rust-lang/rust-clippy/pull/4657)
+ * [`result_expect_used`] [#4657](https://github.com/rust-lang/rust-clippy/pull/4657)
+* Move `redundant_clone` to perf group [#4509](https://github.com/rust-lang/rust-clippy/pull/4509)
+* Move `manual_mul_add` to nursery group [#4736](https://github.com/rust-lang/rust-clippy/pull/4736)
+* Expand `unit_cmp` to also work with `assert_eq!`, `debug_assert_eq!`, `assert_ne!` and `debug_assert_ne!` [#4613](https://github.com/rust-lang/rust-clippy/pull/4613)
+* Expand `integer_arithmetic` to also detect mutating arithmetic like `+=` [#4585](https://github.com/rust-lang/rust-clippy/pull/4585)
+* Fix false positive in `nonminimal_bool` [#4568](https://github.com/rust-lang/rust-clippy/pull/4568)
+* Fix false positive in `missing_safety_doc` [#4611](https://github.com/rust-lang/rust-clippy/pull/4611)
+* Fix false positive in `cast_sign_loss` [#4614](https://github.com/rust-lang/rust-clippy/pull/4614)
+* Fix false positive in `redundant_clone` [#4509](https://github.com/rust-lang/rust-clippy/pull/4509)
+* Fix false positive in `try_err` [#4721](https://github.com/rust-lang/rust-clippy/pull/4721)
+* Fix false positive in `toplevel_ref_arg` [#4570](https://github.com/rust-lang/rust-clippy/pull/4570)
+* Fix false positive in `multiple_inherent_impl` [#4593](https://github.com/rust-lang/rust-clippy/pull/4593)
+* Improve more suggestions and tests in preparation for the unstable `cargo fix --clippy` [#4575](https://github.com/rust-lang/rust-clippy/pull/4575)
+* Improve suggestion for `zero_ptr` [#4599](https://github.com/rust-lang/rust-clippy/pull/4599)
+* Improve suggestion for `explicit_counter_loop` [#4691](https://github.com/rust-lang/rust-clippy/pull/4691)
+* Improve suggestion for `mul_add` [#4602](https://github.com/rust-lang/rust-clippy/pull/4602)
+* Improve suggestion for `assertions_on_constants` [#4635](https://github.com/rust-lang/rust-clippy/pull/4635)
+* Fix ICE in `use_self` [#4671](https://github.com/rust-lang/rust-clippy/pull/4671)
+* Fix ICE when encountering const casts [#4590](https://github.com/rust-lang/rust-clippy/pull/4590)
+
+## Rust 1.39
+
+Released 2019-11-07
+
+[3aea860...4e7e71b](https://github.com/rust-lang/rust-clippy/compare/3aea860...4e7e71b)
+
+* New Lints:
+ * [`uninit_assumed_init`] [#4479](https://github.com/rust-lang/rust-clippy/pull/4479)
+ * [`flat_map_identity`] [#4231](https://github.com/rust-lang/rust-clippy/pull/4231)
+ * [`missing_safety_doc`] [#4535](https://github.com/rust-lang/rust-clippy/pull/4535)
+ * [`mem_replace_with_uninit`] [#4511](https://github.com/rust-lang/rust-clippy/pull/4511)
+ * [`suspicious_map`] [#4394](https://github.com/rust-lang/rust-clippy/pull/4394)
+ * [`option_and_then_some`] [#4386](https://github.com/rust-lang/rust-clippy/pull/4386)
+ * [`manual_saturating_arithmetic`] [#4498](https://github.com/rust-lang/rust-clippy/pull/4498)
+* Deprecate `unused_collect` lint. This is fully covered by rustc's `#[must_use]` on `collect` [#4348](https://github.com/rust-lang/rust-clippy/pull/4348)
+* Move `type_repetition_in_bounds` to pedantic group [#4403](https://github.com/rust-lang/rust-clippy/pull/4403)
+* Move `cast_lossless` to pedantic group [#4539](https://github.com/rust-lang/rust-clippy/pull/4539)
+* `temporary_cstring_as_ptr` now catches more cases [#4425](https://github.com/rust-lang/rust-clippy/pull/4425)
+* `use_self` now works in constructors, too [#4525](https://github.com/rust-lang/rust-clippy/pull/4525)
+* `cargo_common_metadata` now checks for license files [#4518](https://github.com/rust-lang/rust-clippy/pull/4518)
+* `cognitive_complexity` now includes the measured complexity in the warning message [#4469](https://github.com/rust-lang/rust-clippy/pull/4469)
+* Fix false positives in `block_in_if_*` lints [#4458](https://github.com/rust-lang/rust-clippy/pull/4458)
+* Fix false positive in `cast_lossless` [#4473](https://github.com/rust-lang/rust-clippy/pull/4473)
+* Fix false positive in `clone_on_copy` [#4411](https://github.com/rust-lang/rust-clippy/pull/4411)
+* Fix false positive in `deref_addrof` [#4487](https://github.com/rust-lang/rust-clippy/pull/4487)
+* Fix false positive in `too_many_lines` [#4490](https://github.com/rust-lang/rust-clippy/pull/4490)
+* Fix false positive in `new_ret_no_self` [#4365](https://github.com/rust-lang/rust-clippy/pull/4365)
+* Fix false positive in `manual_swap` [#4478](https://github.com/rust-lang/rust-clippy/pull/4478)
+* Fix false positive in `missing_const_for_fn` [#4450](https://github.com/rust-lang/rust-clippy/pull/4450)
+* Fix false positive in `extra_unused_lifetimes` [#4477](https://github.com/rust-lang/rust-clippy/pull/4477)
+* Fix false positive in `inherent_to_string` [#4460](https://github.com/rust-lang/rust-clippy/pull/4460)
+* Fix false positive in `map_entry` [#4495](https://github.com/rust-lang/rust-clippy/pull/4495)
+* Fix false positive in `unused_unit` [#4445](https://github.com/rust-lang/rust-clippy/pull/4445)
+* Fix false positive in `redundant_pattern` [#4489](https://github.com/rust-lang/rust-clippy/pull/4489)
+* Fix false positive in `wrong_self_convention` [#4369](https://github.com/rust-lang/rust-clippy/pull/4369)
+* Improve various suggestions and tests in preparation for the unstable `cargo fix --clippy` [#4558](https://github.com/rust-lang/rust-clippy/pull/4558)
+* Improve suggestions for `redundant_pattern_matching` [#4352](https://github.com/rust-lang/rust-clippy/pull/4352)
+* Improve suggestions for `explicit_write` [#4544](https://github.com/rust-lang/rust-clippy/pull/4544)
+* Improve suggestion for `or_fun_call` [#4522](https://github.com/rust-lang/rust-clippy/pull/4522)
+* Improve suggestion for `match_as_ref` [#4446](https://github.com/rust-lang/rust-clippy/pull/4446)
+* Improve suggestion for `unnecessary_fold_span` [#4382](https://github.com/rust-lang/rust-clippy/pull/4382)
+* Add suggestions for `unseparated_literal_suffix` [#4401](https://github.com/rust-lang/rust-clippy/pull/4401)
+* Add suggestions for `char_lit_as_u8` [#4418](https://github.com/rust-lang/rust-clippy/pull/4418)
+
+## Rust 1.38
+
+Released 2019-09-26
+
+[e3cb40e...3aea860](https://github.com/rust-lang/rust-clippy/compare/e3cb40e...3aea860)
+
+* New Lints:
+ * [`main_recursion`] [#4203](https://github.com/rust-lang/rust-clippy/pull/4203)
+ * [`inherent_to_string`] [#4259](https://github.com/rust-lang/rust-clippy/pull/4259)
+ * [`inherent_to_string_shadow_display`] [#4259](https://github.com/rust-lang/rust-clippy/pull/4259)
+ * [`type_repetition_in_bounds`] [#3766](https://github.com/rust-lang/rust-clippy/pull/3766)
+ * [`try_err`] [#4222](https://github.com/rust-lang/rust-clippy/pull/4222)
+* Move `{unnnecessary,panicking}_unwrap` out of nursery [#4307](https://github.com/rust-lang/rust-clippy/pull/4307)
+* Extend the `use_self` lint to suggest uses of `Self::Variant` [#4308](https://github.com/rust-lang/rust-clippy/pull/4308)
+* Improve suggestion for needless return [#4262](https://github.com/rust-lang/rust-clippy/pull/4262)
+* Add auto-fixable suggestion for `let_unit` [#4337](https://github.com/rust-lang/rust-clippy/pull/4337)
+* Fix false positive in `pub_enum_variant_names` and `enum_variant_names` [#4345](https://github.com/rust-lang/rust-clippy/pull/4345)
+* Fix false positive in `cast_ptr_alignment` [#4257](https://github.com/rust-lang/rust-clippy/pull/4257)
+* Fix false positive in `string_lit_as_bytes` [#4233](https://github.com/rust-lang/rust-clippy/pull/4233)
+* Fix false positive in `needless_lifetimes` [#4266](https://github.com/rust-lang/rust-clippy/pull/4266)
+* Fix false positive in `float_cmp` [#4275](https://github.com/rust-lang/rust-clippy/pull/4275)
+* Fix false positives in `needless_return` [#4274](https://github.com/rust-lang/rust-clippy/pull/4274)
+* Fix false negative in `match_same_arms` [#4246](https://github.com/rust-lang/rust-clippy/pull/4246)
+* Fix incorrect suggestion for `needless_bool` [#4335](https://github.com/rust-lang/rust-clippy/pull/4335)
+* Improve suggestion for `cast_ptr_alignment` [#4257](https://github.com/rust-lang/rust-clippy/pull/4257)
+* Improve suggestion for `single_char_literal` [#4361](https://github.com/rust-lang/rust-clippy/pull/4361)
+* Improve suggestion for `len_zero` [#4314](https://github.com/rust-lang/rust-clippy/pull/4314)
+* Fix ICE in `implicit_hasher` [#4268](https://github.com/rust-lang/rust-clippy/pull/4268)
+* Fix allow bug in `trivially_copy_pass_by_ref` [#4250](https://github.com/rust-lang/rust-clippy/pull/4250)
+
+## Rust 1.37
+
+Released 2019-08-15
+
+[082cfa7...e3cb40e](https://github.com/rust-lang/rust-clippy/compare/082cfa7...e3cb40e)
+
+* New Lints:
+ * [`checked_conversions`] [#4088](https://github.com/rust-lang/rust-clippy/pull/4088)
+ * [`get_last_with_len`] [#3832](https://github.com/rust-lang/rust-clippy/pull/3832)
+ * [`integer_division`] [#4195](https://github.com/rust-lang/rust-clippy/pull/4195)
+* Renamed Lint: `const_static_lifetime` is now called [`redundant_static_lifetimes`].
+ The lint now covers statics in addition to consts [#4162](https://github.com/rust-lang/rust-clippy/pull/4162)
+* [`match_same_arms`] now warns for all identical arms, instead of only the first one [#4102](https://github.com/rust-lang/rust-clippy/pull/4102)
+* [`needless_return`] now works with void functions [#4220](https://github.com/rust-lang/rust-clippy/pull/4220)
+* Fix false positive in [`redundant_closure`] [#4190](https://github.com/rust-lang/rust-clippy/pull/4190)
+* Fix false positive in [`useless_attribute`] [#4107](https://github.com/rust-lang/rust-clippy/pull/4107)
+* Fix incorrect suggestion for [`float_cmp`] [#4214](https://github.com/rust-lang/rust-clippy/pull/4214)
+* Add suggestions for [`print_with_newline`] and [`write_with_newline`] [#4136](https://github.com/rust-lang/rust-clippy/pull/4136)
+* Improve suggestions for [`option_map_unwrap_or_else`] and [`result_map_unwrap_or_else`] [#4164](https://github.com/rust-lang/rust-clippy/pull/4164)
+* Improve suggestions for [`non_ascii_literal`] [#4119](https://github.com/rust-lang/rust-clippy/pull/4119)
+* Improve diagnostics for [`let_and_return`] [#4137](https://github.com/rust-lang/rust-clippy/pull/4137)
+* Improve diagnostics for [`trivially_copy_pass_by_ref`] [#4071](https://github.com/rust-lang/rust-clippy/pull/4071)
+* Add macro check for [`unreadable_literal`] [#4099](https://github.com/rust-lang/rust-clippy/pull/4099)
+
+## Rust 1.36
+
+Released 2019-07-04
+
+[eb9f9b1...082cfa7](https://github.com/rust-lang/rust-clippy/compare/eb9f9b1...082cfa7)
+
+* New lints: [`find_map`], [`filter_map_next`] [#4039](https://github.com/rust-lang/rust-clippy/pull/4039)
+* New lint: [`path_buf_push_overwrite`] [#3954](https://github.com/rust-lang/rust-clippy/pull/3954)
+* Move `path_buf_push_overwrite` to the nursery [#4013](https://github.com/rust-lang/rust-clippy/pull/4013)
+* Split [`redundant_closure`] into [`redundant_closure`] and [`redundant_closure_for_method_calls`] [#4110](https://github.com/rust-lang/rust-clippy/pull/4101)
+* Allow allowing of [`toplevel_ref_arg`] lint [#4007](https://github.com/rust-lang/rust-clippy/pull/4007)
+* Fix false negative in [`or_fun_call`] pertaining to nested constructors [#4084](https://github.com/rust-lang/rust-clippy/pull/4084)
+* Fix false positive in [`or_fun_call`] pertaining to enum variant constructors [#4018](https://github.com/rust-lang/rust-clippy/pull/4018)
+* Fix false positive in [`useless_let_if_seq`] pertaining to interior mutability [#4035](https://github.com/rust-lang/rust-clippy/pull/4035)
+* Fix false positive in [`redundant_closure`] pertaining to non-function types [#4008](https://github.com/rust-lang/rust-clippy/pull/4008)
+* Fix false positive in [`let_and_return`] pertaining to attributes on `let`s [#4024](https://github.com/rust-lang/rust-clippy/pull/4024)
+* Fix false positive in [`module_name_repetitions`] lint pertaining to attributes [#4006](https://github.com/rust-lang/rust-clippy/pull/4006)
+* Fix false positive on [`assertions_on_constants`] pertaining to `debug_assert!` [#3989](https://github.com/rust-lang/rust-clippy/pull/3989)
+* Improve suggestion in [`map_clone`] to suggest `.copied()` where applicable [#3970](https://github.com/rust-lang/rust-clippy/pull/3970) [#4043](https://github.com/rust-lang/rust-clippy/pull/4043)
+* Improve suggestion for [`search_is_some`] [#4049](https://github.com/rust-lang/rust-clippy/pull/4049)
+* Improve suggestion applicability for [`naive_bytecount`] [#3984](https://github.com/rust-lang/rust-clippy/pull/3984)
+* Improve suggestion applicability for [`while_let_loop`] [#3975](https://github.com/rust-lang/rust-clippy/pull/3975)
+* Improve diagnostics for [`too_many_arguments`] [#4053](https://github.com/rust-lang/rust-clippy/pull/4053)
+* Improve diagnostics for [`cast_lossless`] [#4021](https://github.com/rust-lang/rust-clippy/pull/4021)
+* Deal with macro checks in desugarings better [#4082](https://github.com/rust-lang/rust-clippy/pull/4082)
+* Add macro check for [`unnecessary_cast`] [#4026](https://github.com/rust-lang/rust-clippy/pull/4026)
+* Remove [`approx_constant`]'s documentation's "Known problems" section. [#4027](https://github.com/rust-lang/rust-clippy/pull/4027)
+* Fix ICE in [`suspicious_else_formatting`] [#3960](https://github.com/rust-lang/rust-clippy/pull/3960)
+* Fix ICE in [`decimal_literal_representation`] [#3931](https://github.com/rust-lang/rust-clippy/pull/3931)
+
+
+## Rust 1.35
+
+Released 2019-05-20
+
+[1fac380..37f5c1e](https://github.com/rust-lang/rust-clippy/compare/1fac380...37f5c1e)
+
+* New lint: [`drop_bounds`] to detect `T: Drop` bounds
+* Split [`redundant_closure`] into [`redundant_closure`] and [`redundant_closure_for_method_calls`] [#4110](https://github.com/rust-lang/rust-clippy/pull/4101)
+* Rename `cyclomatic_complexity` to [`cognitive_complexity`], start work on making lint more practical for Rust code
+* Move [`get_unwrap`] to the restriction category
+* Improve suggestions for [`iter_cloned_collect`]
+* Improve suggestions for [`cast_lossless`] to suggest suffixed literals
+* Fix false positives in [`print_with_newline`] and [`write_with_newline`] pertaining to raw strings
+* Fix false positive in [`needless_range_loop`] pertaining to structs without a `.iter()`
+* Fix false positive in [`bool_comparison`] pertaining to non-bool types
+* Fix false positive in [`redundant_closure`] pertaining to differences in borrows
+* Fix false positive in [`option_map_unwrap_or`] on non-copy types
+* Fix false positives in [`missing_const_for_fn`] pertaining to macros and trait method impls
+* Fix false positive in [`needless_pass_by_value`] pertaining to procedural macros
+* Fix false positive in [`needless_continue`] pertaining to loop labels
+* Fix false positive for [`boxed_local`] pertaining to arguments moved into closures
+* Fix false positive for [`use_self`] in nested functions
+* Fix suggestion for [`expect_fun_call`] (https://github.com/rust-lang/rust-clippy/pull/3846)
+* Fix suggestion for [`explicit_counter_loop`] to deal with parenthesizing range variables
+* Fix suggestion for [`single_char_pattern`] to correctly escape single quotes
+* Avoid triggering [`redundant_closure`] in macros
+* ICE fixes: [#3805](https://github.com/rust-lang/rust-clippy/pull/3805), [#3772](https://github.com/rust-lang/rust-clippy/pull/3772), [#3741](https://github.com/rust-lang/rust-clippy/pull/3741)
+
+## Rust 1.34
+
+Released 2019-04-10
+
+[1b89724...1fac380](https://github.com/rust-lang/rust-clippy/compare/1b89724...1fac380)
+
+* New lint: [`assertions_on_constants`] to detect for example `assert!(true)`
+* New lint: [`dbg_macro`] to detect uses of the `dbg!` macro
+* New lint: [`missing_const_for_fn`] that can suggest functions to be made `const`
+* New lint: [`too_many_lines`] to detect functions with excessive LOC. It can be
+ configured using the `too-many-lines-threshold` configuration.
+* New lint: [`wildcard_enum_match_arm`] to check for wildcard enum matches using `_`
+* Expand `redundant_closure` to also work for methods (not only functions)
+* Fix ICEs in `vec_box`, `needless_pass_by_value` and `implicit_hasher`
+* Fix false positive in `cast_sign_loss`
+* Fix false positive in `integer_arithmetic`
+* Fix false positive in `unit_arg`
+* Fix false positives in `implicit_return`
+* Add suggestion to `explicit_write`
+* Improve suggestions for `question_mark` lint
+* Fix incorrect suggestion for `cast_lossless`
+* Fix incorrect suggestion for `expect_fun_call`
+* Fix incorrect suggestion for `needless_bool`
+* Fix incorrect suggestion for `needless_range_loop`
+* Fix incorrect suggestion for `use_self`
+* Fix incorrect suggestion for `while_let_on_iterator`
+* Clippy is now slightly easier to invoke in non-cargo contexts. See
+ [#3665][pull3665] for more details.
+* We now have [improved documentation][adding_lints] on how to add new lints
+
+## Rust 1.33
+
+Released 2019-02-26
+
+[b2601be...1b89724](https://github.com/rust-lang/rust-clippy/compare/b2601be...1b89724)
+
+* New lints: [`implicit_return`], [`vec_box`], [`cast_ref_to_mut`]
+* The `rust-clippy` repository is now part of the `rust-lang` org.
+* Rename `stutter` to `module_name_repetitions`
+* Merge `new_without_default_derive` into `new_without_default` lint
+* Move `large_digit_groups` from `style` group to `pedantic`
+* Expand `bool_comparison` to check for `<`, `<=`, `>`, `>=`, and `!=`
+ comparisons against booleans
+* Expand `no_effect` to detect writes to constants such as `A_CONST.field = 2`
+* Expand `redundant_clone` to work on struct fields
+* Expand `suspicious_else_formatting` to detect `if .. {..} {..}`
+* Expand `use_self` to work on tuple structs and also in local macros
+* Fix ICE in `result_map_unit_fn` and `option_map_unit_fn`
+* Fix false positives in `implicit_return`
+* Fix false positives in `use_self`
+* Fix false negative in `clone_on_copy`
+* Fix false positive in `doc_markdown`
+* Fix false positive in `empty_loop`
+* Fix false positive in `if_same_then_else`
+* Fix false positive in `infinite_iter`
+* Fix false positive in `question_mark`
+* Fix false positive in `useless_asref`
+* Fix false positive in `wildcard_dependencies`
+* Fix false positive in `write_with_newline`
+* Add suggestion to `explicit_write`
+* Improve suggestions for `question_mark` lint
+* Fix incorrect suggestion for `get_unwrap`
+
+## Rust 1.32
+
+Released 2019-01-17
+
+[2e26fdc2...b2601be](https://github.com/rust-lang/rust-clippy/compare/2e26fdc2...b2601be)
+
+* New lints: [`slow_vector_initialization`], [`mem_discriminant_non_enum`],
+ [`redundant_clone`], [`wildcard_dependencies`],
+ [`into_iter_on_ref`], [`into_iter_on_array`], [`deprecated_cfg_attr`],
+ [`mem_discriminant_non_enum`], [`cargo_common_metadata`]
+* Add support for `u128` and `i128` to integer related lints
+* Add float support to `mistyped_literal_suffixes`
+* Fix false positives in `use_self`
+* Fix false positives in `missing_comma`
+* Fix false positives in `new_ret_no_self`
+* Fix false positives in `possible_missing_comma`
+* Fix false positive in `integer_arithmetic` in constant items
+* Fix false positive in `needless_borrow`
+* Fix false positive in `out_of_bounds_indexing`
+* Fix false positive in `new_without_default_derive`
+* Fix false positive in `string_lit_as_bytes`
+* Fix false negative in `out_of_bounds_indexing`
+* Fix false negative in `use_self`. It will now also check existential types
+* Fix incorrect suggestion for `redundant_closure_call`
+* Fix various suggestions that contained expanded macros
+* Fix `bool_comparison` triggering 3 times on on on the same code
+* Expand `trivially_copy_pass_by_ref` to work on trait methods
+* Improve suggestion for `needless_range_loop`
+* Move `needless_pass_by_value` from `pedantic` group to `style`
+
+## Rust 1.31
+
+Released 2018-12-06
+
+[125907ad..2e26fdc2](https://github.com/rust-lang/rust-clippy/compare/125907ad..2e26fdc2)
+
+* Clippy has been relicensed under a dual MIT / Apache license.
+ See [#3093](https://github.com/rust-lang/rust-clippy/issues/3093) for more
+ information.
+* With Rust 1.31, Clippy is no longer available via crates.io. The recommended
+ installation method is via `rustup component add clippy`.
+* New lints: [`redundant_pattern_matching`], [`unnecessary_filter_map`],
+ [`unused_unit`], [`map_flatten`], [`mem_replace_option_with_none`]
+* Fix ICE in `if_let_redundant_pattern_matching`
+* Fix ICE in `needless_pass_by_value` when encountering a generic function
+ argument with a lifetime parameter
+* Fix ICE in `needless_range_loop`
+* Fix ICE in `single_char_pattern` when encountering a constant value
+* Fix false positive in `assign_op_pattern`
+* Fix false positive in `boxed_local` on trait implementations
+* Fix false positive in `cmp_owned`
+* Fix false positive in `collapsible_if` when conditionals have comments
+* Fix false positive in `double_parens`
+* Fix false positive in `excessive_precision`
+* Fix false positive in `explicit_counter_loop`
+* Fix false positive in `fn_to_numeric_cast_with_truncation`
+* Fix false positive in `map_clone`
+* Fix false positive in `new_ret_no_self`
+* Fix false positive in `new_without_default` when `new` is unsafe
+* Fix false positive in `type_complexity` when using extern types
+* Fix false positive in `useless_format`
+* Fix false positive in `wrong_self_convention`
+* Fix incorrect suggestion for `excessive_precision`
+* Fix incorrect suggestion for `expect_fun_call`
+* Fix incorrect suggestion for `get_unwrap`
+* Fix incorrect suggestion for `useless_format`
+* `fn_to_numeric_cast_with_truncation` lint can be disabled again
+* Improve suggestions for `manual_memcpy`
+* Improve help message for `needless_lifetimes`
+
+## Rust 1.30
+
+Released 2018-10-25
+
+[14207503...125907ad](https://github.com/rust-lang/rust-clippy/compare/14207503...125907ad)
+
+* Deprecate `assign_ops` lint
+* New lints: [`mistyped_literal_suffixes`], [`ptr_offset_with_cast`],
+ [`needless_collect`], [`copy_iterator`]
+* `cargo clippy -V` now includes the Clippy commit hash of the Rust
+ Clippy component
+* Fix ICE in `implicit_hasher`
+* Fix ICE when encountering `println!("{}" a);`
+* Fix ICE when encountering a macro call in match statements
+* Fix false positive in `default_trait_access`
+* Fix false positive in `trivially_copy_pass_by_ref`
+* Fix false positive in `similar_names`
+* Fix false positive in `redundant_field_name`
+* Fix false positive in `expect_fun_call`
+* Fix false negative in `identity_conversion`
+* Fix false negative in `explicit_counter_loop`
+* Fix `range_plus_one` suggestion and false negative
+* `print_with_newline` / `write_with_newline`: don't warn about string with several `\n`s in them
+* Fix `useless_attribute` to also whitelist `unused_extern_crates`
+* Fix incorrect suggestion for `single_char_pattern`
+* Improve suggestion for `identity_conversion` lint
+* Move `explicit_iter_loop` and `explicit_into_iter_loop` from `style` group to `pedantic`
+* Move `range_plus_one` and `range_minus_one` from `nursery` group to `complexity`
+* Move `shadow_unrelated` from `restriction` group to `pedantic`
+* Move `indexing_slicing` from `pedantic` group to `restriction`
+
+## Rust 1.29
+
+Released 2018-09-13
+
+[v0.0.212...14207503](https://github.com/rust-lang/rust-clippy/compare/v0.0.212...14207503)
+
+* :tada: :tada: **Rust 1.29 is the first stable Rust that includes a bundled Clippy** :tada:
+ :tada:
+ You can now run `rustup component add clippy-preview` and then `cargo
+ clippy` to run Clippy. This should put an end to the continuous nightly
+ upgrades for Clippy users.
+* Clippy now follows the Rust versioning scheme instead of its own
+* Fix ICE when encountering a `while let (..) = x.iter()` construct
+* Fix false positives in `use_self`
+* Fix false positive in `trivially_copy_pass_by_ref`
+* Fix false positive in `useless_attribute` lint
+* Fix false positive in `print_literal`
+* Fix `use_self` regressions
+* Improve lint message for `neg_cmp_op_on_partial_ord`
+* Improve suggestion highlight for `single_char_pattern`
+* Improve suggestions for various print/write macro lints
+* Improve website header
+
+## 0.0.212 (2018-07-10)
+* Rustup to *rustc 1.29.0-nightly (e06c87544 2018-07-06)*
+
+## 0.0.211
+* Rustup to *rustc 1.28.0-nightly (e3bf634e0 2018-06-28)*
+
+## 0.0.210
+* Rustup to *rustc 1.28.0-nightly (01cc982e9 2018-06-24)*
+
+## 0.0.209
+* Rustup to *rustc 1.28.0-nightly (523097979 2018-06-18)*
+
+## 0.0.208
+* Rustup to *rustc 1.28.0-nightly (86a8f1a63 2018-06-17)*
+
+## 0.0.207
+* Rustup to *rustc 1.28.0-nightly (2a0062974 2018-06-09)*
+
+## 0.0.206
+* Rustup to *rustc 1.28.0-nightly (5bf68db6e 2018-05-28)*
+
+## 0.0.205
+* Rustup to *rustc 1.28.0-nightly (990d8aa74 2018-05-25)*
+* Rename `unused_lifetimes` to `extra_unused_lifetimes` because of naming conflict with new rustc lint
+
+## 0.0.204
+* Rustup to *rustc 1.28.0-nightly (71e87be38 2018-05-22)*
+
+## 0.0.203
+* Rustup to *rustc 1.28.0-nightly (a3085756e 2018-05-19)*
+* Clippy attributes are now of the form `clippy::cyclomatic_complexity` instead of `clippy(cyclomatic_complexity)`
+
+## 0.0.202
+* Rustup to *rustc 1.28.0-nightly (952f344cd 2018-05-18)*
+
+## 0.0.201
+* Rustup to *rustc 1.27.0-nightly (2f2a11dfc 2018-05-16)*
+
+## 0.0.200
+* Rustup to *rustc 1.27.0-nightly (9fae15374 2018-05-13)*
+
+## 0.0.199
+* Rustup to *rustc 1.27.0-nightly (ff2ac35db 2018-05-12)*
+
+## 0.0.198
+* Rustup to *rustc 1.27.0-nightly (acd3871ba 2018-05-10)*
+
+## 0.0.197
+* Rustup to *rustc 1.27.0-nightly (428ea5f6b 2018-05-06)*
+
+## 0.0.196
+* Rustup to *rustc 1.27.0-nightly (e82261dfb 2018-05-03)*
+
+## 0.0.195
+* Rustup to *rustc 1.27.0-nightly (ac3c2288f 2018-04-18)*
+
+## 0.0.194
+* Rustup to *rustc 1.27.0-nightly (bd40cbbe1 2018-04-14)*
+* New lints: [`cast_ptr_alignment`], [`transmute_ptr_to_ptr`], [`write_literal`], [`write_with_newline`], [`writeln_empty_string`]
+
+## 0.0.193
+* Rustup to *rustc 1.27.0-nightly (eeea94c11 2018-04-06)*
+
+## 0.0.192
+* Rustup to *rustc 1.27.0-nightly (fb44b4c0e 2018-04-04)*
+* New lint: [`print_literal`]
+
+## 0.0.191
+* Rustup to *rustc 1.26.0-nightly (ae544ee1c 2018-03-29)*
+* Lint audit; categorize lints as style, correctness, complexity, pedantic, nursery, restriction.
+
+## 0.0.190
+* Fix a bunch of intermittent cargo bugs
+
+## 0.0.189
+* Rustup to *rustc 1.26.0-nightly (5508b2714 2018-03-18)*
+
+## 0.0.188
+* Rustup to *rustc 1.26.0-nightly (392645394 2018-03-15)*
+* New lint: [`while_immutable_condition`]
+
+## 0.0.187
+* Rustup to *rustc 1.26.0-nightly (322d7f7b9 2018-02-25)*
+* New lints: [`redundant_field_names`], [`suspicious_arithmetic_impl`], [`suspicious_op_assign_impl`]
+
+## 0.0.186
+* Rustup to *rustc 1.25.0-nightly (0c6091fbd 2018-02-04)*
+* Various false positive fixes
+
+## 0.0.185
+* Rustup to *rustc 1.25.0-nightly (56733bc9f 2018-02-01)*
+* New lint: [`question_mark`]
+
+## 0.0.184
+* Rustup to *rustc 1.25.0-nightly (90eb44a58 2018-01-29)*
+* New lints: [`double_comparisons`], [`empty_line_after_outer_attr`]
+
+## 0.0.183
+* Rustup to *rustc 1.25.0-nightly (21882aad7 2018-01-28)*
+* New lint: [`misaligned_transmute`]
+
+## 0.0.182
+* Rustup to *rustc 1.25.0-nightly (a0dcecff9 2018-01-24)*
+* New lint: [`decimal_literal_representation`]
+
+## 0.0.181
+* Rustup to *rustc 1.25.0-nightly (97520ccb1 2018-01-21)*
+* New lints: [`else_if_without_else`], [`option_option`], [`unit_arg`], [`unnecessary_fold`]
+* Removed `unit_expr`
+* Various false positive fixes for [`needless_pass_by_value`]
+
+## 0.0.180
+* Rustup to *rustc 1.25.0-nightly (3f92e8d89 2018-01-14)*
+
+## 0.0.179
+* Rustup to *rustc 1.25.0-nightly (61452e506 2018-01-09)*
+
+## 0.0.178
+* Rustup to *rustc 1.25.0-nightly (ee220daca 2018-01-07)*
+
+## 0.0.177
+* Rustup to *rustc 1.24.0-nightly (250b49205 2017-12-21)*
+* New lint: [`match_as_ref`]
+
+## 0.0.176
+* Rustup to *rustc 1.24.0-nightly (0077d128d 2017-12-14)*
+
+## 0.0.175
+* Rustup to *rustc 1.24.0-nightly (bb42071f6 2017-12-01)*
+
+## 0.0.174
+* Rustup to *rustc 1.23.0-nightly (63739ab7b 2017-11-21)*
+
+## 0.0.173
+* Rustup to *rustc 1.23.0-nightly (33374fa9d 2017-11-20)*
+
+## 0.0.172
+* Rustup to *rustc 1.23.0-nightly (d0f8e2913 2017-11-16)*
+
+## 0.0.171
+* Rustup to *rustc 1.23.0-nightly (ff0f5de3b 2017-11-14)*
+
+## 0.0.170
+* Rustup to *rustc 1.23.0-nightly (d6b06c63a 2017-11-09)*
+
+## 0.0.169
+* Rustup to *rustc 1.23.0-nightly (3b82e4c74 2017-11-05)*
+* New lints: [`just_underscores_and_digits`], [`result_map_unwrap_or_else`], [`transmute_bytes_to_str`]
+
+## 0.0.168
+* Rustup to *rustc 1.23.0-nightly (f0fe716db 2017-10-30)*
+
+## 0.0.167
+* Rustup to *rustc 1.23.0-nightly (90ef3372e 2017-10-29)*
+* New lints: `const_static_lifetime`, [`erasing_op`], [`fallible_impl_from`], [`println_empty_string`], [`useless_asref`]
+
+## 0.0.166
+* Rustup to *rustc 1.22.0-nightly (b7960878b 2017-10-18)*
+* New lints: [`explicit_write`], [`identity_conversion`], [`implicit_hasher`], [`invalid_ref`], [`option_map_or_none`],
+ [`range_minus_one`], [`range_plus_one`], [`transmute_int_to_bool`], [`transmute_int_to_char`],
+ [`transmute_int_to_float`]
+
+## 0.0.165
+* Rust upgrade to rustc 1.22.0-nightly (0e6f4cf51 2017-09-27)
+* New lint: [`mut_range_bound`]
+
+## 0.0.164
+* Update to *rustc 1.22.0-nightly (6c476ce46 2017-09-25)*
+* New lint: [`int_plus_one`]
+
+## 0.0.163
+* Update to *rustc 1.22.0-nightly (14039a42a 2017-09-22)*
+
+## 0.0.162
+* Update to *rustc 1.22.0-nightly (0701b37d9 2017-09-18)*
+* New lint: [`chars_last_cmp`]
+* Improved suggestions for [`needless_borrow`], [`ptr_arg`],
+
+## 0.0.161
+* Update to *rustc 1.22.0-nightly (539f2083d 2017-09-13)*
+
+## 0.0.160
+* Update to *rustc 1.22.0-nightly (dd08c3070 2017-09-12)*
+
+## 0.0.159
+* Update to *rustc 1.22.0-nightly (eba374fb2 2017-09-11)*
+* New lint: [`clone_on_ref_ptr`]
+
+## 0.0.158
+* New lint: [`manual_memcpy`]
+* [`cast_lossless`] no longer has redundant parentheses in its suggestions
+* Update to *rustc 1.22.0-nightly (dead08cb3 2017-09-08)*
+
+## 0.0.157 - 2017-09-04
+* Update to *rustc 1.22.0-nightly (981ce7d8d 2017-09-03)*
+* New lint: `unit_expr`
+
+## 0.0.156 - 2017-09-03
+* Update to *rustc 1.22.0-nightly (744dd6c1d 2017-09-02)*
+
+## 0.0.155
+* Update to *rustc 1.21.0-nightly (c11f689d2 2017-08-29)*
+* New lint: [`infinite_iter`], [`maybe_infinite_iter`], [`cast_lossless`]
+
+## 0.0.154
+* Update to *rustc 1.21.0-nightly (2c0558f63 2017-08-24)*
+* Fix [`use_self`] triggering inside derives
+* Add support for linting an entire workspace with `cargo clippy --all`
+* New lint: [`naive_bytecount`]
+
+## 0.0.153
+* Update to *rustc 1.21.0-nightly (8c303ed87 2017-08-20)*
+* New lint: [`use_self`]
+
+## 0.0.152
+* Update to *rustc 1.21.0-nightly (df511d554 2017-08-14)*
+
+## 0.0.151
+* Update to *rustc 1.21.0-nightly (13d94d5fa 2017-08-10)*
+
+## 0.0.150
+* Update to *rustc 1.21.0-nightly (215e0b10e 2017-08-08)*
+
+## 0.0.148
+* Update to *rustc 1.21.0-nightly (37c7d0ebb 2017-07-31)*
+* New lints: [`unreadable_literal`], [`inconsistent_digit_grouping`], [`large_digit_groups`]
+
+## 0.0.147
+* Update to *rustc 1.21.0-nightly (aac223f4f 2017-07-30)*
+
+## 0.0.146
+* Update to *rustc 1.21.0-nightly (52a330969 2017-07-27)*
+* Fixes false positives in `inline_always`
+* Fixes false negatives in `panic_params`
+
+## 0.0.145
+* Update to *rustc 1.20.0-nightly (afe145d22 2017-07-23)*
+
+## 0.0.144
+* Update to *rustc 1.20.0-nightly (086eaa78e 2017-07-15)*
+
+## 0.0.143
+* Update to *rustc 1.20.0-nightly (d84693b93 2017-07-09)*
+* Fix `cargo clippy` crashing on `dylib` projects
+* Fix false positives around `nested_while_let` and `never_loop`
+
+## 0.0.142
+* Update to *rustc 1.20.0-nightly (067971139 2017-07-02)*
+
+## 0.0.141
+* Rewrite of the `doc_markdown` lint.
+* Deprecated [`range_step_by_zero`]
+* New lint: [`iterator_step_by_zero`]
+* New lint: [`needless_borrowed_reference`]
+* Update to *rustc 1.20.0-nightly (69c65d296 2017-06-28)*
+
+## 0.0.140 - 2017-06-16
+* Update to *rustc 1.19.0-nightly (258ae6dd9 2017-06-15)*
+
+## 0.0.139 — 2017-06-10
+* Update to *rustc 1.19.0-nightly (4bf5c99af 2017-06-10)*
+* Fix bugs with for loop desugaring
+* Check for [`AsRef`]/[`AsMut`] arguments in [`wrong_self_convention`]
+
+## 0.0.138 — 2017-06-05
+* Update to *rustc 1.19.0-nightly (0418fa9d3 2017-06-04)*
+
+## 0.0.137 — 2017-06-05
+* Update to *rustc 1.19.0-nightly (6684d176c 2017-06-03)*
+
+## 0.0.136 — 2017—05—26
+* Update to *rustc 1.19.0-nightly (557967766 2017-05-26)*
+
+## 0.0.135 — 2017—05—24
+* Update to *rustc 1.19.0-nightly (5b13bff52 2017-05-23)*
+
+## 0.0.134 — 2017—05—19
+* Update to *rustc 1.19.0-nightly (0ed1ec9f9 2017-05-18)*
+
+## 0.0.133 — 2017—05—14
+* Update to *rustc 1.19.0-nightly (826d8f385 2017-05-13)*
+
+## 0.0.132 — 2017—05—05
+* Fix various bugs and some ices
+
+## 0.0.131 — 2017—05—04
+* Update to *rustc 1.19.0-nightly (2d4ed8e0c 2017-05-03)*
+
+## 0.0.130 — 2017—05—03
+* Update to *rustc 1.19.0-nightly (6a5fc9eec 2017-05-02)*
+
+## 0.0.129 — 2017-05-01
+* Update to *rustc 1.19.0-nightly (06fb4d256 2017-04-30)*
+
+## 0.0.128 — 2017-04-28
+* Update to *rustc 1.18.0-nightly (94e884b63 2017-04-27)*
+
+## 0.0.127 — 2017-04-27
+* Update to *rustc 1.18.0-nightly (036983201 2017-04-26)*
+* New lint: [`needless_continue`]
+
+## 0.0.126 — 2017-04-24
+* Update to *rustc 1.18.0-nightly (2bd4b5c6d 2017-04-23)*
+
+## 0.0.125 — 2017-04-19
+* Update to *rustc 1.18.0-nightly (9f2abadca 2017-04-18)*
+
+## 0.0.124 — 2017-04-16
+* Update to *rustc 1.18.0-nightly (d5cf1cb64 2017-04-15)*
+
+## 0.0.123 — 2017-04-07
+* Fix various false positives
+
+## 0.0.122 — 2017-04-07
+* Rustup to *rustc 1.18.0-nightly (91ae22a01 2017-04-05)*
+* New lint: [`op_ref`]
+
+## 0.0.121 — 2017-03-21
+* Rustup to *rustc 1.17.0-nightly (134c4a0f0 2017-03-20)*
+
+## 0.0.120 — 2017-03-17
+* Rustup to *rustc 1.17.0-nightly (0aeb9c129 2017-03-15)*
+
+## 0.0.119 — 2017-03-13
+* Rustup to *rustc 1.17.0-nightly (824c9ebbd 2017-03-12)*
+
+## 0.0.118 — 2017-03-05
+* Rustup to *rustc 1.17.0-nightly (b1e31766d 2017-03-03)*
+
+## 0.0.117 — 2017-03-01
+* Rustup to *rustc 1.17.0-nightly (be760566c 2017-02-28)*
+
+## 0.0.116 — 2017-02-28
+* Fix `cargo clippy` on 64 bit windows systems
+
+## 0.0.115 — 2017-02-27
+* Rustup to *rustc 1.17.0-nightly (60a0edc6c 2017-02-26)*
+* New lints: [`zero_ptr`], [`never_loop`], [`mut_from_ref`]
+
+## 0.0.114 — 2017-02-08
+* Rustup to *rustc 1.17.0-nightly (c49d10207 2017-02-07)*
+* Tests are now ui tests (testing the exact output of rustc)
+
+## 0.0.113 — 2017-02-04
+* Rustup to *rustc 1.16.0-nightly (eedaa94e3 2017-02-02)*
+* New lint: [`large_enum_variant`]
+* `explicit_into_iter_loop` provides suggestions
+
+## 0.0.112 — 2017-01-27
+* Rustup to *rustc 1.16.0-nightly (df8debf6d 2017-01-25)*
+
+## 0.0.111 — 2017-01-21
+* Rustup to *rustc 1.16.0-nightly (a52da95ce 2017-01-20)*
+
+## 0.0.110 — 2017-01-20
+* Add badges and categories to `Cargo.toml`
+
+## 0.0.109 — 2017-01-19
+* Update to *rustc 1.16.0-nightly (c07a6ae77 2017-01-17)*
+
+## 0.0.108 — 2017-01-12
+* Update to *rustc 1.16.0-nightly (2782e8f8f 2017-01-12)*
+
+## 0.0.107 — 2017-01-11
+* Update regex dependency
+* Fix FP when matching `&&mut` by `&ref`
+* Reintroduce `for (_, x) in &mut hash_map` -> `for x in hash_map.values_mut()`
+* New lints: [`unused_io_amount`], [`forget_ref`], [`short_circuit_statement`]
+
+## 0.0.106 — 2017-01-04
+* Fix FP introduced by rustup in [`wrong_self_convention`]
+
+## 0.0.105 — 2017-01-04
+* Update to *rustc 1.16.0-nightly (468227129 2017-01-03)*
+* New lints: [`deref_addrof`], [`double_parens`], [`pub_enum_variant_names`]
+* Fix suggestion in [`new_without_default`]
+* FP fix in [`absurd_extreme_comparisons`]
+
+## 0.0.104 — 2016-12-15
+* Update to *rustc 1.15.0-nightly (8f02c429a 2016-12-15)*
+
+## 0.0.103 — 2016-11-25
+* Update to *rustc 1.15.0-nightly (d5814b03e 2016-11-23)*
+
+## 0.0.102 — 2016-11-24
+* Update to *rustc 1.15.0-nightly (3bf2be9ce 2016-11-22)*
+
+## 0.0.101 — 2016-11-23
+* Update to *rustc 1.15.0-nightly (7b3eeea22 2016-11-21)*
+* New lint: [`string_extend_chars`]
+
+## 0.0.100 — 2016-11-20
+* Update to *rustc 1.15.0-nightly (ac635aa95 2016-11-18)*
+
+## 0.0.99 — 2016-11-18
+* Update to rustc 1.15.0-nightly (0ed951993 2016-11-14)
+* New lint: [`get_unwrap`]
+
+## 0.0.98 — 2016-11-08
+* Fixes an issue due to a change in how cargo handles `--sysroot`, which broke `cargo clippy`
+
+## 0.0.97 — 2016-11-03
+* For convenience, `cargo clippy` defines a `cargo-clippy` feature. This was
+ previously added for a short time under the name `clippy` but removed for
+ compatibility.
+* `cargo clippy --help` is more helping (and less helpful :smile:)
+* Rustup to *rustc 1.14.0-nightly (5665bdf3e 2016-11-02)*
+* New lints: [`if_let_redundant_pattern_matching`], [`partialeq_ne_impl`]
+
+## 0.0.96 — 2016-10-22
+* Rustup to *rustc 1.14.0-nightly (f09420685 2016-10-20)*
+* New lint: [`iter_skip_next`]
+
+## 0.0.95 — 2016-10-06
+* Rustup to *rustc 1.14.0-nightly (3210fd5c2 2016-10-05)*
+
+## 0.0.94 — 2016-10-04
+* Fixes bustage on Windows due to forbidden directory name
+
+## 0.0.93 — 2016-10-03
+* Rustup to *rustc 1.14.0-nightly (144af3e97 2016-10-02)*
+* [`option_map_unwrap_or`] and [`option_map_unwrap_or_else`] are now
+ allowed by default.
+* New lint: [`explicit_into_iter_loop`]
+
+## 0.0.92 — 2016-09-30
+* Rustup to *rustc 1.14.0-nightly (289f3a4ca 2016-09-29)*
+
+## 0.0.91 — 2016-09-28
+* Rustup to *rustc 1.13.0-nightly (d0623cf7b 2016-09-26)*
+
+## 0.0.90 — 2016-09-09
+* Rustup to *rustc 1.13.0-nightly (f1f40f850 2016-09-09)*
+
+## 0.0.89 — 2016-09-06
+* Rustup to *rustc 1.13.0-nightly (cbe4de78e 2016-09-05)*
+
+## 0.0.88 — 2016-09-04
+* Rustup to *rustc 1.13.0-nightly (70598e04f 2016-09-03)*
+* The following lints are not new but were only usable through the `clippy`
+ lint groups: [`filter_next`], [`for_loop_over_option`],
+ [`for_loop_over_result`] and [`match_overlapping_arm`]. You should now be
+ able to `#[allow/deny]` them individually and they are available directly
+ through `cargo clippy`.
+
+## 0.0.87 — 2016-08-31
+* Rustup to *rustc 1.13.0-nightly (eac41469d 2016-08-30)*
+* New lints: [`builtin_type_shadow`]
+* Fix FP in [`zero_prefixed_literal`] and `0b`/`0o`
+
+## 0.0.86 — 2016-08-28
+* Rustup to *rustc 1.13.0-nightly (a23064af5 2016-08-27)*
+* New lints: [`missing_docs_in_private_items`], [`zero_prefixed_literal`]
+
+## 0.0.85 — 2016-08-19
+* Fix ICE with [`useless_attribute`]
+* [`useless_attribute`] ignores `unused_imports` on `use` statements
+
+## 0.0.84 — 2016-08-18
+* Rustup to *rustc 1.13.0-nightly (aef6971ca 2016-08-17)*
+
+## 0.0.83 — 2016-08-17
+* Rustup to *rustc 1.12.0-nightly (1bf5fa326 2016-08-16)*
+* New lints: [`print_with_newline`], [`useless_attribute`]
+
+## 0.0.82 — 2016-08-17
+* Rustup to *rustc 1.12.0-nightly (197be89f3 2016-08-15)*
+* New lint: [`module_inception`]
+
+## 0.0.81 — 2016-08-14
+* Rustup to *rustc 1.12.0-nightly (1deb02ea6 2016-08-12)*
+* New lints: [`eval_order_dependence`], [`mixed_case_hex_literals`], [`unseparated_literal_suffix`]
+* False positive fix in [`too_many_arguments`]
+* Addition of functionality to [`needless_borrow`]
+* Suggestions for [`clone_on_copy`]
+* Bug fix in [`wrong_self_convention`]
+* Doc improvements
+
+## 0.0.80 — 2016-07-31
+* Rustup to *rustc 1.12.0-nightly (1225e122f 2016-07-30)*
+* New lints: [`misrefactored_assign_op`], [`serde_api_misuse`]
+
+## 0.0.79 — 2016-07-10
+* Rustup to *rustc 1.12.0-nightly (f93aaf84c 2016-07-09)*
+* Major suggestions refactoring
+
+## 0.0.78 — 2016-07-02
+* Rustup to *rustc 1.11.0-nightly (01411937f 2016-07-01)*
+* New lints: [`wrong_transmute`], [`double_neg`], [`filter_map`]
+* For compatibility, `cargo clippy` does not defines the `clippy` feature
+ introduced in 0.0.76 anymore
+* [`collapsible_if`] now considers `if let`
+
+## 0.0.77 — 2016-06-21
+* Rustup to *rustc 1.11.0-nightly (5522e678b 2016-06-20)*
+* New lints: `stutter` and [`iter_nth`]
+
+## 0.0.76 — 2016-06-10
+* Rustup to *rustc 1.11.0-nightly (7d2f75a95 2016-06-09)*
+* `cargo clippy` now automatically defines the `clippy` feature
+* New lint: [`not_unsafe_ptr_arg_deref`]
+
+## 0.0.75 — 2016-06-08
+* Rustup to *rustc 1.11.0-nightly (763f9234b 2016-06-06)*
+
+## 0.0.74 — 2016-06-07
+* Fix bug with `cargo-clippy` JSON parsing
+* Add the `CLIPPY_DISABLE_DOCS_LINKS` environment variable to deactivate the
+ “for further information visit *lint-link*” message.
+
+## 0.0.73 — 2016-06-05
+* Fix false positives in [`useless_let_if_seq`]
+
+## 0.0.72 — 2016-06-04
+* Fix false positives in [`useless_let_if_seq`]
+
+## 0.0.71 — 2016-05-31
+* Rustup to *rustc 1.11.0-nightly (a967611d8 2016-05-30)*
+* New lint: [`useless_let_if_seq`]
+
+## 0.0.70 — 2016-05-28
+* Rustup to *rustc 1.10.0-nightly (7bddce693 2016-05-27)*
+* [`invalid_regex`] and [`trivial_regex`] can now warn on `RegexSet::new`,
+ `RegexBuilder::new` and byte regexes
+
+## 0.0.69 — 2016-05-20
+* Rustup to *rustc 1.10.0-nightly (476fe6eef 2016-05-21)*
+* [`used_underscore_binding`] has been made `Allow` temporarily
+
+## 0.0.68 — 2016-05-17
+* Rustup to *rustc 1.10.0-nightly (cd6a40017 2016-05-16)*
+* New lint: [`unnecessary_operation`]
+
+## 0.0.67 — 2016-05-12
+* Rustup to *rustc 1.10.0-nightly (22ac88f1a 2016-05-11)*
+
+## 0.0.66 — 2016-05-11
+* New `cargo clippy` subcommand
+* New lints: [`assign_op_pattern`], [`assign_ops`], [`needless_borrow`]
+
+## 0.0.65 — 2016-05-08
+* Rustup to *rustc 1.10.0-nightly (62e2b2fb7 2016-05-06)*
+* New lints: [`float_arithmetic`], [`integer_arithmetic`]
+
+## 0.0.64 — 2016-04-26
+* Rustup to *rustc 1.10.0-nightly (645dd013a 2016-04-24)*
+* New lints: [`temporary_cstring_as_ptr`], [`unsafe_removed_from_name`], and [`mem_forget`]
+
+## 0.0.63 — 2016-04-08
+* Rustup to *rustc 1.9.0-nightly (7979dd608 2016-04-07)*
+
+## 0.0.62 — 2016-04-07
+* Rustup to *rustc 1.9.0-nightly (bf5da36f1 2016-04-06)*
+
+## 0.0.61 — 2016-04-03
+* Rustup to *rustc 1.9.0-nightly (5ab11d72c 2016-04-02)*
+* New lint: [`invalid_upcast_comparisons`]
+
+## 0.0.60 — 2016-04-01
+* Rustup to *rustc 1.9.0-nightly (e1195c24b 2016-03-31)*
+
+## 0.0.59 — 2016-03-31
+* Rustup to *rustc 1.9.0-nightly (30a3849f2 2016-03-30)*
+* New lints: [`logic_bug`], [`nonminimal_bool`]
+* Fixed: [`match_same_arms`] now ignores arms with guards
+* Improved: [`useless_vec`] now warns on `for … in vec![…]`
+
+## 0.0.58 — 2016-03-27
+* Rustup to *rustc 1.9.0-nightly (d5a91e695 2016-03-26)*
+* New lint: [`doc_markdown`]
+
+## 0.0.57 — 2016-03-27
+* Update to *rustc 1.9.0-nightly (a1e29daf1 2016-03-25)*
+* Deprecated lints: [`str_to_string`], [`string_to_string`], [`unstable_as_slice`], [`unstable_as_mut_slice`]
+* New lint: [`crosspointer_transmute`]
+
+## 0.0.56 — 2016-03-23
+* Update to *rustc 1.9.0-nightly (0dcc413e4 2016-03-22)*
+* New lints: [`many_single_char_names`] and [`similar_names`]
+
+## 0.0.55 — 2016-03-21
+* Update to *rustc 1.9.0-nightly (02310fd31 2016-03-19)*
+
+## 0.0.54 — 2016-03-16
+* Update to *rustc 1.9.0-nightly (c66d2380a 2016-03-15)*
+
+## 0.0.53 — 2016-03-15
+* Add a [configuration file]
+
+## ~~0.0.52~~
+
+## 0.0.51 — 2016-03-13
+* Add `str` to types considered by [`len_zero`]
+* New lints: [`indexing_slicing`]
+
+## 0.0.50 — 2016-03-11
+* Update to *rustc 1.9.0-nightly (c9629d61c 2016-03-10)*
+
+## 0.0.49 — 2016-03-09
+* Update to *rustc 1.9.0-nightly (eabfc160f 2016-03-08)*
+* New lints: [`overflow_check_conditional`], [`unused_label`], [`new_without_default`]
+
+## 0.0.48 — 2016-03-07
+* Fixed: ICE in [`needless_range_loop`] with globals
+
+## 0.0.47 — 2016-03-07
+* Update to *rustc 1.9.0-nightly (998a6720b 2016-03-07)*
+* New lint: [`redundant_closure_call`]
+
+[`AsMut`]: https://doc.rust-lang.org/std/convert/trait.AsMut.html
+[`AsRef`]: https://doc.rust-lang.org/std/convert/trait.AsRef.html
+[configuration file]: ./rust-clippy#configuration
+[pull3665]: https://github.com/rust-lang/rust-clippy/pull/3665
+[adding_lints]: https://github.com/rust-lang/rust-clippy/blob/master/doc/adding_lints.md
+
+
+
+[`absurd_extreme_comparisons`]: https://rust-lang.github.io/rust-clippy/master/index.html#absurd_extreme_comparisons
+[`almost_swapped`]: https://rust-lang.github.io/rust-clippy/master/index.html#almost_swapped
+[`approx_constant`]: https://rust-lang.github.io/rust-clippy/master/index.html#approx_constant
+[`as_conversions`]: https://rust-lang.github.io/rust-clippy/master/index.html#as_conversions
+[`assertions_on_constants`]: https://rust-lang.github.io/rust-clippy/master/index.html#assertions_on_constants
+[`assign_op_pattern`]: https://rust-lang.github.io/rust-clippy/master/index.html#assign_op_pattern
+[`assign_ops`]: https://rust-lang.github.io/rust-clippy/master/index.html#assign_ops
+[`await_holding_lock`]: https://rust-lang.github.io/rust-clippy/master/index.html#await_holding_lock
+[`bad_bit_mask`]: https://rust-lang.github.io/rust-clippy/master/index.html#bad_bit_mask
+[`blacklisted_name`]: https://rust-lang.github.io/rust-clippy/master/index.html#blacklisted_name
+[`block_in_if_condition_expr`]: https://rust-lang.github.io/rust-clippy/master/index.html#block_in_if_condition_expr
+[`block_in_if_condition_stmt`]: https://rust-lang.github.io/rust-clippy/master/index.html#block_in_if_condition_stmt
+[`bool_comparison`]: https://rust-lang.github.io/rust-clippy/master/index.html#bool_comparison
+[`borrow_interior_mutable_const`]: https://rust-lang.github.io/rust-clippy/master/index.html#borrow_interior_mutable_const
+[`borrowed_box`]: https://rust-lang.github.io/rust-clippy/master/index.html#borrowed_box
+[`box_vec`]: https://rust-lang.github.io/rust-clippy/master/index.html#box_vec
+[`boxed_local`]: https://rust-lang.github.io/rust-clippy/master/index.html#boxed_local
+[`builtin_type_shadow`]: https://rust-lang.github.io/rust-clippy/master/index.html#builtin_type_shadow
+[`cargo_common_metadata`]: https://rust-lang.github.io/rust-clippy/master/index.html#cargo_common_metadata
+[`cast_lossless`]: https://rust-lang.github.io/rust-clippy/master/index.html#cast_lossless
+[`cast_possible_truncation`]: https://rust-lang.github.io/rust-clippy/master/index.html#cast_possible_truncation
+[`cast_possible_wrap`]: https://rust-lang.github.io/rust-clippy/master/index.html#cast_possible_wrap
+[`cast_precision_loss`]: https://rust-lang.github.io/rust-clippy/master/index.html#cast_precision_loss
+[`cast_ptr_alignment`]: https://rust-lang.github.io/rust-clippy/master/index.html#cast_ptr_alignment
+[`cast_ref_to_mut`]: https://rust-lang.github.io/rust-clippy/master/index.html#cast_ref_to_mut
+[`cast_sign_loss`]: https://rust-lang.github.io/rust-clippy/master/index.html#cast_sign_loss
+[`char_lit_as_u8`]: https://rust-lang.github.io/rust-clippy/master/index.html#char_lit_as_u8
+[`chars_last_cmp`]: https://rust-lang.github.io/rust-clippy/master/index.html#chars_last_cmp
+[`chars_next_cmp`]: https://rust-lang.github.io/rust-clippy/master/index.html#chars_next_cmp
+[`checked_conversions`]: https://rust-lang.github.io/rust-clippy/master/index.html#checked_conversions
+[`clone_double_ref`]: https://rust-lang.github.io/rust-clippy/master/index.html#clone_double_ref
+[`clone_on_copy`]: https://rust-lang.github.io/rust-clippy/master/index.html#clone_on_copy
+[`clone_on_ref_ptr`]: https://rust-lang.github.io/rust-clippy/master/index.html#clone_on_ref_ptr
+[`cmp_nan`]: https://rust-lang.github.io/rust-clippy/master/index.html#cmp_nan
+[`cmp_null`]: https://rust-lang.github.io/rust-clippy/master/index.html#cmp_null
+[`cmp_owned`]: https://rust-lang.github.io/rust-clippy/master/index.html#cmp_owned
+[`cognitive_complexity`]: https://rust-lang.github.io/rust-clippy/master/index.html#cognitive_complexity
+[`collapsible_if`]: https://rust-lang.github.io/rust-clippy/master/index.html#collapsible_if
+[`comparison_chain`]: https://rust-lang.github.io/rust-clippy/master/index.html#comparison_chain
+[`copy_iterator`]: https://rust-lang.github.io/rust-clippy/master/index.html#copy_iterator
+[`crosspointer_transmute`]: https://rust-lang.github.io/rust-clippy/master/index.html#crosspointer_transmute
+[`dbg_macro`]: https://rust-lang.github.io/rust-clippy/master/index.html#dbg_macro
+[`debug_assert_with_mut_call`]: https://rust-lang.github.io/rust-clippy/master/index.html#debug_assert_with_mut_call
+[`decimal_literal_representation`]: https://rust-lang.github.io/rust-clippy/master/index.html#decimal_literal_representation
+[`declare_interior_mutable_const`]: https://rust-lang.github.io/rust-clippy/master/index.html#declare_interior_mutable_const
+[`default_trait_access`]: https://rust-lang.github.io/rust-clippy/master/index.html#default_trait_access
+[`deprecated_cfg_attr`]: https://rust-lang.github.io/rust-clippy/master/index.html#deprecated_cfg_attr
+[`deprecated_semver`]: https://rust-lang.github.io/rust-clippy/master/index.html#deprecated_semver
+[`deref_addrof`]: https://rust-lang.github.io/rust-clippy/master/index.html#deref_addrof
+[`derive_hash_xor_eq`]: https://rust-lang.github.io/rust-clippy/master/index.html#derive_hash_xor_eq
+[`diverging_sub_expression`]: https://rust-lang.github.io/rust-clippy/master/index.html#diverging_sub_expression
+[`doc_markdown`]: https://rust-lang.github.io/rust-clippy/master/index.html#doc_markdown
+[`double_comparisons`]: https://rust-lang.github.io/rust-clippy/master/index.html#double_comparisons
+[`double_must_use`]: https://rust-lang.github.io/rust-clippy/master/index.html#double_must_use
+[`double_neg`]: https://rust-lang.github.io/rust-clippy/master/index.html#double_neg
+[`double_parens`]: https://rust-lang.github.io/rust-clippy/master/index.html#double_parens
+[`drop_bounds`]: https://rust-lang.github.io/rust-clippy/master/index.html#drop_bounds
+[`drop_copy`]: https://rust-lang.github.io/rust-clippy/master/index.html#drop_copy
+[`drop_ref`]: https://rust-lang.github.io/rust-clippy/master/index.html#drop_ref
+[`duplicate_underscore_argument`]: https://rust-lang.github.io/rust-clippy/master/index.html#duplicate_underscore_argument
+[`duration_subsec`]: https://rust-lang.github.io/rust-clippy/master/index.html#duration_subsec
+[`else_if_without_else`]: https://rust-lang.github.io/rust-clippy/master/index.html#else_if_without_else
+[`empty_enum`]: https://rust-lang.github.io/rust-clippy/master/index.html#empty_enum
+[`empty_line_after_outer_attr`]: https://rust-lang.github.io/rust-clippy/master/index.html#empty_line_after_outer_attr
+[`empty_loop`]: https://rust-lang.github.io/rust-clippy/master/index.html#empty_loop
+[`enum_clike_unportable_variant`]: https://rust-lang.github.io/rust-clippy/master/index.html#enum_clike_unportable_variant
+[`enum_glob_use`]: https://rust-lang.github.io/rust-clippy/master/index.html#enum_glob_use
+[`enum_variant_names`]: https://rust-lang.github.io/rust-clippy/master/index.html#enum_variant_names
+[`eq_op`]: https://rust-lang.github.io/rust-clippy/master/index.html#eq_op
+[`erasing_op`]: https://rust-lang.github.io/rust-clippy/master/index.html#erasing_op
+[`eval_order_dependence`]: https://rust-lang.github.io/rust-clippy/master/index.html#eval_order_dependence
+[`excessive_precision`]: https://rust-lang.github.io/rust-clippy/master/index.html#excessive_precision
+[`exit`]: https://rust-lang.github.io/rust-clippy/master/index.html#exit
+[`expect_fun_call`]: https://rust-lang.github.io/rust-clippy/master/index.html#expect_fun_call
+[`expl_impl_clone_on_copy`]: https://rust-lang.github.io/rust-clippy/master/index.html#expl_impl_clone_on_copy
+[`explicit_counter_loop`]: https://rust-lang.github.io/rust-clippy/master/index.html#explicit_counter_loop
+[`explicit_deref_methods`]: https://rust-lang.github.io/rust-clippy/master/index.html#explicit_deref_methods
+[`explicit_into_iter_loop`]: https://rust-lang.github.io/rust-clippy/master/index.html#explicit_into_iter_loop
+[`explicit_iter_loop`]: https://rust-lang.github.io/rust-clippy/master/index.html#explicit_iter_loop
+[`explicit_write`]: https://rust-lang.github.io/rust-clippy/master/index.html#explicit_write
+[`extend_from_slice`]: https://rust-lang.github.io/rust-clippy/master/index.html#extend_from_slice
+[`extra_unused_lifetimes`]: https://rust-lang.github.io/rust-clippy/master/index.html#extra_unused_lifetimes
+[`fallible_impl_from`]: https://rust-lang.github.io/rust-clippy/master/index.html#fallible_impl_from
+[`filetype_is_file`]: https://rust-lang.github.io/rust-clippy/master/index.html#filetype_is_file
+[`filter_map`]: https://rust-lang.github.io/rust-clippy/master/index.html#filter_map
+[`filter_map_next`]: https://rust-lang.github.io/rust-clippy/master/index.html#filter_map_next
+[`filter_next`]: https://rust-lang.github.io/rust-clippy/master/index.html#filter_next
+[`find_map`]: https://rust-lang.github.io/rust-clippy/master/index.html#find_map
+[`flat_map_identity`]: https://rust-lang.github.io/rust-clippy/master/index.html#flat_map_identity
+[`float_arithmetic`]: https://rust-lang.github.io/rust-clippy/master/index.html#float_arithmetic
+[`float_cmp`]: https://rust-lang.github.io/rust-clippy/master/index.html#float_cmp
+[`float_cmp_const`]: https://rust-lang.github.io/rust-clippy/master/index.html#float_cmp_const
+[`fn_address_comparisons`]: https://rust-lang.github.io/rust-clippy/master/index.html#fn_address_comparisons
+[`fn_params_excessive_bools`]: https://rust-lang.github.io/rust-clippy/master/index.html#fn_params_excessive_bools
+[`fn_to_numeric_cast`]: https://rust-lang.github.io/rust-clippy/master/index.html#fn_to_numeric_cast
+[`fn_to_numeric_cast_with_truncation`]: https://rust-lang.github.io/rust-clippy/master/index.html#fn_to_numeric_cast_with_truncation
+[`for_kv_map`]: https://rust-lang.github.io/rust-clippy/master/index.html#for_kv_map
+[`for_loop_over_option`]: https://rust-lang.github.io/rust-clippy/master/index.html#for_loop_over_option
+[`for_loop_over_result`]: https://rust-lang.github.io/rust-clippy/master/index.html#for_loop_over_result
+[`forget_copy`]: https://rust-lang.github.io/rust-clippy/master/index.html#forget_copy
+[`forget_ref`]: https://rust-lang.github.io/rust-clippy/master/index.html#forget_ref
+[`future_not_send`]: https://rust-lang.github.io/rust-clippy/master/index.html#future_not_send
+[`get_last_with_len`]: https://rust-lang.github.io/rust-clippy/master/index.html#get_last_with_len
+[`get_unwrap`]: https://rust-lang.github.io/rust-clippy/master/index.html#get_unwrap
+[`identity_conversion`]: https://rust-lang.github.io/rust-clippy/master/index.html#identity_conversion
+[`identity_op`]: https://rust-lang.github.io/rust-clippy/master/index.html#identity_op
+[`if_let_mutex`]: https://rust-lang.github.io/rust-clippy/master/index.html#if_let_mutex
+[`if_let_redundant_pattern_matching`]: https://rust-lang.github.io/rust-clippy/master/index.html#if_let_redundant_pattern_matching
+[`if_let_some_result`]: https://rust-lang.github.io/rust-clippy/master/index.html#if_let_some_result
+[`if_not_else`]: https://rust-lang.github.io/rust-clippy/master/index.html#if_not_else
+[`if_same_then_else`]: https://rust-lang.github.io/rust-clippy/master/index.html#if_same_then_else
+[`ifs_same_cond`]: https://rust-lang.github.io/rust-clippy/master/index.html#ifs_same_cond
+[`implicit_hasher`]: https://rust-lang.github.io/rust-clippy/master/index.html#implicit_hasher
+[`implicit_return`]: https://rust-lang.github.io/rust-clippy/master/index.html#implicit_return
+[`implicit_saturating_sub`]: https://rust-lang.github.io/rust-clippy/master/index.html#implicit_saturating_sub
+[`imprecise_flops`]: https://rust-lang.github.io/rust-clippy/master/index.html#imprecise_flops
+[`inconsistent_digit_grouping`]: https://rust-lang.github.io/rust-clippy/master/index.html#inconsistent_digit_grouping
+[`indexing_slicing`]: https://rust-lang.github.io/rust-clippy/master/index.html#indexing_slicing
+[`ineffective_bit_mask`]: https://rust-lang.github.io/rust-clippy/master/index.html#ineffective_bit_mask
+[`inefficient_to_string`]: https://rust-lang.github.io/rust-clippy/master/index.html#inefficient_to_string
+[`infallible_destructuring_match`]: https://rust-lang.github.io/rust-clippy/master/index.html#infallible_destructuring_match
+[`infinite_iter`]: https://rust-lang.github.io/rust-clippy/master/index.html#infinite_iter
+[`inherent_to_string`]: https://rust-lang.github.io/rust-clippy/master/index.html#inherent_to_string
+[`inherent_to_string_shadow_display`]: https://rust-lang.github.io/rust-clippy/master/index.html#inherent_to_string_shadow_display
+[`inline_always`]: https://rust-lang.github.io/rust-clippy/master/index.html#inline_always
+[`inline_fn_without_body`]: https://rust-lang.github.io/rust-clippy/master/index.html#inline_fn_without_body
+[`int_plus_one`]: https://rust-lang.github.io/rust-clippy/master/index.html#int_plus_one
+[`integer_arithmetic`]: https://rust-lang.github.io/rust-clippy/master/index.html#integer_arithmetic
+[`integer_division`]: https://rust-lang.github.io/rust-clippy/master/index.html#integer_division
+[`into_iter_on_array`]: https://rust-lang.github.io/rust-clippy/master/index.html#into_iter_on_array
+[`into_iter_on_ref`]: https://rust-lang.github.io/rust-clippy/master/index.html#into_iter_on_ref
+[`invalid_atomic_ordering`]: https://rust-lang.github.io/rust-clippy/master/index.html#invalid_atomic_ordering
+[`invalid_ref`]: https://rust-lang.github.io/rust-clippy/master/index.html#invalid_ref
+[`invalid_regex`]: https://rust-lang.github.io/rust-clippy/master/index.html#invalid_regex
+[`invalid_upcast_comparisons`]: https://rust-lang.github.io/rust-clippy/master/index.html#invalid_upcast_comparisons
+[`items_after_statements`]: https://rust-lang.github.io/rust-clippy/master/index.html#items_after_statements
+[`iter_cloned_collect`]: https://rust-lang.github.io/rust-clippy/master/index.html#iter_cloned_collect
+[`iter_next_loop`]: https://rust-lang.github.io/rust-clippy/master/index.html#iter_next_loop
+[`iter_nth`]: https://rust-lang.github.io/rust-clippy/master/index.html#iter_nth
+[`iter_nth_zero`]: https://rust-lang.github.io/rust-clippy/master/index.html#iter_nth_zero
+[`iter_skip_next`]: https://rust-lang.github.io/rust-clippy/master/index.html#iter_skip_next
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+[`unsafe_removed_from_name`]: https://rust-lang.github.io/rust-clippy/master/index.html#unsafe_removed_from_name
+[`unsafe_vector_initialization`]: https://rust-lang.github.io/rust-clippy/master/index.html#unsafe_vector_initialization
+[`unseparated_literal_suffix`]: https://rust-lang.github.io/rust-clippy/master/index.html#unseparated_literal_suffix
+[`unsound_collection_transmute`]: https://rust-lang.github.io/rust-clippy/master/index.html#unsound_collection_transmute
+[`unstable_as_mut_slice`]: https://rust-lang.github.io/rust-clippy/master/index.html#unstable_as_mut_slice
+[`unstable_as_slice`]: https://rust-lang.github.io/rust-clippy/master/index.html#unstable_as_slice
+[`unused_collect`]: https://rust-lang.github.io/rust-clippy/master/index.html#unused_collect
+[`unused_io_amount`]: https://rust-lang.github.io/rust-clippy/master/index.html#unused_io_amount
+[`unused_label`]: https://rust-lang.github.io/rust-clippy/master/index.html#unused_label
+[`unused_self`]: https://rust-lang.github.io/rust-clippy/master/index.html#unused_self
+[`unused_unit`]: https://rust-lang.github.io/rust-clippy/master/index.html#unused_unit
+[`use_debug`]: https://rust-lang.github.io/rust-clippy/master/index.html#use_debug
+[`use_self`]: https://rust-lang.github.io/rust-clippy/master/index.html#use_self
+[`used_underscore_binding`]: https://rust-lang.github.io/rust-clippy/master/index.html#used_underscore_binding
+[`useless_asref`]: https://rust-lang.github.io/rust-clippy/master/index.html#useless_asref
+[`useless_attribute`]: https://rust-lang.github.io/rust-clippy/master/index.html#useless_attribute
+[`useless_format`]: https://rust-lang.github.io/rust-clippy/master/index.html#useless_format
+[`useless_let_if_seq`]: https://rust-lang.github.io/rust-clippy/master/index.html#useless_let_if_seq
+[`useless_transmute`]: https://rust-lang.github.io/rust-clippy/master/index.html#useless_transmute
+[`useless_vec`]: https://rust-lang.github.io/rust-clippy/master/index.html#useless_vec
+[`vec_box`]: https://rust-lang.github.io/rust-clippy/master/index.html#vec_box
+[`verbose_bit_mask`]: https://rust-lang.github.io/rust-clippy/master/index.html#verbose_bit_mask
+[`verbose_file_reads`]: https://rust-lang.github.io/rust-clippy/master/index.html#verbose_file_reads
+[`vtable_address_comparisons`]: https://rust-lang.github.io/rust-clippy/master/index.html#vtable_address_comparisons
+[`while_immutable_condition`]: https://rust-lang.github.io/rust-clippy/master/index.html#while_immutable_condition
+[`while_let_loop`]: https://rust-lang.github.io/rust-clippy/master/index.html#while_let_loop
+[`while_let_on_iterator`]: https://rust-lang.github.io/rust-clippy/master/index.html#while_let_on_iterator
+[`wildcard_dependencies`]: https://rust-lang.github.io/rust-clippy/master/index.html#wildcard_dependencies
+[`wildcard_enum_match_arm`]: https://rust-lang.github.io/rust-clippy/master/index.html#wildcard_enum_match_arm
+[`wildcard_imports`]: https://rust-lang.github.io/rust-clippy/master/index.html#wildcard_imports
+[`wildcard_in_or_patterns`]: https://rust-lang.github.io/rust-clippy/master/index.html#wildcard_in_or_patterns
+[`write_literal`]: https://rust-lang.github.io/rust-clippy/master/index.html#write_literal
+[`write_with_newline`]: https://rust-lang.github.io/rust-clippy/master/index.html#write_with_newline
+[`writeln_empty_string`]: https://rust-lang.github.io/rust-clippy/master/index.html#writeln_empty_string
+[`wrong_pub_self_convention`]: https://rust-lang.github.io/rust-clippy/master/index.html#wrong_pub_self_convention
+[`wrong_self_convention`]: https://rust-lang.github.io/rust-clippy/master/index.html#wrong_self_convention
+[`wrong_transmute`]: https://rust-lang.github.io/rust-clippy/master/index.html#wrong_transmute
+[`zero_divided_by_zero`]: https://rust-lang.github.io/rust-clippy/master/index.html#zero_divided_by_zero
+[`zero_prefixed_literal`]: https://rust-lang.github.io/rust-clippy/master/index.html#zero_prefixed_literal
+[`zero_ptr`]: https://rust-lang.github.io/rust-clippy/master/index.html#zero_ptr
+[`zero_width_space`]: https://rust-lang.github.io/rust-clippy/master/index.html#zero_width_space
+[`zst_offset`]: https://rust-lang.github.io/rust-clippy/master/index.html#zst_offset
+
diff --git a/src/tools/clippy/CODE_OF_CONDUCT.md b/src/tools/clippy/CODE_OF_CONDUCT.md
new file mode 100644
index 00000000000..dec13e44a17
--- /dev/null
+++ b/src/tools/clippy/CODE_OF_CONDUCT.md
@@ -0,0 +1,70 @@
+# The Rust Code of Conduct
+
+A version of this document [can be found online](https://www.rust-lang.org/conduct.html).
+
+## Conduct
+
+**Contact**: [rust-mods@rust-lang.org](mailto:rust-mods@rust-lang.org)
+
+* We are committed to providing a friendly, safe and welcoming environment for all, regardless of level of experience,
+ gender identity and expression, sexual orientation, disability, personal appearance, body size, race, ethnicity, age,
+ religion, nationality, or other similar characteristic.
+* On IRC, please avoid using overtly sexual nicknames or other nicknames that might detract from a friendly, safe and
+ welcoming environment for all.
+* Please be kind and courteous. There's no need to be mean or rude.
+* Respect that people have differences of opinion and that every design or implementation choice carries a trade-off and
+ numerous costs. There is seldom a right answer.
+* Please keep unstructured critique to a minimum. If you have solid ideas you want to experiment with, make a fork and
+ see how it works.
+* We will exclude you from interaction if you insult, demean or harass anyone. That is not welcome behavior. We
+ interpret the term "harassment" as including the definition in the Citizen
+ Code of Conduct; if you have any lack of clarity about what might be included in that concept, please read their
+ definition. In particular, we don't tolerate behavior that excludes people in socially marginalized groups.
+* Private harassment is also unacceptable. No matter who you are, if you feel you have been or are being harassed or
+ made uncomfortable by a community member, please contact one of the channel ops or any of the [Rust moderation
+ team][mod_team] immediately. Whether you're a regular contributor or a newcomer, we care about making this community a
+ safe place for you and we've got your back.
+* Likewise any spamming, trolling, flaming, baiting or other attention-stealing behavior is not welcome.
+
+## Moderation
+
+
+These are the policies for upholding our community's standards of conduct. If you feel that a thread needs moderation,
+please contact the [Rust moderation team][mod_team].
+
+1. Remarks that violate the Rust standards of conduct, including hateful, hurtful, oppressive, or exclusionary remarks,
+ are not allowed. (Cursing is allowed, but never targeting another user, and never in a hateful manner.)
+2. Remarks that moderators find inappropriate, whether listed in the code of conduct or not, are also not allowed.
+3. Moderators will first respond to such remarks with a warning.
+4. If the warning is unheeded, the user will be "kicked," i.e., kicked out of the communication channel to cool off.
+5. If the user comes back and continues to make trouble, they will be banned, i.e., indefinitely excluded.
+6. Moderators may choose at their discretion to un-ban the user if it was a first offense and they offer the offended
+ party a genuine apology.
+7. If a moderator bans someone and you think it was unjustified, please take it up with that moderator, or with a
+ different moderator, **in private**. Complaints about bans in-channel are not allowed.
+8. Moderators are held to a higher standard than other community members. If a moderator creates an inappropriate
+ situation, they should expect less leeway than others.
+
+In the Rust community we strive to go the extra step to look out for each other. Don't just aim to be technically
+unimpeachable, try to be your best self. In particular, avoid flirting with offensive or sensitive issues, particularly
+if they're off-topic; this all too often leads to unnecessary fights, hurt feelings, and damaged trust; worse, it can
+drive people away from the community entirely.
+
+And if someone takes issue with something you said or did, resist the urge to be defensive. Just stop doing what it was
+they complained about and apologize. Even if you feel you were misinterpreted or unfairly accused, chances are good
+there was something you could've communicated better — remember that it's your responsibility to make your fellow
+Rustaceans comfortable. Everyone wants to get along and we are all here first and foremost because we want to talk about
+cool technology. You will find that people will be eager to assume good intent and forgive as long as you earn their
+trust.
+
+The enforcement policies listed above apply to all official Rust venues; including official IRC channels (#rust,
+#rust-internals, #rust-tools, #rust-libs, #rustc, #rust-beginners, #rust-docs, #rust-community, #rust-lang, and #cargo);
+GitHub repositories under rust-lang, rust-lang-nursery, and rust-lang-deprecated; and all forums under rust-lang.org
+(users.rust-lang.org, internals.rust-lang.org). For other projects adopting the Rust Code of Conduct, please contact the
+maintainers of those projects for enforcement. If you wish to use this code of conduct for your own project, consider
+explicitly mentioning your moderation policy or making a copy with your own moderation policy so as to avoid confusion.
+
+*Adapted from the [Node.js Policy on Trolling](http://blog.izs.me/post/30036893703/policy-on-trolling) as well as the
+[Contributor Covenant v1.3.0](https://www.contributor-covenant.org/version/1/3/0/).*
+
+[mod_team]: https://www.rust-lang.org/team.html#Moderation-team
diff --git a/src/tools/clippy/CONTRIBUTING.md b/src/tools/clippy/CONTRIBUTING.md
new file mode 100644
index 00000000000..50a5ee8bbf3
--- /dev/null
+++ b/src/tools/clippy/CONTRIBUTING.md
@@ -0,0 +1,243 @@
+# Contributing to Clippy
+
+Hello fellow Rustacean! Great to see your interest in compiler internals and lints!
+
+**First**: if you're unsure or afraid of _anything_, just ask or submit the issue or pull request anyway. You won't be
+yelled at for giving it your best effort. The worst that can happen is that you'll be politely asked to change
+something. We appreciate any sort of contributions, and don't want a wall of rules to get in the way of that.
+
+Clippy welcomes contributions from everyone. There are many ways to contribute to Clippy and the following document
+explains how you can contribute and how to get started. If you have any questions about contributing or need help with
+anything, feel free to ask questions on issues or visit the `#clippy` on [Discord].
+
+All contributors are expected to follow the [Rust Code of Conduct].
+
+* [Getting started](#getting-started)
+ * [Finding something to fix/improve](#finding-something-to-fiximprove)
+* [Writing code](#writing-code)
+* [How Clippy works](#how-clippy-works)
+* [Fixing nightly build failures](#fixing-build-failures-caused-by-rust)
+* [Issue and PR Triage](#issue-and-pr-triage)
+* [Bors and Homu](#bors-and-homu)
+* [Contributions](#contributions)
+
+[Discord]: https://discord.gg/rust-lang
+[Rust Code of Conduct]: https://www.rust-lang.org/policies/code-of-conduct
+
+## Getting started
+
+High level approach:
+
+1. Find something to fix/improve
+2. Change code (likely some file in `clippy_lints/src/`)
+3. Follow the instructions in the [docs for writing lints](doc/adding_lints.md) such as running the `setup-toolchain.sh` script
+4. Run `cargo test` in the root directory and wiggle code until it passes
+5. Open a PR (also can be done after 2. if you run into problems)
+
+### Finding something to fix/improve
+
+All issues on Clippy are mentored, if you want help with a bug just ask
+@Manishearth, @flip1995, @phansch or @yaahc.
+
+Some issues are easier than others. The [`good first issue`] label can be used to find the easy issues.
+If you want to work on an issue, please leave a comment so that we can assign it to you!
+
+There are also some abandoned PRs, marked with [`S-inactive-closed`].
+Pretty often these PRs are nearly completed and just need some extra steps
+(formatting, addressing review comments, ...) to be merged. If you want to
+complete such a PR, please leave a comment in the PR and open a new one based
+on it.
+
+Issues marked [`T-AST`] involve simple matching of the syntax tree structure,
+and are generally easier than [`T-middle`] issues, which involve types
+and resolved paths.
+
+[`T-AST`] issues will generally need you to match against a predefined syntax structure.
+To figure out how this syntax structure is encoded in the AST, it is recommended to run
+`rustc -Z ast-json` on an example of the structure and compare with the [nodes in the AST docs].
+Usually the lint will end up to be a nested series of matches and ifs, [like so][deep-nesting].
+But we can make it nest-less by using [if_chain] macro, [like this][nest-less].
+
+[`E-medium`] issues are generally pretty easy too, though it's recommended you work on an E-easy issue first.
+They are mostly classified as [`E-medium`], since they might be somewhat involved code wise,
+but not difficult per-se.
+
+[`T-middle`] issues can be more involved and require verifying types. The [`ty`] module contains a
+lot of methods that are useful, though one of the most useful would be `expr_ty` (gives the type of
+an AST expression). `match_def_path()` in Clippy's `utils` module can also be useful.
+
+[`good first issue`]: https://github.com/rust-lang/rust-clippy/labels/good%20first%20issue
+[`S-inactive-closed`]: https://github.com/rust-lang/rust-clippy/pulls?q=is%3Aclosed+label%3AS-inactive-closed
+[`T-AST`]: https://github.com/rust-lang/rust-clippy/labels/T-AST
+[`T-middle`]: https://github.com/rust-lang/rust-clippy/labels/T-middle
+[`E-medium`]: https://github.com/rust-lang/rust-clippy/labels/E-medium
+[`ty`]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_middle/ty
+[nodes in the AST docs]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_ast/ast/
+[deep-nesting]: https://github.com/rust-lang/rust-clippy/blob/557f6848bd5b7183f55c1e1522a326e9e1df6030/clippy_lints/src/mem_forget.rs#L29-L43
+[if_chain]: https://docs.rs/if_chain/*/if_chain
+[nest-less]: https://github.com/rust-lang/rust-clippy/blob/557f6848bd5b7183f55c1e1522a326e9e1df6030/clippy_lints/src/bit_mask.rs#L124-L150
+
+## Writing code
+
+Have a look at the [docs for writing lints][adding_lints] for more details.
+
+If you want to add a new lint or change existing ones apart from bugfixing, it's
+also a good idea to give the [stability guarantees][rfc_stability] and
+[lint categories][rfc_lint_cats] sections of the [Clippy 1.0 RFC][clippy_rfc] a
+quick read.
+
+[adding_lints]: https://github.com/rust-lang/rust-clippy/blob/master/doc/adding_lints.md
+[clippy_rfc]: https://github.com/rust-lang/rfcs/blob/master/text/2476-clippy-uno.md
+[rfc_stability]: https://github.com/rust-lang/rfcs/blob/master/text/2476-clippy-uno.md#stability-guarantees
+[rfc_lint_cats]: https://github.com/rust-lang/rfcs/blob/master/text/2476-clippy-uno.md#lint-audit-and-categories
+
+## How Clippy works
+
+[`clippy_lints/src/lib.rs`][lint_crate_entry] imports all the different lint modules and registers in the [`LintStore`].
+For example, the [`else_if_without_else`][else_if_without_else] lint is registered like this:
+
+```rust
+// ./clippy_lints/src/lib.rs
+
+// ...
+pub mod else_if_without_else;
+// ...
+
+pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: &Conf) {
+ // ...
+ store.register_early_pass(|| box else_if_without_else::ElseIfWithoutElse);
+ // ...
+
+ store.register_group(true, "clippy::restriction", Some("clippy_restriction"), vec![
+ // ...
+ LintId::of(&else_if_without_else::ELSE_IF_WITHOUT_ELSE),
+ // ...
+ ]);
+}
+```
+
+The [`rustc_lint::LintStore`][`LintStore`] provides two methods to register lints:
+[register_early_pass][reg_early_pass] and [register_late_pass][reg_late_pass]. Both take an object
+that implements an [`EarlyLintPass`][early_lint_pass] or [`LateLintPass`][late_lint_pass] respectively. This is done in
+every single lint. It's worth noting that the majority of `clippy_lints/src/lib.rs` is autogenerated by `cargo dev
+update_lints`. When you are writing your own lint, you can use that script to save you some time.
+
+```rust
+// ./clippy_lints/src/else_if_without_else.rs
+
+use rustc_lint::{EarlyLintPass, EarlyContext};
+
+// ...
+
+pub struct ElseIfWithoutElse;
+
+// ...
+
+impl EarlyLintPass for ElseIfWithoutElse {
+ // ... the functions needed, to make the lint work
+}
+```
+
+The difference between `EarlyLintPass` and `LateLintPass` is that the methods of the `EarlyLintPass` trait only provide
+AST information. The methods of the `LateLintPass` trait are executed after type checking and contain type information
+via the `LateContext` parameter.
+
+That's why the `else_if_without_else` example uses the `register_early_pass` function. Because the
+[actual lint logic][else_if_without_else] does not depend on any type information.
+
+[lint_crate_entry]: https://github.com/rust-lang/rust-clippy/blob/master/clippy_lints/src/lib.rs
+[else_if_without_else]: https://github.com/rust-lang/rust-clippy/blob/4253aa7137cb7378acc96133c787e49a345c2b3c/clippy_lints/src/else_if_without_else.rs
+[`LintStore`]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_lint/struct.LintStore.html
+[reg_early_pass]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_lint/struct.LintStore.html#method.register_early_pass
+[reg_late_pass]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_lint/struct.LintStore.html#method.register_late_pass
+[early_lint_pass]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_lint/trait.EarlyLintPass.html
+[late_lint_pass]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_lint/trait.LateLintPass.html
+
+## Fixing build failures caused by Rust
+
+Clippy will sometimes fail to build from source because building it depends on unstable internal Rust features. Most of
+the times we have to adapt to the changes and only very rarely there's an actual bug in Rust. Fixing build failures
+caused by Rust updates, can be a good way to learn about Rust internals.
+
+In order to find out why Clippy does not work properly with a new Rust commit, you can use the [rust-toolstate commit
+history][toolstate_commit_history]. You will then have to look for the last commit that contains
+`test-pass -> build-fail` or `test-pass -> test-fail` for the `clippy-driver` component.
+[Here][toolstate_commit] is an example.
+
+The commit message contains a link to the PR. The PRs are usually small enough to discover the breaking API change and
+if they are bigger, they likely include some discussion that may help you to fix Clippy.
+
+To check if Clippy is available for a specific target platform, you can check
+the [rustup component history][rustup_component_history].
+
+If you decide to make Clippy work again with a Rust commit that breaks it,
+you probably want to install the latest Rust from master locally and run Clippy
+using that version of Rust.
+
+You can set up the master toolchain by running `./setup-toolchain.sh`. That script will install
+[rustup-toolchain-install-master][rtim] and master toolchain, then run `rustup override set master`.
+
+After fixing the build failure on this repository, we can submit a pull request
+to [`rust-lang/rust`] to fix the toolstate.
+
+To submit a pull request, you should follow these steps:
+
+```bash
+# Assuming you already cloned the rust-lang/rust repo and you're in the correct directory
+git submodule update --remote src/tools/clippy
+cargo update -p clippy
+git add -u
+git commit -m "Update Clippy"
+./x.py test -i --stage 1 src/tools/clippy # This is optional and should succeed anyway
+# Open a PR in rust-lang/rust
+```
+
+[rustup_component_history]: https://rust-lang.github.io/rustup-components-history
+[toolstate_commit_history]: https://github.com/rust-lang-nursery/rust-toolstate/commits/master
+[toolstate_commit]: https://github.com/rust-lang-nursery/rust-toolstate/commit/aad74d8294e198a7cf8ac81a91aebb7f3bbcf727
+[rtim]: https://github.com/kennytm/rustup-toolchain-install-master
+[`rust-lang/rust`]: https://github.com/rust-lang/rust
+
+## Issue and PR triage
+
+Clippy is following the [Rust triage procedure][triage] for issues and pull
+requests.
+
+However, we are a smaller project with all contributors being volunteers
+currently. Between writing new lints, fixing issues, reviewing pull requests and
+responding to issues there may not always be enough time to stay on top of it
+all.
+
+Our highest priority is fixing [crashes][l-crash] and [bugs][l-bug]. We don't
+want Clippy to crash on your code and we want it to be as reliable as the
+suggestions from Rust compiler errors.
+
+## Bors and Homu
+
+We use a bot powered by [Homu][homu] to help automate testing and landing of pull
+requests in Clippy. The bot's username is @bors.
+
+You can find the Clippy bors queue [here][homu_queue].
+
+If you have @bors permissions, you can find an overview of the available
+commands [here][homu_instructions].
+
+[triage]: https://forge.rust-lang.org/release/triage-procedure.html
+[l-crash]: https://github.com/rust-lang/rust-clippy/labels/L-crash%20%3Aboom%3A
+[l-bug]: https://github.com/rust-lang/rust-clippy/labels/L-bug%20%3Abeetle%3A
+[homu]: https://github.com/rust-lang/homu
+[homu_instructions]: https://buildbot2.rust-lang.org/homu/
+[homu_queue]: https://buildbot2.rust-lang.org/homu/queue/clippy
+
+## Contributions
+
+Contributions to Clippy should be made in the form of GitHub pull requests. Each pull request will
+be reviewed by a core contributor (someone with permission to land patches) and either landed in the
+main tree or given feedback for changes that would be required.
+
+All code in this repository is under the [Apache-2.0] or the [MIT] license.
+
+
+
+[Apache-2.0]: https://www.apache.org/licenses/LICENSE-2.0
+[MIT]: https://opensource.org/licenses/MIT
diff --git a/src/tools/clippy/COPYRIGHT b/src/tools/clippy/COPYRIGHT
new file mode 100644
index 00000000000..80d64472c70
--- /dev/null
+++ b/src/tools/clippy/COPYRIGHT
@@ -0,0 +1,7 @@
+Copyright 2014-2020 The Rust Project Developers
+
+Licensed under the Apache License, Version 2.0 or the MIT license
+, at your
+option. All files in the project carrying such notice may not be
+copied, modified, or distributed except according to those terms.
diff --git a/src/tools/clippy/Cargo.toml b/src/tools/clippy/Cargo.toml
new file mode 100644
index 00000000000..63ce2cd8cad
--- /dev/null
+++ b/src/tools/clippy/Cargo.toml
@@ -0,0 +1,59 @@
+[package]
+name = "clippy"
+version = "0.0.212"
+authors = [
+ "Manish Goregaokar ",
+ "Andre Bogus ",
+ "Georg Brandl ",
+ "Martin Carton ",
+ "Oliver Schneider "
+]
+description = "A bunch of helpful lints to avoid common pitfalls in Rust"
+repository = "https://github.com/rust-lang/rust-clippy"
+readme = "README.md"
+license = "MIT OR Apache-2.0"
+keywords = ["clippy", "lint", "plugin"]
+categories = ["development-tools", "development-tools::cargo-plugins"]
+build = "build.rs"
+edition = "2018"
+publish = false
+
+[[bin]]
+name = "cargo-clippy"
+test = false
+path = "src/main.rs"
+
+[[bin]]
+name = "clippy-driver"
+path = "src/driver.rs"
+
+[dependencies]
+# begin automatic update
+clippy_lints = { version = "0.0.212", path = "clippy_lints" }
+# end automatic update
+regex = "1"
+semver = "0.9"
+rustc_tools_util = { version = "0.2.0", path = "rustc_tools_util"}
+tempfile = { version = "3.1.0", optional = true }
+lazy_static = "1.0"
+
+[dev-dependencies]
+cargo_metadata = "0.9.0"
+compiletest_rs = { version = "0.5.0", features = ["tmp"] }
+tester = "0.7"
+lazy_static = "1.0"
+clippy-mini-macro-test = { version = "0.2", path = "mini-macro" }
+serde = { version = "1.0", features = ["derive"] }
+derive-new = "0.5"
+
+# A noop dependency that changes in the Rust repository, it's a bit of a hack.
+# See the `src/tools/rustc-workspace-hack/README.md` file in `rust-lang/rust`
+# for more information.
+rustc-workspace-hack = "1.0.0"
+
+[build-dependencies]
+rustc_tools_util = { version = "0.2.0", path = "rustc_tools_util"}
+
+[features]
+deny-warnings = []
+integration = ["tempfile"]
diff --git a/src/tools/clippy/LICENSE-APACHE b/src/tools/clippy/LICENSE-APACHE
new file mode 100644
index 00000000000..d821a4de2be
--- /dev/null
+++ b/src/tools/clippy/LICENSE-APACHE
@@ -0,0 +1,201 @@
+ Apache License
+ Version 2.0, January 2004
+ http://www.apache.org/licenses/
+
+TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+1. Definitions.
+
+ "License" shall mean the terms and conditions for use, reproduction,
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+ "Contribution" shall mean any work of authorship, including
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+ (a) You must give any other recipients of the Work or
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+ (b) You must cause any modified files to carry prominent notices
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+ may provide additional or different license terms and conditions
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+ for any such Derivative Works as a whole, provided Your use,
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+ the conditions stated in this License.
+
+5. Submission of Contributions. Unless You explicitly state otherwise,
+ any Contribution intentionally submitted for inclusion in the Work
+ by You to the Licensor shall be under the terms and conditions of
+ this License, without any additional terms or conditions.
+ Notwithstanding the above, nothing herein shall supersede or modify
+ the terms of any separate license agreement you may have executed
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+6. Trademarks. This License does not grant permission to use the trade
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+
+7. Disclaimer of Warranty. Unless required by applicable law or
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+8. Limitation of Liability. In no event and under no legal theory,
+ whether in tort (including negligence), contract, or otherwise,
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+9. Accepting Warranty or Additional Liability. While redistributing
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+ or other liability obligations and/or rights consistent with this
+ License. However, in accepting such obligations, You may act only
+ on Your own behalf and on Your sole responsibility, not on behalf
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+ defend, and hold each Contributor harmless for any liability
+ incurred by, or claims asserted against, such Contributor by reason
+ of your accepting any such warranty or additional liability.
+
+END OF TERMS AND CONDITIONS
+
+APPENDIX: How to apply the Apache License to your work.
+
+ To apply the Apache License to your work, attach the following
+ boilerplate notice, with the fields enclosed by brackets "[]"
+ replaced with your own identifying information. (Don't include
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+ comment syntax for the file format. We also recommend that a
+ file or class name and description of purpose be included on the
+ same "printed page" as the copyright notice for easier
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+
+Copyright 2014-2020 The Rust Project Developers
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
diff --git a/src/tools/clippy/LICENSE-MIT b/src/tools/clippy/LICENSE-MIT
new file mode 100644
index 00000000000..b7c70dd4026
--- /dev/null
+++ b/src/tools/clippy/LICENSE-MIT
@@ -0,0 +1,27 @@
+MIT License
+
+Copyright (c) 2014-2020 The Rust Project Developers
+
+Permission is hereby granted, free of charge, to any
+person obtaining a copy of this software and associated
+documentation files (the "Software"), to deal in the
+Software without restriction, including without
+limitation the rights to use, copy, modify, merge,
+publish, distribute, sublicense, and/or sell copies of
+the Software, and to permit persons to whom the Software
+is furnished to do so, subject to the following
+conditions:
+
+The above copyright notice and this permission notice
+shall be included in all copies or substantial portions
+of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF
+ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
+TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
+PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT
+SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR
+IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+DEALINGS IN THE SOFTWARE.
diff --git a/src/tools/clippy/README.md b/src/tools/clippy/README.md
new file mode 100644
index 00000000000..222b81023a7
--- /dev/null
+++ b/src/tools/clippy/README.md
@@ -0,0 +1,193 @@
+# Clippy
+
+[](https://github.com/rust-lang/rust-clippy/actions?query=workflow%3A%22Clippy+Test%22+event%3Apush+branch%3Aauto)
+[](#license)
+
+A collection of lints to catch common mistakes and improve your [Rust](https://github.com/rust-lang/rust) code.
+
+[There are over 350 lints included in this crate!](https://rust-lang.github.io/rust-clippy/master/index.html)
+
+We have a bunch of lint categories to allow you to choose how much Clippy is supposed to ~~annoy~~ help you:
+
+* `clippy::all` (everything that is on by default: all the categories below except for `nursery`, `pedantic`, and `cargo`)
+* `clippy::correctness` (code that is just **outright wrong** or **very very useless**, causes hard errors by default)
+* `clippy::style` (code that should be written in a more idiomatic way)
+* `clippy::complexity` (code that does something simple but in a complex way)
+* `clippy::perf` (code that can be written in a faster way)
+* `clippy::pedantic` (lints which are rather strict, off by default)
+* `clippy::nursery` (new lints that aren't quite ready yet, off by default)
+* `clippy::cargo` (checks against the cargo manifest, off by default)
+
+More to come, please [file an issue](https://github.com/rust-lang/rust-clippy/issues) if you have ideas!
+
+Only the following of those categories are enabled by default:
+
+* `clippy::style`
+* `clippy::correctness`
+* `clippy::complexity`
+* `clippy::perf`
+
+Other categories need to be enabled in order for their lints to be executed.
+
+The [lint list](https://rust-lang.github.io/rust-clippy/master/index.html) also contains "restriction lints", which are
+for things which are usually not considered "bad", but may be useful to turn on in specific cases. These should be used
+very selectively, if at all.
+
+Table of contents:
+
+* [Usage instructions](#usage)
+* [Configuration](#configuration)
+* [Contributing](#contributing)
+* [License](#license)
+
+## Usage
+
+Since this is a tool for helping the developer of a library or application
+write better code, it is recommended not to include Clippy as a hard dependency.
+Options include using it as an optional dependency, as a cargo subcommand, or
+as an included feature during build. These options are detailed below.
+
+### As a cargo subcommand (`cargo clippy`)
+
+One way to use Clippy is by installing Clippy through rustup as a cargo
+subcommand.
+
+#### Step 1: Install rustup
+
+You can install [rustup](https://rustup.rs/) on supported platforms. This will help
+us install Clippy and its dependencies.
+
+If you already have rustup installed, update to ensure you have the latest
+rustup and compiler:
+
+```terminal
+rustup update
+```
+
+#### Step 2: Install Clippy
+
+Once you have rustup and the latest stable release (at least Rust 1.29) installed, run the following command:
+
+```terminal
+rustup component add clippy
+```
+If it says that it can't find the `clippy` component, please run `rustup self update`.
+
+#### Step 3: Run Clippy
+
+Now you can run Clippy by invoking the following command:
+
+```terminal
+cargo clippy
+```
+
+#### Automatically applying Clippy suggestions
+
+Clippy can automatically apply some lint suggestions.
+Note that this is still experimental and only supported on the nightly channel:
+
+```terminal
+cargo clippy --fix -Z unstable-options
+```
+
+### Running Clippy from the command line without installing it
+
+To have cargo compile your crate with Clippy without Clippy installation
+in your code, you can use:
+
+```terminal
+cargo run --bin cargo-clippy --manifest-path=path_to_clippys_Cargo.toml
+```
+
+*Note:* Be sure that Clippy was compiled with the same version of rustc that cargo invokes here!
+
+### Travis CI
+
+You can add Clippy to Travis CI in the same way you use it locally:
+
+```yml
+language: rust
+rust:
+ - stable
+ - beta
+before_script:
+ - rustup component add clippy
+script:
+ - cargo clippy
+ # if you want the build job to fail when encountering warnings, use
+ - cargo clippy -- -D warnings
+ # in order to also check tests and non-default crate features, use
+ - cargo clippy --all-targets --all-features -- -D warnings
+ - cargo test
+ # etc.
+```
+
+If you are on nightly, It might happen that Clippy is not available for a certain nightly release.
+In this case you can try to conditionally install Clippy from the Git repo.
+
+```yaml
+language: rust
+rust:
+ - nightly
+before_script:
+ - rustup component add clippy --toolchain=nightly || cargo install --git https://github.com/rust-lang/rust-clippy/ --force clippy
+ # etc.
+```
+
+Note that adding `-D warnings` will cause your build to fail if **any** warnings are found in your code.
+That includes warnings found by rustc (e.g. `dead_code`, etc.). If you want to avoid this and only cause
+an error for Clippy warnings, use `#![deny(clippy::all)]` in your code or `-D clippy::all` on the command
+line. (You can swap `clippy::all` with the specific lint category you are targeting.)
+
+## Configuration
+
+Some lints can be configured in a TOML file named `clippy.toml` or `.clippy.toml`. It contains a basic `variable =
+value` mapping eg.
+
+```toml
+blacklisted-names = ["toto", "tata", "titi"]
+cognitive-complexity-threshold = 30
+```
+
+See the [list of lints](https://rust-lang.github.io/rust-clippy/master/index.html) for more information about which
+lints can be configured and the meaning of the variables.
+
+To deactivate the “for further information visit *lint-link*” message you can
+define the `CLIPPY_DISABLE_DOCS_LINKS` environment variable.
+
+### Allowing/denying lints
+
+You can add options to your code to `allow`/`warn`/`deny` Clippy lints:
+
+* the whole set of `Warn` lints using the `clippy` lint group (`#![deny(clippy::all)]`)
+
+* all lints using both the `clippy` and `clippy::pedantic` lint groups (`#![deny(clippy::all)]`,
+ `#![deny(clippy::pedantic)]`). Note that `clippy::pedantic` contains some very aggressive
+ lints prone to false positives.
+
+* only some lints (`#![deny(clippy::single_match, clippy::box_vec)]`, etc.)
+
+* `allow`/`warn`/`deny` can be limited to a single function or module using `#[allow(...)]`, etc.
+
+Note: `deny` produces errors instead of warnings.
+
+If you do not want to include your lint levels in your code, you can globally enable/disable lints by passing extra
+flags to Clippy during the run: `cargo clippy -- -A clippy::lint_name` will run Clippy with `lint_name` disabled and
+`cargo clippy -- -W clippy::lint_name` will run it with that enabled. This also works with lint groups. For example you
+can run Clippy with warnings for all lints enabled: `cargo clippy -- -W clippy::pedantic`
+If you care only about a single lint, you can allow all others and then explicitly reenable
+the lint(s) you are interested in: `cargo clippy -- -Aclippy::all -Wclippy::useless_format -Wclippy::...`
+
+## Contributing
+
+If you want to contribute to Clippy, you can find more information in [CONTRIBUTING.md](https://github.com/rust-lang/rust-clippy/blob/master/CONTRIBUTING.md).
+
+## License
+
+Copyright 2014-2020 The Rust Project Developers
+
+Licensed under the Apache License, Version 2.0 or the MIT license
+, at your
+option. Files in the project may not be
+copied, modified, or distributed except according to those terms.
diff --git a/src/tools/clippy/build.rs b/src/tools/clippy/build.rs
new file mode 100644
index 00000000000..018375dbada
--- /dev/null
+++ b/src/tools/clippy/build.rs
@@ -0,0 +1,19 @@
+fn main() {
+ // Forward the profile to the main compilation
+ println!("cargo:rustc-env=PROFILE={}", std::env::var("PROFILE").unwrap());
+ // Don't rebuild even if nothing changed
+ println!("cargo:rerun-if-changed=build.rs");
+ // forward git repo hashes we build at
+ println!(
+ "cargo:rustc-env=GIT_HASH={}",
+ rustc_tools_util::get_commit_hash().unwrap_or_default()
+ );
+ println!(
+ "cargo:rustc-env=COMMIT_DATE={}",
+ rustc_tools_util::get_commit_date().unwrap_or_default()
+ );
+ println!(
+ "cargo:rustc-env=RUSTC_RELEASE_CHANNEL={}",
+ rustc_tools_util::get_channel().unwrap_or_default()
+ );
+}
diff --git a/src/tools/clippy/clippy_dev/Cargo.toml b/src/tools/clippy/clippy_dev/Cargo.toml
new file mode 100644
index 00000000000..c861efc8afb
--- /dev/null
+++ b/src/tools/clippy/clippy_dev/Cargo.toml
@@ -0,0 +1,17 @@
+[package]
+name = "clippy_dev"
+version = "0.0.1"
+authors = ["Philipp Hansch "]
+edition = "2018"
+
+[dependencies]
+bytecount = "0.6"
+clap = "2.33"
+itertools = "0.9"
+regex = "1"
+lazy_static = "1.0"
+shell-escape = "0.1"
+walkdir = "2"
+
+[features]
+deny-warnings = []
diff --git a/src/tools/clippy/clippy_dev/src/fmt.rs b/src/tools/clippy/clippy_dev/src/fmt.rs
new file mode 100644
index 00000000000..6ae3f58c1f2
--- /dev/null
+++ b/src/tools/clippy/clippy_dev/src/fmt.rs
@@ -0,0 +1,175 @@
+use crate::clippy_project_root;
+use shell_escape::escape;
+use std::ffi::OsStr;
+use std::io;
+use std::path::Path;
+use std::process::{self, Command};
+use walkdir::WalkDir;
+
+#[derive(Debug)]
+pub enum CliError {
+ CommandFailed(String),
+ IoError(io::Error),
+ RustfmtNotInstalled,
+ WalkDirError(walkdir::Error),
+}
+
+impl From for CliError {
+ fn from(error: io::Error) -> Self {
+ Self::IoError(error)
+ }
+}
+
+impl From for CliError {
+ fn from(error: walkdir::Error) -> Self {
+ Self::WalkDirError(error)
+ }
+}
+
+struct FmtContext {
+ check: bool,
+ verbose: bool,
+}
+
+pub fn run(check: bool, verbose: bool) {
+ fn try_run(context: &FmtContext) -> Result {
+ let mut success = true;
+
+ let project_root = clippy_project_root();
+
+ rustfmt_test(context)?;
+
+ success &= cargo_fmt(context, project_root.as_path())?;
+ success &= cargo_fmt(context, &project_root.join("clippy_dev"))?;
+ success &= cargo_fmt(context, &project_root.join("rustc_tools_util"))?;
+
+ for entry in WalkDir::new(project_root.join("tests")) {
+ let entry = entry?;
+ let path = entry.path();
+
+ if path.extension() != Some("rs".as_ref())
+ || entry.file_name() == "ice-3891.rs"
+ // Avoid rustfmt bug rust-lang/rustfmt#1873
+ || cfg!(windows) && entry.file_name() == "implicit_hasher.rs"
+ {
+ continue;
+ }
+
+ success &= rustfmt(context, &path)?;
+ }
+
+ Ok(success)
+ }
+
+ fn output_err(err: CliError) {
+ match err {
+ CliError::CommandFailed(command) => {
+ eprintln!("error: A command failed! `{}`", command);
+ },
+ CliError::IoError(err) => {
+ eprintln!("error: {}", err);
+ },
+ CliError::RustfmtNotInstalled => {
+ eprintln!("error: rustfmt nightly is not installed.");
+ },
+ CliError::WalkDirError(err) => {
+ eprintln!("error: {}", err);
+ },
+ }
+ }
+
+ let context = FmtContext { check, verbose };
+ let result = try_run(&context);
+ let code = match result {
+ Ok(true) => 0,
+ Ok(false) => {
+ eprintln!();
+ eprintln!("Formatting check failed.");
+ eprintln!("Run `cargo dev fmt` to update formatting.");
+ 1
+ },
+ Err(err) => {
+ output_err(err);
+ 1
+ },
+ };
+ process::exit(code);
+}
+
+fn format_command(program: impl AsRef, dir: impl AsRef, args: &[impl AsRef]) -> String {
+ let arg_display: Vec<_> = args.iter().map(|a| escape(a.as_ref().to_string_lossy())).collect();
+
+ format!(
+ "cd {} && {} {}",
+ escape(dir.as_ref().to_string_lossy()),
+ escape(program.as_ref().to_string_lossy()),
+ arg_display.join(" ")
+ )
+}
+
+fn exec(
+ context: &FmtContext,
+ program: impl AsRef,
+ dir: impl AsRef,
+ args: &[impl AsRef],
+) -> Result {
+ if context.verbose {
+ println!("{}", format_command(&program, &dir, args));
+ }
+
+ let mut child = Command::new(&program).current_dir(&dir).args(args.iter()).spawn()?;
+ let code = child.wait()?;
+ let success = code.success();
+
+ if !context.check && !success {
+ return Err(CliError::CommandFailed(format_command(&program, &dir, args)));
+ }
+
+ Ok(success)
+}
+
+fn cargo_fmt(context: &FmtContext, path: &Path) -> Result {
+ let mut args = vec!["+nightly", "fmt", "--all"];
+ if context.check {
+ args.push("--");
+ args.push("--check");
+ }
+ let success = exec(context, "cargo", path, &args)?;
+
+ Ok(success)
+}
+
+fn rustfmt_test(context: &FmtContext) -> Result<(), CliError> {
+ let program = "rustfmt";
+ let dir = std::env::current_dir()?;
+ let args = &["+nightly", "--version"];
+
+ if context.verbose {
+ println!("{}", format_command(&program, &dir, args));
+ }
+
+ let output = Command::new(&program).current_dir(&dir).args(args.iter()).output()?;
+
+ if output.status.success() {
+ Ok(())
+ } else if std::str::from_utf8(&output.stderr)
+ .unwrap_or("")
+ .starts_with("error: 'rustfmt' is not installed")
+ {
+ Err(CliError::RustfmtNotInstalled)
+ } else {
+ Err(CliError::CommandFailed(format_command(&program, &dir, args)))
+ }
+}
+
+fn rustfmt(context: &FmtContext, path: &Path) -> Result {
+ let mut args = vec!["+nightly".as_ref(), path.as_os_str()];
+ if context.check {
+ args.push("--check".as_ref());
+ }
+ let success = exec(context, "rustfmt", std::env::current_dir()?, &args)?;
+ if !success {
+ eprintln!("rustfmt failed on {}", path.display());
+ }
+ Ok(success)
+}
diff --git a/src/tools/clippy/clippy_dev/src/lib.rs b/src/tools/clippy/clippy_dev/src/lib.rs
new file mode 100644
index 00000000000..6fdd282c684
--- /dev/null
+++ b/src/tools/clippy/clippy_dev/src/lib.rs
@@ -0,0 +1,524 @@
+#![cfg_attr(feature = "deny-warnings", deny(warnings))]
+
+use itertools::Itertools;
+use lazy_static::lazy_static;
+use regex::Regex;
+use std::collections::HashMap;
+use std::ffi::OsStr;
+use std::fs;
+use std::path::{Path, PathBuf};
+use walkdir::WalkDir;
+
+pub mod fmt;
+pub mod new_lint;
+pub mod stderr_length_check;
+pub mod update_lints;
+
+lazy_static! {
+ static ref DEC_CLIPPY_LINT_RE: Regex = Regex::new(
+ r#"(?x)
+ declare_clippy_lint!\s*[\{(]
+ (?:\s+///.*)*
+ \s+pub\s+(?P[A-Z_][A-Z_0-9]*)\s*,\s*
+ (?P[a-z_]+)\s*,\s*
+ "(?P(?:[^"\\]+|\\(?s).(?-s))*)"\s*[})]
+ "#
+ )
+ .unwrap();
+ static ref DEC_DEPRECATED_LINT_RE: Regex = Regex::new(
+ r#"(?x)
+ declare_deprecated_lint!\s*[{(]\s*
+ (?:\s+///.*)*
+ \s+pub\s+(?P[A-Z_][A-Z_0-9]*)\s*,\s*
+ "(?P(?:[^"\\]+|\\(?s).(?-s))*)"\s*[})]
+ "#
+ )
+ .unwrap();
+ static ref NL_ESCAPE_RE: Regex = Regex::new(r#"\\\n\s*"#).unwrap();
+}
+
+pub static DOCS_LINK: &str = "https://rust-lang.github.io/rust-clippy/master/index.html";
+
+/// Lint data parsed from the Clippy source code.
+#[derive(Clone, PartialEq, Debug)]
+pub struct Lint {
+ pub name: String,
+ pub group: String,
+ pub desc: String,
+ pub deprecation: Option,
+ pub module: String,
+}
+
+impl Lint {
+ #[must_use]
+ pub fn new(name: &str, group: &str, desc: &str, deprecation: Option<&str>, module: &str) -> Self {
+ Self {
+ name: name.to_lowercase(),
+ group: group.to_string(),
+ desc: NL_ESCAPE_RE.replace(&desc.replace("\\\"", "\""), "").to_string(),
+ deprecation: deprecation.map(ToString::to_string),
+ module: module.to_string(),
+ }
+ }
+
+ /// Returns all non-deprecated lints and non-internal lints
+ #[must_use]
+ pub fn usable_lints(lints: &[Self]) -> Vec {
+ lints
+ .iter()
+ .filter(|l| l.deprecation.is_none() && !l.group.starts_with("internal"))
+ .cloned()
+ .collect()
+ }
+
+ /// Returns all internal lints (not `internal_warn` lints)
+ #[must_use]
+ pub fn internal_lints(lints: &[Self]) -> Vec {
+ lints.iter().filter(|l| l.group == "internal").cloned().collect()
+ }
+
+ /// Returns all deprecated lints
+ #[must_use]
+ pub fn deprecated_lints(lints: &[Self]) -> Vec {
+ lints.iter().filter(|l| l.deprecation.is_some()).cloned().collect()
+ }
+
+ /// Returns the lints in a `HashMap`, grouped by the different lint groups
+ #[must_use]
+ pub fn by_lint_group(lints: impl Iterator- ) -> HashMap> {
+ lints.map(|lint| (lint.group.to_string(), lint)).into_group_map()
+ }
+}
+
+/// Generates the Vec items for `register_lint_group` calls in `clippy_lints/src/lib.rs`.
+#[must_use]
+pub fn gen_lint_group_list<'a>(lints: impl Iterator
- ) -> Vec {
+ lints
+ .map(|l| format!(" LintId::of(&{}::{}),", l.module, l.name.to_uppercase()))
+ .sorted()
+ .collect::>()
+}
+
+/// Generates the `pub mod module_name` list in `clippy_lints/src/lib.rs`.
+#[must_use]
+pub fn gen_modules_list<'a>(lints: impl Iterator
- ) -> Vec {
+ lints
+ .map(|l| &l.module)
+ .unique()
+ .map(|module| format!("mod {};", module))
+ .sorted()
+ .collect::>()
+}
+
+/// Generates the list of lint links at the bottom of the README
+#[must_use]
+pub fn gen_changelog_lint_list<'a>(lints: impl Iterator
- ) -> Vec {
+ lints
+ .sorted_by_key(|l| &l.name)
+ .map(|l| format!("[`{}`]: {}#{}", l.name, DOCS_LINK, l.name))
+ .collect()
+}
+
+/// Generates the `register_removed` code in `./clippy_lints/src/lib.rs`.
+#[must_use]
+pub fn gen_deprecated<'a>(lints: impl Iterator
- ) -> Vec {
+ lints
+ .flat_map(|l| {
+ l.deprecation
+ .clone()
+ .map(|depr_text| {
+ vec![
+ " store.register_removed(".to_string(),
+ format!(" \"clippy::{}\",", l.name),
+ format!(" \"{}\",", depr_text),
+ " );".to_string(),
+ ]
+ })
+ .expect("only deprecated lints should be passed")
+ })
+ .collect::>()
+}
+
+#[must_use]
+pub fn gen_register_lint_list<'a>(lints: impl Iterator
- ) -> Vec {
+ let pre = " store.register_lints(&[".to_string();
+ let post = " ]);".to_string();
+ let mut inner = lints
+ .map(|l| format!(" &{}::{},", l.module, l.name.to_uppercase()))
+ .sorted()
+ .collect::>();
+ inner.insert(0, pre);
+ inner.push(post);
+ inner
+}
+
+/// Gathers all files in `src/clippy_lints` and gathers all lints inside
+pub fn gather_all() -> impl Iterator
- {
+ lint_files().flat_map(|f| gather_from_file(&f))
+}
+
+fn gather_from_file(dir_entry: &walkdir::DirEntry) -> impl Iterator
- {
+ let content = fs::read_to_string(dir_entry.path()).unwrap();
+ let path = dir_entry.path();
+ let filename = path.file_stem().unwrap();
+ let path_buf = path.with_file_name(filename);
+ let mut rel_path = path_buf
+ .strip_prefix(clippy_project_root().join("clippy_lints/src"))
+ .expect("only files in `clippy_lints/src` should be looked at");
+ // If the lints are stored in mod.rs, we get the module name from
+ // the containing directory:
+ if filename == "mod" {
+ rel_path = rel_path.parent().unwrap();
+ }
+
+ let module = rel_path
+ .components()
+ .map(|c| c.as_os_str().to_str().unwrap())
+ .collect::>()
+ .join("::");
+
+ parse_contents(&content, &module)
+}
+
+fn parse_contents(content: &str, module: &str) -> impl Iterator
- {
+ let lints = DEC_CLIPPY_LINT_RE
+ .captures_iter(content)
+ .map(|m| Lint::new(&m["name"], &m["cat"], &m["desc"], None, module));
+ let deprecated = DEC_DEPRECATED_LINT_RE
+ .captures_iter(content)
+ .map(|m| Lint::new(&m["name"], "Deprecated", &m["desc"], Some(&m["desc"]), module));
+ // Removing the `.collect::>().into_iter()` causes some lifetime issues due to the map
+ lints.chain(deprecated).collect::>().into_iter()
+}
+
+/// Collects all .rs files in the `clippy_lints/src` directory
+fn lint_files() -> impl Iterator
- {
+ // We use `WalkDir` instead of `fs::read_dir` here in order to recurse into subdirectories.
+ // Otherwise we would not collect all the lints, for example in `clippy_lints/src/methods/`.
+ let path = clippy_project_root().join("clippy_lints/src");
+ WalkDir::new(path)
+ .into_iter()
+ .filter_map(Result::ok)
+ .filter(|f| f.path().extension() == Some(OsStr::new("rs")))
+}
+
+/// Whether a file has had its text changed or not
+#[derive(PartialEq, Debug)]
+pub struct FileChange {
+ pub changed: bool,
+ pub new_lines: String,
+}
+
+/// Replaces a region in a file delimited by two lines matching regexes.
+///
+/// `path` is the relative path to the file on which you want to perform the replacement.
+///
+/// See `replace_region_in_text` for documentation of the other options.
+pub fn replace_region_in_file(
+ path: &Path,
+ start: &str,
+ end: &str,
+ replace_start: bool,
+ write_back: bool,
+ replacements: F,
+) -> FileChange
+where
+ F: FnOnce() -> Vec,
+{
+ let contents = fs::read_to_string(path).unwrap_or_else(|e| panic!("Cannot read from {}: {}", path.display(), e));
+ let file_change = replace_region_in_text(&contents, start, end, replace_start, replacements);
+
+ if write_back {
+ if let Err(e) = fs::write(path, file_change.new_lines.as_bytes()) {
+ panic!("Cannot write to {}: {}", path.display(), e);
+ }
+ }
+ file_change
+}
+
+/// Replaces a region in a text delimited by two lines matching regexes.
+///
+/// * `text` is the input text on which you want to perform the replacement
+/// * `start` is a `&str` that describes the delimiter line before the region you want to replace.
+/// As the `&str` will be converted to a `Regex`, this can contain regex syntax, too.
+/// * `end` is a `&str` that describes the delimiter line until where the replacement should happen.
+/// As the `&str` will be converted to a `Regex`, this can contain regex syntax, too.
+/// * If `replace_start` is true, the `start` delimiter line is replaced as well. The `end`
+/// delimiter line is never replaced.
+/// * `replacements` is a closure that has to return a `Vec` which contains the new text.
+///
+/// If you want to perform the replacement on files instead of already parsed text,
+/// use `replace_region_in_file`.
+///
+/// # Example
+///
+/// ```
+/// let the_text = "replace_start\nsome text\nthat will be replaced\nreplace_end";
+/// let result =
+/// clippy_dev::replace_region_in_text(the_text, "replace_start", "replace_end", false, || {
+/// vec!["a different".to_string(), "text".to_string()]
+/// })
+/// .new_lines;
+/// assert_eq!("replace_start\na different\ntext\nreplace_end", result);
+/// ```
+pub fn replace_region_in_text(text: &str, start: &str, end: &str, replace_start: bool, replacements: F) -> FileChange
+where
+ F: FnOnce() -> Vec,
+{
+ let replace_it = replacements();
+ let mut in_old_region = false;
+ let mut found = false;
+ let mut new_lines = vec![];
+ let start = Regex::new(start).unwrap();
+ let end = Regex::new(end).unwrap();
+
+ for line in text.lines() {
+ if in_old_region {
+ if end.is_match(line) {
+ in_old_region = false;
+ new_lines.extend(replace_it.clone());
+ new_lines.push(line.to_string());
+ }
+ } else if start.is_match(line) {
+ if !replace_start {
+ new_lines.push(line.to_string());
+ }
+ in_old_region = true;
+ found = true;
+ } else {
+ new_lines.push(line.to_string());
+ }
+ }
+
+ if !found {
+ // This happens if the provided regex in `clippy_dev/src/main.rs` does not match in the
+ // given text or file. Most likely this is an error on the programmer's side and the Regex
+ // is incorrect.
+ eprintln!("error: regex \n{:?}\ndoesn't match. You may have to update it.", start);
+ std::process::exit(1);
+ }
+
+ let mut new_lines = new_lines.join("\n");
+ if text.ends_with('\n') {
+ new_lines.push('\n');
+ }
+ let changed = new_lines != text;
+ FileChange { changed, new_lines }
+}
+
+/// Returns the path to the Clippy project directory
+#[must_use]
+pub fn clippy_project_root() -> PathBuf {
+ let current_dir = std::env::current_dir().unwrap();
+ for path in current_dir.ancestors() {
+ let result = std::fs::read_to_string(path.join("Cargo.toml"));
+ if let Err(err) = &result {
+ if err.kind() == std::io::ErrorKind::NotFound {
+ continue;
+ }
+ }
+
+ let content = result.unwrap();
+ if content.contains("[package]\nname = \"clippy\"") {
+ return path.to_path_buf();
+ }
+ }
+ panic!("error: Can't determine root of project. Please run inside a Clippy working dir.");
+}
+
+#[test]
+fn test_parse_contents() {
+ let result: Vec = parse_contents(
+ r#"
+declare_clippy_lint! {
+ pub PTR_ARG,
+ style,
+ "really long \
+ text"
+}
+
+declare_clippy_lint!{
+ pub DOC_MARKDOWN,
+ pedantic,
+ "single line"
+}
+
+/// some doc comment
+declare_deprecated_lint! {
+ pub SHOULD_ASSERT_EQ,
+ "`assert!()` will be more flexible with RFC 2011"
+}
+ "#,
+ "module_name",
+ )
+ .collect();
+
+ let expected = vec![
+ Lint::new("ptr_arg", "style", "really long text", None, "module_name"),
+ Lint::new("doc_markdown", "pedantic", "single line", None, "module_name"),
+ Lint::new(
+ "should_assert_eq",
+ "Deprecated",
+ "`assert!()` will be more flexible with RFC 2011",
+ Some("`assert!()` will be more flexible with RFC 2011"),
+ "module_name",
+ ),
+ ];
+ assert_eq!(expected, result);
+}
+
+#[test]
+fn test_replace_region() {
+ let text = "\nabc\n123\n789\ndef\nghi";
+ let expected = FileChange {
+ changed: true,
+ new_lines: "\nabc\nhello world\ndef\nghi".to_string(),
+ };
+ let result = replace_region_in_text(text, r#"^\s*abc$"#, r#"^\s*def"#, false, || {
+ vec!["hello world".to_string()]
+ });
+ assert_eq!(expected, result);
+}
+
+#[test]
+fn test_replace_region_with_start() {
+ let text = "\nabc\n123\n789\ndef\nghi";
+ let expected = FileChange {
+ changed: true,
+ new_lines: "\nhello world\ndef\nghi".to_string(),
+ };
+ let result = replace_region_in_text(text, r#"^\s*abc$"#, r#"^\s*def"#, true, || {
+ vec!["hello world".to_string()]
+ });
+ assert_eq!(expected, result);
+}
+
+#[test]
+fn test_replace_region_no_changes() {
+ let text = "123\n456\n789";
+ let expected = FileChange {
+ changed: false,
+ new_lines: "123\n456\n789".to_string(),
+ };
+ let result = replace_region_in_text(text, r#"^\s*123$"#, r#"^\s*456"#, false, || vec![]);
+ assert_eq!(expected, result);
+}
+
+#[test]
+fn test_usable_lints() {
+ let lints = vec![
+ Lint::new("should_assert_eq", "Deprecated", "abc", Some("Reason"), "module_name"),
+ Lint::new("should_assert_eq2", "Not Deprecated", "abc", None, "module_name"),
+ Lint::new("should_assert_eq2", "internal", "abc", None, "module_name"),
+ Lint::new("should_assert_eq2", "internal_style", "abc", None, "module_name"),
+ ];
+ let expected = vec![Lint::new(
+ "should_assert_eq2",
+ "Not Deprecated",
+ "abc",
+ None,
+ "module_name",
+ )];
+ assert_eq!(expected, Lint::usable_lints(&lints));
+}
+
+#[test]
+fn test_by_lint_group() {
+ let lints = vec![
+ Lint::new("should_assert_eq", "group1", "abc", None, "module_name"),
+ Lint::new("should_assert_eq2", "group2", "abc", None, "module_name"),
+ Lint::new("incorrect_match", "group1", "abc", None, "module_name"),
+ ];
+ let mut expected: HashMap> = HashMap::new();
+ expected.insert(
+ "group1".to_string(),
+ vec![
+ Lint::new("should_assert_eq", "group1", "abc", None, "module_name"),
+ Lint::new("incorrect_match", "group1", "abc", None, "module_name"),
+ ],
+ );
+ expected.insert(
+ "group2".to_string(),
+ vec![Lint::new("should_assert_eq2", "group2", "abc", None, "module_name")],
+ );
+ assert_eq!(expected, Lint::by_lint_group(lints.into_iter()));
+}
+
+#[test]
+fn test_gen_changelog_lint_list() {
+ let lints = vec![
+ Lint::new("should_assert_eq", "group1", "abc", None, "module_name"),
+ Lint::new("should_assert_eq2", "group2", "abc", None, "module_name"),
+ ];
+ let expected = vec![
+ format!("[`should_assert_eq`]: {}#should_assert_eq", DOCS_LINK.to_string()),
+ format!("[`should_assert_eq2`]: {}#should_assert_eq2", DOCS_LINK.to_string()),
+ ];
+ assert_eq!(expected, gen_changelog_lint_list(lints.iter()));
+}
+
+#[test]
+fn test_gen_deprecated() {
+ let lints = vec![
+ Lint::new(
+ "should_assert_eq",
+ "group1",
+ "abc",
+ Some("has been superseded by should_assert_eq2"),
+ "module_name",
+ ),
+ Lint::new(
+ "another_deprecated",
+ "group2",
+ "abc",
+ Some("will be removed"),
+ "module_name",
+ ),
+ ];
+ let expected: Vec = vec![
+ " store.register_removed(",
+ " \"clippy::should_assert_eq\",",
+ " \"has been superseded by should_assert_eq2\",",
+ " );",
+ " store.register_removed(",
+ " \"clippy::another_deprecated\",",
+ " \"will be removed\",",
+ " );",
+ ]
+ .into_iter()
+ .map(String::from)
+ .collect();
+ assert_eq!(expected, gen_deprecated(lints.iter()));
+}
+
+#[test]
+#[should_panic]
+fn test_gen_deprecated_fail() {
+ let lints = vec![Lint::new("should_assert_eq2", "group2", "abc", None, "module_name")];
+ let _ = gen_deprecated(lints.iter());
+}
+
+#[test]
+fn test_gen_modules_list() {
+ let lints = vec![
+ Lint::new("should_assert_eq", "group1", "abc", None, "module_name"),
+ Lint::new("incorrect_stuff", "group3", "abc", None, "another_module"),
+ ];
+ let expected = vec!["mod another_module;".to_string(), "mod module_name;".to_string()];
+ assert_eq!(expected, gen_modules_list(lints.iter()));
+}
+
+#[test]
+fn test_gen_lint_group_list() {
+ let lints = vec![
+ Lint::new("abc", "group1", "abc", None, "module_name"),
+ Lint::new("should_assert_eq", "group1", "abc", None, "module_name"),
+ Lint::new("internal", "internal_style", "abc", None, "module_name"),
+ ];
+ let expected = vec![
+ " LintId::of(&module_name::ABC),".to_string(),
+ " LintId::of(&module_name::INTERNAL),".to_string(),
+ " LintId::of(&module_name::SHOULD_ASSERT_EQ),".to_string(),
+ ];
+ assert_eq!(expected, gen_lint_group_list(lints.iter()));
+}
diff --git a/src/tools/clippy/clippy_dev/src/main.rs b/src/tools/clippy/clippy_dev/src/main.rs
new file mode 100644
index 00000000000..d99235f7c07
--- /dev/null
+++ b/src/tools/clippy/clippy_dev/src/main.rs
@@ -0,0 +1,120 @@
+#![cfg_attr(feature = "deny-warnings", deny(warnings))]
+
+use clap::{App, Arg, SubCommand};
+use clippy_dev::{fmt, new_lint, stderr_length_check, update_lints};
+
+fn main() {
+ let matches = App::new("Clippy developer tooling")
+ .subcommand(
+ SubCommand::with_name("fmt")
+ .about("Run rustfmt on all projects and tests")
+ .arg(
+ Arg::with_name("check")
+ .long("check")
+ .help("Use the rustfmt --check option"),
+ )
+ .arg(
+ Arg::with_name("verbose")
+ .short("v")
+ .long("verbose")
+ .help("Echo commands run"),
+ ),
+ )
+ .subcommand(
+ SubCommand::with_name("update_lints")
+ .about("Updates lint registration and information from the source code")
+ .long_about(
+ "Makes sure that:\n \
+ * the lint count in README.md is correct\n \
+ * the changelog contains markdown link references at the bottom\n \
+ * all lint groups include the correct lints\n \
+ * lint modules in `clippy_lints/*` are visible in `src/lib.rs` via `pub mod`\n \
+ * all lints are registered in the lint store",
+ )
+ .arg(Arg::with_name("print-only").long("print-only").help(
+ "Print a table of lints to STDOUT. \
+ This does not include deprecated and internal lints. \
+ (Does not modify any files)",
+ ))
+ .arg(
+ Arg::with_name("check")
+ .long("check")
+ .help("Checks that `cargo dev update_lints` has been run. Used on CI."),
+ ),
+ )
+ .subcommand(
+ SubCommand::with_name("new_lint")
+ .about("Create new lint and run `cargo dev update_lints`")
+ .arg(
+ Arg::with_name("pass")
+ .short("p")
+ .long("pass")
+ .help("Specify whether the lint runs during the early or late pass")
+ .takes_value(true)
+ .possible_values(&["early", "late"])
+ .required(true),
+ )
+ .arg(
+ Arg::with_name("name")
+ .short("n")
+ .long("name")
+ .help("Name of the new lint in snake case, ex: fn_too_long")
+ .takes_value(true)
+ .required(true),
+ )
+ .arg(
+ Arg::with_name("category")
+ .short("c")
+ .long("category")
+ .help("What category the lint belongs to")
+ .default_value("nursery")
+ .possible_values(&[
+ "style",
+ "correctness",
+ "complexity",
+ "perf",
+ "pedantic",
+ "restriction",
+ "cargo",
+ "nursery",
+ "internal",
+ "internal_warn",
+ ])
+ .takes_value(true),
+ ),
+ )
+ .subcommand(
+ SubCommand::with_name("limit_stderr_length")
+ .about("Ensures that stderr files do not grow longer than a certain amount of lines."),
+ )
+ .get_matches();
+
+ match matches.subcommand() {
+ ("fmt", Some(matches)) => {
+ fmt::run(matches.is_present("check"), matches.is_present("verbose"));
+ },
+ ("update_lints", Some(matches)) => {
+ if matches.is_present("print-only") {
+ update_lints::print_lints();
+ } else if matches.is_present("check") {
+ update_lints::run(update_lints::UpdateMode::Check);
+ } else {
+ update_lints::run(update_lints::UpdateMode::Change);
+ }
+ },
+ ("new_lint", Some(matches)) => {
+ match new_lint::create(
+ matches.value_of("pass"),
+ matches.value_of("name"),
+ matches.value_of("category"),
+ ) {
+ Ok(_) => update_lints::run(update_lints::UpdateMode::Change),
+ Err(e) => eprintln!("Unable to create lint: {}", e),
+ }
+ },
+ ("limit_stderr_length", _) => {
+ stderr_length_check::check();
+ },
+ _ => {},
+ }
+}
diff --git a/src/tools/clippy/clippy_dev/src/new_lint.rs b/src/tools/clippy/clippy_dev/src/new_lint.rs
new file mode 100644
index 00000000000..44b2a5383d2
--- /dev/null
+++ b/src/tools/clippy/clippy_dev/src/new_lint.rs
@@ -0,0 +1,177 @@
+use crate::clippy_project_root;
+use std::fs::{File, OpenOptions};
+use std::io;
+use std::io::prelude::*;
+use std::io::ErrorKind;
+use std::path::Path;
+
+/// Creates files required to implement and test a new lint and runs `update_lints`.
+///
+/// # Errors
+///
+/// This function errors, if the files couldn't be created
+pub fn create(pass: Option<&str>, lint_name: Option<&str>, category: Option<&str>) -> Result<(), io::Error> {
+ let pass = pass.expect("`pass` argument is validated by clap");
+ let lint_name = lint_name.expect("`name` argument is validated by clap");
+ let category = category.expect("`category` argument is validated by clap");
+
+ match open_files(lint_name) {
+ Ok((mut test_file, mut lint_file)) => {
+ let (pass_type, pass_lifetimes, pass_import, context_import) = match pass {
+ "early" => ("EarlyLintPass", "", "use rustc_ast::ast::*;", "EarlyContext"),
+ "late" => ("LateLintPass", "<'_, '_>", "use rustc_hir::*;", "LateContext"),
+ _ => {
+ unreachable!("`pass_type` should only ever be `early` or `late`!");
+ },
+ };
+
+ let camel_case_name = to_camel_case(lint_name);
+
+ if let Err(e) = test_file.write_all(get_test_file_contents(lint_name).as_bytes()) {
+ return Err(io::Error::new(
+ ErrorKind::Other,
+ format!("Could not write to test file: {}", e),
+ ));
+ };
+
+ if let Err(e) = lint_file.write_all(
+ get_lint_file_contents(
+ pass_type,
+ pass_lifetimes,
+ lint_name,
+ &camel_case_name,
+ category,
+ pass_import,
+ context_import,
+ )
+ .as_bytes(),
+ ) {
+ return Err(io::Error::new(
+ ErrorKind::Other,
+ format!("Could not write to lint file: {}", e),
+ ));
+ }
+ Ok(())
+ },
+ Err(e) => Err(io::Error::new(
+ ErrorKind::Other,
+ format!("Unable to create lint: {}", e),
+ )),
+ }
+}
+
+fn open_files(lint_name: &str) -> Result<(File, File), io::Error> {
+ let project_root = clippy_project_root();
+
+ let test_file_path = project_root.join("tests").join("ui").join(format!("{}.rs", lint_name));
+ let lint_file_path = project_root
+ .join("clippy_lints")
+ .join("src")
+ .join(format!("{}.rs", lint_name));
+
+ if Path::new(&test_file_path).exists() {
+ return Err(io::Error::new(
+ ErrorKind::AlreadyExists,
+ format!("test file {:?} already exists", test_file_path),
+ ));
+ }
+ if Path::new(&lint_file_path).exists() {
+ return Err(io::Error::new(
+ ErrorKind::AlreadyExists,
+ format!("lint file {:?} already exists", lint_file_path),
+ ));
+ }
+
+ let test_file = OpenOptions::new().write(true).create_new(true).open(test_file_path)?;
+ let lint_file = OpenOptions::new().write(true).create_new(true).open(lint_file_path)?;
+
+ Ok((test_file, lint_file))
+}
+
+fn to_camel_case(name: &str) -> String {
+ name.split('_')
+ .map(|s| {
+ if s.is_empty() {
+ String::from("")
+ } else {
+ [&s[0..1].to_uppercase(), &s[1..]].concat()
+ }
+ })
+ .collect()
+}
+
+fn get_test_file_contents(lint_name: &str) -> String {
+ format!(
+ "#![warn(clippy::{})]
+
+fn main() {{
+ // test code goes here
+}}
+",
+ lint_name
+ )
+}
+
+fn get_lint_file_contents(
+ pass_type: &str,
+ pass_lifetimes: &str,
+ lint_name: &str,
+ camel_case_name: &str,
+ category: &str,
+ pass_import: &str,
+ context_import: &str,
+) -> String {
+ format!(
+ "use rustc_lint::{{{type}, {context_import}}};
+use rustc_session::{{declare_lint_pass, declare_tool_lint}};
+{pass_import}
+
+declare_clippy_lint! {{
+ /// **What it does:**
+ ///
+ /// **Why is this bad?**
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ ///
+ /// ```rust
+ /// // example code where clippy issues a warning
+ /// ```
+ /// Use instead:
+ /// ```rust
+ /// // example code which does not raise clippy warning
+ /// ```
+ pub {name_upper},
+ {category},
+ \"default lint description\"
+}}
+
+declare_lint_pass!({name_camel} => [{name_upper}]);
+
+impl {type}{lifetimes} for {name_camel} {{}}
+",
+ type=pass_type,
+ lifetimes=pass_lifetimes,
+ name_upper=lint_name.to_uppercase(),
+ name_camel=camel_case_name,
+ category=category,
+ pass_import=pass_import,
+ context_import=context_import
+ )
+}
+
+#[test]
+fn test_camel_case() {
+ let s = "a_lint";
+ let s2 = to_camel_case(s);
+ assert_eq!(s2, "ALint");
+
+ let name = "a_really_long_new_lint";
+ let name2 = to_camel_case(name);
+ assert_eq!(name2, "AReallyLongNewLint");
+
+ let name3 = "lint__name";
+ let name4 = to_camel_case(name3);
+ assert_eq!(name4, "LintName");
+}
diff --git a/src/tools/clippy/clippy_dev/src/stderr_length_check.rs b/src/tools/clippy/clippy_dev/src/stderr_length_check.rs
new file mode 100644
index 00000000000..e02b6f7da5f
--- /dev/null
+++ b/src/tools/clippy/clippy_dev/src/stderr_length_check.rs
@@ -0,0 +1,51 @@
+use crate::clippy_project_root;
+use std::ffi::OsStr;
+use std::fs;
+use std::path::{Path, PathBuf};
+use walkdir::WalkDir;
+
+// The maximum length allowed for stderr files.
+//
+// We limit this because small files are easier to deal with than bigger files.
+const LENGTH_LIMIT: usize = 200;
+
+pub fn check() {
+ let exceeding_files: Vec<_> = exceeding_stderr_files();
+
+ if !exceeding_files.is_empty() {
+ eprintln!("Error: stderr files exceeding limit of {} lines:", LENGTH_LIMIT);
+ for (path, count) in exceeding_files {
+ println!("{}: {}", path.display(), count);
+ }
+ std::process::exit(1);
+ }
+}
+
+fn exceeding_stderr_files() -> Vec<(PathBuf, usize)> {
+ // We use `WalkDir` instead of `fs::read_dir` here in order to recurse into subdirectories.
+ WalkDir::new(clippy_project_root().join("tests/ui"))
+ .into_iter()
+ .filter_map(Result::ok)
+ .filter(|f| !f.file_type().is_dir())
+ .filter_map(|e| {
+ let p = e.into_path();
+ let count = count_linenumbers(&p);
+ if p.extension() == Some(OsStr::new("stderr")) && count > LENGTH_LIMIT {
+ Some((p, count))
+ } else {
+ None
+ }
+ })
+ .collect()
+}
+
+#[must_use]
+fn count_linenumbers(filepath: &Path) -> usize {
+ match fs::read(filepath) {
+ Ok(content) => bytecount::count(&content, b'\n'),
+ Err(e) => {
+ eprintln!("Failed to read file: {}", e);
+ 0
+ },
+ }
+}
diff --git a/src/tools/clippy/clippy_dev/src/update_lints.rs b/src/tools/clippy/clippy_dev/src/update_lints.rs
new file mode 100644
index 00000000000..a9a70929942
--- /dev/null
+++ b/src/tools/clippy/clippy_dev/src/update_lints.rs
@@ -0,0 +1,162 @@
+use crate::{
+ gather_all, gen_changelog_lint_list, gen_deprecated, gen_lint_group_list, gen_modules_list, gen_register_lint_list,
+ replace_region_in_file, Lint, DOCS_LINK,
+};
+use std::path::Path;
+
+#[derive(Clone, Copy, PartialEq)]
+pub enum UpdateMode {
+ Check,
+ Change,
+}
+
+#[allow(clippy::too_many_lines)]
+pub fn run(update_mode: UpdateMode) {
+ let lint_list: Vec = gather_all().collect();
+
+ let internal_lints = Lint::internal_lints(&lint_list);
+ let deprecated_lints = Lint::deprecated_lints(&lint_list);
+ let usable_lints = Lint::usable_lints(&lint_list);
+ let mut sorted_usable_lints = usable_lints.clone();
+ sorted_usable_lints.sort_by_key(|lint| lint.name.clone());
+
+ let usable_lint_count = round_to_fifty(usable_lints.len());
+
+ let mut file_change = replace_region_in_file(
+ Path::new("src/lintlist/mod.rs"),
+ "begin lint list",
+ "end lint list",
+ false,
+ update_mode == UpdateMode::Change,
+ || {
+ format!("pub static ref ALL_LINTS: Vec = vec!{:#?};", sorted_usable_lints)
+ .lines()
+ .map(ToString::to_string)
+ .collect::>()
+ },
+ )
+ .changed;
+
+ file_change |= replace_region_in_file(
+ Path::new("README.md"),
+ &format!(
+ r#"\[There are over \d+ lints included in this crate!\]\({}\)"#,
+ DOCS_LINK
+ ),
+ "",
+ true,
+ update_mode == UpdateMode::Change,
+ || {
+ vec",
+ usable_lint_count, DOCS_LINK
+ )]
+ },
+ )
+ .changed;
+
+ file_change |= replace_region_in_file(
+ Path::new("CHANGELOG.md"),
+ "",
+ "",
+ false,
+ update_mode == UpdateMode::Change,
+ || gen_changelog_lint_list(usable_lints.iter().chain(deprecated_lints.iter())),
+ )
+ .changed;
+
+ file_change |= replace_region_in_file(
+ Path::new("clippy_lints/src/lib.rs"),
+ "begin deprecated lints",
+ "end deprecated lints",
+ false,
+ update_mode == UpdateMode::Change,
+ || gen_deprecated(deprecated_lints.iter()),
+ )
+ .changed;
+
+ file_change |= replace_region_in_file(
+ Path::new("clippy_lints/src/lib.rs"),
+ "begin register lints",
+ "end register lints",
+ false,
+ update_mode == UpdateMode::Change,
+ || gen_register_lint_list(usable_lints.iter().chain(internal_lints.iter())),
+ )
+ .changed;
+
+ file_change |= replace_region_in_file(
+ Path::new("clippy_lints/src/lib.rs"),
+ "begin lints modules",
+ "end lints modules",
+ false,
+ update_mode == UpdateMode::Change,
+ || gen_modules_list(usable_lints.iter()),
+ )
+ .changed;
+
+ // Generate lists of lints in the clippy::all lint group
+ file_change |= replace_region_in_file(
+ Path::new("clippy_lints/src/lib.rs"),
+ r#"store.register_group\(true, "clippy::all""#,
+ r#"\]\);"#,
+ false,
+ update_mode == UpdateMode::Change,
+ || {
+ // clippy::all should only include the following lint groups:
+ let all_group_lints = usable_lints.iter().filter(|l| {
+ l.group == "correctness" || l.group == "style" || l.group == "complexity" || l.group == "perf"
+ });
+
+ gen_lint_group_list(all_group_lints)
+ },
+ )
+ .changed;
+
+ // Generate the list of lints for all other lint groups
+ for (lint_group, lints) in Lint::by_lint_group(usable_lints.into_iter().chain(internal_lints)) {
+ file_change |= replace_region_in_file(
+ Path::new("clippy_lints/src/lib.rs"),
+ &format!("store.register_group\\(true, \"clippy::{}\"", lint_group),
+ r#"\]\);"#,
+ false,
+ update_mode == UpdateMode::Change,
+ || gen_lint_group_list(lints.iter()),
+ )
+ .changed;
+ }
+
+ if update_mode == UpdateMode::Check && file_change {
+ println!(
+ "Not all lints defined properly. \
+ Please run `cargo dev update_lints` to make sure all lints are defined properly."
+ );
+ std::process::exit(1);
+ }
+}
+
+pub fn print_lints() {
+ let lint_list: Vec = gather_all().collect();
+ let usable_lints = Lint::usable_lints(&lint_list);
+ let usable_lint_count = usable_lints.len();
+ let grouped_by_lint_group = Lint::by_lint_group(usable_lints.into_iter());
+
+ for (lint_group, mut lints) in grouped_by_lint_group {
+ if lint_group == "Deprecated" {
+ continue;
+ }
+ println!("\n## {}", lint_group);
+
+ lints.sort_by_key(|l| l.name.clone());
+
+ for lint in lints {
+ println!("* [{}]({}#{}) ({})", lint.name, DOCS_LINK, lint.name, lint.desc);
+ }
+ }
+
+ println!("there are {} lints", usable_lint_count);
+}
+
+fn round_to_fifty(count: usize) -> usize {
+ count / 50 * 50
+}
diff --git a/src/tools/clippy/clippy_dummy/Cargo.toml b/src/tools/clippy/clippy_dummy/Cargo.toml
new file mode 100644
index 00000000000..7b11795fafd
--- /dev/null
+++ b/src/tools/clippy/clippy_dummy/Cargo.toml
@@ -0,0 +1,17 @@
+[package]
+name = "clippy_dummy" # rename to clippy before publishing
+version = "0.0.303"
+authors = ["Manish Goregaokar "]
+edition = "2018"
+readme = "crates-readme.md"
+description = "A bunch of helpful lints to avoid common pitfalls in Rust."
+build = 'build.rs'
+
+repository = "https://github.com/rust-lang/rust-clippy"
+
+license = "MIT OR Apache-2.0"
+keywords = ["clippy", "lint", "plugin"]
+categories = ["development-tools", "development-tools::cargo-plugins"]
+
+[build-dependencies]
+term = "0.6"
diff --git a/src/tools/clippy/clippy_dummy/PUBLISH.md b/src/tools/clippy/clippy_dummy/PUBLISH.md
new file mode 100644
index 00000000000..8e420ec959a
--- /dev/null
+++ b/src/tools/clippy/clippy_dummy/PUBLISH.md
@@ -0,0 +1,6 @@
+This is a dummy crate to publish to crates.io. It primarily exists to ensure
+that folks trying to install clippy from crates.io get redirected to the
+`rustup` technique.
+
+Before publishing, be sure to rename `clippy_dummy` to `clippy` in `Cargo.toml`,
+it has a different name to avoid workspace issues.
diff --git a/src/tools/clippy/clippy_dummy/build.rs b/src/tools/clippy/clippy_dummy/build.rs
new file mode 100644
index 00000000000..21af4f8244f
--- /dev/null
+++ b/src/tools/clippy/clippy_dummy/build.rs
@@ -0,0 +1,42 @@
+use term::color::{GREEN, RED, WHITE};
+use term::{Attr, Error, Result};
+
+fn main() {
+ if foo().is_err() {
+ eprintln!(
+ "error: Clippy is no longer available via crates.io\n\n\
+ help: please run `rustup component add clippy` instead"
+ );
+ }
+ std::process::exit(1);
+}
+
+fn foo() -> Result<()> {
+ let mut t = term::stderr().ok_or(Error::NotSupported)?;
+
+ t.attr(Attr::Bold)?;
+ t.fg(RED)?;
+ write!(t, "\nerror: ")?;
+
+ t.reset()?;
+ t.fg(WHITE)?;
+ writeln!(t, "Clippy is no longer available via crates.io\n")?;
+
+ t.attr(Attr::Bold)?;
+ t.fg(GREEN)?;
+ write!(t, "help: ")?;
+
+ t.reset()?;
+ t.fg(WHITE)?;
+ write!(t, "please run `")?;
+
+ t.attr(Attr::Bold)?;
+ write!(t, "rustup component add clippy")?;
+
+ t.reset()?;
+ t.fg(WHITE)?;
+ writeln!(t, "` instead")?;
+
+ t.reset()?;
+ Ok(())
+}
diff --git a/src/tools/clippy/clippy_dummy/crates-readme.md b/src/tools/clippy/clippy_dummy/crates-readme.md
new file mode 100644
index 00000000000..0decae8b910
--- /dev/null
+++ b/src/tools/clippy/clippy_dummy/crates-readme.md
@@ -0,0 +1,9 @@
+Installing clippy via crates.io is deprecated. Please use the following:
+
+```terminal
+rustup component add clippy
+```
+
+on a Rust version 1.29 or later. You may need to run `rustup self update` if it complains about a missing clippy binary.
+
+See [the homepage](https://github.com/rust-lang/rust-clippy/#clippy) for more information
diff --git a/src/tools/clippy/clippy_dummy/src/main.rs b/src/tools/clippy/clippy_dummy/src/main.rs
new file mode 100644
index 00000000000..a118834f1fd
--- /dev/null
+++ b/src/tools/clippy/clippy_dummy/src/main.rs
@@ -0,0 +1,3 @@
+fn main() {
+ panic!("This shouldn't even compile")
+}
diff --git a/src/tools/clippy/clippy_lints/Cargo.toml b/src/tools/clippy/clippy_lints/Cargo.toml
new file mode 100644
index 00000000000..1c0be727834
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/Cargo.toml
@@ -0,0 +1,37 @@
+[package]
+name = "clippy_lints"
+# begin automatic update
+version = "0.0.212"
+# end automatic update
+authors = [
+ "Manish Goregaokar ",
+ "Andre Bogus ",
+ "Georg Brandl ",
+ "Martin Carton "
+]
+description = "A bunch of helpful lints to avoid common pitfalls in Rust"
+repository = "https://github.com/rust-lang/rust-clippy"
+readme = "README.md"
+license = "MIT OR Apache-2.0"
+keywords = ["clippy", "lint", "plugin"]
+edition = "2018"
+
+[dependencies]
+cargo_metadata = "0.9.0"
+if_chain = "1.0.0"
+itertools = "0.9"
+lazy_static = "1.0.2"
+pulldown-cmark = { version = "0.7", default-features = false }
+quine-mc_cluskey = "0.2.2"
+regex-syntax = "0.6"
+serde = { version = "1.0", features = ["derive"] }
+smallvec = { version = "1", features = ["union"] }
+toml = "0.5.3"
+unicode-normalization = "0.1"
+semver = "0.9.0"
+# NOTE: cargo requires serde feat in its url dep
+# see
+url = { version = "2.1.0", features = ["serde"] }
+
+[features]
+deny-warnings = []
diff --git a/src/tools/clippy/clippy_lints/README.md b/src/tools/clippy/clippy_lints/README.md
new file mode 100644
index 00000000000..513583b7e34
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/README.md
@@ -0,0 +1 @@
+This crate contains Clippy lints. For the main crate, check [GitHub](https://github.com/rust-lang/rust-clippy).
diff --git a/src/tools/clippy/clippy_lints/src/approx_const.rs b/src/tools/clippy/clippy_lints/src/approx_const.rs
new file mode 100644
index 00000000000..7e6e2c7eaeb
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/approx_const.rs
@@ -0,0 +1,117 @@
+use crate::utils::span_lint;
+use rustc_ast::ast::{FloatTy, LitFloatType, LitKind};
+use rustc_hir::{Expr, ExprKind};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::symbol;
+use std::f64::consts as f64;
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for floating point literals that approximate
+ /// constants which are defined in
+ /// [`std::f32::consts`](https://doc.rust-lang.org/stable/std/f32/consts/#constants)
+ /// or
+ /// [`std::f64::consts`](https://doc.rust-lang.org/stable/std/f64/consts/#constants),
+ /// respectively, suggesting to use the predefined constant.
+ ///
+ /// **Why is this bad?** Usually, the definition in the standard library is more
+ /// precise than what people come up with. If you find that your definition is
+ /// actually more precise, please [file a Rust
+ /// issue](https://github.com/rust-lang/rust/issues).
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```rust
+ /// let x = 3.14;
+ /// let y = 1_f64 / x;
+ /// ```
+ /// Use predefined constants instead:
+ /// ```rust
+ /// let x = std::f32::consts::PI;
+ /// let y = std::f64::consts::FRAC_1_PI;
+ /// ```
+ pub APPROX_CONSTANT,
+ correctness,
+ "the approximate of a known float constant (in `std::fXX::consts`)"
+}
+
+// Tuples are of the form (constant, name, min_digits)
+const KNOWN_CONSTS: [(f64, &str, usize); 18] = [
+ (f64::E, "E", 4),
+ (f64::FRAC_1_PI, "FRAC_1_PI", 4),
+ (f64::FRAC_1_SQRT_2, "FRAC_1_SQRT_2", 5),
+ (f64::FRAC_2_PI, "FRAC_2_PI", 5),
+ (f64::FRAC_2_SQRT_PI, "FRAC_2_SQRT_PI", 5),
+ (f64::FRAC_PI_2, "FRAC_PI_2", 5),
+ (f64::FRAC_PI_3, "FRAC_PI_3", 5),
+ (f64::FRAC_PI_4, "FRAC_PI_4", 5),
+ (f64::FRAC_PI_6, "FRAC_PI_6", 5),
+ (f64::FRAC_PI_8, "FRAC_PI_8", 5),
+ (f64::LN_10, "LN_10", 5),
+ (f64::LN_2, "LN_2", 5),
+ (f64::LOG10_E, "LOG10_E", 5),
+ (f64::LOG2_E, "LOG2_E", 5),
+ (f64::LOG2_10, "LOG2_10", 5),
+ (f64::LOG10_2, "LOG10_2", 5),
+ (f64::PI, "PI", 3),
+ (f64::SQRT_2, "SQRT_2", 5),
+];
+
+declare_lint_pass!(ApproxConstant => [APPROX_CONSTANT]);
+
+impl<'a, 'tcx> LateLintPass<'a, 'tcx> for ApproxConstant {
+ fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, e: &'tcx Expr<'_>) {
+ if let ExprKind::Lit(lit) = &e.kind {
+ check_lit(cx, &lit.node, e);
+ }
+ }
+}
+
+fn check_lit(cx: &LateContext<'_, '_>, lit: &LitKind, e: &Expr<'_>) {
+ match *lit {
+ LitKind::Float(s, LitFloatType::Suffixed(fty)) => match fty {
+ FloatTy::F32 => check_known_consts(cx, e, s, "f32"),
+ FloatTy::F64 => check_known_consts(cx, e, s, "f64"),
+ },
+ LitKind::Float(s, LitFloatType::Unsuffixed) => check_known_consts(cx, e, s, "f{32, 64}"),
+ _ => (),
+ }
+}
+
+fn check_known_consts(cx: &LateContext<'_, '_>, e: &Expr<'_>, s: symbol::Symbol, module: &str) {
+ let s = s.as_str();
+ if s.parse::().is_ok() {
+ for &(constant, name, min_digits) in &KNOWN_CONSTS {
+ if is_approx_const(constant, &s, min_digits) {
+ span_lint(
+ cx,
+ APPROX_CONSTANT,
+ e.span,
+ &format!(
+ "approximate value of `{}::consts::{}` found. \
+ Consider using it directly",
+ module, &name
+ ),
+ );
+ return;
+ }
+ }
+ }
+}
+
+/// Returns `false` if the number of significant figures in `value` are
+/// less than `min_digits`; otherwise, returns true if `value` is equal
+/// to `constant`, rounded to the number of digits present in `value`.
+#[must_use]
+fn is_approx_const(constant: f64, value: &str, min_digits: usize) -> bool {
+ if value.len() <= min_digits {
+ false
+ } else if constant.to_string().starts_with(value) {
+ // The value is a truncated constant
+ true
+ } else {
+ let round_const = format!("{:.*}", value.len() - 2, constant);
+ value == round_const
+ }
+}
diff --git a/src/tools/clippy/clippy_lints/src/arithmetic.rs b/src/tools/clippy/clippy_lints/src/arithmetic.rs
new file mode 100644
index 00000000000..6cbe10a5352
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/arithmetic.rs
@@ -0,0 +1,149 @@
+use crate::consts::constant_simple;
+use crate::utils::span_lint;
+use rustc_hir as hir;
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_tool_lint, impl_lint_pass};
+use rustc_span::source_map::Span;
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for integer arithmetic operations which could overflow or panic.
+ ///
+ /// Specifically, checks for any operators (`+`, `-`, `*`, `<<`, etc) which are capable
+ /// of overflowing according to the [Rust
+ /// Reference](https://doc.rust-lang.org/reference/expressions/operator-expr.html#overflow),
+ /// or which can panic (`/`, `%`). No bounds analysis or sophisticated reasoning is
+ /// attempted.
+ ///
+ /// **Why is this bad?** Integer overflow will trigger a panic in debug builds or will wrap in
+ /// release mode. Division by zero will cause a panic in either mode. In some applications one
+ /// wants explicitly checked, wrapping or saturating arithmetic.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```rust
+ /// # let a = 0;
+ /// a + 1;
+ /// ```
+ pub INTEGER_ARITHMETIC,
+ restriction,
+ "any integer arithmetic expression which could overflow or panic"
+}
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for float arithmetic.
+ ///
+ /// **Why is this bad?** For some embedded systems or kernel development, it
+ /// can be useful to rule out floating-point numbers.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```rust
+ /// # let a = 0.0;
+ /// a + 1.0;
+ /// ```
+ pub FLOAT_ARITHMETIC,
+ restriction,
+ "any floating-point arithmetic statement"
+}
+
+#[derive(Copy, Clone, Default)]
+pub struct Arithmetic {
+ expr_span: Option,
+ /// This field is used to check whether expressions are constants, such as in enum discriminants
+ /// and consts
+ const_span: Option,
+}
+
+impl_lint_pass!(Arithmetic => [INTEGER_ARITHMETIC, FLOAT_ARITHMETIC]);
+
+impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Arithmetic {
+ fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx hir::Expr<'_>) {
+ if self.expr_span.is_some() {
+ return;
+ }
+
+ if let Some(span) = self.const_span {
+ if span.contains(expr.span) {
+ return;
+ }
+ }
+ match &expr.kind {
+ hir::ExprKind::Binary(op, l, r) | hir::ExprKind::AssignOp(op, l, r) => {
+ match op.node {
+ hir::BinOpKind::And
+ | hir::BinOpKind::Or
+ | hir::BinOpKind::BitAnd
+ | hir::BinOpKind::BitOr
+ | hir::BinOpKind::BitXor
+ | hir::BinOpKind::Eq
+ | hir::BinOpKind::Lt
+ | hir::BinOpKind::Le
+ | hir::BinOpKind::Ne
+ | hir::BinOpKind::Ge
+ | hir::BinOpKind::Gt => return,
+ _ => (),
+ }
+
+ let (l_ty, r_ty) = (cx.tables.expr_ty(l), cx.tables.expr_ty(r));
+ if l_ty.peel_refs().is_integral() && r_ty.peel_refs().is_integral() {
+ span_lint(cx, INTEGER_ARITHMETIC, expr.span, "integer arithmetic detected");
+ self.expr_span = Some(expr.span);
+ } else if l_ty.peel_refs().is_floating_point() && r_ty.peel_refs().is_floating_point() {
+ span_lint(cx, FLOAT_ARITHMETIC, expr.span, "floating-point arithmetic detected");
+ self.expr_span = Some(expr.span);
+ }
+ },
+ hir::ExprKind::Unary(hir::UnOp::UnNeg, arg) => {
+ let ty = cx.tables.expr_ty(arg);
+ if constant_simple(cx, cx.tables, expr).is_none() {
+ if ty.is_integral() {
+ span_lint(cx, INTEGER_ARITHMETIC, expr.span, "integer arithmetic detected");
+ self.expr_span = Some(expr.span);
+ } else if ty.is_floating_point() {
+ span_lint(cx, FLOAT_ARITHMETIC, expr.span, "floating-point arithmetic detected");
+ self.expr_span = Some(expr.span);
+ }
+ }
+ },
+ _ => (),
+ }
+ }
+
+ fn check_expr_post(&mut self, _: &LateContext<'a, 'tcx>, expr: &'tcx hir::Expr<'_>) {
+ if Some(expr.span) == self.expr_span {
+ self.expr_span = None;
+ }
+ }
+
+ fn check_body(&mut self, cx: &LateContext<'_, '_>, body: &hir::Body<'_>) {
+ let body_owner = cx.tcx.hir().body_owner(body.id());
+
+ match cx.tcx.hir().body_owner_kind(body_owner) {
+ hir::BodyOwnerKind::Static(_) | hir::BodyOwnerKind::Const => {
+ let body_span = cx.tcx.hir().span(body_owner);
+
+ if let Some(span) = self.const_span {
+ if span.contains(body_span) {
+ return;
+ }
+ }
+ self.const_span = Some(body_span);
+ },
+ hir::BodyOwnerKind::Fn | hir::BodyOwnerKind::Closure => (),
+ }
+ }
+
+ fn check_body_post(&mut self, cx: &LateContext<'_, '_>, body: &hir::Body<'_>) {
+ let body_owner = cx.tcx.hir().body_owner(body.id());
+ let body_span = cx.tcx.hir().span(body_owner);
+
+ if let Some(span) = self.const_span {
+ if span.contains(body_span) {
+ return;
+ }
+ }
+ self.const_span = None;
+ }
+}
diff --git a/src/tools/clippy/clippy_lints/src/as_conversions.rs b/src/tools/clippy/clippy_lints/src/as_conversions.rs
new file mode 100644
index 00000000000..0c8efd75514
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/as_conversions.rs
@@ -0,0 +1,58 @@
+use rustc_ast::ast::{Expr, ExprKind};
+use rustc_lint::{EarlyContext, EarlyLintPass, LintContext};
+use rustc_middle::lint::in_external_macro;
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+
+use crate::utils::span_lint_and_help;
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for usage of `as` conversions.
+ ///
+ /// **Why is this bad?** `as` conversions will perform many kinds of
+ /// conversions, including silently lossy conversions and dangerous coercions.
+ /// There are cases when it makes sense to use `as`, so the lint is
+ /// Allow by default.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```rust,ignore
+ /// let a: u32;
+ /// ...
+ /// f(a as u16);
+ /// ```
+ ///
+ /// Usually better represents the semantics you expect:
+ /// ```rust,ignore
+ /// f(a.try_into()?);
+ /// ```
+ /// or
+ /// ```rust,ignore
+ /// f(a.try_into().expect("Unexpected u16 overflow in f"));
+ /// ```
+ ///
+ pub AS_CONVERSIONS,
+ restriction,
+ "using a potentially dangerous silent `as` conversion"
+}
+
+declare_lint_pass!(AsConversions => [AS_CONVERSIONS]);
+
+impl EarlyLintPass for AsConversions {
+ fn check_expr(&mut self, cx: &EarlyContext<'_>, expr: &Expr) {
+ if in_external_macro(cx.sess(), expr.span) {
+ return;
+ }
+
+ if let ExprKind::Cast(_, _) = expr.kind {
+ span_lint_and_help(
+ cx,
+ AS_CONVERSIONS,
+ expr.span,
+ "using a potentially dangerous silent `as` conversion",
+ None,
+ "consider using a safe wrapper for this conversion",
+ );
+ }
+ }
+}
diff --git a/src/tools/clippy/clippy_lints/src/assertions_on_constants.rs b/src/tools/clippy/clippy_lints/src/assertions_on_constants.rs
new file mode 100644
index 00000000000..f8a8fdcd3aa
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/assertions_on_constants.rs
@@ -0,0 +1,152 @@
+use crate::consts::{constant, Constant};
+use crate::utils::paths;
+use crate::utils::{is_direct_expn_of, is_expn_of, match_function_call, snippet_opt, span_lint_and_help};
+use if_chain::if_chain;
+use rustc_ast::ast::LitKind;
+use rustc_hir::{Expr, ExprKind, PatKind, UnOp};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for `assert!(true)` and `assert!(false)` calls.
+ ///
+ /// **Why is this bad?** Will be optimized out by the compiler or should probably be replaced by a
+ /// `panic!()` or `unreachable!()`
+ ///
+ /// **Known problems:** None
+ ///
+ /// **Example:**
+ /// ```rust,ignore
+ /// assert!(false)
+ /// assert!(true)
+ /// const B: bool = false;
+ /// assert!(B)
+ /// ```
+ pub ASSERTIONS_ON_CONSTANTS,
+ style,
+ "`assert!(true)` / `assert!(false)` will be optimized out by the compiler, and should probably be replaced by a `panic!()` or `unreachable!()`"
+}
+
+declare_lint_pass!(AssertionsOnConstants => [ASSERTIONS_ON_CONSTANTS]);
+
+impl<'a, 'tcx> LateLintPass<'a, 'tcx> for AssertionsOnConstants {
+ fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, e: &'tcx Expr<'_>) {
+ let lint_true = |is_debug: bool| {
+ span_lint_and_help(
+ cx,
+ ASSERTIONS_ON_CONSTANTS,
+ e.span,
+ if is_debug {
+ "`debug_assert!(true)` will be optimized out by the compiler"
+ } else {
+ "`assert!(true)` will be optimized out by the compiler"
+ },
+ None,
+ "remove it",
+ );
+ };
+ let lint_false_without_message = || {
+ span_lint_and_help(
+ cx,
+ ASSERTIONS_ON_CONSTANTS,
+ e.span,
+ "`assert!(false)` should probably be replaced",
+ None,
+ "use `panic!()` or `unreachable!()`",
+ );
+ };
+ let lint_false_with_message = |panic_message: String| {
+ span_lint_and_help(
+ cx,
+ ASSERTIONS_ON_CONSTANTS,
+ e.span,
+ &format!("`assert!(false, {})` should probably be replaced", panic_message),
+ None,
+ &format!("use `panic!({})` or `unreachable!({})`", panic_message, panic_message),
+ )
+ };
+
+ if let Some(debug_assert_span) = is_expn_of(e.span, "debug_assert") {
+ if debug_assert_span.from_expansion() {
+ return;
+ }
+ if_chain! {
+ if let ExprKind::Unary(_, ref lit) = e.kind;
+ if let Some((Constant::Bool(is_true), _)) = constant(cx, cx.tables, lit);
+ if is_true;
+ then {
+ lint_true(true);
+ }
+ };
+ } else if let Some(assert_span) = is_direct_expn_of(e.span, "assert") {
+ if assert_span.from_expansion() {
+ return;
+ }
+ if let Some(assert_match) = match_assert_with_message(&cx, e) {
+ match assert_match {
+ // matched assert but not message
+ AssertKind::WithoutMessage(false) => lint_false_without_message(),
+ AssertKind::WithoutMessage(true) | AssertKind::WithMessage(_, true) => lint_true(false),
+ AssertKind::WithMessage(panic_message, false) => lint_false_with_message(panic_message),
+ };
+ }
+ }
+ }
+}
+
+/// Result of calling `match_assert_with_message`.
+enum AssertKind {
+ WithMessage(String, bool),
+ WithoutMessage(bool),
+}
+
+/// Check if the expression matches
+///
+/// ```rust,ignore
+/// match { let _t = !c; _t } {
+/// true => {
+/// {
+/// ::std::rt::begin_panic(message, _)
+/// }
+/// }
+/// _ => { }
+/// };
+/// ```
+///
+/// where `message` is any expression and `c` is a constant bool.
+fn match_assert_with_message<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr<'_>) -> Option {
+ if_chain! {
+ if let ExprKind::Match(ref expr, ref arms, _) = expr.kind;
+ // matches { let _t = expr; _t }
+ if let ExprKind::DropTemps(ref expr) = expr.kind;
+ if let ExprKind::Unary(UnOp::UnNot, ref expr) = expr.kind;
+ // bind the first argument of the `assert!` macro
+ if let Some((Constant::Bool(is_true), _)) = constant(cx, cx.tables, expr);
+ // arm 1 pattern
+ if let PatKind::Lit(ref lit_expr) = arms[0].pat.kind;
+ if let ExprKind::Lit(ref lit) = lit_expr.kind;
+ if let LitKind::Bool(true) = lit.node;
+ // arm 1 block
+ if let ExprKind::Block(ref block, _) = arms[0].body.kind;
+ if block.stmts.is_empty();
+ if let Some(block_expr) = &block.expr;
+ if let ExprKind::Block(ref inner_block, _) = block_expr.kind;
+ if let Some(begin_panic_call) = &inner_block.expr;
+ // function call
+ if let Some(args) = match_function_call(cx, begin_panic_call, &paths::BEGIN_PANIC);
+ if args.len() == 1;
+ // bind the second argument of the `assert!` macro if it exists
+ if let panic_message = snippet_opt(cx, args[0].span);
+ // second argument of begin_panic is irrelevant
+ // as is the second match arm
+ then {
+ // an empty message occurs when it was generated by the macro
+ // (and not passed by the user)
+ return panic_message
+ .filter(|msg| !msg.is_empty())
+ .map(|msg| AssertKind::WithMessage(msg, is_true))
+ .or(Some(AssertKind::WithoutMessage(is_true)));
+ }
+ }
+ None
+}
diff --git a/src/tools/clippy/clippy_lints/src/assign_ops.rs b/src/tools/clippy/clippy_lints/src/assign_ops.rs
new file mode 100644
index 00000000000..05e2650d0b7
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/assign_ops.rs
@@ -0,0 +1,261 @@
+use crate::utils::{
+ get_trait_def_id, implements_trait, snippet_opt, span_lint_and_then, trait_ref_of_method, SpanlessEq,
+};
+use crate::utils::{higher, sugg};
+use if_chain::if_chain;
+use rustc_errors::Applicability;
+use rustc_hir as hir;
+use rustc_hir::intravisit::{walk_expr, NestedVisitorMap, Visitor};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::hir::map::Map;
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for `a = a op b` or `a = b commutative_op a`
+ /// patterns.
+ ///
+ /// **Why is this bad?** These can be written as the shorter `a op= b`.
+ ///
+ /// **Known problems:** While forbidden by the spec, `OpAssign` traits may have
+ /// implementations that differ from the regular `Op` impl.
+ ///
+ /// **Example:**
+ /// ```rust
+ /// let mut a = 5;
+ /// let b = 0;
+ /// // ...
+ /// a = a + b;
+ /// ```
+ pub ASSIGN_OP_PATTERN,
+ style,
+ "assigning the result of an operation on a variable to that same variable"
+}
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for `a op= a op b` or `a op= b op a` patterns.
+ ///
+ /// **Why is this bad?** Most likely these are bugs where one meant to write `a
+ /// op= b`.
+ ///
+ /// **Known problems:** Clippy cannot know for sure if `a op= a op b` should have
+ /// been `a = a op a op b` or `a = a op b`/`a op= b`. Therefore, it suggests both.
+ /// If `a op= a op b` is really the correct behaviour it should be
+ /// written as `a = a op a op b` as it's less confusing.
+ ///
+ /// **Example:**
+ /// ```rust
+ /// let mut a = 5;
+ /// let b = 2;
+ /// // ...
+ /// a += a + b;
+ /// ```
+ pub MISREFACTORED_ASSIGN_OP,
+ complexity,
+ "having a variable on both sides of an assign op"
+}
+
+declare_lint_pass!(AssignOps => [ASSIGN_OP_PATTERN, MISREFACTORED_ASSIGN_OP]);
+
+impl<'a, 'tcx> LateLintPass<'a, 'tcx> for AssignOps {
+ #[allow(clippy::too_many_lines)]
+ fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx hir::Expr<'_>) {
+ match &expr.kind {
+ hir::ExprKind::AssignOp(op, lhs, rhs) => {
+ if let hir::ExprKind::Binary(binop, l, r) = &rhs.kind {
+ if op.node != binop.node {
+ return;
+ }
+ // lhs op= l op r
+ if SpanlessEq::new(cx).ignore_fn().eq_expr(lhs, l) {
+ lint_misrefactored_assign_op(cx, expr, *op, rhs, lhs, r);
+ }
+ // lhs op= l commutative_op r
+ if is_commutative(op.node) && SpanlessEq::new(cx).ignore_fn().eq_expr(lhs, r) {
+ lint_misrefactored_assign_op(cx, expr, *op, rhs, lhs, l);
+ }
+ }
+ },
+ hir::ExprKind::Assign(assignee, e, _) => {
+ if let hir::ExprKind::Binary(op, l, r) = &e.kind {
+ let lint = |assignee: &hir::Expr<'_>, rhs: &hir::Expr<'_>| {
+ let ty = cx.tables.expr_ty(assignee);
+ let rty = cx.tables.expr_ty(rhs);
+ macro_rules! ops {
+ ($op:expr,
+ $cx:expr,
+ $ty:expr,
+ $rty:expr,
+ $($trait_name:ident),+) => {
+ match $op {
+ $(hir::BinOpKind::$trait_name => {
+ let [krate, module] = crate::utils::paths::OPS_MODULE;
+ let path: [&str; 3] = [krate, module, concat!(stringify!($trait_name), "Assign")];
+ let trait_id = if let Some(trait_id) = get_trait_def_id($cx, &path) {
+ trait_id
+ } else {
+ return; // useless if the trait doesn't exist
+ };
+ // check that we are not inside an `impl AssignOp` of this exact operation
+ let parent_fn = cx.tcx.hir().get_parent_item(e.hir_id);
+ if_chain! {
+ if let Some(trait_ref) = trait_ref_of_method(cx, parent_fn);
+ if trait_ref.path.res.def_id() == trait_id;
+ then { return; }
+ }
+ implements_trait($cx, $ty, trait_id, &[$rty])
+ },)*
+ _ => false,
+ }
+ }
+ }
+ if ops!(
+ op.node,
+ cx,
+ ty,
+ rty.into(),
+ Add,
+ Sub,
+ Mul,
+ Div,
+ Rem,
+ And,
+ Or,
+ BitAnd,
+ BitOr,
+ BitXor,
+ Shr,
+ Shl
+ ) {
+ span_lint_and_then(
+ cx,
+ ASSIGN_OP_PATTERN,
+ expr.span,
+ "manual implementation of an assign operation",
+ |diag| {
+ if let (Some(snip_a), Some(snip_r)) =
+ (snippet_opt(cx, assignee.span), snippet_opt(cx, rhs.span))
+ {
+ diag.span_suggestion(
+ expr.span,
+ "replace it with",
+ format!("{} {}= {}", snip_a, op.node.as_str(), snip_r),
+ Applicability::MachineApplicable,
+ );
+ }
+ },
+ );
+ }
+ };
+
+ let mut visitor = ExprVisitor {
+ assignee,
+ counter: 0,
+ cx,
+ };
+
+ walk_expr(&mut visitor, e);
+
+ if visitor.counter == 1 {
+ // a = a op b
+ if SpanlessEq::new(cx).ignore_fn().eq_expr(assignee, l) {
+ lint(assignee, r);
+ }
+ // a = b commutative_op a
+ // Limited to primitive type as these ops are know to be commutative
+ if SpanlessEq::new(cx).ignore_fn().eq_expr(assignee, r)
+ && cx.tables.expr_ty(assignee).is_primitive_ty()
+ {
+ match op.node {
+ hir::BinOpKind::Add
+ | hir::BinOpKind::Mul
+ | hir::BinOpKind::And
+ | hir::BinOpKind::Or
+ | hir::BinOpKind::BitXor
+ | hir::BinOpKind::BitAnd
+ | hir::BinOpKind::BitOr => {
+ lint(assignee, l);
+ },
+ _ => {},
+ }
+ }
+ }
+ }
+ },
+ _ => {},
+ }
+ }
+}
+
+fn lint_misrefactored_assign_op(
+ cx: &LateContext<'_, '_>,
+ expr: &hir::Expr<'_>,
+ op: hir::BinOp,
+ rhs: &hir::Expr<'_>,
+ assignee: &hir::Expr<'_>,
+ rhs_other: &hir::Expr<'_>,
+) {
+ span_lint_and_then(
+ cx,
+ MISREFACTORED_ASSIGN_OP,
+ expr.span,
+ "variable appears on both sides of an assignment operation",
+ |diag| {
+ if let (Some(snip_a), Some(snip_r)) = (snippet_opt(cx, assignee.span), snippet_opt(cx, rhs_other.span)) {
+ let a = &sugg::Sugg::hir(cx, assignee, "..");
+ let r = &sugg::Sugg::hir(cx, rhs, "..");
+ let long = format!("{} = {}", snip_a, sugg::make_binop(higher::binop(op.node), a, r));
+ diag.span_suggestion(
+ expr.span,
+ &format!(
+ "Did you mean `{} = {} {} {}` or `{}`? Consider replacing it with",
+ snip_a,
+ snip_a,
+ op.node.as_str(),
+ snip_r,
+ long
+ ),
+ format!("{} {}= {}", snip_a, op.node.as_str(), snip_r),
+ Applicability::MaybeIncorrect,
+ );
+ diag.span_suggestion(
+ expr.span,
+ "or",
+ long,
+ Applicability::MaybeIncorrect, // snippet
+ );
+ }
+ },
+ );
+}
+
+#[must_use]
+fn is_commutative(op: hir::BinOpKind) -> bool {
+ use rustc_hir::BinOpKind::{
+ Add, And, BitAnd, BitOr, BitXor, Div, Eq, Ge, Gt, Le, Lt, Mul, Ne, Or, Rem, Shl, Shr, Sub,
+ };
+ match op {
+ Add | Mul | And | Or | BitXor | BitAnd | BitOr | Eq | Ne => true,
+ Sub | Div | Rem | Shl | Shr | Lt | Le | Ge | Gt => false,
+ }
+}
+
+struct ExprVisitor<'a, 'tcx> {
+ assignee: &'a hir::Expr<'a>,
+ counter: u8,
+ cx: &'a LateContext<'a, 'tcx>,
+}
+
+impl<'a, 'tcx> Visitor<'tcx> for ExprVisitor<'a, 'tcx> {
+ type Map = Map<'tcx>;
+
+ fn visit_expr(&mut self, expr: &'tcx hir::Expr<'_>) {
+ if SpanlessEq::new(self.cx).ignore_fn().eq_expr(self.assignee, expr) {
+ self.counter += 1;
+ }
+
+ walk_expr(self, expr);
+ }
+ fn nested_visit_map(&mut self) -> NestedVisitorMap {
+ NestedVisitorMap::None
+ }
+}
diff --git a/src/tools/clippy/clippy_lints/src/atomic_ordering.rs b/src/tools/clippy/clippy_lints/src/atomic_ordering.rs
new file mode 100644
index 00000000000..73b4cef4725
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/atomic_ordering.rs
@@ -0,0 +1,135 @@
+use crate::utils::{match_def_path, span_lint_and_help};
+use if_chain::if_chain;
+use rustc_hir::def_id::DefId;
+use rustc_hir::{Expr, ExprKind};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty;
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for usage of invalid atomic
+ /// ordering in atomic loads/stores and memory fences.
+ ///
+ /// **Why is this bad?** Using an invalid atomic ordering
+ /// will cause a panic at run-time.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```rust,no_run
+ /// # use std::sync::atomic::{self, AtomicBool, Ordering};
+ ///
+ /// let x = AtomicBool::new(true);
+ ///
+ /// let _ = x.load(Ordering::Release);
+ /// let _ = x.load(Ordering::AcqRel);
+ ///
+ /// x.store(false, Ordering::Acquire);
+ /// x.store(false, Ordering::AcqRel);
+ ///
+ /// atomic::fence(Ordering::Relaxed);
+ /// atomic::compiler_fence(Ordering::Relaxed);
+ /// ```
+ pub INVALID_ATOMIC_ORDERING,
+ correctness,
+ "usage of invalid atomic ordering in atomic loads/stores and memory fences"
+}
+
+declare_lint_pass!(AtomicOrdering => [INVALID_ATOMIC_ORDERING]);
+
+const ATOMIC_TYPES: [&str; 12] = [
+ "AtomicBool",
+ "AtomicI8",
+ "AtomicI16",
+ "AtomicI32",
+ "AtomicI64",
+ "AtomicIsize",
+ "AtomicPtr",
+ "AtomicU8",
+ "AtomicU16",
+ "AtomicU32",
+ "AtomicU64",
+ "AtomicUsize",
+];
+
+fn type_is_atomic(cx: &LateContext<'_, '_>, expr: &Expr<'_>) -> bool {
+ if let ty::Adt(&ty::AdtDef { did, .. }, _) = cx.tables.expr_ty(expr).kind {
+ ATOMIC_TYPES
+ .iter()
+ .any(|ty| match_def_path(cx, did, &["core", "sync", "atomic", ty]))
+ } else {
+ false
+ }
+}
+
+fn match_ordering_def_path(cx: &LateContext<'_, '_>, did: DefId, orderings: &[&str]) -> bool {
+ orderings
+ .iter()
+ .any(|ordering| match_def_path(cx, did, &["core", "sync", "atomic", "Ordering", ordering]))
+}
+
+fn check_atomic_load_store(cx: &LateContext<'_, '_>, expr: &Expr<'_>) {
+ if_chain! {
+ if let ExprKind::MethodCall(ref method_path, _, args) = &expr.kind;
+ let method = method_path.ident.name.as_str();
+ if type_is_atomic(cx, &args[0]);
+ if method == "load" || method == "store";
+ let ordering_arg = if method == "load" { &args[1] } else { &args[2] };
+ if let ExprKind::Path(ref ordering_qpath) = ordering_arg.kind;
+ if let Some(ordering_def_id) = cx.tables.qpath_res(ordering_qpath, ordering_arg.hir_id).opt_def_id();
+ then {
+ if method == "load" &&
+ match_ordering_def_path(cx, ordering_def_id, &["Release", "AcqRel"]) {
+ span_lint_and_help(
+ cx,
+ INVALID_ATOMIC_ORDERING,
+ ordering_arg.span,
+ "atomic loads cannot have `Release` and `AcqRel` ordering",
+ None,
+ "consider using ordering modes `Acquire`, `SeqCst` or `Relaxed`"
+ );
+ } else if method == "store" &&
+ match_ordering_def_path(cx, ordering_def_id, &["Acquire", "AcqRel"]) {
+ span_lint_and_help(
+ cx,
+ INVALID_ATOMIC_ORDERING,
+ ordering_arg.span,
+ "atomic stores cannot have `Acquire` and `AcqRel` ordering",
+ None,
+ "consider using ordering modes `Release`, `SeqCst` or `Relaxed`"
+ );
+ }
+ }
+ }
+}
+
+fn check_memory_fence(cx: &LateContext<'_, '_>, expr: &Expr<'_>) {
+ if_chain! {
+ if let ExprKind::Call(ref func, ref args) = expr.kind;
+ if let ExprKind::Path(ref func_qpath) = func.kind;
+ if let Some(def_id) = cx.tables.qpath_res(func_qpath, func.hir_id).opt_def_id();
+ if ["fence", "compiler_fence"]
+ .iter()
+ .any(|func| match_def_path(cx, def_id, &["core", "sync", "atomic", func]));
+ if let ExprKind::Path(ref ordering_qpath) = &args[0].kind;
+ if let Some(ordering_def_id) = cx.tables.qpath_res(ordering_qpath, args[0].hir_id).opt_def_id();
+ if match_ordering_def_path(cx, ordering_def_id, &["Relaxed"]);
+ then {
+ span_lint_and_help(
+ cx,
+ INVALID_ATOMIC_ORDERING,
+ args[0].span,
+ "memory fences cannot have `Relaxed` ordering",
+ None,
+ "consider using ordering modes `Acquire`, `Release`, `AcqRel` or `SeqCst`"
+ );
+ }
+ }
+}
+
+impl<'a, 'tcx> LateLintPass<'a, 'tcx> for AtomicOrdering {
+ fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr<'_>) {
+ check_atomic_load_store(cx, expr);
+ check_memory_fence(cx, expr);
+ }
+}
diff --git a/src/tools/clippy/clippy_lints/src/attrs.rs b/src/tools/clippy/clippy_lints/src/attrs.rs
new file mode 100644
index 00000000000..64abc9fdc71
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/attrs.rs
@@ -0,0 +1,657 @@
+//! checks for attributes
+
+use crate::reexport::Name;
+use crate::utils::{
+ first_line_of_span, is_present_in_source, match_def_path, paths, snippet_opt, span_lint, span_lint_and_sugg,
+ span_lint_and_then, without_block_comments,
+};
+use if_chain::if_chain;
+use rustc_ast::ast::{AttrKind, AttrStyle, Attribute, Lit, LitKind, MetaItemKind, NestedMetaItem};
+use rustc_ast::util::lev_distance::find_best_match_for_name;
+use rustc_errors::Applicability;
+use rustc_hir::{
+ Block, Expr, ExprKind, ImplItem, ImplItemKind, Item, ItemKind, StmtKind, TraitFn, TraitItem, TraitItemKind,
+};
+use rustc_lint::{CheckLintNameResult, EarlyContext, EarlyLintPass, LateContext, LateLintPass, LintContext};
+use rustc_middle::lint::in_external_macro;
+use rustc_middle::ty;
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::source_map::Span;
+use rustc_span::symbol::Symbol;
+use semver::Version;
+
+static UNIX_SYSTEMS: &[&str] = &[
+ "android",
+ "dragonfly",
+ "emscripten",
+ "freebsd",
+ "fuchsia",
+ "haiku",
+ "illumos",
+ "ios",
+ "l4re",
+ "linux",
+ "macos",
+ "netbsd",
+ "openbsd",
+ "redox",
+ "solaris",
+ "vxworks",
+];
+
+// NOTE: windows is excluded from the list because it's also a valid target family.
+static NON_UNIX_SYSTEMS: &[&str] = &["cloudabi", "hermit", "none", "wasi"];
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for items annotated with `#[inline(always)]`,
+ /// unless the annotated function is empty or simply panics.
+ ///
+ /// **Why is this bad?** While there are valid uses of this annotation (and once
+ /// you know when to use it, by all means `allow` this lint), it's a common
+ /// newbie-mistake to pepper one's code with it.
+ ///
+ /// As a rule of thumb, before slapping `#[inline(always)]` on a function,
+ /// measure if that additional function call really affects your runtime profile
+ /// sufficiently to make up for the increase in compile time.
+ ///
+ /// **Known problems:** False positives, big time. This lint is meant to be
+ /// deactivated by everyone doing serious performance work. This means having
+ /// done the measurement.
+ ///
+ /// **Example:**
+ /// ```ignore
+ /// #[inline(always)]
+ /// fn not_quite_hot_code(..) { ... }
+ /// ```
+ pub INLINE_ALWAYS,
+ pedantic,
+ "use of `#[inline(always)]`"
+}
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for `extern crate` and `use` items annotated with
+ /// lint attributes.
+ ///
+ /// This lint whitelists `#[allow(unused_imports)]`, `#[allow(deprecated)]` and
+ /// `#[allow(unreachable_pub)]` on `use` items and `#[allow(unused_imports)]` on
+ /// `extern crate` items with a `#[macro_use]` attribute.
+ ///
+ /// **Why is this bad?** Lint attributes have no effect on crate imports. Most
+ /// likely a `!` was forgotten.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```ignore
+ /// // Bad
+ /// #[deny(dead_code)]
+ /// extern crate foo;
+ /// #[forbid(dead_code)]
+ /// use foo::bar;
+ ///
+ /// // Ok
+ /// #[allow(unused_imports)]
+ /// use foo::baz;
+ /// #[allow(unused_imports)]
+ /// #[macro_use]
+ /// extern crate baz;
+ /// ```
+ pub USELESS_ATTRIBUTE,
+ correctness,
+ "use of lint attributes on `extern crate` items"
+}
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for `#[deprecated]` annotations with a `since`
+ /// field that is not a valid semantic version.
+ ///
+ /// **Why is this bad?** For checking the version of the deprecation, it must be
+ /// a valid semver. Failing that, the contained information is useless.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```rust
+ /// #[deprecated(since = "forever")]
+ /// fn something_else() { /* ... */ }
+ /// ```
+ pub DEPRECATED_SEMVER,
+ correctness,
+ "use of `#[deprecated(since = \"x\")]` where x is not semver"
+}
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for empty lines after outer attributes
+ ///
+ /// **Why is this bad?**
+ /// Most likely the attribute was meant to be an inner attribute using a '!'.
+ /// If it was meant to be an outer attribute, then the following item
+ /// should not be separated by empty lines.
+ ///
+ /// **Known problems:** Can cause false positives.
+ ///
+ /// From the clippy side it's difficult to detect empty lines between an attributes and the
+ /// following item because empty lines and comments are not part of the AST. The parsing
+ /// currently works for basic cases but is not perfect.
+ ///
+ /// **Example:**
+ /// ```rust
+ /// // Good (as inner attribute)
+ /// #![inline(always)]
+ ///
+ /// fn this_is_fine() { }
+ ///
+ /// // Bad
+ /// #[inline(always)]
+ ///
+ /// fn not_quite_good_code() { }
+ ///
+ /// // Good (as outer attribute)
+ /// #[inline(always)]
+ /// fn this_is_fine_too() { }
+ /// ```
+ pub EMPTY_LINE_AFTER_OUTER_ATTR,
+ nursery,
+ "empty line after outer attribute"
+}
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for `allow`/`warn`/`deny`/`forbid` attributes with scoped clippy
+ /// lints and if those lints exist in clippy. If there is an uppercase letter in the lint name
+ /// (not the tool name) and a lowercase version of this lint exists, it will suggest to lowercase
+ /// the lint name.
+ ///
+ /// **Why is this bad?** A lint attribute with a mistyped lint name won't have an effect.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// Bad:
+ /// ```rust
+ /// #![warn(if_not_els)]
+ /// #![deny(clippy::All)]
+ /// ```
+ ///
+ /// Good:
+ /// ```rust
+ /// #![warn(if_not_else)]
+ /// #![deny(clippy::all)]
+ /// ```
+ pub UNKNOWN_CLIPPY_LINTS,
+ style,
+ "unknown_lints for scoped Clippy lints"
+}
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for `#[cfg_attr(rustfmt, rustfmt_skip)]` and suggests to replace it
+ /// with `#[rustfmt::skip]`.
+ ///
+ /// **Why is this bad?** Since tool_attributes ([rust-lang/rust#44690](https://github.com/rust-lang/rust/issues/44690))
+ /// are stable now, they should be used instead of the old `cfg_attr(rustfmt)` attributes.
+ ///
+ /// **Known problems:** This lint doesn't detect crate level inner attributes, because they get
+ /// processed before the PreExpansionPass lints get executed. See
+ /// [#3123](https://github.com/rust-lang/rust-clippy/pull/3123#issuecomment-422321765)
+ ///
+ /// **Example:**
+ ///
+ /// Bad:
+ /// ```rust
+ /// #[cfg_attr(rustfmt, rustfmt_skip)]
+ /// fn main() { }
+ /// ```
+ ///
+ /// Good:
+ /// ```rust
+ /// #[rustfmt::skip]
+ /// fn main() { }
+ /// ```
+ pub DEPRECATED_CFG_ATTR,
+ complexity,
+ "usage of `cfg_attr(rustfmt)` instead of tool attributes"
+}
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for cfg attributes having operating systems used in target family position.
+ ///
+ /// **Why is this bad?** The configuration option will not be recognised and the related item will not be included
+ /// by the conditional compilation engine.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ ///
+ /// Bad:
+ /// ```rust
+ /// #[cfg(linux)]
+ /// fn conditional() { }
+ /// ```
+ ///
+ /// Good:
+ /// ```rust
+ /// #[cfg(target_os = "linux")]
+ /// fn conditional() { }
+ /// ```
+ ///
+ /// Or:
+ /// ```rust
+ /// #[cfg(unix)]
+ /// fn conditional() { }
+ /// ```
+ /// Check the [Rust Reference](https://doc.rust-lang.org/reference/conditional-compilation.html#target_os) for more details.
+ pub MISMATCHED_TARGET_OS,
+ correctness,
+ "usage of `cfg(operating_system)` instead of `cfg(target_os = \"operating_system\")`"
+}
+
+declare_lint_pass!(Attributes => [
+ INLINE_ALWAYS,
+ DEPRECATED_SEMVER,
+ USELESS_ATTRIBUTE,
+ EMPTY_LINE_AFTER_OUTER_ATTR,
+ UNKNOWN_CLIPPY_LINTS,
+]);
+
+impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Attributes {
+ fn check_attribute(&mut self, cx: &LateContext<'a, 'tcx>, attr: &'tcx Attribute) {
+ if let Some(items) = &attr.meta_item_list() {
+ if let Some(ident) = attr.ident() {
+ match &*ident.as_str() {
+ "allow" | "warn" | "deny" | "forbid" => {
+ check_clippy_lint_names(cx, items);
+ },
+ _ => {},
+ }
+ if items.is_empty() || !attr.check_name(sym!(deprecated)) {
+ return;
+ }
+ for item in items {
+ if_chain! {
+ if let NestedMetaItem::MetaItem(mi) = &item;
+ if let MetaItemKind::NameValue(lit) = &mi.kind;
+ if mi.check_name(sym!(since));
+ then {
+ check_semver(cx, item.span(), lit);
+ }
+ }
+ }
+ }
+ }
+ }
+
+ fn check_item(&mut self, cx: &LateContext<'a, 'tcx>, item: &'tcx Item<'_>) {
+ if is_relevant_item(cx, item) {
+ check_attrs(cx, item.span, item.ident.name, &item.attrs)
+ }
+ match item.kind {
+ ItemKind::ExternCrate(..) | ItemKind::Use(..) => {
+ let skip_unused_imports = item.attrs.iter().any(|attr| attr.check_name(sym!(macro_use)));
+
+ for attr in item.attrs {
+ if in_external_macro(cx.sess(), attr.span) {
+ return;
+ }
+ if let Some(lint_list) = &attr.meta_item_list() {
+ if let Some(ident) = attr.ident() {
+ match &*ident.as_str() {
+ "allow" | "warn" | "deny" | "forbid" => {
+ // whitelist `unused_imports`, `deprecated` and `unreachable_pub` for `use` items
+ // and `unused_imports` for `extern crate` items with `macro_use`
+ for lint in lint_list {
+ match item.kind {
+ ItemKind::Use(..) => {
+ if is_word(lint, sym!(unused_imports))
+ || is_word(lint, sym!(deprecated))
+ || is_word(lint, sym!(unreachable_pub))
+ || is_word(lint, sym!(unused))
+ {
+ return;
+ }
+ },
+ ItemKind::ExternCrate(..) => {
+ if is_word(lint, sym!(unused_imports)) && skip_unused_imports {
+ return;
+ }
+ if is_word(lint, sym!(unused_extern_crates)) {
+ return;
+ }
+ },
+ _ => {},
+ }
+ }
+ let line_span = first_line_of_span(cx, attr.span);
+
+ if let Some(mut sugg) = snippet_opt(cx, line_span) {
+ if sugg.contains("#[") {
+ span_lint_and_then(
+ cx,
+ USELESS_ATTRIBUTE,
+ line_span,
+ "useless lint attribute",
+ |diag| {
+ sugg = sugg.replacen("#[", "#![", 1);
+ diag.span_suggestion(
+ line_span,
+ "if you just forgot a `!`, use",
+ sugg,
+ Applicability::MaybeIncorrect,
+ );
+ },
+ );
+ }
+ }
+ },
+ _ => {},
+ }
+ }
+ }
+ }
+ },
+ _ => {},
+ }
+ }
+
+ fn check_impl_item(&mut self, cx: &LateContext<'a, 'tcx>, item: &'tcx ImplItem<'_>) {
+ if is_relevant_impl(cx, item) {
+ check_attrs(cx, item.span, item.ident.name, &item.attrs)
+ }
+ }
+
+ fn check_trait_item(&mut self, cx: &LateContext<'a, 'tcx>, item: &'tcx TraitItem<'_>) {
+ if is_relevant_trait(cx, item) {
+ check_attrs(cx, item.span, item.ident.name, &item.attrs)
+ }
+ }
+}
+
+#[allow(clippy::single_match_else)]
+fn check_clippy_lint_names(cx: &LateContext<'_, '_>, items: &[NestedMetaItem]) {
+ let lint_store = cx.lints();
+ for lint in items {
+ if_chain! {
+ if let Some(meta_item) = lint.meta_item();
+ if meta_item.path.segments.len() > 1;
+ if let tool_name = meta_item.path.segments[0].ident;
+ if tool_name.as_str() == "clippy";
+ let name = meta_item.path.segments.last().unwrap().ident.name;
+ if let CheckLintNameResult::Tool(Err((None, _))) = lint_store.check_lint_name(
+ &name.as_str(),
+ Some(tool_name.name),
+ );
+ then {
+ span_lint_and_then(
+ cx,
+ UNKNOWN_CLIPPY_LINTS,
+ lint.span(),
+ &format!("unknown clippy lint: clippy::{}", name),
+ |diag| {
+ let name_lower = name.as_str().to_lowercase();
+ let symbols = lint_store.get_lints().iter().map(
+ |l| Symbol::intern(&l.name_lower())
+ ).collect::>();
+ let sugg = find_best_match_for_name(
+ symbols.iter(),
+ &format!("clippy::{}", name_lower),
+ None,
+ );
+ if name.as_str().chars().any(char::is_uppercase)
+ && lint_store.find_lints(&format!("clippy::{}", name_lower)).is_ok() {
+ diag.span_suggestion(
+ lint.span(),
+ "lowercase the lint name",
+ format!("clippy::{}", name_lower),
+ Applicability::MachineApplicable,
+ );
+ } else if let Some(sugg) = sugg {
+ diag.span_suggestion(
+ lint.span(),
+ "did you mean",
+ sugg.to_string(),
+ Applicability::MachineApplicable,
+ );
+ }
+ }
+ );
+ }
+ };
+ }
+}
+
+fn is_relevant_item(cx: &LateContext<'_, '_>, item: &Item<'_>) -> bool {
+ if let ItemKind::Fn(_, _, eid) = item.kind {
+ is_relevant_expr(cx, cx.tcx.body_tables(eid), &cx.tcx.hir().body(eid).value)
+ } else {
+ true
+ }
+}
+
+fn is_relevant_impl(cx: &LateContext<'_, '_>, item: &ImplItem<'_>) -> bool {
+ match item.kind {
+ ImplItemKind::Fn(_, eid) => is_relevant_expr(cx, cx.tcx.body_tables(eid), &cx.tcx.hir().body(eid).value),
+ _ => false,
+ }
+}
+
+fn is_relevant_trait(cx: &LateContext<'_, '_>, item: &TraitItem<'_>) -> bool {
+ match item.kind {
+ TraitItemKind::Fn(_, TraitFn::Required(_)) => true,
+ TraitItemKind::Fn(_, TraitFn::Provided(eid)) => {
+ is_relevant_expr(cx, cx.tcx.body_tables(eid), &cx.tcx.hir().body(eid).value)
+ },
+ _ => false,
+ }
+}
+
+fn is_relevant_block(cx: &LateContext<'_, '_>, tables: &ty::TypeckTables<'_>, block: &Block<'_>) -> bool {
+ if let Some(stmt) = block.stmts.first() {
+ match &stmt.kind {
+ StmtKind::Local(_) => true,
+ StmtKind::Expr(expr) | StmtKind::Semi(expr) => is_relevant_expr(cx, tables, expr),
+ _ => false,
+ }
+ } else {
+ block.expr.as_ref().map_or(false, |e| is_relevant_expr(cx, tables, e))
+ }
+}
+
+fn is_relevant_expr(cx: &LateContext<'_, '_>, tables: &ty::TypeckTables<'_>, expr: &Expr<'_>) -> bool {
+ match &expr.kind {
+ ExprKind::Block(block, _) => is_relevant_block(cx, tables, block),
+ ExprKind::Ret(Some(e)) => is_relevant_expr(cx, tables, e),
+ ExprKind::Ret(None) | ExprKind::Break(_, None) => false,
+ ExprKind::Call(path_expr, _) => {
+ if let ExprKind::Path(qpath) = &path_expr.kind {
+ if let Some(fun_id) = tables.qpath_res(qpath, path_expr.hir_id).opt_def_id() {
+ !match_def_path(cx, fun_id, &paths::BEGIN_PANIC)
+ } else {
+ true
+ }
+ } else {
+ true
+ }
+ },
+ _ => true,
+ }
+}
+
+fn check_attrs(cx: &LateContext<'_, '_>, span: Span, name: Name, attrs: &[Attribute]) {
+ if span.from_expansion() {
+ return;
+ }
+
+ for attr in attrs {
+ let attr_item = if let AttrKind::Normal(ref attr) = attr.kind {
+ attr
+ } else {
+ continue;
+ };
+
+ if attr.style == AttrStyle::Outer {
+ if attr_item.args.inner_tokens().is_empty() || !is_present_in_source(cx, attr.span) {
+ return;
+ }
+
+ let begin_of_attr_to_item = Span::new(attr.span.lo(), span.lo(), span.ctxt());
+ let end_of_attr_to_item = Span::new(attr.span.hi(), span.lo(), span.ctxt());
+
+ if let Some(snippet) = snippet_opt(cx, end_of_attr_to_item) {
+ let lines = snippet.split('\n').collect::>();
+ let lines = without_block_comments(lines);
+
+ if lines.iter().filter(|l| l.trim().is_empty()).count() > 2 {
+ span_lint(
+ cx,
+ EMPTY_LINE_AFTER_OUTER_ATTR,
+ begin_of_attr_to_item,
+ "Found an empty line after an outer attribute. \
+ Perhaps you forgot to add a `!` to make it an inner attribute?",
+ );
+ }
+ }
+ }
+
+ if let Some(values) = attr.meta_item_list() {
+ if values.len() != 1 || !attr.check_name(sym!(inline)) {
+ continue;
+ }
+ if is_word(&values[0], sym!(always)) {
+ span_lint(
+ cx,
+ INLINE_ALWAYS,
+ attr.span,
+ &format!(
+ "you have declared `#[inline(always)]` on `{}`. This is usually a bad idea",
+ name
+ ),
+ );
+ }
+ }
+ }
+}
+
+fn check_semver(cx: &LateContext<'_, '_>, span: Span, lit: &Lit) {
+ if let LitKind::Str(is, _) = lit.kind {
+ if Version::parse(&is.as_str()).is_ok() {
+ return;
+ }
+ }
+ span_lint(
+ cx,
+ DEPRECATED_SEMVER,
+ span,
+ "the since field must contain a semver-compliant version",
+ );
+}
+
+fn is_word(nmi: &NestedMetaItem, expected: Symbol) -> bool {
+ if let NestedMetaItem::MetaItem(mi) = &nmi {
+ mi.is_word() && mi.check_name(expected)
+ } else {
+ false
+ }
+}
+
+declare_lint_pass!(EarlyAttributes => [DEPRECATED_CFG_ATTR, MISMATCHED_TARGET_OS]);
+
+impl EarlyLintPass for EarlyAttributes {
+ fn check_attribute(&mut self, cx: &EarlyContext<'_>, attr: &Attribute) {
+ check_deprecated_cfg_attr(cx, attr);
+ check_mismatched_target_os(cx, attr);
+ }
+}
+
+fn check_deprecated_cfg_attr(cx: &EarlyContext<'_>, attr: &Attribute) {
+ if_chain! {
+ // check cfg_attr
+ if attr.check_name(sym!(cfg_attr));
+ if let Some(items) = attr.meta_item_list();
+ if items.len() == 2;
+ // check for `rustfmt`
+ if let Some(feature_item) = items[0].meta_item();
+ if feature_item.check_name(sym!(rustfmt));
+ // check for `rustfmt_skip` and `rustfmt::skip`
+ if let Some(skip_item) = &items[1].meta_item();
+ if skip_item.check_name(sym!(rustfmt_skip)) ||
+ skip_item.path.segments.last().expect("empty path in attribute").ident.name == sym!(skip);
+ // Only lint outer attributes, because custom inner attributes are unstable
+ // Tracking issue: https://github.com/rust-lang/rust/issues/54726
+ if let AttrStyle::Outer = attr.style;
+ then {
+ span_lint_and_sugg(
+ cx,
+ DEPRECATED_CFG_ATTR,
+ attr.span,
+ "`cfg_attr` is deprecated for rustfmt and got replaced by tool attributes",
+ "use",
+ "#[rustfmt::skip]".to_string(),
+ Applicability::MachineApplicable,
+ );
+ }
+ }
+}
+
+fn check_mismatched_target_os(cx: &EarlyContext<'_>, attr: &Attribute) {
+ fn find_os(name: &str) -> Option<&'static str> {
+ UNIX_SYSTEMS
+ .iter()
+ .chain(NON_UNIX_SYSTEMS.iter())
+ .find(|&&os| os == name)
+ .copied()
+ }
+
+ fn is_unix(name: &str) -> bool {
+ UNIX_SYSTEMS.iter().any(|&os| os == name)
+ }
+
+ fn find_mismatched_target_os(items: &[NestedMetaItem]) -> Vec<(&str, Span)> {
+ let mut mismatched = Vec::new();
+
+ for item in items {
+ if let NestedMetaItem::MetaItem(meta) = item {
+ match &meta.kind {
+ MetaItemKind::List(list) => {
+ mismatched.extend(find_mismatched_target_os(&list));
+ },
+ MetaItemKind::Word => {
+ if_chain! {
+ if let Some(ident) = meta.ident();
+ if let Some(os) = find_os(&*ident.name.as_str());
+ then {
+ mismatched.push((os, ident.span));
+ }
+ }
+ },
+ _ => {},
+ }
+ }
+ }
+
+ mismatched
+ }
+
+ if_chain! {
+ if attr.check_name(sym!(cfg));
+ if let Some(list) = attr.meta_item_list();
+ let mismatched = find_mismatched_target_os(&list);
+ if !mismatched.is_empty();
+ then {
+ let mess = "operating system used in target family position";
+
+ span_lint_and_then(cx, MISMATCHED_TARGET_OS, attr.span, &mess, |diag| {
+ // Avoid showing the unix suggestion multiple times in case
+ // we have more than one mismatch for unix-like systems
+ let mut unix_suggested = false;
+
+ for (os, span) in mismatched {
+ let sugg = format!("target_os = \"{}\"", os);
+ diag.span_suggestion(span, "try", sugg, Applicability::MaybeIncorrect);
+
+ if !unix_suggested && is_unix(os) {
+ diag.help("Did you mean `unix`?");
+ unix_suggested = true;
+ }
+ }
+ });
+ }
+ }
+}
diff --git a/src/tools/clippy/clippy_lints/src/await_holding_lock.rs b/src/tools/clippy/clippy_lints/src/await_holding_lock.rs
new file mode 100644
index 00000000000..832910763e6
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/await_holding_lock.rs
@@ -0,0 +1,97 @@
+use crate::utils::{match_def_path, paths, span_lint_and_note};
+use rustc_hir::def_id::DefId;
+use rustc_hir::{AsyncGeneratorKind, Body, BodyId, GeneratorKind};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty::GeneratorInteriorTypeCause;
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::Span;
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for calls to await while holding a
+ /// non-async-aware MutexGuard.
+ ///
+ /// **Why is this bad?** The Mutex types found in syd::sync and parking_lot
+ /// are not designed to operator in an async context across await points.
+ ///
+ /// There are two potential solutions. One is to use an asynx-aware Mutex
+ /// type. Many asynchronous foundation crates provide such a Mutex type. The
+ /// other solution is to ensure the mutex is unlocked before calling await,
+ /// either by introducing a scope or an explicit call to Drop::drop.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ ///
+ /// ```rust,ignore
+ /// use std::sync::Mutex;
+ ///
+ /// async fn foo(x: &Mutex) {
+ /// let guard = x.lock().unwrap();
+ /// *guard += 1;
+ /// bar.await;
+ /// }
+ /// ```
+ ///
+ /// Use instead:
+ /// ```rust,ignore
+ /// use std::sync::Mutex;
+ ///
+ /// async fn foo(x: &Mutex) {
+ /// {
+ /// let guard = x.lock().unwrap();
+ /// *guard += 1;
+ /// }
+ /// bar.await;
+ /// }
+ /// ```
+ pub AWAIT_HOLDING_LOCK,
+ pedantic,
+ "Inside an async function, holding a MutexGuard while calling await"
+}
+
+declare_lint_pass!(AwaitHoldingLock => [AWAIT_HOLDING_LOCK]);
+
+impl LateLintPass<'_, '_> for AwaitHoldingLock {
+ fn check_body(&mut self, cx: &LateContext<'_, '_>, body: &'_ Body<'_>) {
+ use AsyncGeneratorKind::{Block, Closure, Fn};
+ match body.generator_kind {
+ Some(GeneratorKind::Async(Block))
+ | Some(GeneratorKind::Async(Closure))
+ | Some(GeneratorKind::Async(Fn)) => {
+ let body_id = BodyId {
+ hir_id: body.value.hir_id,
+ };
+ let def_id = cx.tcx.hir().body_owner_def_id(body_id);
+ let tables = cx.tcx.typeck_tables_of(def_id);
+ check_interior_types(cx, &tables.generator_interior_types, body.value.span);
+ },
+ _ => {},
+ }
+ }
+}
+
+fn check_interior_types(cx: &LateContext<'_, '_>, ty_causes: &[GeneratorInteriorTypeCause<'_>], span: Span) {
+ for ty_cause in ty_causes {
+ if let rustc_middle::ty::Adt(adt, _) = ty_cause.ty.kind {
+ if is_mutex_guard(cx, adt.did) {
+ span_lint_and_note(
+ cx,
+ AWAIT_HOLDING_LOCK,
+ ty_cause.span,
+ "this MutexGuard is held across an 'await' point. Consider using an async-aware Mutex type or ensuring the MutexGuard is dropped before calling await.",
+ ty_cause.scope_span.or(Some(span)),
+ "these are all the await points this lock is held through",
+ );
+ }
+ }
+ }
+}
+
+fn is_mutex_guard(cx: &LateContext<'_, '_>, def_id: DefId) -> bool {
+ match_def_path(cx, def_id, &paths::MUTEX_GUARD)
+ || match_def_path(cx, def_id, &paths::RWLOCK_READ_GUARD)
+ || match_def_path(cx, def_id, &paths::RWLOCK_WRITE_GUARD)
+ || match_def_path(cx, def_id, &paths::PARKING_LOT_MUTEX_GUARD)
+ || match_def_path(cx, def_id, &paths::PARKING_LOT_RWLOCK_READ_GUARD)
+ || match_def_path(cx, def_id, &paths::PARKING_LOT_RWLOCK_WRITE_GUARD)
+}
diff --git a/src/tools/clippy/clippy_lints/src/bit_mask.rs b/src/tools/clippy/clippy_lints/src/bit_mask.rs
new file mode 100644
index 00000000000..ccb62cb038f
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/bit_mask.rs
@@ -0,0 +1,326 @@
+use crate::consts::{constant, Constant};
+use crate::utils::sugg::Sugg;
+use crate::utils::{span_lint, span_lint_and_then};
+use if_chain::if_chain;
+use rustc_ast::ast::LitKind;
+use rustc_errors::Applicability;
+use rustc_hir::{BinOpKind, Expr, ExprKind};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_tool_lint, impl_lint_pass};
+use rustc_span::source_map::Span;
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for incompatible bit masks in comparisons.
+ ///
+ /// The formula for detecting if an expression of the type `_ m
+ /// c` (where `` is one of {`&`, `|`} and `` is one of
+ /// {`!=`, `>=`, `>`, `!=`, `>=`, `>`}) can be determined from the following
+ /// table:
+ ///
+ /// |Comparison |Bit Op|Example |is always|Formula |
+ /// |------------|------|------------|---------|----------------------|
+ /// |`==` or `!=`| `&` |`x & 2 == 3`|`false` |`c & m != c` |
+ /// |`<` or `>=`| `&` |`x & 2 < 3` |`true` |`m < c` |
+ /// |`>` or `<=`| `&` |`x & 1 > 1` |`false` |`m <= c` |
+ /// |`==` or `!=`| `|` |`x | 1 == 0`|`false` |`c | m != c` |
+ /// |`<` or `>=`| `|` |`x | 1 < 1` |`false` |`m >= c` |
+ /// |`<=` or `>` | `|` |`x | 1 > 0` |`true` |`m > c` |
+ ///
+ /// **Why is this bad?** If the bits that the comparison cares about are always
+ /// set to zero or one by the bit mask, the comparison is constant `true` or
+ /// `false` (depending on mask, compared value, and operators).
+ ///
+ /// So the code is actively misleading, and the only reason someone would write
+ /// this intentionally is to win an underhanded Rust contest or create a
+ /// test-case for this lint.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```rust
+ /// # let x = 1;
+ /// if (x & 1 == 2) { }
+ /// ```
+ pub BAD_BIT_MASK,
+ correctness,
+ "expressions of the form `_ & mask == select` that will only ever return `true` or `false`"
+}
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for bit masks in comparisons which can be removed
+ /// without changing the outcome. The basic structure can be seen in the
+ /// following table:
+ ///
+ /// |Comparison| Bit Op |Example |equals |
+ /// |----------|---------|-----------|-------|
+ /// |`>` / `<=`|`|` / `^`|`x | 2 > 3`|`x > 3`|
+ /// |`<` / `>=`|`|` / `^`|`x ^ 1 < 4`|`x < 4`|
+ ///
+ /// **Why is this bad?** Not equally evil as [`bad_bit_mask`](#bad_bit_mask),
+ /// but still a bit misleading, because the bit mask is ineffective.
+ ///
+ /// **Known problems:** False negatives: This lint will only match instances
+ /// where we have figured out the math (which is for a power-of-two compared
+ /// value). This means things like `x | 1 >= 7` (which would be better written
+ /// as `x >= 6`) will not be reported (but bit masks like this are fairly
+ /// uncommon).
+ ///
+ /// **Example:**
+ /// ```rust
+ /// # let x = 1;
+ /// if (x | 1 > 3) { }
+ /// ```
+ pub INEFFECTIVE_BIT_MASK,
+ correctness,
+ "expressions where a bit mask will be rendered useless by a comparison, e.g., `(x | 1) > 2`"
+}
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for bit masks that can be replaced by a call
+ /// to `trailing_zeros`
+ ///
+ /// **Why is this bad?** `x.trailing_zeros() > 4` is much clearer than `x & 15
+ /// == 0`
+ ///
+ /// **Known problems:** llvm generates better code for `x & 15 == 0` on x86
+ ///
+ /// **Example:**
+ /// ```rust
+ /// # let x = 1;
+ /// if x & 0b1111 == 0 { }
+ /// ```
+ pub VERBOSE_BIT_MASK,
+ style,
+ "expressions where a bit mask is less readable than the corresponding method call"
+}
+
+#[derive(Copy, Clone)]
+pub struct BitMask {
+ verbose_bit_mask_threshold: u64,
+}
+
+impl BitMask {
+ #[must_use]
+ pub fn new(verbose_bit_mask_threshold: u64) -> Self {
+ Self {
+ verbose_bit_mask_threshold,
+ }
+ }
+}
+
+impl_lint_pass!(BitMask => [BAD_BIT_MASK, INEFFECTIVE_BIT_MASK, VERBOSE_BIT_MASK]);
+
+impl<'a, 'tcx> LateLintPass<'a, 'tcx> for BitMask {
+ fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, e: &'tcx Expr<'_>) {
+ if let ExprKind::Binary(cmp, left, right) = &e.kind {
+ if cmp.node.is_comparison() {
+ if let Some(cmp_opt) = fetch_int_literal(cx, right) {
+ check_compare(cx, left, cmp.node, cmp_opt, e.span)
+ } else if let Some(cmp_val) = fetch_int_literal(cx, left) {
+ check_compare(cx, right, invert_cmp(cmp.node), cmp_val, e.span)
+ }
+ }
+ }
+ if_chain! {
+ if let ExprKind::Binary(op, left, right) = &e.kind;
+ if BinOpKind::Eq == op.node;
+ if let ExprKind::Binary(op1, left1, right1) = &left.kind;
+ if BinOpKind::BitAnd == op1.node;
+ if let ExprKind::Lit(lit) = &right1.kind;
+ if let LitKind::Int(n, _) = lit.node;
+ if let ExprKind::Lit(lit1) = &right.kind;
+ if let LitKind::Int(0, _) = lit1.node;
+ if n.leading_zeros() == n.count_zeros();
+ if n > u128::from(self.verbose_bit_mask_threshold);
+ then {
+ span_lint_and_then(cx,
+ VERBOSE_BIT_MASK,
+ e.span,
+ "bit mask could be simplified with a call to `trailing_zeros`",
+ |diag| {
+ let sugg = Sugg::hir(cx, left1, "...").maybe_par();
+ diag.span_suggestion(
+ e.span,
+ "try",
+ format!("{}.trailing_zeros() >= {}", sugg, n.count_ones()),
+ Applicability::MaybeIncorrect,
+ );
+ });
+ }
+ }
+ }
+}
+
+#[must_use]
+fn invert_cmp(cmp: BinOpKind) -> BinOpKind {
+ match cmp {
+ BinOpKind::Eq => BinOpKind::Eq,
+ BinOpKind::Ne => BinOpKind::Ne,
+ BinOpKind::Lt => BinOpKind::Gt,
+ BinOpKind::Gt => BinOpKind::Lt,
+ BinOpKind::Le => BinOpKind::Ge,
+ BinOpKind::Ge => BinOpKind::Le,
+ _ => BinOpKind::Or, // Dummy
+ }
+}
+
+fn check_compare(cx: &LateContext<'_, '_>, bit_op: &Expr<'_>, cmp_op: BinOpKind, cmp_value: u128, span: Span) {
+ if let ExprKind::Binary(op, left, right) = &bit_op.kind {
+ if op.node != BinOpKind::BitAnd && op.node != BinOpKind::BitOr {
+ return;
+ }
+ fetch_int_literal(cx, right)
+ .or_else(|| fetch_int_literal(cx, left))
+ .map_or((), |mask| check_bit_mask(cx, op.node, cmp_op, mask, cmp_value, span))
+ }
+}
+
+#[allow(clippy::too_many_lines)]
+fn check_bit_mask(
+ cx: &LateContext<'_, '_>,
+ bit_op: BinOpKind,
+ cmp_op: BinOpKind,
+ mask_value: u128,
+ cmp_value: u128,
+ span: Span,
+) {
+ match cmp_op {
+ BinOpKind::Eq | BinOpKind::Ne => match bit_op {
+ BinOpKind::BitAnd => {
+ if mask_value & cmp_value != cmp_value {
+ if cmp_value != 0 {
+ span_lint(
+ cx,
+ BAD_BIT_MASK,
+ span,
+ &format!(
+ "incompatible bit mask: `_ & {}` can never be equal to `{}`",
+ mask_value, cmp_value
+ ),
+ );
+ }
+ } else if mask_value == 0 {
+ span_lint(cx, BAD_BIT_MASK, span, "&-masking with zero");
+ }
+ },
+ BinOpKind::BitOr => {
+ if mask_value | cmp_value != cmp_value {
+ span_lint(
+ cx,
+ BAD_BIT_MASK,
+ span,
+ &format!(
+ "incompatible bit mask: `_ | {}` can never be equal to `{}`",
+ mask_value, cmp_value
+ ),
+ );
+ }
+ },
+ _ => (),
+ },
+ BinOpKind::Lt | BinOpKind::Ge => match bit_op {
+ BinOpKind::BitAnd => {
+ if mask_value < cmp_value {
+ span_lint(
+ cx,
+ BAD_BIT_MASK,
+ span,
+ &format!(
+ "incompatible bit mask: `_ & {}` will always be lower than `{}`",
+ mask_value, cmp_value
+ ),
+ );
+ } else if mask_value == 0 {
+ span_lint(cx, BAD_BIT_MASK, span, "&-masking with zero");
+ }
+ },
+ BinOpKind::BitOr => {
+ if mask_value >= cmp_value {
+ span_lint(
+ cx,
+ BAD_BIT_MASK,
+ span,
+ &format!(
+ "incompatible bit mask: `_ | {}` will never be lower than `{}`",
+ mask_value, cmp_value
+ ),
+ );
+ } else {
+ check_ineffective_lt(cx, span, mask_value, cmp_value, "|");
+ }
+ },
+ BinOpKind::BitXor => check_ineffective_lt(cx, span, mask_value, cmp_value, "^"),
+ _ => (),
+ },
+ BinOpKind::Le | BinOpKind::Gt => match bit_op {
+ BinOpKind::BitAnd => {
+ if mask_value <= cmp_value {
+ span_lint(
+ cx,
+ BAD_BIT_MASK,
+ span,
+ &format!(
+ "incompatible bit mask: `_ & {}` will never be higher than `{}`",
+ mask_value, cmp_value
+ ),
+ );
+ } else if mask_value == 0 {
+ span_lint(cx, BAD_BIT_MASK, span, "&-masking with zero");
+ }
+ },
+ BinOpKind::BitOr => {
+ if mask_value > cmp_value {
+ span_lint(
+ cx,
+ BAD_BIT_MASK,
+ span,
+ &format!(
+ "incompatible bit mask: `_ | {}` will always be higher than `{}`",
+ mask_value, cmp_value
+ ),
+ );
+ } else {
+ check_ineffective_gt(cx, span, mask_value, cmp_value, "|");
+ }
+ },
+ BinOpKind::BitXor => check_ineffective_gt(cx, span, mask_value, cmp_value, "^"),
+ _ => (),
+ },
+ _ => (),
+ }
+}
+
+fn check_ineffective_lt(cx: &LateContext<'_, '_>, span: Span, m: u128, c: u128, op: &str) {
+ if c.is_power_of_two() && m < c {
+ span_lint(
+ cx,
+ INEFFECTIVE_BIT_MASK,
+ span,
+ &format!(
+ "ineffective bit mask: `x {} {}` compared to `{}`, is the same as x compared directly",
+ op, m, c
+ ),
+ );
+ }
+}
+
+fn check_ineffective_gt(cx: &LateContext<'_, '_>, span: Span, m: u128, c: u128, op: &str) {
+ if (c + 1).is_power_of_two() && m <= c {
+ span_lint(
+ cx,
+ INEFFECTIVE_BIT_MASK,
+ span,
+ &format!(
+ "ineffective bit mask: `x {} {}` compared to `{}`, is the same as x compared directly",
+ op, m, c
+ ),
+ );
+ }
+}
+
+fn fetch_int_literal(cx: &LateContext<'_, '_>, lit: &Expr<'_>) -> Option {
+ match constant(cx, cx.tables, lit)?.0 {
+ Constant::Int(n) => Some(n),
+ _ => None,
+ }
+}
diff --git a/src/tools/clippy/clippy_lints/src/blacklisted_name.rs b/src/tools/clippy/clippy_lints/src/blacklisted_name.rs
new file mode 100644
index 00000000000..6f26f031431
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/blacklisted_name.rs
@@ -0,0 +1,51 @@
+use crate::utils::span_lint;
+use rustc_data_structures::fx::FxHashSet;
+use rustc_hir::{Pat, PatKind};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_tool_lint, impl_lint_pass};
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for usage of blacklisted names for variables, such
+ /// as `foo`.
+ ///
+ /// **Why is this bad?** These names are usually placeholder names and should be
+ /// avoided.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```rust
+ /// let foo = 3.14;
+ /// ```
+ pub BLACKLISTED_NAME,
+ style,
+ "usage of a blacklisted/placeholder name"
+}
+
+#[derive(Clone, Debug)]
+pub struct BlacklistedName {
+ blacklist: FxHashSet,
+}
+
+impl BlacklistedName {
+ pub fn new(blacklist: FxHashSet) -> Self {
+ Self { blacklist }
+ }
+}
+
+impl_lint_pass!(BlacklistedName => [BLACKLISTED_NAME]);
+
+impl<'a, 'tcx> LateLintPass<'a, 'tcx> for BlacklistedName {
+ fn check_pat(&mut self, cx: &LateContext<'a, 'tcx>, pat: &'tcx Pat<'_>) {
+ if let PatKind::Binding(.., ident, _) = pat.kind {
+ if self.blacklist.contains(&ident.name.to_string()) {
+ span_lint(
+ cx,
+ BLACKLISTED_NAME,
+ ident.span,
+ &format!("use of a blacklisted/placeholder name `{}`", ident.name),
+ );
+ }
+ }
+ }
+}
diff --git a/src/tools/clippy/clippy_lints/src/block_in_if_condition.rs b/src/tools/clippy/clippy_lints/src/block_in_if_condition.rs
new file mode 100644
index 00000000000..9e533eaa32c
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/block_in_if_condition.rs
@@ -0,0 +1,148 @@
+use crate::utils::{differing_macro_contexts, higher, snippet_block_with_applicability, span_lint, span_lint_and_sugg};
+use rustc_errors::Applicability;
+use rustc_hir::intravisit::{walk_expr, NestedVisitorMap, Visitor};
+use rustc_hir::{BlockCheckMode, Expr, ExprKind};
+use rustc_lint::{LateContext, LateLintPass, LintContext};
+use rustc_middle::hir::map::Map;
+use rustc_middle::lint::in_external_macro;
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for `if` conditions that use blocks to contain an
+ /// expression.
+ ///
+ /// **Why is this bad?** It isn't really Rust style, same as using parentheses
+ /// to contain expressions.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```rust
+ /// if { true } { /* ... */ }
+ /// ```
+ pub BLOCK_IN_IF_CONDITION_EXPR,
+ style,
+ "braces that can be eliminated in conditions, e.g., `if { true } ...`"
+}
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for `if` conditions that use blocks containing
+ /// statements, or conditions that use closures with blocks.
+ ///
+ /// **Why is this bad?** Using blocks in the condition makes it hard to read.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```rust,ignore
+ /// if { let x = somefunc(); x } {}
+ /// // or
+ /// if somefunc(|x| { x == 47 }) {}
+ /// ```
+ pub BLOCK_IN_IF_CONDITION_STMT,
+ style,
+ "complex blocks in conditions, e.g., `if { let x = true; x } ...`"
+}
+
+declare_lint_pass!(BlockInIfCondition => [BLOCK_IN_IF_CONDITION_EXPR, BLOCK_IN_IF_CONDITION_STMT]);
+
+struct ExVisitor<'a, 'tcx> {
+ found_block: Option<&'tcx Expr<'tcx>>,
+ cx: &'a LateContext<'a, 'tcx>,
+}
+
+impl<'a, 'tcx> Visitor<'tcx> for ExVisitor<'a, 'tcx> {
+ type Map = Map<'tcx>;
+
+ fn visit_expr(&mut self, expr: &'tcx Expr<'tcx>) {
+ if let ExprKind::Closure(_, _, eid, _, _) = expr.kind {
+ let body = self.cx.tcx.hir().body(eid);
+ let ex = &body.value;
+ if matches!(ex.kind, ExprKind::Block(_, _)) && !body.value.span.from_expansion() {
+ self.found_block = Some(ex);
+ return;
+ }
+ }
+ walk_expr(self, expr);
+ }
+ fn nested_visit_map(&mut self) -> NestedVisitorMap {
+ NestedVisitorMap::None
+ }
+}
+
+const BRACED_EXPR_MESSAGE: &str = "omit braces around single expression condition";
+const COMPLEX_BLOCK_MESSAGE: &str = "in an `if` condition, avoid complex blocks or closures with blocks; \
+ instead, move the block or closure higher and bind it with a `let`";
+
+impl<'a, 'tcx> LateLintPass<'a, 'tcx> for BlockInIfCondition {
+ fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr<'_>) {
+ if in_external_macro(cx.sess(), expr.span) {
+ return;
+ }
+ if let Some((cond, _, _)) = higher::if_block(&expr) {
+ if let ExprKind::Block(block, _) = &cond.kind {
+ if block.rules == BlockCheckMode::DefaultBlock {
+ if block.stmts.is_empty() {
+ if let Some(ex) = &block.expr {
+ // don't dig into the expression here, just suggest that they remove
+ // the block
+ if expr.span.from_expansion() || differing_macro_contexts(expr.span, ex.span) {
+ return;
+ }
+ let mut applicability = Applicability::MachineApplicable;
+ span_lint_and_sugg(
+ cx,
+ BLOCK_IN_IF_CONDITION_EXPR,
+ cond.span,
+ BRACED_EXPR_MESSAGE,
+ "try",
+ format!(
+ "{}",
+ snippet_block_with_applicability(
+ cx,
+ ex.span,
+ "..",
+ Some(expr.span),
+ &mut applicability
+ )
+ ),
+ applicability,
+ );
+ }
+ } else {
+ let span = block.expr.as_ref().map_or_else(|| block.stmts[0].span, |e| e.span);
+ if span.from_expansion() || differing_macro_contexts(expr.span, span) {
+ return;
+ }
+ // move block higher
+ let mut applicability = Applicability::MachineApplicable;
+ span_lint_and_sugg(
+ cx,
+ BLOCK_IN_IF_CONDITION_STMT,
+ expr.span.with_hi(cond.span.hi()),
+ COMPLEX_BLOCK_MESSAGE,
+ "try",
+ format!(
+ "let res = {}; if res",
+ snippet_block_with_applicability(
+ cx,
+ block.span,
+ "..",
+ Some(expr.span),
+ &mut applicability
+ ),
+ ),
+ applicability,
+ );
+ }
+ }
+ } else {
+ let mut visitor = ExVisitor { found_block: None, cx };
+ walk_expr(&mut visitor, cond);
+ if let Some(block) = visitor.found_block {
+ span_lint(cx, BLOCK_IN_IF_CONDITION_STMT, block.span, COMPLEX_BLOCK_MESSAGE);
+ }
+ }
+ }
+ }
+}
diff --git a/src/tools/clippy/clippy_lints/src/booleans.rs b/src/tools/clippy/clippy_lints/src/booleans.rs
new file mode 100644
index 00000000000..8031052e073
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/booleans.rs
@@ -0,0 +1,499 @@
+use crate::utils::{
+ get_trait_def_id, implements_trait, in_macro, is_type_diagnostic_item, paths, snippet_opt, span_lint_and_sugg,
+ span_lint_and_then, SpanlessEq,
+};
+use if_chain::if_chain;
+use rustc_ast::ast::LitKind;
+use rustc_errors::Applicability;
+use rustc_hir::intravisit::{walk_expr, FnKind, NestedVisitorMap, Visitor};
+use rustc_hir::{BinOpKind, Body, Expr, ExprKind, FnDecl, HirId, UnOp};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::hir::map::Map;
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::source_map::Span;
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for boolean expressions that can be written more
+ /// concisely.
+ ///
+ /// **Why is this bad?** Readability of boolean expressions suffers from
+ /// unnecessary duplication.
+ ///
+ /// **Known problems:** Ignores short circuiting behavior of `||` and
+ /// `&&`. Ignores `|`, `&` and `^`.
+ ///
+ /// **Example:**
+ /// ```ignore
+ /// if a && true // should be: if a
+ /// if !(a == b) // should be: if a != b
+ /// ```
+ pub NONMINIMAL_BOOL,
+ complexity,
+ "boolean expressions that can be written more concisely"
+}
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for boolean expressions that contain terminals that
+ /// can be eliminated.
+ ///
+ /// **Why is this bad?** This is most likely a logic bug.
+ ///
+ /// **Known problems:** Ignores short circuiting behavior.
+ ///
+ /// **Example:**
+ /// ```ignore
+ /// if a && b || a { ... }
+ /// ```
+ /// The `b` is unnecessary, the expression is equivalent to `if a`.
+ pub LOGIC_BUG,
+ correctness,
+ "boolean expressions that contain terminals which can be eliminated"
+}
+
+// For each pairs, both orders are considered.
+const METHODS_WITH_NEGATION: [(&str, &str); 2] = [("is_some", "is_none"), ("is_err", "is_ok")];
+
+declare_lint_pass!(NonminimalBool => [NONMINIMAL_BOOL, LOGIC_BUG]);
+
+impl<'a, 'tcx> LateLintPass<'a, 'tcx> for NonminimalBool {
+ fn check_fn(
+ &mut self,
+ cx: &LateContext<'a, 'tcx>,
+ _: FnKind<'tcx>,
+ _: &'tcx FnDecl<'_>,
+ body: &'tcx Body<'_>,
+ _: Span,
+ _: HirId,
+ ) {
+ NonminimalBoolVisitor { cx }.visit_body(body)
+ }
+}
+
+struct NonminimalBoolVisitor<'a, 'tcx> {
+ cx: &'a LateContext<'a, 'tcx>,
+}
+
+use quine_mc_cluskey::Bool;
+struct Hir2Qmm<'a, 'tcx, 'v> {
+ terminals: Vec<&'v Expr<'v>>,
+ cx: &'a LateContext<'a, 'tcx>,
+}
+
+impl<'a, 'tcx, 'v> Hir2Qmm<'a, 'tcx, 'v> {
+ fn extract(&mut self, op: BinOpKind, a: &[&'v Expr<'_>], mut v: Vec) -> Result, String> {
+ for a in a {
+ if let ExprKind::Binary(binop, lhs, rhs) = &a.kind {
+ if binop.node == op {
+ v = self.extract(op, &[lhs, rhs], v)?;
+ continue;
+ }
+ }
+ v.push(self.run(a)?);
+ }
+ Ok(v)
+ }
+
+ fn run(&mut self, e: &'v Expr<'_>) -> Result {
+ fn negate(bin_op_kind: BinOpKind) -> Option {
+ match bin_op_kind {
+ BinOpKind::Eq => Some(BinOpKind::Ne),
+ BinOpKind::Ne => Some(BinOpKind::Eq),
+ BinOpKind::Gt => Some(BinOpKind::Le),
+ BinOpKind::Ge => Some(BinOpKind::Lt),
+ BinOpKind::Lt => Some(BinOpKind::Ge),
+ BinOpKind::Le => Some(BinOpKind::Gt),
+ _ => None,
+ }
+ }
+
+ // prevent folding of `cfg!` macros and the like
+ if !e.span.from_expansion() {
+ match &e.kind {
+ ExprKind::Unary(UnOp::UnNot, inner) => return Ok(Bool::Not(box self.run(inner)?)),
+ ExprKind::Binary(binop, lhs, rhs) => match &binop.node {
+ BinOpKind::Or => return Ok(Bool::Or(self.extract(BinOpKind::Or, &[lhs, rhs], Vec::new())?)),
+ BinOpKind::And => return Ok(Bool::And(self.extract(BinOpKind::And, &[lhs, rhs], Vec::new())?)),
+ _ => (),
+ },
+ ExprKind::Lit(lit) => match lit.node {
+ LitKind::Bool(true) => return Ok(Bool::True),
+ LitKind::Bool(false) => return Ok(Bool::False),
+ _ => (),
+ },
+ _ => (),
+ }
+ }
+ for (n, expr) in self.terminals.iter().enumerate() {
+ if SpanlessEq::new(self.cx).ignore_fn().eq_expr(e, expr) {
+ #[allow(clippy::cast_possible_truncation)]
+ return Ok(Bool::Term(n as u8));
+ }
+
+ if_chain! {
+ if let ExprKind::Binary(e_binop, e_lhs, e_rhs) = &e.kind;
+ if implements_ord(self.cx, e_lhs);
+ if let ExprKind::Binary(expr_binop, expr_lhs, expr_rhs) = &expr.kind;
+ if negate(e_binop.node) == Some(expr_binop.node);
+ if SpanlessEq::new(self.cx).ignore_fn().eq_expr(e_lhs, expr_lhs);
+ if SpanlessEq::new(self.cx).ignore_fn().eq_expr(e_rhs, expr_rhs);
+ then {
+ #[allow(clippy::cast_possible_truncation)]
+ return Ok(Bool::Not(Box::new(Bool::Term(n as u8))));
+ }
+ }
+ }
+ let n = self.terminals.len();
+ self.terminals.push(e);
+ if n < 32 {
+ #[allow(clippy::cast_possible_truncation)]
+ Ok(Bool::Term(n as u8))
+ } else {
+ Err("too many literals".to_owned())
+ }
+ }
+}
+
+struct SuggestContext<'a, 'tcx, 'v> {
+ terminals: &'v [&'v Expr<'v>],
+ cx: &'a LateContext<'a, 'tcx>,
+ output: String,
+}
+
+impl<'a, 'tcx, 'v> SuggestContext<'a, 'tcx, 'v> {
+ fn recurse(&mut self, suggestion: &Bool) -> Option<()> {
+ use quine_mc_cluskey::Bool::{And, False, Not, Or, Term, True};
+ match suggestion {
+ True => {
+ self.output.push_str("true");
+ },
+ False => {
+ self.output.push_str("false");
+ },
+ Not(inner) => match **inner {
+ And(_) | Or(_) => {
+ self.output.push('!');
+ self.output.push('(');
+ self.recurse(inner);
+ self.output.push(')');
+ },
+ Term(n) => {
+ let terminal = self.terminals[n as usize];
+ if let Some(str) = simplify_not(self.cx, terminal) {
+ self.output.push_str(&str)
+ } else {
+ self.output.push('!');
+ let snip = snippet_opt(self.cx, terminal.span)?;
+ self.output.push_str(&snip);
+ }
+ },
+ True | False | Not(_) => {
+ self.output.push('!');
+ self.recurse(inner)?;
+ },
+ },
+ And(v) => {
+ for (index, inner) in v.iter().enumerate() {
+ if index > 0 {
+ self.output.push_str(" && ");
+ }
+ if let Or(_) = *inner {
+ self.output.push('(');
+ self.recurse(inner);
+ self.output.push(')');
+ } else {
+ self.recurse(inner);
+ }
+ }
+ },
+ Or(v) => {
+ for (index, inner) in v.iter().rev().enumerate() {
+ if index > 0 {
+ self.output.push_str(" || ");
+ }
+ self.recurse(inner);
+ }
+ },
+ &Term(n) => {
+ let snip = snippet_opt(self.cx, self.terminals[n as usize].span)?;
+ self.output.push_str(&snip);
+ },
+ }
+ Some(())
+ }
+}
+
+fn simplify_not(cx: &LateContext<'_, '_>, expr: &Expr<'_>) -> Option {
+ match &expr.kind {
+ ExprKind::Binary(binop, lhs, rhs) => {
+ if !implements_ord(cx, lhs) {
+ return None;
+ }
+
+ match binop.node {
+ BinOpKind::Eq => Some(" != "),
+ BinOpKind::Ne => Some(" == "),
+ BinOpKind::Lt => Some(" >= "),
+ BinOpKind::Gt => Some(" <= "),
+ BinOpKind::Le => Some(" > "),
+ BinOpKind::Ge => Some(" < "),
+ _ => None,
+ }
+ .and_then(|op| {
+ Some(format!(
+ "{}{}{}",
+ snippet_opt(cx, lhs.span)?,
+ op,
+ snippet_opt(cx, rhs.span)?
+ ))
+ })
+ },
+ ExprKind::MethodCall(path, _, args) if args.len() == 1 => {
+ let type_of_receiver = cx.tables.expr_ty(&args[0]);
+ if !is_type_diagnostic_item(cx, type_of_receiver, sym!(option_type))
+ && !is_type_diagnostic_item(cx, type_of_receiver, sym!(result_type))
+ {
+ return None;
+ }
+ METHODS_WITH_NEGATION
+ .iter()
+ .cloned()
+ .flat_map(|(a, b)| vec![(a, b), (b, a)])
+ .find(|&(a, _)| {
+ let path: &str = &path.ident.name.as_str();
+ a == path
+ })
+ .and_then(|(_, neg_method)| Some(format!("{}.{}()", snippet_opt(cx, args[0].span)?, neg_method)))
+ },
+ _ => None,
+ }
+}
+
+fn suggest(cx: &LateContext<'_, '_>, suggestion: &Bool, terminals: &[&Expr<'_>]) -> String {
+ let mut suggest_context = SuggestContext {
+ terminals,
+ cx,
+ output: String::new(),
+ };
+ suggest_context.recurse(suggestion);
+ suggest_context.output
+}
+
+fn simple_negate(b: Bool) -> Bool {
+ use quine_mc_cluskey::Bool::{And, False, Not, Or, Term, True};
+ match b {
+ True => False,
+ False => True,
+ t @ Term(_) => Not(Box::new(t)),
+ And(mut v) => {
+ for el in &mut v {
+ *el = simple_negate(::std::mem::replace(el, True));
+ }
+ Or(v)
+ },
+ Or(mut v) => {
+ for el in &mut v {
+ *el = simple_negate(::std::mem::replace(el, True));
+ }
+ And(v)
+ },
+ Not(inner) => *inner,
+ }
+}
+
+#[derive(Default)]
+struct Stats {
+ terminals: [usize; 32],
+ negations: usize,
+ ops: usize,
+}
+
+fn terminal_stats(b: &Bool) -> Stats {
+ fn recurse(b: &Bool, stats: &mut Stats) {
+ match b {
+ True | False => stats.ops += 1,
+ Not(inner) => {
+ match **inner {
+ And(_) | Or(_) => stats.ops += 1, // brackets are also operations
+ _ => stats.negations += 1,
+ }
+ recurse(inner, stats);
+ },
+ And(v) | Or(v) => {
+ stats.ops += v.len() - 1;
+ for inner in v {
+ recurse(inner, stats);
+ }
+ },
+ &Term(n) => stats.terminals[n as usize] += 1,
+ }
+ }
+ use quine_mc_cluskey::Bool::{And, False, Not, Or, Term, True};
+ let mut stats = Stats::default();
+ recurse(b, &mut stats);
+ stats
+}
+
+impl<'a, 'tcx> NonminimalBoolVisitor<'a, 'tcx> {
+ fn bool_expr(&self, e: &'tcx Expr<'_>) {
+ let mut h2q = Hir2Qmm {
+ terminals: Vec::new(),
+ cx: self.cx,
+ };
+ if let Ok(expr) = h2q.run(e) {
+ if h2q.terminals.len() > 8 {
+ // QMC has exponentially slow behavior as the number of terminals increases
+ // 8 is reasonable, it takes approximately 0.2 seconds.
+ // See #825
+ return;
+ }
+
+ let stats = terminal_stats(&expr);
+ let mut simplified = expr.simplify();
+ for simple in Bool::Not(Box::new(expr)).simplify() {
+ match simple {
+ Bool::Not(_) | Bool::True | Bool::False => {},
+ _ => simplified.push(Bool::Not(Box::new(simple.clone()))),
+ }
+ let simple_negated = simple_negate(simple);
+ if simplified.iter().any(|s| *s == simple_negated) {
+ continue;
+ }
+ simplified.push(simple_negated);
+ }
+ let mut improvements = Vec::with_capacity(simplified.len());
+ 'simplified: for suggestion in &simplified {
+ let simplified_stats = terminal_stats(suggestion);
+ let mut improvement = false;
+ for i in 0..32 {
+ // ignore any "simplifications" that end up requiring a terminal more often
+ // than in the original expression
+ if stats.terminals[i] < simplified_stats.terminals[i] {
+ continue 'simplified;
+ }
+ if stats.terminals[i] != 0 && simplified_stats.terminals[i] == 0 {
+ span_lint_and_then(
+ self.cx,
+ LOGIC_BUG,
+ e.span,
+ "this boolean expression contains a logic bug",
+ |diag| {
+ diag.span_help(
+ h2q.terminals[i].span,
+ "this expression can be optimized out by applying boolean operations to the \
+ outer expression",
+ );
+ diag.span_suggestion(
+ e.span,
+ "it would look like the following",
+ suggest(self.cx, suggestion, &h2q.terminals),
+ // nonminimal_bool can produce minimal but
+ // not human readable expressions (#3141)
+ Applicability::Unspecified,
+ );
+ },
+ );
+ // don't also lint `NONMINIMAL_BOOL`
+ return;
+ }
+ // if the number of occurrences of a terminal decreases or any of the stats
+ // decreases while none increases
+ improvement |= (stats.terminals[i] > simplified_stats.terminals[i])
+ || (stats.negations > simplified_stats.negations && stats.ops == simplified_stats.ops)
+ || (stats.ops > simplified_stats.ops && stats.negations == simplified_stats.negations);
+ }
+ if improvement {
+ improvements.push(suggestion);
+ }
+ }
+ let nonminimal_bool_lint = |suggestions: Vec<_>| {
+ span_lint_and_then(
+ self.cx,
+ NONMINIMAL_BOOL,
+ e.span,
+ "this boolean expression can be simplified",
+ |diag| {
+ diag.span_suggestions(
+ e.span,
+ "try",
+ suggestions.into_iter(),
+ // nonminimal_bool can produce minimal but
+ // not human readable expressions (#3141)
+ Applicability::Unspecified,
+ );
+ },
+ );
+ };
+ if improvements.is_empty() {
+ let mut visitor = NotSimplificationVisitor { cx: self.cx };
+ visitor.visit_expr(e);
+ } else {
+ nonminimal_bool_lint(
+ improvements
+ .into_iter()
+ .map(|suggestion| suggest(self.cx, suggestion, &h2q.terminals))
+ .collect(),
+ );
+ }
+ }
+ }
+}
+
+impl<'a, 'tcx> Visitor<'tcx> for NonminimalBoolVisitor<'a, 'tcx> {
+ type Map = Map<'tcx>;
+
+ fn visit_expr(&mut self, e: &'tcx Expr<'_>) {
+ if in_macro(e.span) {
+ return;
+ }
+ match &e.kind {
+ ExprKind::Binary(binop, _, _) if binop.node == BinOpKind::Or || binop.node == BinOpKind::And => {
+ self.bool_expr(e)
+ },
+ ExprKind::Unary(UnOp::UnNot, inner) => {
+ if self.cx.tables.node_types()[inner.hir_id].is_bool() {
+ self.bool_expr(e);
+ } else {
+ walk_expr(self, e);
+ }
+ },
+ _ => walk_expr(self, e),
+ }
+ }
+ fn nested_visit_map(&mut self) -> NestedVisitorMap {
+ NestedVisitorMap::None
+ }
+}
+
+fn implements_ord<'a, 'tcx>(cx: &'a LateContext<'a, 'tcx>, expr: &Expr<'_>) -> bool {
+ let ty = cx.tables.expr_ty(expr);
+ get_trait_def_id(cx, &paths::ORD).map_or(false, |id| implements_trait(cx, ty, id, &[]))
+}
+
+struct NotSimplificationVisitor<'a, 'tcx> {
+ cx: &'a LateContext<'a, 'tcx>,
+}
+
+impl<'a, 'tcx> Visitor<'tcx> for NotSimplificationVisitor<'a, 'tcx> {
+ type Map = Map<'tcx>;
+
+ fn visit_expr(&mut self, expr: &'tcx Expr<'_>) {
+ if let ExprKind::Unary(UnOp::UnNot, inner) = &expr.kind {
+ if let Some(suggestion) = simplify_not(self.cx, inner) {
+ span_lint_and_sugg(
+ self.cx,
+ NONMINIMAL_BOOL,
+ expr.span,
+ "this boolean expression can be simplified",
+ "try",
+ suggestion,
+ Applicability::MachineApplicable,
+ );
+ }
+ }
+
+ walk_expr(self, expr);
+ }
+ fn nested_visit_map(&mut self) -> NestedVisitorMap {
+ NestedVisitorMap::None
+ }
+}
diff --git a/src/tools/clippy/clippy_lints/src/bytecount.rs b/src/tools/clippy/clippy_lints/src/bytecount.rs
new file mode 100644
index 00000000000..91d3e47d787
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/bytecount.rs
@@ -0,0 +1,117 @@
+use crate::utils::{
+ contains_name, get_pat_name, match_type, paths, single_segment_path, snippet_with_applicability,
+ span_lint_and_sugg, walk_ptrs_ty,
+};
+use if_chain::if_chain;
+use rustc_ast::ast::{Name, UintTy};
+use rustc_errors::Applicability;
+use rustc_hir::{BinOpKind, BorrowKind, Expr, ExprKind, UnOp};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty;
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for naive byte counts
+ ///
+ /// **Why is this bad?** The [`bytecount`](https://crates.io/crates/bytecount)
+ /// crate has methods to count your bytes faster, especially for large slices.
+ ///
+ /// **Known problems:** If you have predominantly small slices, the
+ /// `bytecount::count(..)` method may actually be slower. However, if you can
+ /// ensure that less than 2³²-1 matches arise, the `naive_count_32(..)` can be
+ /// faster in those cases.
+ ///
+ /// **Example:**
+ ///
+ /// ```rust
+ /// # let vec = vec![1_u8];
+ /// &vec.iter().filter(|x| **x == 0u8).count(); // use bytecount::count instead
+ /// ```
+ pub NAIVE_BYTECOUNT,
+ perf,
+ "use of naive `.filter(|&x| x == y).count()` to count byte values"
+}
+
+declare_lint_pass!(ByteCount => [NAIVE_BYTECOUNT]);
+
+impl<'a, 'tcx> LateLintPass<'a, 'tcx> for ByteCount {
+ fn check_expr(&mut self, cx: &LateContext<'_, '_>, expr: &Expr<'_>) {
+ if_chain! {
+ if let ExprKind::MethodCall(ref count, _, ref count_args) = expr.kind;
+ if count.ident.name == sym!(count);
+ if count_args.len() == 1;
+ if let ExprKind::MethodCall(ref filter, _, ref filter_args) = count_args[0].kind;
+ if filter.ident.name == sym!(filter);
+ if filter_args.len() == 2;
+ if let ExprKind::Closure(_, _, body_id, _, _) = filter_args[1].kind;
+ then {
+ let body = cx.tcx.hir().body(body_id);
+ if_chain! {
+ if body.params.len() == 1;
+ if let Some(argname) = get_pat_name(&body.params[0].pat);
+ if let ExprKind::Binary(ref op, ref l, ref r) = body.value.kind;
+ if op.node == BinOpKind::Eq;
+ if match_type(cx,
+ walk_ptrs_ty(cx.tables.expr_ty(&filter_args[0])),
+ &paths::SLICE_ITER);
+ then {
+ let needle = match get_path_name(l) {
+ Some(name) if check_arg(name, argname, r) => r,
+ _ => match get_path_name(r) {
+ Some(name) if check_arg(name, argname, l) => l,
+ _ => { return; }
+ }
+ };
+ if ty::Uint(UintTy::U8) != walk_ptrs_ty(cx.tables.expr_ty(needle)).kind {
+ return;
+ }
+ let haystack = if let ExprKind::MethodCall(ref path, _, ref args) =
+ filter_args[0].kind {
+ let p = path.ident.name;
+ if (p == sym!(iter) || p == sym!(iter_mut)) && args.len() == 1 {
+ &args[0]
+ } else {
+ &filter_args[0]
+ }
+ } else {
+ &filter_args[0]
+ };
+ let mut applicability = Applicability::MaybeIncorrect;
+ span_lint_and_sugg(
+ cx,
+ NAIVE_BYTECOUNT,
+ expr.span,
+ "You appear to be counting bytes the naive way",
+ "Consider using the bytecount crate",
+ format!("bytecount::count({}, {})",
+ snippet_with_applicability(cx, haystack.span, "..", &mut applicability),
+ snippet_with_applicability(cx, needle.span, "..", &mut applicability)),
+ applicability,
+ );
+ }
+ };
+ }
+ };
+ }
+}
+
+fn check_arg(name: Name, arg: Name, needle: &Expr<'_>) -> bool {
+ name == arg && !contains_name(name, needle)
+}
+
+fn get_path_name(expr: &Expr<'_>) -> Option {
+ match expr.kind {
+ ExprKind::Box(ref e) | ExprKind::AddrOf(BorrowKind::Ref, _, ref e) | ExprKind::Unary(UnOp::UnDeref, ref e) => {
+ get_path_name(e)
+ },
+ ExprKind::Block(ref b, _) => {
+ if b.stmts.is_empty() {
+ b.expr.as_ref().and_then(|p| get_path_name(p))
+ } else {
+ None
+ }
+ },
+ ExprKind::Path(ref qpath) => single_segment_path(qpath).map(|ps| ps.ident.name),
+ _ => None,
+ }
+}
diff --git a/src/tools/clippy/clippy_lints/src/cargo_common_metadata.rs b/src/tools/clippy/clippy_lints/src/cargo_common_metadata.rs
new file mode 100644
index 00000000000..782da249808
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/cargo_common_metadata.rs
@@ -0,0 +1,105 @@
+//! lint on missing cargo common metadata
+
+use std::path::PathBuf;
+
+use crate::utils::{run_lints, span_lint};
+use rustc_hir::{hir_id::CRATE_HIR_ID, Crate};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::source_map::DUMMY_SP;
+
+declare_clippy_lint! {
+ /// **What it does:** Checks to see if all common metadata is defined in
+ /// `Cargo.toml`. See: https://rust-lang-nursery.github.io/api-guidelines/documentation.html#cargotoml-includes-all-common-metadata-c-metadata
+ ///
+ /// **Why is this bad?** It will be more difficult for users to discover the
+ /// purpose of the crate, and key information related to it.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```toml
+ /// # This `Cargo.toml` is missing an authors field:
+ /// [package]
+ /// name = "clippy"
+ /// version = "0.0.212"
+ /// description = "A bunch of helpful lints to avoid common pitfalls in Rust"
+ /// repository = "https://github.com/rust-lang/rust-clippy"
+ /// readme = "README.md"
+ /// license = "MIT OR Apache-2.0"
+ /// keywords = ["clippy", "lint", "plugin"]
+ /// categories = ["development-tools", "development-tools::cargo-plugins"]
+ /// ```
+ pub CARGO_COMMON_METADATA,
+ cargo,
+ "common metadata is defined in `Cargo.toml`"
+}
+
+fn warning(cx: &LateContext<'_, '_>, message: &str) {
+ span_lint(cx, CARGO_COMMON_METADATA, DUMMY_SP, message);
+}
+
+fn missing_warning(cx: &LateContext<'_, '_>, package: &cargo_metadata::Package, field: &str) {
+ let message = format!("package `{}` is missing `{}` metadata", package.name, field);
+ warning(cx, &message);
+}
+
+fn is_empty_str(value: &Option) -> bool {
+ value.as_ref().map_or(true, String::is_empty)
+}
+
+fn is_empty_path(value: &Option) -> bool {
+ value.as_ref().and_then(|x| x.to_str()).map_or(true, str::is_empty)
+}
+
+fn is_empty_vec(value: &[String]) -> bool {
+ // This works because empty iterators return true
+ value.iter().all(String::is_empty)
+}
+
+declare_lint_pass!(CargoCommonMetadata => [CARGO_COMMON_METADATA]);
+
+impl LateLintPass<'_, '_> for CargoCommonMetadata {
+ fn check_crate(&mut self, cx: &LateContext<'_, '_>, _: &Crate<'_>) {
+ if !run_lints(cx, &[CARGO_COMMON_METADATA], CRATE_HIR_ID) {
+ return;
+ }
+
+ let metadata = if let Ok(metadata) = cargo_metadata::MetadataCommand::new().no_deps().exec() {
+ metadata
+ } else {
+ warning(cx, "could not read cargo metadata");
+ return;
+ };
+
+ for package in metadata.packages {
+ if is_empty_vec(&package.authors) {
+ missing_warning(cx, &package, "package.authors");
+ }
+
+ if is_empty_str(&package.description) {
+ missing_warning(cx, &package, "package.description");
+ }
+
+ if is_empty_str(&package.license) && is_empty_path(&package.license_file) {
+ missing_warning(cx, &package, "either package.license or package.license_file");
+ }
+
+ if is_empty_str(&package.repository) {
+ missing_warning(cx, &package, "package.repository");
+ }
+
+ if is_empty_path(&package.readme) {
+ missing_warning(cx, &package, "package.readme");
+ }
+
+ if is_empty_vec(&package.keywords) {
+ missing_warning(cx, &package, "package.keywords");
+ }
+
+ if is_empty_vec(&package.categories) {
+ missing_warning(cx, &package, "package.categories");
+ }
+ }
+ }
+}
diff --git a/src/tools/clippy/clippy_lints/src/checked_conversions.rs b/src/tools/clippy/clippy_lints/src/checked_conversions.rs
new file mode 100644
index 00000000000..d9776dd50a8
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/checked_conversions.rs
@@ -0,0 +1,345 @@
+//! lint on manually implemented checked conversions that could be transformed into `try_from`
+
+use if_chain::if_chain;
+use rustc_ast::ast::LitKind;
+use rustc_errors::Applicability;
+use rustc_hir::{BinOp, BinOpKind, Expr, ExprKind, QPath, TyKind};
+use rustc_lint::{LateContext, LateLintPass, LintContext};
+use rustc_middle::lint::in_external_macro;
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+
+use crate::utils::{snippet_with_applicability, span_lint_and_sugg, SpanlessEq};
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for explicit bounds checking when casting.
+ ///
+ /// **Why is this bad?** Reduces the readability of statements & is error prone.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```rust
+ /// # let foo: u32 = 5;
+ /// # let _ =
+ /// foo <= i32::MAX as u32
+ /// # ;
+ /// ```
+ ///
+ /// Could be written:
+ ///
+ /// ```rust
+ /// # use std::convert::TryFrom;
+ /// # let foo = 1;
+ /// # let _ =
+ /// i32::try_from(foo).is_ok()
+ /// # ;
+ /// ```
+ pub CHECKED_CONVERSIONS,
+ pedantic,
+ "`try_from` could replace manual bounds checking when casting"
+}
+
+declare_lint_pass!(CheckedConversions => [CHECKED_CONVERSIONS]);
+
+impl<'a, 'tcx> LateLintPass<'a, 'tcx> for CheckedConversions {
+ fn check_expr(&mut self, cx: &LateContext<'_, '_>, item: &Expr<'_>) {
+ let result = if_chain! {
+ if !in_external_macro(cx.sess(), item.span);
+ if let ExprKind::Binary(op, ref left, ref right) = &item.kind;
+
+ then {
+ match op.node {
+ BinOpKind::Ge | BinOpKind::Le => single_check(item),
+ BinOpKind::And => double_check(cx, left, right),
+ _ => None,
+ }
+ } else {
+ None
+ }
+ };
+
+ if_chain! {
+ if let Some(cv) = result;
+ if let Some(to_type) = cv.to_type;
+
+ then {
+ let mut applicability = Applicability::MachineApplicable;
+ let snippet = snippet_with_applicability(cx, cv.expr_to_cast.span, "_", &mut
+ applicability);
+ span_lint_and_sugg(
+ cx,
+ CHECKED_CONVERSIONS,
+ item.span,
+ "Checked cast can be simplified.",
+ "try",
+ format!("{}::try_from({}).is_ok()",
+ to_type,
+ snippet),
+ applicability
+ );
+ }
+ }
+ }
+}
+
+/// Searches for a single check from unsigned to _ is done
+/// todo: check for case signed -> larger unsigned == only x >= 0
+fn single_check<'tcx>(expr: &'tcx Expr<'tcx>) -> Option> {
+ check_upper_bound(expr).filter(|cv| cv.cvt == ConversionType::FromUnsigned)
+}
+
+/// Searches for a combination of upper & lower bound checks
+fn double_check<'a>(cx: &LateContext<'_, '_>, left: &'a Expr<'_>, right: &'a Expr<'_>) -> Option> {
+ let upper_lower = |l, r| {
+ let upper = check_upper_bound(l);
+ let lower = check_lower_bound(r);
+
+ transpose(upper, lower).and_then(|(l, r)| l.combine(r, cx))
+ };
+
+ upper_lower(left, right).or_else(|| upper_lower(right, left))
+}
+
+/// Contains the result of a tried conversion check
+#[derive(Clone, Debug)]
+struct Conversion<'a> {
+ cvt: ConversionType,
+ expr_to_cast: &'a Expr<'a>,
+ to_type: Option<&'a str>,
+}
+
+/// The kind of conversion that is checked
+#[derive(Copy, Clone, Debug, PartialEq)]
+enum ConversionType {
+ SignedToUnsigned,
+ SignedToSigned,
+ FromUnsigned,
+}
+
+impl<'a> Conversion<'a> {
+ /// Combine multiple conversions if the are compatible
+ pub fn combine(self, other: Self, cx: &LateContext<'_, '_>) -> Option> {
+ if self.is_compatible(&other, cx) {
+ // Prefer a Conversion that contains a type-constraint
+ Some(if self.to_type.is_some() { self } else { other })
+ } else {
+ None
+ }
+ }
+
+ /// Checks if two conversions are compatible
+ /// same type of conversion, same 'castee' and same 'to type'
+ pub fn is_compatible(&self, other: &Self, cx: &LateContext<'_, '_>) -> bool {
+ (self.cvt == other.cvt)
+ && (SpanlessEq::new(cx).eq_expr(self.expr_to_cast, other.expr_to_cast))
+ && (self.has_compatible_to_type(other))
+ }
+
+ /// Checks if the to-type is the same (if there is a type constraint)
+ fn has_compatible_to_type(&self, other: &Self) -> bool {
+ transpose(self.to_type.as_ref(), other.to_type.as_ref()).map_or(true, |(l, r)| l == r)
+ }
+
+ /// Try to construct a new conversion if the conversion type is valid
+ fn try_new(expr_to_cast: &'a Expr<'_>, from_type: &str, to_type: &'a str) -> Option> {
+ ConversionType::try_new(from_type, to_type).map(|cvt| Conversion {
+ cvt,
+ expr_to_cast,
+ to_type: Some(to_type),
+ })
+ }
+
+ /// Construct a new conversion without type constraint
+ fn new_any(expr_to_cast: &'a Expr<'_>) -> Conversion<'a> {
+ Conversion {
+ cvt: ConversionType::SignedToUnsigned,
+ expr_to_cast,
+ to_type: None,
+ }
+ }
+}
+
+impl ConversionType {
+ /// Creates a conversion type if the type is allowed & conversion is valid
+ #[must_use]
+ fn try_new(from: &str, to: &str) -> Option {
+ if UINTS.contains(&from) {
+ Some(Self::FromUnsigned)
+ } else if SINTS.contains(&from) {
+ if UINTS.contains(&to) {
+ Some(Self::SignedToUnsigned)
+ } else if SINTS.contains(&to) {
+ Some(Self::SignedToSigned)
+ } else {
+ None
+ }
+ } else {
+ None
+ }
+ }
+}
+
+/// Check for `expr <= (to_type::MAX as from_type)`
+fn check_upper_bound<'tcx>(expr: &'tcx Expr<'tcx>) -> Option> {
+ if_chain! {
+ if let ExprKind::Binary(ref op, ref left, ref right) = &expr.kind;
+ if let Some((candidate, check)) = normalize_le_ge(op, left, right);
+ if let Some((from, to)) = get_types_from_cast(check, MAX_VALUE, INTS);
+
+ then {
+ Conversion::try_new(candidate, from, to)
+ } else {
+ None
+ }
+ }
+}
+
+/// Check for `expr >= 0|(to_type::MIN as from_type)`
+fn check_lower_bound<'tcx>(expr: &'tcx Expr<'tcx>) -> Option> {
+ fn check_function<'a>(candidate: &'a Expr<'a>, check: &'a Expr<'a>) -> Option> {
+ (check_lower_bound_zero(candidate, check)).or_else(|| (check_lower_bound_min(candidate, check)))
+ }
+
+ // First of we need a binary containing the expression & the cast
+ if let ExprKind::Binary(ref op, ref left, ref right) = &expr.kind {
+ normalize_le_ge(op, right, left).and_then(|(l, r)| check_function(l, r))
+ } else {
+ None
+ }
+}
+
+/// Check for `expr >= 0`
+fn check_lower_bound_zero<'a>(candidate: &'a Expr<'_>, check: &'a Expr<'_>) -> Option> {
+ if_chain! {
+ if let ExprKind::Lit(ref lit) = &check.kind;
+ if let LitKind::Int(0, _) = &lit.node;
+
+ then {
+ Some(Conversion::new_any(candidate))
+ } else {
+ None
+ }
+ }
+}
+
+/// Check for `expr >= (to_type::MIN as from_type)`
+fn check_lower_bound_min<'a>(candidate: &'a Expr<'_>, check: &'a Expr<'_>) -> Option> {
+ if let Some((from, to)) = get_types_from_cast(check, MIN_VALUE, SINTS) {
+ Conversion::try_new(candidate, from, to)
+ } else {
+ None
+ }
+}
+
+/// Tries to extract the from- and to-type from a cast expression
+fn get_types_from_cast<'a>(expr: &'a Expr<'_>, func: &'a str, types: &'a [&str]) -> Option<(&'a str, &'a str)> {
+ // `to_type::maxmin_value() as from_type`
+ let call_from_cast: Option<(&Expr<'_>, &str)> = if_chain! {
+ // to_type::maxmin_value(), from_type
+ if let ExprKind::Cast(ref limit, ref from_type) = &expr.kind;
+ if let TyKind::Path(ref from_type_path) = &from_type.kind;
+ if let Some(from_sym) = int_ty_to_sym(from_type_path);
+
+ then {
+ Some((limit, from_sym))
+ } else {
+ None
+ }
+ };
+
+ // `from_type::from(to_type::maxmin_value())`
+ let limit_from: Option<(&Expr<'_>, &str)> = call_from_cast.or_else(|| {
+ if_chain! {
+ // `from_type::from, to_type::maxmin_value()`
+ if let ExprKind::Call(ref from_func, ref args) = &expr.kind;
+ // `to_type::maxmin_value()`
+ if args.len() == 1;
+ if let limit = &args[0];
+ // `from_type::from`
+ if let ExprKind::Path(ref path) = &from_func.kind;
+ if let Some(from_sym) = get_implementing_type(path, INTS, FROM);
+
+ then {
+ Some((limit, from_sym))
+ } else {
+ None
+ }
+ }
+ });
+
+ if let Some((limit, from_type)) = limit_from {
+ if_chain! {
+ if let ExprKind::Call(ref fun_name, _) = &limit.kind;
+ // `to_type, maxmin_value`
+ if let ExprKind::Path(ref path) = &fun_name.kind;
+ // `to_type`
+ if let Some(to_type) = get_implementing_type(path, types, func);
+
+ then {
+ Some((from_type, to_type))
+ } else {
+ None
+ }
+ }
+ } else {
+ None
+ }
+}
+
+/// Gets the type which implements the called function
+fn get_implementing_type<'a>(path: &QPath<'_>, candidates: &'a [&str], function: &str) -> Option<&'a str> {
+ if_chain! {
+ if let QPath::TypeRelative(ref ty, ref path) = &path;
+ if path.ident.name.as_str() == function;
+ if let TyKind::Path(QPath::Resolved(None, ref tp)) = &ty.kind;
+ if let [int] = &*tp.segments;
+ let name = &int.ident.name.as_str();
+
+ then {
+ candidates.iter().find(|c| name == *c).cloned()
+ } else {
+ None
+ }
+ }
+}
+
+/// Gets the type as a string, if it is a supported integer
+fn int_ty_to_sym<'tcx>(path: &QPath<'_>) -> Option<&'tcx str> {
+ if_chain! {
+ if let QPath::Resolved(_, ref path) = *path;
+ if let [ty] = &*path.segments;
+ let name = &ty.ident.name.as_str();
+
+ then {
+ INTS.iter().find(|c| name == *c).cloned()
+ } else {
+ None
+ }
+ }
+}
+
+/// (Option, Option) -> Option<(T, U)>
+fn transpose(lhs: Option, rhs: Option) -> Option<(T, U)> {
+ match (lhs, rhs) {
+ (Some(l), Some(r)) => Some((l, r)),
+ _ => None,
+ }
+}
+
+/// Will return the expressions as if they were expr1 <= expr2
+fn normalize_le_ge<'a>(op: &BinOp, left: &'a Expr<'a>, right: &'a Expr<'a>) -> Option<(&'a Expr<'a>, &'a Expr<'a>)> {
+ match op.node {
+ BinOpKind::Le => Some((left, right)),
+ BinOpKind::Ge => Some((right, left)),
+ _ => None,
+ }
+}
+
+// Constants
+const FROM: &str = "from";
+const MAX_VALUE: &str = "max_value";
+const MIN_VALUE: &str = "min_value";
+
+const UINTS: &[&str] = &["u8", "u16", "u32", "u64", "usize"];
+const SINTS: &[&str] = &["i8", "i16", "i32", "i64", "isize"];
+const INTS: &[&str] = &["u8", "u16", "u32", "u64", "usize", "i8", "i16", "i32", "i64", "isize"];
diff --git a/src/tools/clippy/clippy_lints/src/cognitive_complexity.rs b/src/tools/clippy/clippy_lints/src/cognitive_complexity.rs
new file mode 100644
index 00000000000..3ba72e84fa8
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/cognitive_complexity.rs
@@ -0,0 +1,163 @@
+//! calculate cognitive complexity and warn about overly complex functions
+
+use rustc_ast::ast::Attribute;
+use rustc_hir::intravisit::{walk_expr, FnKind, NestedVisitorMap, Visitor};
+use rustc_hir::{Body, Expr, ExprKind, FnDecl, HirId};
+use rustc_lint::{LateContext, LateLintPass, LintContext};
+use rustc_middle::hir::map::Map;
+use rustc_session::{declare_tool_lint, impl_lint_pass};
+use rustc_span::source_map::Span;
+use rustc_span::BytePos;
+
+use crate::utils::{is_type_diagnostic_item, snippet_opt, span_lint_and_help, LimitStack};
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for methods with high cognitive complexity.
+ ///
+ /// **Why is this bad?** Methods of high cognitive complexity tend to be hard to
+ /// both read and maintain. Also LLVM will tend to optimize small methods better.
+ ///
+ /// **Known problems:** Sometimes it's hard to find a way to reduce the
+ /// complexity.
+ ///
+ /// **Example:** No. You'll see it when you get the warning.
+ pub COGNITIVE_COMPLEXITY,
+ nursery,
+ "functions that should be split up into multiple functions"
+}
+
+pub struct CognitiveComplexity {
+ limit: LimitStack,
+}
+
+impl CognitiveComplexity {
+ #[must_use]
+ pub fn new(limit: u64) -> Self {
+ Self {
+ limit: LimitStack::new(limit),
+ }
+ }
+}
+
+impl_lint_pass!(CognitiveComplexity => [COGNITIVE_COMPLEXITY]);
+
+impl CognitiveComplexity {
+ #[allow(clippy::cast_possible_truncation)]
+ fn check<'a, 'tcx>(
+ &mut self,
+ cx: &'a LateContext<'a, 'tcx>,
+ kind: FnKind<'tcx>,
+ decl: &'tcx FnDecl<'_>,
+ body: &'tcx Body<'_>,
+ body_span: Span,
+ ) {
+ if body_span.from_expansion() {
+ return;
+ }
+
+ let expr = &body.value;
+
+ let mut helper = CCHelper { cc: 1, returns: 0 };
+ helper.visit_expr(expr);
+ let CCHelper { cc, returns } = helper;
+ let ret_ty = cx.tables.node_type(expr.hir_id);
+ let ret_adjust = if is_type_diagnostic_item(cx, ret_ty, sym!(result_type)) {
+ returns
+ } else {
+ #[allow(clippy::integer_division)]
+ (returns / 2)
+ };
+
+ let mut rust_cc = cc;
+ // prevent degenerate cases where unreachable code contains `return` statements
+ if rust_cc >= ret_adjust {
+ rust_cc -= ret_adjust;
+ }
+
+ if rust_cc > self.limit.limit() {
+ let fn_span = match kind {
+ FnKind::ItemFn(ident, _, _, _, _) | FnKind::Method(ident, _, _, _) => ident.span,
+ FnKind::Closure(_) => {
+ let header_span = body_span.with_hi(decl.output.span().lo());
+ let pos = snippet_opt(cx, header_span).and_then(|snip| {
+ let low_offset = snip.find('|')?;
+ let high_offset = 1 + snip.get(low_offset + 1..)?.find('|')?;
+ let low = header_span.lo() + BytePos(low_offset as u32);
+ let high = low + BytePos(high_offset as u32 + 1);
+
+ Some((low, high))
+ });
+
+ if let Some((low, high)) = pos {
+ Span::new(low, high, header_span.ctxt())
+ } else {
+ return;
+ }
+ },
+ };
+
+ span_lint_and_help(
+ cx,
+ COGNITIVE_COMPLEXITY,
+ fn_span,
+ &format!(
+ "the function has a cognitive complexity of ({}/{})",
+ rust_cc,
+ self.limit.limit()
+ ),
+ None,
+ "you could split it up into multiple smaller functions",
+ );
+ }
+ }
+}
+
+impl<'a, 'tcx> LateLintPass<'a, 'tcx> for CognitiveComplexity {
+ fn check_fn(
+ &mut self,
+ cx: &LateContext<'a, 'tcx>,
+ kind: FnKind<'tcx>,
+ decl: &'tcx FnDecl<'_>,
+ body: &'tcx Body<'_>,
+ span: Span,
+ hir_id: HirId,
+ ) {
+ let def_id = cx.tcx.hir().local_def_id(hir_id);
+ if !cx.tcx.has_attr(def_id.to_def_id(), sym!(test)) {
+ self.check(cx, kind, decl, body, span);
+ }
+ }
+
+ fn enter_lint_attrs(&mut self, cx: &LateContext<'a, 'tcx>, attrs: &'tcx [Attribute]) {
+ self.limit.push_attrs(cx.sess(), attrs, "cognitive_complexity");
+ }
+ fn exit_lint_attrs(&mut self, cx: &LateContext<'a, 'tcx>, attrs: &'tcx [Attribute]) {
+ self.limit.pop_attrs(cx.sess(), attrs, "cognitive_complexity");
+ }
+}
+
+struct CCHelper {
+ cc: u64,
+ returns: u64,
+}
+
+impl<'tcx> Visitor<'tcx> for CCHelper {
+ type Map = Map<'tcx>;
+
+ fn visit_expr(&mut self, e: &'tcx Expr<'_>) {
+ walk_expr(self, e);
+ match e.kind {
+ ExprKind::Match(_, ref arms, _) => {
+ if arms.len() > 1 {
+ self.cc += 1;
+ }
+ self.cc += arms.iter().filter(|arm| arm.guard.is_some()).count() as u64;
+ },
+ ExprKind::Ret(_) => self.returns += 1,
+ _ => {},
+ }
+ }
+ fn nested_visit_map(&mut self) -> NestedVisitorMap {
+ NestedVisitorMap::None
+ }
+}
diff --git a/src/tools/clippy/clippy_lints/src/collapsible_if.rs b/src/tools/clippy/clippy_lints/src/collapsible_if.rs
new file mode 100644
index 00000000000..8090f4673aa
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/collapsible_if.rs
@@ -0,0 +1,170 @@
+//! Checks for if expressions that contain only an if expression.
+//!
+//! For example, the lint would catch:
+//!
+//! ```rust,ignore
+//! if x {
+//! if y {
+//! println!("Hello world");
+//! }
+//! }
+//! ```
+//!
+//! This lint is **warn** by default
+
+use if_chain::if_chain;
+use rustc_ast::ast;
+use rustc_lint::{EarlyContext, EarlyLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+
+use crate::utils::sugg::Sugg;
+use crate::utils::{snippet_block, snippet_block_with_applicability, span_lint_and_sugg, span_lint_and_then};
+use rustc_errors::Applicability;
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for nested `if` statements which can be collapsed
+ /// by `&&`-combining their conditions and for `else { if ... }` expressions
+ /// that
+ /// can be collapsed to `else if ...`.
+ ///
+ /// **Why is this bad?** Each `if`-statement adds one level of nesting, which
+ /// makes code look more complex than it really is.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```rust,ignore
+ /// if x {
+ /// if y {
+ /// …
+ /// }
+ /// }
+ ///
+ /// // or
+ ///
+ /// if x {
+ /// …
+ /// } else {
+ /// if y {
+ /// …
+ /// }
+ /// }
+ /// ```
+ ///
+ /// Should be written:
+ ///
+ /// ```rust.ignore
+ /// if x && y {
+ /// …
+ /// }
+ ///
+ /// // or
+ ///
+ /// if x {
+ /// …
+ /// } else if y {
+ /// …
+ /// }
+ /// ```
+ pub COLLAPSIBLE_IF,
+ style,
+ "`if`s that can be collapsed (e.g., `if x { if y { ... } }` and `else { if x { ... } }`)"
+}
+
+declare_lint_pass!(CollapsibleIf => [COLLAPSIBLE_IF]);
+
+impl EarlyLintPass for CollapsibleIf {
+ fn check_expr(&mut self, cx: &EarlyContext<'_>, expr: &ast::Expr) {
+ if !expr.span.from_expansion() {
+ check_if(cx, expr)
+ }
+ }
+}
+
+fn check_if(cx: &EarlyContext<'_>, expr: &ast::Expr) {
+ if let ast::ExprKind::If(check, then, else_) = &expr.kind {
+ if let Some(else_) = else_ {
+ check_collapsible_maybe_if_let(cx, else_);
+ } else if let ast::ExprKind::Let(..) = check.kind {
+ // Prevent triggering on `if let a = b { if c { .. } }`.
+ } else {
+ check_collapsible_no_if_let(cx, expr, check, then);
+ }
+ }
+}
+
+fn block_starts_with_comment(cx: &EarlyContext<'_>, expr: &ast::Block) -> bool {
+ // We trim all opening braces and whitespaces and then check if the next string is a comment.
+ let trimmed_block_text = snippet_block(cx, expr.span, "..", None)
+ .trim_start_matches(|c: char| c.is_whitespace() || c == '{')
+ .to_owned();
+ trimmed_block_text.starts_with("//") || trimmed_block_text.starts_with("/*")
+}
+
+fn check_collapsible_maybe_if_let(cx: &EarlyContext<'_>, else_: &ast::Expr) {
+ if_chain! {
+ if let ast::ExprKind::Block(ref block, _) = else_.kind;
+ if !block_starts_with_comment(cx, block);
+ if let Some(else_) = expr_block(block);
+ if !else_.span.from_expansion();
+ if let ast::ExprKind::If(..) = else_.kind;
+ then {
+ let mut applicability = Applicability::MachineApplicable;
+ span_lint_and_sugg(
+ cx,
+ COLLAPSIBLE_IF,
+ block.span,
+ "this `else { if .. }` block can be collapsed",
+ "try",
+ snippet_block_with_applicability(cx, else_.span, "..", Some(block.span), &mut applicability).into_owned(),
+ applicability,
+ );
+ }
+ }
+}
+
+fn check_collapsible_no_if_let(cx: &EarlyContext<'_>, expr: &ast::Expr, check: &ast::Expr, then: &ast::Block) {
+ if_chain! {
+ if !block_starts_with_comment(cx, then);
+ if let Some(inner) = expr_block(then);
+ if let ast::ExprKind::If(ref check_inner, ref content, None) = inner.kind;
+ then {
+ if let ast::ExprKind::Let(..) = check_inner.kind {
+ // Prevent triggering on `if c { if let a = b { .. } }`.
+ return;
+ }
+
+ if expr.span.ctxt() != inner.span.ctxt() {
+ return;
+ }
+ span_lint_and_then(cx, COLLAPSIBLE_IF, expr.span, "this `if` statement can be collapsed", |diag| {
+ let lhs = Sugg::ast(cx, check, "..");
+ let rhs = Sugg::ast(cx, check_inner, "..");
+ diag.span_suggestion(
+ expr.span,
+ "try",
+ format!(
+ "if {} {}",
+ lhs.and(&rhs),
+ snippet_block(cx, content.span, "..", Some(expr.span)),
+ ),
+ Applicability::MachineApplicable, // snippet
+ );
+ });
+ }
+ }
+}
+
+/// If the block contains only one expression, return it.
+fn expr_block(block: &ast::Block) -> Option<&ast::Expr> {
+ let mut it = block.stmts.iter();
+
+ if let (Some(stmt), None) = (it.next(), it.next()) {
+ match stmt.kind {
+ ast::StmtKind::Expr(ref expr) | ast::StmtKind::Semi(ref expr) => Some(expr),
+ _ => None,
+ }
+ } else {
+ None
+ }
+}
diff --git a/src/tools/clippy/clippy_lints/src/comparison_chain.rs b/src/tools/clippy/clippy_lints/src/comparison_chain.rs
new file mode 100644
index 00000000000..96df3ffe3ce
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/comparison_chain.rs
@@ -0,0 +1,118 @@
+use crate::utils::{
+ get_trait_def_id, if_sequence, implements_trait, parent_node_is_if_expr, paths, span_lint_and_help, SpanlessEq,
+};
+use rustc_hir::{BinOpKind, Expr, ExprKind};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+
+declare_clippy_lint! {
+ /// **What it does:** Checks comparison chains written with `if` that can be
+ /// rewritten with `match` and `cmp`.
+ ///
+ /// **Why is this bad?** `if` is not guaranteed to be exhaustive and conditionals can get
+ /// repetitive
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```rust,ignore
+ /// # fn a() {}
+ /// # fn b() {}
+ /// # fn c() {}
+ /// fn f(x: u8, y: u8) {
+ /// if x > y {
+ /// a()
+ /// } else if x < y {
+ /// b()
+ /// } else {
+ /// c()
+ /// }
+ /// }
+ /// ```
+ ///
+ /// Could be written:
+ ///
+ /// ```rust,ignore
+ /// use std::cmp::Ordering;
+ /// # fn a() {}
+ /// # fn b() {}
+ /// # fn c() {}
+ /// fn f(x: u8, y: u8) {
+ /// match x.cmp(&y) {
+ /// Ordering::Greater => a(),
+ /// Ordering::Less => b(),
+ /// Ordering::Equal => c()
+ /// }
+ /// }
+ /// ```
+ pub COMPARISON_CHAIN,
+ style,
+ "`if`s that can be rewritten with `match` and `cmp`"
+}
+
+declare_lint_pass!(ComparisonChain => [COMPARISON_CHAIN]);
+
+impl<'a, 'tcx> LateLintPass<'a, 'tcx> for ComparisonChain {
+ fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr<'_>) {
+ if expr.span.from_expansion() {
+ return;
+ }
+
+ // We only care about the top-most `if` in the chain
+ if parent_node_is_if_expr(expr, cx) {
+ return;
+ }
+
+ // Check that there exists at least one explicit else condition
+ let (conds, _) = if_sequence(expr);
+ if conds.len() < 2 {
+ return;
+ }
+
+ for cond in conds.windows(2) {
+ if let (
+ &ExprKind::Binary(ref kind1, ref lhs1, ref rhs1),
+ &ExprKind::Binary(ref kind2, ref lhs2, ref rhs2),
+ ) = (&cond[0].kind, &cond[1].kind)
+ {
+ if !kind_is_cmp(kind1.node) || !kind_is_cmp(kind2.node) {
+ return;
+ }
+
+ // Check that both sets of operands are equal
+ let mut spanless_eq = SpanlessEq::new(cx);
+ if (!spanless_eq.eq_expr(lhs1, lhs2) || !spanless_eq.eq_expr(rhs1, rhs2))
+ && (!spanless_eq.eq_expr(lhs1, rhs2) || !spanless_eq.eq_expr(rhs1, lhs2))
+ {
+ return;
+ }
+
+ // Check that the type being compared implements `core::cmp::Ord`
+ let ty = cx.tables.expr_ty(lhs1);
+ let is_ord = get_trait_def_id(cx, &paths::ORD).map_or(false, |id| implements_trait(cx, ty, id, &[]));
+
+ if !is_ord {
+ return;
+ }
+ } else {
+ // We only care about comparison chains
+ return;
+ }
+ }
+ span_lint_and_help(
+ cx,
+ COMPARISON_CHAIN,
+ expr.span,
+ "`if` chain can be rewritten with `match`",
+ None,
+ "Consider rewriting the `if` chain to use `cmp` and `match`.",
+ )
+ }
+}
+
+fn kind_is_cmp(kind: BinOpKind) -> bool {
+ match kind {
+ BinOpKind::Lt | BinOpKind::Gt | BinOpKind::Eq => true,
+ _ => false,
+ }
+}
diff --git a/src/tools/clippy/clippy_lints/src/consts.rs b/src/tools/clippy/clippy_lints/src/consts.rs
new file mode 100644
index 00000000000..81ddc8c0067
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/consts.rs
@@ -0,0 +1,559 @@
+#![allow(clippy::float_cmp)]
+
+use crate::utils::{clip, higher, sext, unsext};
+use if_chain::if_chain;
+use rustc_ast::ast::{FloatTy, LitFloatType, LitKind};
+use rustc_data_structures::sync::Lrc;
+use rustc_hir::def::{DefKind, Res};
+use rustc_hir::{BinOp, BinOpKind, Block, Expr, ExprKind, HirId, QPath, UnOp};
+use rustc_lint::LateContext;
+use rustc_middle::ty::subst::{Subst, SubstsRef};
+use rustc_middle::ty::{self, Ty, TyCtxt};
+use rustc_middle::{bug, span_bug};
+use rustc_span::symbol::Symbol;
+use std::cmp::Ordering::{self, Equal};
+use std::convert::TryInto;
+use std::hash::{Hash, Hasher};
+
+/// A `LitKind`-like enum to fold constant `Expr`s into.
+#[derive(Debug, Clone)]
+pub enum Constant {
+ /// A `String` (e.g., "abc").
+ Str(String),
+ /// A binary string (e.g., `b"abc"`).
+ Binary(Lrc>),
+ /// A single `char` (e.g., `'a'`).
+ Char(char),
+ /// An integer's bit representation.
+ Int(u128),
+ /// An `f32`.
+ F32(f32),
+ /// An `f64`.
+ F64(f64),
+ /// `true` or `false`.
+ Bool(bool),
+ /// An array of constants.
+ Vec(Vec),
+ /// Also an array, but with only one constant, repeated N times.
+ Repeat(Box, u64),
+ /// A tuple of constants.
+ Tuple(Vec),
+ /// A raw pointer.
+ RawPtr(u128),
+ /// A literal with syntax error.
+ Err(Symbol),
+}
+
+impl PartialEq for Constant {
+ fn eq(&self, other: &Self) -> bool {
+ match (self, other) {
+ (&Self::Str(ref ls), &Self::Str(ref rs)) => ls == rs,
+ (&Self::Binary(ref l), &Self::Binary(ref r)) => l == r,
+ (&Self::Char(l), &Self::Char(r)) => l == r,
+ (&Self::Int(l), &Self::Int(r)) => l == r,
+ (&Self::F64(l), &Self::F64(r)) => {
+ // We want `Fw32 == FwAny` and `FwAny == Fw64`, and by transitivity we must have
+ // `Fw32 == Fw64`, so don’t compare them.
+ // `to_bits` is required to catch non-matching 0.0, -0.0, and NaNs.
+ l.to_bits() == r.to_bits()
+ },
+ (&Self::F32(l), &Self::F32(r)) => {
+ // We want `Fw32 == FwAny` and `FwAny == Fw64`, and by transitivity we must have
+ // `Fw32 == Fw64`, so don’t compare them.
+ // `to_bits` is required to catch non-matching 0.0, -0.0, and NaNs.
+ f64::from(l).to_bits() == f64::from(r).to_bits()
+ },
+ (&Self::Bool(l), &Self::Bool(r)) => l == r,
+ (&Self::Vec(ref l), &Self::Vec(ref r)) | (&Self::Tuple(ref l), &Self::Tuple(ref r)) => l == r,
+ (&Self::Repeat(ref lv, ref ls), &Self::Repeat(ref rv, ref rs)) => ls == rs && lv == rv,
+ // TODO: are there inter-type equalities?
+ _ => false,
+ }
+ }
+}
+
+impl Hash for Constant {
+ fn hash(&self, state: &mut H)
+ where
+ H: Hasher,
+ {
+ std::mem::discriminant(self).hash(state);
+ match *self {
+ Self::Str(ref s) => {
+ s.hash(state);
+ },
+ Self::Binary(ref b) => {
+ b.hash(state);
+ },
+ Self::Char(c) => {
+ c.hash(state);
+ },
+ Self::Int(i) => {
+ i.hash(state);
+ },
+ Self::F32(f) => {
+ f64::from(f).to_bits().hash(state);
+ },
+ Self::F64(f) => {
+ f.to_bits().hash(state);
+ },
+ Self::Bool(b) => {
+ b.hash(state);
+ },
+ Self::Vec(ref v) | Self::Tuple(ref v) => {
+ v.hash(state);
+ },
+ Self::Repeat(ref c, l) => {
+ c.hash(state);
+ l.hash(state);
+ },
+ Self::RawPtr(u) => {
+ u.hash(state);
+ },
+ Self::Err(ref s) => {
+ s.hash(state);
+ },
+ }
+ }
+}
+
+impl Constant {
+ pub fn partial_cmp(tcx: TyCtxt<'_>, cmp_type: Ty<'_>, left: &Self, right: &Self) -> Option {
+ match (left, right) {
+ (&Self::Str(ref ls), &Self::Str(ref rs)) => Some(ls.cmp(rs)),
+ (&Self::Char(ref l), &Self::Char(ref r)) => Some(l.cmp(r)),
+ (&Self::Int(l), &Self::Int(r)) => {
+ if let ty::Int(int_ty) = cmp_type.kind {
+ Some(sext(tcx, l, int_ty).cmp(&sext(tcx, r, int_ty)))
+ } else {
+ Some(l.cmp(&r))
+ }
+ },
+ (&Self::F64(l), &Self::F64(r)) => l.partial_cmp(&r),
+ (&Self::F32(l), &Self::F32(r)) => l.partial_cmp(&r),
+ (&Self::Bool(ref l), &Self::Bool(ref r)) => Some(l.cmp(r)),
+ (&Self::Tuple(ref l), &Self::Tuple(ref r)) | (&Self::Vec(ref l), &Self::Vec(ref r)) => l
+ .iter()
+ .zip(r.iter())
+ .map(|(li, ri)| Self::partial_cmp(tcx, cmp_type, li, ri))
+ .find(|r| r.map_or(true, |o| o != Ordering::Equal))
+ .unwrap_or_else(|| Some(l.len().cmp(&r.len()))),
+ (&Self::Repeat(ref lv, ref ls), &Self::Repeat(ref rv, ref rs)) => {
+ match Self::partial_cmp(tcx, cmp_type, lv, rv) {
+ Some(Equal) => Some(ls.cmp(rs)),
+ x => x,
+ }
+ },
+ // TODO: are there any useful inter-type orderings?
+ _ => None,
+ }
+ }
+}
+
+/// Parses a `LitKind` to a `Constant`.
+pub fn lit_to_constant(lit: &LitKind, ty: Option>) -> Constant {
+ match *lit {
+ LitKind::Str(ref is, _) => Constant::Str(is.to_string()),
+ LitKind::Byte(b) => Constant::Int(u128::from(b)),
+ LitKind::ByteStr(ref s) => Constant::Binary(Lrc::clone(s)),
+ LitKind::Char(c) => Constant::Char(c),
+ LitKind::Int(n, _) => Constant::Int(n),
+ LitKind::Float(ref is, LitFloatType::Suffixed(fty)) => match fty {
+ FloatTy::F32 => Constant::F32(is.as_str().parse().unwrap()),
+ FloatTy::F64 => Constant::F64(is.as_str().parse().unwrap()),
+ },
+ LitKind::Float(ref is, LitFloatType::Unsuffixed) => match ty.expect("type of float is known").kind {
+ ty::Float(FloatTy::F32) => Constant::F32(is.as_str().parse().unwrap()),
+ ty::Float(FloatTy::F64) => Constant::F64(is.as_str().parse().unwrap()),
+ _ => bug!(),
+ },
+ LitKind::Bool(b) => Constant::Bool(b),
+ LitKind::Err(s) => Constant::Err(s),
+ }
+}
+
+pub fn constant<'c, 'cc>(
+ lcx: &LateContext<'c, 'cc>,
+ tables: &'c ty::TypeckTables<'cc>,
+ e: &Expr<'_>,
+) -> Option<(Constant, bool)> {
+ let mut cx = ConstEvalLateContext {
+ lcx,
+ tables,
+ param_env: lcx.param_env,
+ needed_resolution: false,
+ substs: lcx.tcx.intern_substs(&[]),
+ };
+ cx.expr(e).map(|cst| (cst, cx.needed_resolution))
+}
+
+pub fn constant_simple<'c, 'cc>(
+ lcx: &LateContext<'c, 'cc>,
+ tables: &'c ty::TypeckTables<'cc>,
+ e: &Expr<'_>,
+) -> Option {
+ constant(lcx, tables, e).and_then(|(cst, res)| if res { None } else { Some(cst) })
+}
+
+/// Creates a `ConstEvalLateContext` from the given `LateContext` and `TypeckTables`.
+pub fn constant_context<'c, 'cc>(
+ lcx: &'c LateContext<'c, 'cc>,
+ tables: &'c ty::TypeckTables<'cc>,
+) -> ConstEvalLateContext<'c, 'cc> {
+ ConstEvalLateContext {
+ lcx,
+ tables,
+ param_env: lcx.param_env,
+ needed_resolution: false,
+ substs: lcx.tcx.intern_substs(&[]),
+ }
+}
+
+pub struct ConstEvalLateContext<'a, 'tcx> {
+ lcx: &'a LateContext<'a, 'tcx>,
+ tables: &'a ty::TypeckTables<'tcx>,
+ param_env: ty::ParamEnv<'tcx>,
+ needed_resolution: bool,
+ substs: SubstsRef<'tcx>,
+}
+
+impl<'c, 'cc> ConstEvalLateContext<'c, 'cc> {
+ /// Simple constant folding: Insert an expression, get a constant or none.
+ pub fn expr(&mut self, e: &Expr<'_>) -> Option {
+ if let Some((ref cond, ref then, otherwise)) = higher::if_block(&e) {
+ return self.ifthenelse(cond, then, otherwise);
+ }
+ match e.kind {
+ ExprKind::Path(ref qpath) => self.fetch_path(qpath, e.hir_id, self.tables.expr_ty(e)),
+ ExprKind::Block(ref block, _) => self.block(block),
+ ExprKind::Lit(ref lit) => Some(lit_to_constant(&lit.node, self.tables.expr_ty_opt(e))),
+ ExprKind::Array(ref vec) => self.multi(vec).map(Constant::Vec),
+ ExprKind::Tup(ref tup) => self.multi(tup).map(Constant::Tuple),
+ ExprKind::Repeat(ref value, _) => {
+ let n = match self.tables.expr_ty(e).kind {
+ ty::Array(_, n) => n.try_eval_usize(self.lcx.tcx, self.lcx.param_env)?,
+ _ => span_bug!(e.span, "typeck error"),
+ };
+ self.expr(value).map(|v| Constant::Repeat(Box::new(v), n))
+ },
+ ExprKind::Unary(op, ref operand) => self.expr(operand).and_then(|o| match op {
+ UnOp::UnNot => self.constant_not(&o, self.tables.expr_ty(e)),
+ UnOp::UnNeg => self.constant_negate(&o, self.tables.expr_ty(e)),
+ UnOp::UnDeref => Some(o),
+ }),
+ ExprKind::Binary(op, ref left, ref right) => self.binop(op, left, right),
+ ExprKind::Call(ref callee, ref args) => {
+ // We only handle a few const functions for now.
+ if_chain! {
+ if args.is_empty();
+ if let ExprKind::Path(qpath) = &callee.kind;
+ let res = self.tables.qpath_res(qpath, callee.hir_id);
+ if let Some(def_id) = res.opt_def_id();
+ let def_path: Vec<_> = self.lcx.get_def_path(def_id).into_iter().map(Symbol::as_str).collect();
+ let def_path: Vec<&str> = def_path.iter().take(4).map(|s| &**s).collect();
+ if let ["core", "num", int_impl, "max_value"] = *def_path;
+ then {
+ let value = match int_impl {
+ "" => i8::max_value() as u128,
+ "" => i16::max_value() as u128,
+ "" => i32::max_value() as u128,
+ "" => i64::max_value() as u128,
+ "" => i128::max_value() as u128,
+ _ => return None,
+ };
+ Some(Constant::Int(value))
+ }
+ else {
+ None
+ }
+ }
+ },
+ ExprKind::Index(ref arr, ref index) => self.index(arr, index),
+ // TODO: add other expressions.
+ _ => None,
+ }
+ }
+
+ #[allow(clippy::cast_possible_wrap)]
+ fn constant_not(&self, o: &Constant, ty: Ty<'_>) -> Option {
+ use self::Constant::{Bool, Int};
+ match *o {
+ Bool(b) => Some(Bool(!b)),
+ Int(value) => {
+ let value = !value;
+ match ty.kind {
+ ty::Int(ity) => Some(Int(unsext(self.lcx.tcx, value as i128, ity))),
+ ty::Uint(ity) => Some(Int(clip(self.lcx.tcx, value, ity))),
+ _ => None,
+ }
+ },
+ _ => None,
+ }
+ }
+
+ fn constant_negate(&self, o: &Constant, ty: Ty<'_>) -> Option {
+ use self::Constant::{Int, F32, F64};
+ match *o {
+ Int(value) => {
+ let ity = match ty.kind {
+ ty::Int(ity) => ity,
+ _ => return None,
+ };
+ // sign extend
+ let value = sext(self.lcx.tcx, value, ity);
+ let value = value.checked_neg()?;
+ // clear unused bits
+ Some(Int(unsext(self.lcx.tcx, value, ity)))
+ },
+ F32(f) => Some(F32(-f)),
+ F64(f) => Some(F64(-f)),
+ _ => None,
+ }
+ }
+
+ /// Create `Some(Vec![..])` of all constants, unless there is any
+ /// non-constant part.
+ fn multi(&mut self, vec: &[Expr<'_>]) -> Option> {
+ vec.iter().map(|elem| self.expr(elem)).collect::>()
+ }
+
+ /// Lookup a possibly constant expression from a `ExprKind::Path`.
+ fn fetch_path(&mut self, qpath: &QPath<'_>, id: HirId, ty: Ty<'cc>) -> Option {
+ let res = self.tables.qpath_res(qpath, id);
+ match res {
+ Res::Def(DefKind::Const | DefKind::AssocConst, def_id) => {
+ let substs = self.tables.node_substs(id);
+ let substs = if self.substs.is_empty() {
+ substs
+ } else {
+ substs.subst(self.lcx.tcx, self.substs)
+ };
+
+ let result = self
+ .lcx
+ .tcx
+ .const_eval_resolve(self.param_env, def_id, substs, None, None)
+ .ok()
+ .map(|val| rustc_middle::ty::Const::from_value(self.lcx.tcx, val, ty))?;
+ let result = miri_to_const(&result);
+ if result.is_some() {
+ self.needed_resolution = true;
+ }
+ result
+ },
+ // FIXME: cover all usable cases.
+ _ => None,
+ }
+ }
+
+ fn index(&mut self, lhs: &'_ Expr<'_>, index: &'_ Expr<'_>) -> Option {
+ let lhs = self.expr(lhs);
+ let index = self.expr(index);
+
+ match (lhs, index) {
+ (Some(Constant::Vec(vec)), Some(Constant::Int(index))) => match vec.get(index as usize) {
+ Some(Constant::F32(x)) => Some(Constant::F32(*x)),
+ Some(Constant::F64(x)) => Some(Constant::F64(*x)),
+ _ => None,
+ },
+ (Some(Constant::Vec(vec)), _) => {
+ if !vec.is_empty() && vec.iter().all(|x| *x == vec[0]) {
+ match vec.get(0) {
+ Some(Constant::F32(x)) => Some(Constant::F32(*x)),
+ Some(Constant::F64(x)) => Some(Constant::F64(*x)),
+ _ => None,
+ }
+ } else {
+ None
+ }
+ },
+ _ => None,
+ }
+ }
+
+ /// A block can only yield a constant if it only has one constant expression.
+ fn block(&mut self, block: &Block<'_>) -> Option {
+ if block.stmts.is_empty() {
+ block.expr.as_ref().and_then(|b| self.expr(b))
+ } else {
+ None
+ }
+ }
+
+ fn ifthenelse(&mut self, cond: &Expr<'_>, then: &Expr<'_>, otherwise: Option<&Expr<'_>>) -> Option {
+ if let Some(Constant::Bool(b)) = self.expr(cond) {
+ if b {
+ self.expr(&*then)
+ } else {
+ otherwise.as_ref().and_then(|expr| self.expr(expr))
+ }
+ } else {
+ None
+ }
+ }
+
+ fn binop(&mut self, op: BinOp, left: &Expr<'_>, right: &Expr<'_>) -> Option {
+ let l = self.expr(left)?;
+ let r = self.expr(right);
+ match (l, r) {
+ (Constant::Int(l), Some(Constant::Int(r))) => match self.tables.expr_ty(left).kind {
+ ty::Int(ity) => {
+ let l = sext(self.lcx.tcx, l, ity);
+ let r = sext(self.lcx.tcx, r, ity);
+ let zext = |n: i128| Constant::Int(unsext(self.lcx.tcx, n, ity));
+ match op.node {
+ BinOpKind::Add => l.checked_add(r).map(zext),
+ BinOpKind::Sub => l.checked_sub(r).map(zext),
+ BinOpKind::Mul => l.checked_mul(r).map(zext),
+ BinOpKind::Div if r != 0 => l.checked_div(r).map(zext),
+ BinOpKind::Rem if r != 0 => l.checked_rem(r).map(zext),
+ BinOpKind::Shr => l.checked_shr(r.try_into().expect("invalid shift")).map(zext),
+ BinOpKind::Shl => l.checked_shl(r.try_into().expect("invalid shift")).map(zext),
+ BinOpKind::BitXor => Some(zext(l ^ r)),
+ BinOpKind::BitOr => Some(zext(l | r)),
+ BinOpKind::BitAnd => Some(zext(l & r)),
+ BinOpKind::Eq => Some(Constant::Bool(l == r)),
+ BinOpKind::Ne => Some(Constant::Bool(l != r)),
+ BinOpKind::Lt => Some(Constant::Bool(l < r)),
+ BinOpKind::Le => Some(Constant::Bool(l <= r)),
+ BinOpKind::Ge => Some(Constant::Bool(l >= r)),
+ BinOpKind::Gt => Some(Constant::Bool(l > r)),
+ _ => None,
+ }
+ },
+ ty::Uint(_) => match op.node {
+ BinOpKind::Add => l.checked_add(r).map(Constant::Int),
+ BinOpKind::Sub => l.checked_sub(r).map(Constant::Int),
+ BinOpKind::Mul => l.checked_mul(r).map(Constant::Int),
+ BinOpKind::Div => l.checked_div(r).map(Constant::Int),
+ BinOpKind::Rem => l.checked_rem(r).map(Constant::Int),
+ BinOpKind::Shr => l.checked_shr(r.try_into().expect("shift too large")).map(Constant::Int),
+ BinOpKind::Shl => l.checked_shl(r.try_into().expect("shift too large")).map(Constant::Int),
+ BinOpKind::BitXor => Some(Constant::Int(l ^ r)),
+ BinOpKind::BitOr => Some(Constant::Int(l | r)),
+ BinOpKind::BitAnd => Some(Constant::Int(l & r)),
+ BinOpKind::Eq => Some(Constant::Bool(l == r)),
+ BinOpKind::Ne => Some(Constant::Bool(l != r)),
+ BinOpKind::Lt => Some(Constant::Bool(l < r)),
+ BinOpKind::Le => Some(Constant::Bool(l <= r)),
+ BinOpKind::Ge => Some(Constant::Bool(l >= r)),
+ BinOpKind::Gt => Some(Constant::Bool(l > r)),
+ _ => None,
+ },
+ _ => None,
+ },
+ (Constant::F32(l), Some(Constant::F32(r))) => match op.node {
+ BinOpKind::Add => Some(Constant::F32(l + r)),
+ BinOpKind::Sub => Some(Constant::F32(l - r)),
+ BinOpKind::Mul => Some(Constant::F32(l * r)),
+ BinOpKind::Div => Some(Constant::F32(l / r)),
+ BinOpKind::Rem => Some(Constant::F32(l % r)),
+ BinOpKind::Eq => Some(Constant::Bool(l == r)),
+ BinOpKind::Ne => Some(Constant::Bool(l != r)),
+ BinOpKind::Lt => Some(Constant::Bool(l < r)),
+ BinOpKind::Le => Some(Constant::Bool(l <= r)),
+ BinOpKind::Ge => Some(Constant::Bool(l >= r)),
+ BinOpKind::Gt => Some(Constant::Bool(l > r)),
+ _ => None,
+ },
+ (Constant::F64(l), Some(Constant::F64(r))) => match op.node {
+ BinOpKind::Add => Some(Constant::F64(l + r)),
+ BinOpKind::Sub => Some(Constant::F64(l - r)),
+ BinOpKind::Mul => Some(Constant::F64(l * r)),
+ BinOpKind::Div => Some(Constant::F64(l / r)),
+ BinOpKind::Rem => Some(Constant::F64(l % r)),
+ BinOpKind::Eq => Some(Constant::Bool(l == r)),
+ BinOpKind::Ne => Some(Constant::Bool(l != r)),
+ BinOpKind::Lt => Some(Constant::Bool(l < r)),
+ BinOpKind::Le => Some(Constant::Bool(l <= r)),
+ BinOpKind::Ge => Some(Constant::Bool(l >= r)),
+ BinOpKind::Gt => Some(Constant::Bool(l > r)),
+ _ => None,
+ },
+ (l, r) => match (op.node, l, r) {
+ (BinOpKind::And, Constant::Bool(false), _) => Some(Constant::Bool(false)),
+ (BinOpKind::Or, Constant::Bool(true), _) => Some(Constant::Bool(true)),
+ (BinOpKind::And, Constant::Bool(true), Some(r)) | (BinOpKind::Or, Constant::Bool(false), Some(r)) => {
+ Some(r)
+ },
+ (BinOpKind::BitXor, Constant::Bool(l), Some(Constant::Bool(r))) => Some(Constant::Bool(l ^ r)),
+ (BinOpKind::BitAnd, Constant::Bool(l), Some(Constant::Bool(r))) => Some(Constant::Bool(l & r)),
+ (BinOpKind::BitOr, Constant::Bool(l), Some(Constant::Bool(r))) => Some(Constant::Bool(l | r)),
+ _ => None,
+ },
+ }
+ }
+}
+
+pub fn miri_to_const(result: &ty::Const<'_>) -> Option {
+ use rustc_middle::mir::interpret::{ConstValue, Scalar};
+ match result.val {
+ ty::ConstKind::Value(ConstValue::Scalar(Scalar::Raw { data: d, .. })) => match result.ty.kind {
+ ty::Bool => Some(Constant::Bool(d == 1)),
+ ty::Uint(_) | ty::Int(_) => Some(Constant::Int(d)),
+ ty::Float(FloatTy::F32) => Some(Constant::F32(f32::from_bits(
+ d.try_into().expect("invalid f32 bit representation"),
+ ))),
+ ty::Float(FloatTy::F64) => Some(Constant::F64(f64::from_bits(
+ d.try_into().expect("invalid f64 bit representation"),
+ ))),
+ ty::RawPtr(type_and_mut) => {
+ if let ty::Uint(_) = type_and_mut.ty.kind {
+ return Some(Constant::RawPtr(d));
+ }
+ None
+ },
+ // FIXME: implement other conversions.
+ _ => None,
+ },
+ ty::ConstKind::Value(ConstValue::Slice { data, start, end }) => match result.ty.kind {
+ ty::Ref(_, tam, _) => match tam.kind {
+ ty::Str => String::from_utf8(
+ data.inspect_with_undef_and_ptr_outside_interpreter(start..end)
+ .to_owned(),
+ )
+ .ok()
+ .map(Constant::Str),
+ _ => None,
+ },
+ _ => None,
+ },
+ ty::ConstKind::Value(ConstValue::ByRef { alloc, offset: _ }) => match result.ty.kind {
+ ty::Array(sub_type, len) => match sub_type.kind {
+ ty::Float(FloatTy::F32) => match miri_to_const(len) {
+ Some(Constant::Int(len)) => alloc
+ .inspect_with_undef_and_ptr_outside_interpreter(0..(4 * len as usize))
+ .to_owned()
+ .chunks(4)
+ .map(|chunk| {
+ Some(Constant::F32(f32::from_le_bytes(
+ chunk.try_into().expect("this shouldn't happen"),
+ )))
+ })
+ .collect::>>()
+ .map(Constant::Vec),
+ _ => None,
+ },
+ ty::Float(FloatTy::F64) => match miri_to_const(len) {
+ Some(Constant::Int(len)) => alloc
+ .inspect_with_undef_and_ptr_outside_interpreter(0..(8 * len as usize))
+ .to_owned()
+ .chunks(8)
+ .map(|chunk| {
+ Some(Constant::F64(f64::from_le_bytes(
+ chunk.try_into().expect("this shouldn't happen"),
+ )))
+ })
+ .collect::>>()
+ .map(Constant::Vec),
+ _ => None,
+ },
+ // FIXME: implement other array type conversions.
+ _ => None,
+ },
+ _ => None,
+ },
+ // FIXME: implement other conversions.
+ _ => None,
+ }
+}
diff --git a/src/tools/clippy/clippy_lints/src/copies.rs b/src/tools/clippy/clippy_lints/src/copies.rs
new file mode 100644
index 00000000000..66722786eab
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/copies.rs
@@ -0,0 +1,417 @@
+use crate::utils::{get_parent_expr, higher, if_sequence, same_tys, snippet, span_lint_and_note, span_lint_and_then};
+use crate::utils::{SpanlessEq, SpanlessHash};
+use rustc_data_structures::fx::FxHashMap;
+use rustc_hir::{Arm, Block, Expr, ExprKind, MatchSource, Pat, PatKind};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty::Ty;
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::symbol::Symbol;
+use std::collections::hash_map::Entry;
+use std::hash::BuildHasherDefault;
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for consecutive `if`s with the same condition.
+ ///
+ /// **Why is this bad?** This is probably a copy & paste error.
+ ///
+ /// **Known problems:** Hopefully none.
+ ///
+ /// **Example:**
+ /// ```ignore
+ /// if a == b {
+ /// …
+ /// } else if a == b {
+ /// …
+ /// }
+ /// ```
+ ///
+ /// Note that this lint ignores all conditions with a function call as it could
+ /// have side effects:
+ ///
+ /// ```ignore
+ /// if foo() {
+ /// …
+ /// } else if foo() { // not linted
+ /// …
+ /// }
+ /// ```
+ pub IFS_SAME_COND,
+ correctness,
+ "consecutive `if`s with the same condition"
+}
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for consecutive `if`s with the same function call.
+ ///
+ /// **Why is this bad?** This is probably a copy & paste error.
+ /// Despite the fact that function can have side effects and `if` works as
+ /// intended, such an approach is implicit and can be considered a "code smell".
+ ///
+ /// **Known problems:** Hopefully none.
+ ///
+ /// **Example:**
+ /// ```ignore
+ /// if foo() == bar {
+ /// …
+ /// } else if foo() == bar {
+ /// …
+ /// }
+ /// ```
+ ///
+ /// This probably should be:
+ /// ```ignore
+ /// if foo() == bar {
+ /// …
+ /// } else if foo() == baz {
+ /// …
+ /// }
+ /// ```
+ ///
+ /// or if the original code was not a typo and called function mutates a state,
+ /// consider move the mutation out of the `if` condition to avoid similarity to
+ /// a copy & paste error:
+ ///
+ /// ```ignore
+ /// let first = foo();
+ /// if first == bar {
+ /// …
+ /// } else {
+ /// let second = foo();
+ /// if second == bar {
+ /// …
+ /// }
+ /// }
+ /// ```
+ pub SAME_FUNCTIONS_IN_IF_CONDITION,
+ pedantic,
+ "consecutive `if`s with the same function call"
+}
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for `if/else` with the same body as the *then* part
+ /// and the *else* part.
+ ///
+ /// **Why is this bad?** This is probably a copy & paste error.
+ ///
+ /// **Known problems:** Hopefully none.
+ ///
+ /// **Example:**
+ /// ```ignore
+ /// let foo = if … {
+ /// 42
+ /// } else {
+ /// 42
+ /// };
+ /// ```
+ pub IF_SAME_THEN_ELSE,
+ correctness,
+ "`if` with the same `then` and `else` blocks"
+}
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for `match` with identical arm bodies.
+ ///
+ /// **Why is this bad?** This is probably a copy & paste error. If arm bodies
+ /// are the same on purpose, you can factor them
+ /// [using `|`](https://doc.rust-lang.org/book/patterns.html#multiple-patterns).
+ ///
+ /// **Known problems:** False positive possible with order dependent `match`
+ /// (see issue
+ /// [#860](https://github.com/rust-lang/rust-clippy/issues/860)).
+ ///
+ /// **Example:**
+ /// ```rust,ignore
+ /// match foo {
+ /// Bar => bar(),
+ /// Quz => quz(),
+ /// Baz => bar(), // <= oops
+ /// }
+ /// ```
+ ///
+ /// This should probably be
+ /// ```rust,ignore
+ /// match foo {
+ /// Bar => bar(),
+ /// Quz => quz(),
+ /// Baz => baz(), // <= fixed
+ /// }
+ /// ```
+ ///
+ /// or if the original code was not a typo:
+ /// ```rust,ignore
+ /// match foo {
+ /// Bar | Baz => bar(), // <= shows the intent better
+ /// Quz => quz(),
+ /// }
+ /// ```
+ pub MATCH_SAME_ARMS,
+ pedantic,
+ "`match` with identical arm bodies"
+}
+
+declare_lint_pass!(CopyAndPaste => [IFS_SAME_COND, SAME_FUNCTIONS_IN_IF_CONDITION, IF_SAME_THEN_ELSE, MATCH_SAME_ARMS]);
+
+impl<'a, 'tcx> LateLintPass<'a, 'tcx> for CopyAndPaste {
+ fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr<'_>) {
+ if !expr.span.from_expansion() {
+ // skip ifs directly in else, it will be checked in the parent if
+ if let Some(expr) = get_parent_expr(cx, expr) {
+ if let Some((_, _, Some(ref else_expr))) = higher::if_block(&expr) {
+ if else_expr.hir_id == expr.hir_id {
+ return;
+ }
+ }
+ }
+
+ let (conds, blocks) = if_sequence(expr);
+ lint_same_then_else(cx, &blocks);
+ lint_same_cond(cx, &conds);
+ lint_same_fns_in_if_cond(cx, &conds);
+ lint_match_arms(cx, expr);
+ }
+ }
+}
+
+/// Implementation of `IF_SAME_THEN_ELSE`.
+fn lint_same_then_else(cx: &LateContext<'_, '_>, blocks: &[&Block<'_>]) {
+ let eq: &dyn Fn(&&Block<'_>, &&Block<'_>) -> bool =
+ &|&lhs, &rhs| -> bool { SpanlessEq::new(cx).eq_block(lhs, rhs) };
+
+ if let Some((i, j)) = search_same_sequenced(blocks, eq) {
+ span_lint_and_note(
+ cx,
+ IF_SAME_THEN_ELSE,
+ j.span,
+ "this `if` has identical blocks",
+ Some(i.span),
+ "same as this",
+ );
+ }
+}
+
+/// Implementation of `IFS_SAME_COND`.
+fn lint_same_cond(cx: &LateContext<'_, '_>, conds: &[&Expr<'_>]) {
+ let hash: &dyn Fn(&&Expr<'_>) -> u64 = &|expr| -> u64 {
+ let mut h = SpanlessHash::new(cx, cx.tables);
+ h.hash_expr(expr);
+ h.finish()
+ };
+
+ let eq: &dyn Fn(&&Expr<'_>, &&Expr<'_>) -> bool =
+ &|&lhs, &rhs| -> bool { SpanlessEq::new(cx).ignore_fn().eq_expr(lhs, rhs) };
+
+ for (i, j) in search_same(conds, hash, eq) {
+ span_lint_and_note(
+ cx,
+ IFS_SAME_COND,
+ j.span,
+ "this `if` has the same condition as a previous `if`",
+ Some(i.span),
+ "same as this",
+ );
+ }
+}
+
+/// Implementation of `SAME_FUNCTIONS_IN_IF_CONDITION`.
+fn lint_same_fns_in_if_cond(cx: &LateContext<'_, '_>, conds: &[&Expr<'_>]) {
+ let hash: &dyn Fn(&&Expr<'_>) -> u64 = &|expr| -> u64 {
+ let mut h = SpanlessHash::new(cx, cx.tables);
+ h.hash_expr(expr);
+ h.finish()
+ };
+
+ let eq: &dyn Fn(&&Expr<'_>, &&Expr<'_>) -> bool = &|&lhs, &rhs| -> bool {
+ // Do not spawn warning if `IFS_SAME_COND` already produced it.
+ if SpanlessEq::new(cx).ignore_fn().eq_expr(lhs, rhs) {
+ return false;
+ }
+ SpanlessEq::new(cx).eq_expr(lhs, rhs)
+ };
+
+ for (i, j) in search_same(conds, hash, eq) {
+ span_lint_and_note(
+ cx,
+ SAME_FUNCTIONS_IN_IF_CONDITION,
+ j.span,
+ "this `if` has the same function call as a previous `if`",
+ Some(i.span),
+ "same as this",
+ );
+ }
+}
+
+/// Implementation of `MATCH_SAME_ARMS`.
+fn lint_match_arms<'tcx>(cx: &LateContext<'_, 'tcx>, expr: &Expr<'_>) {
+ fn same_bindings<'tcx>(
+ cx: &LateContext<'_, 'tcx>,
+ lhs: &FxHashMap>,
+ rhs: &FxHashMap>,
+ ) -> bool {
+ lhs.len() == rhs.len()
+ && lhs
+ .iter()
+ .all(|(name, l_ty)| rhs.get(name).map_or(false, |r_ty| same_tys(cx, l_ty, r_ty)))
+ }
+
+ if let ExprKind::Match(_, ref arms, MatchSource::Normal) = expr.kind {
+ let hash = |&(_, arm): &(usize, &Arm<'_>)| -> u64 {
+ let mut h = SpanlessHash::new(cx, cx.tables);
+ h.hash_expr(&arm.body);
+ h.finish()
+ };
+
+ let eq = |&(lindex, lhs): &(usize, &Arm<'_>), &(rindex, rhs): &(usize, &Arm<'_>)| -> bool {
+ let min_index = usize::min(lindex, rindex);
+ let max_index = usize::max(lindex, rindex);
+
+ // Arms with a guard are ignored, those can’t always be merged together
+ // This is also the case for arms in-between each there is an arm with a guard
+ (min_index..=max_index).all(|index| arms[index].guard.is_none()) &&
+ SpanlessEq::new(cx).eq_expr(&lhs.body, &rhs.body) &&
+ // all patterns should have the same bindings
+ same_bindings(cx, &bindings(cx, &lhs.pat), &bindings(cx, &rhs.pat))
+ };
+
+ let indexed_arms: Vec<(usize, &Arm<'_>)> = arms.iter().enumerate().collect();
+ for (&(_, i), &(_, j)) in search_same(&indexed_arms, hash, eq) {
+ span_lint_and_then(
+ cx,
+ MATCH_SAME_ARMS,
+ j.body.span,
+ "this `match` has identical arm bodies",
+ |diag| {
+ diag.span_note(i.body.span, "same as this");
+
+ // Note: this does not use `span_suggestion` on purpose:
+ // there is no clean way
+ // to remove the other arm. Building a span and suggest to replace it to ""
+ // makes an even more confusing error message. Also in order not to make up a
+ // span for the whole pattern, the suggestion is only shown when there is only
+ // one pattern. The user should know about `|` if they are already using it…
+
+ let lhs = snippet(cx, i.pat.span, "");
+ let rhs = snippet(cx, j.pat.span, "");
+
+ if let PatKind::Wild = j.pat.kind {
+ // if the last arm is _, then i could be integrated into _
+ // note that i.pat cannot be _, because that would mean that we're
+ // hiding all the subsequent arms, and rust won't compile
+ diag.span_note(
+ i.body.span,
+ &format!(
+ "`{}` has the same arm body as the `_` wildcard, consider removing it",
+ lhs
+ ),
+ );
+ } else {
+ diag.span_help(i.pat.span, &format!("consider refactoring into `{} | {}`", lhs, rhs));
+ }
+ },
+ );
+ }
+ }
+}
+
+/// Returns the list of bindings in a pattern.
+fn bindings<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, pat: &Pat<'_>) -> FxHashMap> {
+ fn bindings_impl<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, pat: &Pat<'_>, map: &mut FxHashMap>) {
+ match pat.kind {
+ PatKind::Box(ref pat) | PatKind::Ref(ref pat, _) => bindings_impl(cx, pat, map),
+ PatKind::TupleStruct(_, pats, _) => {
+ for pat in pats {
+ bindings_impl(cx, pat, map);
+ }
+ },
+ PatKind::Binding(.., ident, ref as_pat) => {
+ if let Entry::Vacant(v) = map.entry(ident.name) {
+ v.insert(cx.tables.pat_ty(pat));
+ }
+ if let Some(ref as_pat) = *as_pat {
+ bindings_impl(cx, as_pat, map);
+ }
+ },
+ PatKind::Or(fields) | PatKind::Tuple(fields, _) => {
+ for pat in fields {
+ bindings_impl(cx, pat, map);
+ }
+ },
+ PatKind::Struct(_, fields, _) => {
+ for pat in fields {
+ bindings_impl(cx, &pat.pat, map);
+ }
+ },
+ PatKind::Slice(lhs, ref mid, rhs) => {
+ for pat in lhs {
+ bindings_impl(cx, pat, map);
+ }
+ if let Some(ref mid) = *mid {
+ bindings_impl(cx, mid, map);
+ }
+ for pat in rhs {
+ bindings_impl(cx, pat, map);
+ }
+ },
+ PatKind::Lit(..) | PatKind::Range(..) | PatKind::Wild | PatKind::Path(..) => (),
+ }
+ }
+
+ let mut result = FxHashMap::default();
+ bindings_impl(cx, pat, &mut result);
+ result
+}
+
+fn search_same_sequenced(exprs: &[T], eq: Eq) -> Option<(&T, &T)>
+where
+ Eq: Fn(&T, &T) -> bool,
+{
+ for win in exprs.windows(2) {
+ if eq(&win[0], &win[1]) {
+ return Some((&win[0], &win[1]));
+ }
+ }
+ None
+}
+
+fn search_common_cases<'a, T, Eq>(exprs: &'a [T], eq: &Eq) -> Option<(&'a T, &'a T)>
+where
+ Eq: Fn(&T, &T) -> bool,
+{
+ if exprs.len() == 2 && eq(&exprs[0], &exprs[1]) {
+ Some((&exprs[0], &exprs[1]))
+ } else {
+ None
+ }
+}
+
+fn search_same(exprs: &[T], hash: Hash, eq: Eq) -> Vec<(&T, &T)>
+where
+ Hash: Fn(&T) -> u64,
+ Eq: Fn(&T, &T) -> bool,
+{
+ if let Some(expr) = search_common_cases(&exprs, &eq) {
+ return vec![expr];
+ }
+
+ let mut match_expr_list: Vec<(&T, &T)> = Vec::new();
+
+ let mut map: FxHashMap<_, Vec<&_>> =
+ FxHashMap::with_capacity_and_hasher(exprs.len(), BuildHasherDefault::default());
+
+ for expr in exprs {
+ match map.entry(hash(expr)) {
+ Entry::Occupied(mut o) => {
+ for o in o.get() {
+ if eq(o, expr) {
+ match_expr_list.push((o, expr));
+ }
+ }
+ o.get_mut().push(expr);
+ },
+ Entry::Vacant(v) => {
+ v.insert(vec![expr]);
+ },
+ }
+ }
+
+ match_expr_list
+}
diff --git a/src/tools/clippy/clippy_lints/src/copy_iterator.rs b/src/tools/clippy/clippy_lints/src/copy_iterator.rs
new file mode 100644
index 00000000000..d79aa2ef020
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/copy_iterator.rs
@@ -0,0 +1,55 @@
+use crate::utils::{is_copy, match_path, paths, span_lint_and_note};
+use rustc_hir::{Item, ItemKind};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for types that implement `Copy` as well as
+ /// `Iterator`.
+ ///
+ /// **Why is this bad?** Implicit copies can be confusing when working with
+ /// iterator combinators.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```rust,ignore
+ /// #[derive(Copy, Clone)]
+ /// struct Countdown(u8);
+ ///
+ /// impl Iterator for Countdown {
+ /// // ...
+ /// }
+ ///
+ /// let a: Vec<_> = my_iterator.take(1).collect();
+ /// let b: Vec<_> = my_iterator.collect();
+ /// ```
+ pub COPY_ITERATOR,
+ pedantic,
+ "implementing `Iterator` on a `Copy` type"
+}
+
+declare_lint_pass!(CopyIterator => [COPY_ITERATOR]);
+
+impl<'a, 'tcx> LateLintPass<'a, 'tcx> for CopyIterator {
+ fn check_item(&mut self, cx: &LateContext<'a, 'tcx>, item: &'tcx Item<'_>) {
+ if let ItemKind::Impl {
+ of_trait: Some(ref trait_ref),
+ ..
+ } = item.kind
+ {
+ let ty = cx.tcx.type_of(cx.tcx.hir().local_def_id(item.hir_id));
+
+ if is_copy(cx, ty) && match_path(&trait_ref.path, &paths::ITERATOR) {
+ span_lint_and_note(
+ cx,
+ COPY_ITERATOR,
+ item.span,
+ "you are implementing `Iterator` on a `Copy` type",
+ None,
+ "consider implementing `IntoIterator` instead",
+ );
+ }
+ }
+ }
+}
diff --git a/src/tools/clippy/clippy_lints/src/dbg_macro.rs b/src/tools/clippy/clippy_lints/src/dbg_macro.rs
new file mode 100644
index 00000000000..e513dcce64e
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/dbg_macro.rs
@@ -0,0 +1,65 @@
+use crate::utils::{snippet_opt, span_lint_and_help, span_lint_and_sugg};
+use rustc_ast::ast;
+use rustc_ast::tokenstream::TokenStream;
+use rustc_errors::Applicability;
+use rustc_lint::{EarlyContext, EarlyLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::source_map::Span;
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for usage of dbg!() macro.
+ ///
+ /// **Why is this bad?** `dbg!` macro is intended as a debugging tool. It
+ /// should not be in version control.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```rust,ignore
+ /// // Bad
+ /// dbg!(true)
+ ///
+ /// // Good
+ /// true
+ /// ```
+ pub DBG_MACRO,
+ restriction,
+ "`dbg!` macro is intended as a debugging tool"
+}
+
+declare_lint_pass!(DbgMacro => [DBG_MACRO]);
+
+impl EarlyLintPass for DbgMacro {
+ fn check_mac(&mut self, cx: &EarlyContext<'_>, mac: &ast::MacCall) {
+ if mac.path == sym!(dbg) {
+ if let Some(sugg) = tts_span(mac.args.inner_tokens()).and_then(|span| snippet_opt(cx, span)) {
+ span_lint_and_sugg(
+ cx,
+ DBG_MACRO,
+ mac.span(),
+ "`dbg!` macro is intended as a debugging tool",
+ "ensure to avoid having uses of it in version control",
+ sugg,
+ Applicability::MaybeIncorrect,
+ );
+ } else {
+ span_lint_and_help(
+ cx,
+ DBG_MACRO,
+ mac.span(),
+ "`dbg!` macro is intended as a debugging tool",
+ None,
+ "ensure to avoid having uses of it in version control",
+ );
+ }
+ }
+ }
+}
+
+// Get span enclosing entire the token stream.
+fn tts_span(tts: TokenStream) -> Option {
+ let mut cursor = tts.into_trees();
+ let first = cursor.next()?.span();
+ let span = cursor.last().map_or(first, |tree| first.to(tree.span()));
+ Some(span)
+}
diff --git a/src/tools/clippy/clippy_lints/src/default_trait_access.rs b/src/tools/clippy/clippy_lints/src/default_trait_access.rs
new file mode 100644
index 00000000000..635d609c382
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/default_trait_access.rs
@@ -0,0 +1,76 @@
+use if_chain::if_chain;
+use rustc_errors::Applicability;
+use rustc_hir::{Expr, ExprKind, QPath};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty;
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+
+use crate::utils::{any_parent_is_automatically_derived, match_def_path, paths, span_lint_and_sugg};
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for literal calls to `Default::default()`.
+ ///
+ /// **Why is this bad?** It's more clear to the reader to use the name of the type whose default is
+ /// being gotten than the generic `Default`.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```rust
+ /// // Bad
+ /// let s: String = Default::default();
+ ///
+ /// // Good
+ /// let s = String::default();
+ /// ```
+ pub DEFAULT_TRAIT_ACCESS,
+ pedantic,
+ "checks for literal calls to `Default::default()`"
+}
+
+declare_lint_pass!(DefaultTraitAccess => [DEFAULT_TRAIT_ACCESS]);
+
+impl<'a, 'tcx> LateLintPass<'a, 'tcx> for DefaultTraitAccess {
+ fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr<'_>) {
+ if_chain! {
+ if let ExprKind::Call(ref path, ..) = expr.kind;
+ if !any_parent_is_automatically_derived(cx.tcx, expr.hir_id);
+ if let ExprKind::Path(ref qpath) = path.kind;
+ if let Some(def_id) = cx.tables.qpath_res(qpath, path.hir_id).opt_def_id();
+ if match_def_path(cx, def_id, &paths::DEFAULT_TRAIT_METHOD);
+ then {
+ match qpath {
+ QPath::Resolved(..) => {
+ if_chain! {
+ // Detect and ignore ::default() because these calls do
+ // explicitly name the type.
+ if let ExprKind::Call(ref method, ref _args) = expr.kind;
+ if let ExprKind::Path(ref p) = method.kind;
+ if let QPath::Resolved(Some(_ty), _path) = p;
+ then {
+ return;
+ }
+ }
+
+ // TODO: Work out a way to put "whatever the imported way of referencing
+ // this type in this file" rather than a fully-qualified type.
+ let expr_ty = cx.tables.expr_ty(expr);
+ if let ty::Adt(..) = expr_ty.kind {
+ let replacement = format!("{}::default()", expr_ty);
+ span_lint_and_sugg(
+ cx,
+ DEFAULT_TRAIT_ACCESS,
+ expr.span,
+ &format!("Calling `{}` is more clear than this expression", replacement),
+ "try",
+ replacement,
+ Applicability::Unspecified, // First resolve the TODO above
+ );
+ }
+ },
+ QPath::TypeRelative(..) => {},
+ }
+ }
+ }
+ }
+}
diff --git a/src/tools/clippy/clippy_lints/src/deprecated_lints.rs b/src/tools/clippy/clippy_lints/src/deprecated_lints.rs
new file mode 100644
index 00000000000..6e8ca647dd7
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/deprecated_lints.rs
@@ -0,0 +1,157 @@
+macro_rules! declare_deprecated_lint {
+ (pub $name: ident, $_reason: expr) => {
+ declare_lint!(pub $name, Allow, "deprecated lint")
+ }
+}
+
+declare_deprecated_lint! {
+ /// **What it does:** Nothing. This lint has been deprecated.
+ ///
+ /// **Deprecation reason:** This used to check for `assert!(a == b)` and recommend
+ /// replacement with `assert_eq!(a, b)`, but this is no longer needed after RFC 2011.
+ pub SHOULD_ASSERT_EQ,
+ "`assert!()` will be more flexible with RFC 2011"
+}
+
+declare_deprecated_lint! {
+ /// **What it does:** Nothing. This lint has been deprecated.
+ ///
+ /// **Deprecation reason:** This used to check for `Vec::extend`, which was slower than
+ /// `Vec::extend_from_slice`. Thanks to specialization, this is no longer true.
+ pub EXTEND_FROM_SLICE,
+ "`.extend_from_slice(_)` is a faster way to extend a Vec by a slice"
+}
+
+declare_deprecated_lint! {
+ /// **What it does:** Nothing. This lint has been deprecated.
+ ///
+ /// **Deprecation reason:** `Range::step_by(0)` used to be linted since it's
+ /// an infinite iterator, which is better expressed by `iter::repeat`,
+ /// but the method has been removed for `Iterator::step_by` which panics
+ /// if given a zero
+ pub RANGE_STEP_BY_ZERO,
+ "`iterator.step_by(0)` panics nowadays"
+}
+
+declare_deprecated_lint! {
+ /// **What it does:** Nothing. This lint has been deprecated.
+ ///
+ /// **Deprecation reason:** This used to check for `Vec::as_slice`, which was unstable with good
+ /// stable alternatives. `Vec::as_slice` has now been stabilized.
+ pub UNSTABLE_AS_SLICE,
+ "`Vec::as_slice` has been stabilized in 1.7"
+}
+
+declare_deprecated_lint! {
+ /// **What it does:** Nothing. This lint has been deprecated.
+ ///
+ /// **Deprecation reason:** This used to check for `Vec::as_mut_slice`, which was unstable with good
+ /// stable alternatives. `Vec::as_mut_slice` has now been stabilized.
+ pub UNSTABLE_AS_MUT_SLICE,
+ "`Vec::as_mut_slice` has been stabilized in 1.7"
+}
+
+declare_deprecated_lint! {
+ /// **What it does:** Nothing. This lint has been deprecated.
+ ///
+ /// **Deprecation reason:** This used to check for `.to_string()` method calls on values
+ /// of type `&str`. This is not unidiomatic and with specialization coming, `to_string` could be
+ /// specialized to be as efficient as `to_owned`.
+ pub STR_TO_STRING,
+ "using `str::to_string` is common even today and specialization will likely happen soon"
+}
+
+declare_deprecated_lint! {
+ /// **What it does:** Nothing. This lint has been deprecated.
+ ///
+ /// **Deprecation reason:** This used to check for `.to_string()` method calls on values
+ /// of type `String`. This is not unidiomatic and with specialization coming, `to_string` could be
+ /// specialized to be as efficient as `clone`.
+ pub STRING_TO_STRING,
+ "using `string::to_string` is common even today and specialization will likely happen soon"
+}
+
+declare_deprecated_lint! {
+ /// **What it does:** Nothing. This lint has been deprecated.
+ ///
+ /// **Deprecation reason:** This lint should never have applied to non-pointer types, as transmuting
+ /// between non-pointer types of differing alignment is well-defined behavior (it's semantically
+ /// equivalent to a memcpy). This lint has thus been refactored into two separate lints:
+ /// cast_ptr_alignment and transmute_ptr_to_ptr.
+ pub MISALIGNED_TRANSMUTE,
+ "this lint has been split into cast_ptr_alignment and transmute_ptr_to_ptr"
+}
+
+declare_deprecated_lint! {
+ /// **What it does:** Nothing. This lint has been deprecated.
+ ///
+ /// **Deprecation reason:** This lint is too subjective, not having a good reason for being in clippy.
+ /// Additionally, compound assignment operators may be overloaded separately from their non-assigning
+ /// counterparts, so this lint may suggest a change in behavior or the code may not compile.
+ pub ASSIGN_OPS,
+ "using compound assignment operators (e.g., `+=`) is harmless"
+}
+
+declare_deprecated_lint! {
+ /// **What it does:** Nothing. This lint has been deprecated.
+ ///
+ /// **Deprecation reason:** The original rule will only lint for `if let`. After
+ /// making it support to lint `match`, naming as `if let` is not suitable for it.
+ /// So, this lint is deprecated.
+ pub IF_LET_REDUNDANT_PATTERN_MATCHING,
+ "this lint has been changed to redundant_pattern_matching"
+}
+
+declare_deprecated_lint! {
+ /// **What it does:** Nothing. This lint has been deprecated.
+ ///
+ /// **Deprecation reason:** This lint used to suggest replacing `let mut vec =
+ /// Vec::with_capacity(n); vec.set_len(n);` with `let vec = vec![0; n];`. The
+ /// replacement has very different performance characteristics so the lint is
+ /// deprecated.
+ pub UNSAFE_VECTOR_INITIALIZATION,
+ "the replacement suggested by this lint had substantially different behavior"
+}
+
+declare_deprecated_lint! {
+ /// **What it does:** Nothing. This lint has been deprecated.
+ ///
+ /// **Deprecation reason:** This lint has been superseded by the warn-by-default
+ /// `invalid_value` rustc lint.
+ pub INVALID_REF,
+ "superseded by rustc lint `invalid_value`"
+}
+
+declare_deprecated_lint! {
+ /// **What it does:** Nothing. This lint has been deprecated.
+ ///
+ /// **Deprecation reason:** This lint has been superseded by #[must_use] in rustc.
+ pub UNUSED_COLLECT,
+ "`collect` has been marked as #[must_use] in rustc and that covers all cases of this lint"
+}
+
+declare_deprecated_lint! {
+ /// **What it does:** Nothing. This lint has been deprecated.
+ ///
+ /// **Deprecation reason:** This lint has been uplifted to rustc and is now called
+ /// `array_into_iter`.
+ pub INTO_ITER_ON_ARRAY,
+ "this lint has been uplifted to rustc and is now called `array_into_iter`"
+}
+
+declare_deprecated_lint! {
+ /// **What it does:** Nothing. This lint has been deprecated.
+ ///
+ /// **Deprecation reason:** This lint has been uplifted to rustc and is now called
+ /// `unused_labels`.
+ pub UNUSED_LABEL,
+ "this lint has been uplifted to rustc and is now called `unused_labels`"
+}
+
+declare_deprecated_lint! {
+ /// **What it does:** Nothing. This lint has been deprecated.
+ ///
+ /// **Deprecation reason:** Associated-constants are now preferred.
+ pub REPLACE_CONSTS,
+ "associated-constants `MIN`/`MAX` of integers are prefer to `{min,max}_value()` and module constants"
+}
diff --git a/src/tools/clippy/clippy_lints/src/dereference.rs b/src/tools/clippy/clippy_lints/src/dereference.rs
new file mode 100644
index 00000000000..68ec07e2bcb
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/dereference.rs
@@ -0,0 +1,113 @@
+use crate::utils::{get_parent_expr, implements_trait, snippet, span_lint_and_sugg};
+use if_chain::if_chain;
+use rustc_ast::util::parser::{ExprPrecedence, PREC_POSTFIX, PREC_PREFIX};
+use rustc_errors::Applicability;
+use rustc_hir::{Expr, ExprKind};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::source_map::Span;
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for explicit `deref()` or `deref_mut()` method calls.
+ ///
+ /// **Why is this bad?** Derefencing by `&*x` or `&mut *x` is clearer and more concise,
+ /// when not part of a method chain.
+ ///
+ /// **Example:**
+ /// ```rust
+ /// use std::ops::Deref;
+ /// let a: &mut String = &mut String::from("foo");
+ /// let b: &str = a.deref();
+ /// ```
+ /// Could be written as:
+ /// ```rust
+ /// let a: &mut String = &mut String::from("foo");
+ /// let b = &*a;
+ /// ```
+ ///
+ /// This lint excludes
+ /// ```rust,ignore
+ /// let _ = d.unwrap().deref();
+ /// ```
+ pub EXPLICIT_DEREF_METHODS,
+ pedantic,
+ "Explicit use of deref or deref_mut method while not in a method chain."
+}
+
+declare_lint_pass!(Dereferencing => [
+ EXPLICIT_DEREF_METHODS
+]);
+
+impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Dereferencing {
+ fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr<'_>) {
+ if_chain! {
+ if !expr.span.from_expansion();
+ if let ExprKind::MethodCall(ref method_name, _, ref args) = &expr.kind;
+ if args.len() == 1;
+
+ then {
+ if let Some(parent_expr) = get_parent_expr(cx, expr) {
+ // Check if we have the whole call chain here
+ if let ExprKind::MethodCall(..) = parent_expr.kind {
+ return;
+ }
+ // Check for Expr that we don't want to be linted
+ let precedence = parent_expr.precedence();
+ match precedence {
+ // Lint a Call is ok though
+ ExprPrecedence::Call | ExprPrecedence::AddrOf => (),
+ _ => {
+ if precedence.order() >= PREC_PREFIX && precedence.order() <= PREC_POSTFIX {
+ return;
+ }
+ }
+ }
+ }
+ let name = method_name.ident.as_str();
+ lint_deref(cx, &*name, &args[0], args[0].span, expr.span);
+ }
+ }
+ }
+}
+
+fn lint_deref(cx: &LateContext<'_, '_>, method_name: &str, call_expr: &Expr<'_>, var_span: Span, expr_span: Span) {
+ match method_name {
+ "deref" => {
+ if cx
+ .tcx
+ .lang_items()
+ .deref_trait()
+ .map_or(false, |id| implements_trait(cx, cx.tables.expr_ty(&call_expr), id, &[]))
+ {
+ span_lint_and_sugg(
+ cx,
+ EXPLICIT_DEREF_METHODS,
+ expr_span,
+ "explicit deref method call",
+ "try this",
+ format!("&*{}", &snippet(cx, var_span, "..")),
+ Applicability::MachineApplicable,
+ );
+ }
+ },
+ "deref_mut" => {
+ if cx
+ .tcx
+ .lang_items()
+ .deref_mut_trait()
+ .map_or(false, |id| implements_trait(cx, cx.tables.expr_ty(&call_expr), id, &[]))
+ {
+ span_lint_and_sugg(
+ cx,
+ EXPLICIT_DEREF_METHODS,
+ expr_span,
+ "explicit deref_mut method call",
+ "try this",
+ format!("&mut *{}", &snippet(cx, var_span, "..")),
+ Applicability::MachineApplicable,
+ );
+ }
+ },
+ _ => (),
+ }
+}
diff --git a/src/tools/clippy/clippy_lints/src/derive.rs b/src/tools/clippy/clippy_lints/src/derive.rs
new file mode 100644
index 00000000000..3cbb8fa72f7
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/derive.rs
@@ -0,0 +1,309 @@
+use crate::utils::paths;
+use crate::utils::{
+ is_automatically_derived, is_copy, match_path, span_lint_and_help, span_lint_and_note, span_lint_and_then,
+};
+use if_chain::if_chain;
+use rustc_hir::def_id::DefId;
+use rustc_hir::intravisit::{walk_expr, walk_fn, walk_item, FnKind, NestedVisitorMap, Visitor};
+use rustc_hir::{
+ BlockCheckMode, BodyId, Expr, ExprKind, FnDecl, HirId, Item, ItemKind, TraitRef, UnsafeSource, Unsafety,
+};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::hir::map::Map;
+use rustc_middle::ty::{self, Ty};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::source_map::Span;
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for deriving `Hash` but implementing `PartialEq`
+ /// explicitly or vice versa.
+ ///
+ /// **Why is this bad?** The implementation of these traits must agree (for
+ /// example for use with `HashMap`) so it’s probably a bad idea to use a
+ /// default-generated `Hash` implementation with an explicitly defined
+ /// `PartialEq`. In particular, the following must hold for any type:
+ ///
+ /// ```text
+ /// k1 == k2 ⇒ hash(k1) == hash(k2)
+ /// ```
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```ignore
+ /// #[derive(Hash)]
+ /// struct Foo;
+ ///
+ /// impl PartialEq for Foo {
+ /// ...
+ /// }
+ /// ```
+ pub DERIVE_HASH_XOR_EQ,
+ correctness,
+ "deriving `Hash` but implementing `PartialEq` explicitly"
+}
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for explicit `Clone` implementations for `Copy`
+ /// types.
+ ///
+ /// **Why is this bad?** To avoid surprising behaviour, these traits should
+ /// agree and the behaviour of `Copy` cannot be overridden. In almost all
+ /// situations a `Copy` type should have a `Clone` implementation that does
+ /// nothing more than copy the object, which is what `#[derive(Copy, Clone)]`
+ /// gets you.
+ ///
+ /// **Known problems:** Bounds of generic types are sometimes wrong: https://github.com/rust-lang/rust/issues/26925
+ ///
+ /// **Example:**
+ /// ```rust,ignore
+ /// #[derive(Copy)]
+ /// struct Foo;
+ ///
+ /// impl Clone for Foo {
+ /// // ..
+ /// }
+ /// ```
+ pub EXPL_IMPL_CLONE_ON_COPY,
+ pedantic,
+ "implementing `Clone` explicitly on `Copy` types"
+}
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for deriving `serde::Deserialize` on a type that
+ /// has methods using `unsafe`.
+ ///
+ /// **Why is this bad?** Deriving `serde::Deserialize` will create a constructor
+ /// that may violate invariants hold by another constructor.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ ///
+ /// ```rust,ignore
+ /// use serde::Deserialize;
+ ///
+ /// #[derive(Deserialize)]
+ /// pub struct Foo {
+ /// // ..
+ /// }
+ ///
+ /// impl Foo {
+ /// pub fn new() -> Self {
+ /// // setup here ..
+ /// }
+ ///
+ /// pub unsafe fn parts() -> (&str, &str) {
+ /// // assumes invariants hold
+ /// }
+ /// }
+ /// ```
+ pub UNSAFE_DERIVE_DESERIALIZE,
+ pedantic,
+ "deriving `serde::Deserialize` on a type that has methods using `unsafe`"
+}
+
+declare_lint_pass!(Derive => [EXPL_IMPL_CLONE_ON_COPY, DERIVE_HASH_XOR_EQ, UNSAFE_DERIVE_DESERIALIZE]);
+
+impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Derive {
+ fn check_item(&mut self, cx: &LateContext<'a, 'tcx>, item: &'tcx Item<'_>) {
+ if let ItemKind::Impl {
+ of_trait: Some(ref trait_ref),
+ ..
+ } = item.kind
+ {
+ let ty = cx.tcx.type_of(cx.tcx.hir().local_def_id(item.hir_id));
+ let is_automatically_derived = is_automatically_derived(&*item.attrs);
+
+ check_hash_peq(cx, item.span, trait_ref, ty, is_automatically_derived);
+
+ if is_automatically_derived {
+ check_unsafe_derive_deserialize(cx, item, trait_ref, ty);
+ } else {
+ check_copy_clone(cx, item, trait_ref, ty);
+ }
+ }
+ }
+}
+
+/// Implementation of the `DERIVE_HASH_XOR_EQ` lint.
+fn check_hash_peq<'a, 'tcx>(
+ cx: &LateContext<'a, 'tcx>,
+ span: Span,
+ trait_ref: &TraitRef<'_>,
+ ty: Ty<'tcx>,
+ hash_is_automatically_derived: bool,
+) {
+ if_chain! {
+ if match_path(&trait_ref.path, &paths::HASH);
+ if let Some(peq_trait_def_id) = cx.tcx.lang_items().eq_trait();
+ if let Some(def_id) = &trait_ref.trait_def_id();
+ if !def_id.is_local();
+ then {
+ // Look for the PartialEq implementations for `ty`
+ cx.tcx.for_each_relevant_impl(peq_trait_def_id, ty, |impl_id| {
+ let peq_is_automatically_derived = is_automatically_derived(&cx.tcx.get_attrs(impl_id));
+
+ if peq_is_automatically_derived == hash_is_automatically_derived {
+ return;
+ }
+
+ let trait_ref = cx.tcx.impl_trait_ref(impl_id).expect("must be a trait implementation");
+
+ // Only care about `impl PartialEq for Foo`
+ // For `impl PartialEq for A, input_types is [A, B]
+ if trait_ref.substs.type_at(1) == ty {
+ let mess = if peq_is_automatically_derived {
+ "you are implementing `Hash` explicitly but have derived `PartialEq`"
+ } else {
+ "you are deriving `Hash` but have implemented `PartialEq` explicitly"
+ };
+
+ span_lint_and_then(
+ cx,
+ DERIVE_HASH_XOR_EQ,
+ span,
+ mess,
+ |diag| {
+ if let Some(local_def_id) = impl_id.as_local() {
+ let hir_id = cx.tcx.hir().as_local_hir_id(local_def_id);
+ diag.span_note(
+ cx.tcx.hir().span(hir_id),
+ "`PartialEq` implemented here"
+ );
+ }
+ }
+ );
+ }
+ });
+ }
+ }
+}
+
+/// Implementation of the `EXPL_IMPL_CLONE_ON_COPY` lint.
+fn check_copy_clone<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, item: &Item<'_>, trait_ref: &TraitRef<'_>, ty: Ty<'tcx>) {
+ if match_path(&trait_ref.path, &paths::CLONE_TRAIT) {
+ if !is_copy(cx, ty) {
+ return;
+ }
+
+ match ty.kind {
+ ty::Adt(def, _) if def.is_union() => return,
+
+ // Some types are not Clone by default but could be cloned “by hand” if necessary
+ ty::Adt(def, substs) => {
+ for variant in &def.variants {
+ for field in &variant.fields {
+ if let ty::FnDef(..) = field.ty(cx.tcx, substs).kind {
+ return;
+ }
+ }
+ for subst in substs {
+ if let ty::subst::GenericArgKind::Type(subst) = subst.unpack() {
+ if let ty::Param(_) = subst.kind {
+ return;
+ }
+ }
+ }
+ }
+ },
+ _ => (),
+ }
+
+ span_lint_and_note(
+ cx,
+ EXPL_IMPL_CLONE_ON_COPY,
+ item.span,
+ "you are implementing `Clone` explicitly on a `Copy` type",
+ Some(item.span),
+ "consider deriving `Clone` or removing `Copy`",
+ );
+ }
+}
+
+/// Implementation of the `UNSAFE_DERIVE_DESERIALIZE` lint.
+fn check_unsafe_derive_deserialize<'a, 'tcx>(
+ cx: &LateContext<'a, 'tcx>,
+ item: &Item<'_>,
+ trait_ref: &TraitRef<'_>,
+ ty: Ty<'tcx>,
+) {
+ fn item_from_def_id<'tcx>(cx: &LateContext<'_, 'tcx>, def_id: DefId) -> &'tcx Item<'tcx> {
+ let hir_id = cx.tcx.hir().as_local_hir_id(def_id.expect_local());
+ cx.tcx.hir().expect_item(hir_id)
+ }
+
+ fn has_unsafe<'tcx>(cx: &LateContext<'_, 'tcx>, item: &'tcx Item<'_>) -> bool {
+ let mut visitor = UnsafeVisitor { cx, has_unsafe: false };
+ walk_item(&mut visitor, item);
+ visitor.has_unsafe
+ }
+
+ if_chain! {
+ if match_path(&trait_ref.path, &paths::SERDE_DESERIALIZE);
+ if let ty::Adt(def, _) = ty.kind;
+ if def.did.is_local();
+ if cx.tcx.inherent_impls(def.did)
+ .iter()
+ .map(|imp_did| item_from_def_id(cx, *imp_did))
+ .any(|imp| has_unsafe(cx, imp));
+ then {
+ span_lint_and_help(
+ cx,
+ UNSAFE_DERIVE_DESERIALIZE,
+ item.span,
+ "you are deriving `serde::Deserialize` on a type that has methods using `unsafe`",
+ None,
+ "consider implementing `serde::Deserialize` manually. See https://serde.rs/impl-deserialize.html"
+ );
+ }
+ }
+}
+
+struct UnsafeVisitor<'a, 'tcx> {
+ cx: &'a LateContext<'a, 'tcx>,
+ has_unsafe: bool,
+}
+
+impl<'tcx> Visitor<'tcx> for UnsafeVisitor<'_, 'tcx> {
+ type Map = Map<'tcx>;
+
+ fn visit_fn(&mut self, kind: FnKind<'tcx>, decl: &'tcx FnDecl<'_>, body_id: BodyId, span: Span, id: HirId) {
+ if self.has_unsafe {
+ return;
+ }
+
+ if_chain! {
+ if let Some(header) = kind.header();
+ if let Unsafety::Unsafe = header.unsafety;
+ then {
+ self.has_unsafe = true;
+ }
+ }
+
+ walk_fn(self, kind, decl, body_id, span, id);
+ }
+
+ fn visit_expr(&mut self, expr: &'tcx Expr<'_>) {
+ if self.has_unsafe {
+ return;
+ }
+
+ if let ExprKind::Block(block, _) = expr.kind {
+ match block.rules {
+ BlockCheckMode::UnsafeBlock(UnsafeSource::UserProvided)
+ | BlockCheckMode::PushUnsafeBlock(UnsafeSource::UserProvided)
+ | BlockCheckMode::PopUnsafeBlock(UnsafeSource::UserProvided) => {
+ self.has_unsafe = true;
+ },
+ _ => {},
+ }
+ }
+
+ walk_expr(self, expr);
+ }
+
+ fn nested_visit_map(&mut self) -> NestedVisitorMap {
+ NestedVisitorMap::All(self.cx.tcx.hir())
+ }
+}
diff --git a/src/tools/clippy/clippy_lints/src/doc.rs b/src/tools/clippy/clippy_lints/src/doc.rs
new file mode 100644
index 00000000000..8d1e91f9adb
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/doc.rs
@@ -0,0 +1,525 @@
+use crate::utils::{implements_trait, is_entrypoint_fn, is_type_diagnostic_item, return_ty, span_lint};
+use if_chain::if_chain;
+use itertools::Itertools;
+use rustc_ast::ast::{AttrKind, Attribute};
+use rustc_data_structures::fx::FxHashSet;
+use rustc_hir as hir;
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::lint::in_external_macro;
+use rustc_middle::ty;
+use rustc_session::{declare_tool_lint, impl_lint_pass};
+use rustc_span::source_map::{BytePos, MultiSpan, Span};
+use rustc_span::Pos;
+use std::ops::Range;
+use url::Url;
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for the presence of `_`, `::` or camel-case words
+ /// outside ticks in documentation.
+ ///
+ /// **Why is this bad?** *Rustdoc* supports markdown formatting, `_`, `::` and
+ /// camel-case probably indicates some code which should be included between
+ /// ticks. `_` can also be used for emphasis in markdown, this lint tries to
+ /// consider that.
+ ///
+ /// **Known problems:** Lots of bad docs won’t be fixed, what the lint checks
+ /// for is limited, and there are still false positives.
+ ///
+ /// **Examples:**
+ /// ```rust
+ /// /// Do something with the foo_bar parameter. See also
+ /// /// that::other::module::foo.
+ /// // ^ `foo_bar` and `that::other::module::foo` should be ticked.
+ /// fn doit(foo_bar: usize) {}
+ /// ```
+ pub DOC_MARKDOWN,
+ pedantic,
+ "presence of `_`, `::` or camel-case outside backticks in documentation"
+}
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for the doc comments of publicly visible
+ /// unsafe functions and warns if there is no `# Safety` section.
+ ///
+ /// **Why is this bad?** Unsafe functions should document their safety
+ /// preconditions, so that users can be sure they are using them safely.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Examples:**
+ /// ```rust
+ ///# type Universe = ();
+ /// /// This function should really be documented
+ /// pub unsafe fn start_apocalypse(u: &mut Universe) {
+ /// unimplemented!();
+ /// }
+ /// ```
+ ///
+ /// At least write a line about safety:
+ ///
+ /// ```rust
+ ///# type Universe = ();
+ /// /// # Safety
+ /// ///
+ /// /// This function should not be called before the horsemen are ready.
+ /// pub unsafe fn start_apocalypse(u: &mut Universe) {
+ /// unimplemented!();
+ /// }
+ /// ```
+ pub MISSING_SAFETY_DOC,
+ style,
+ "`pub unsafe fn` without `# Safety` docs"
+}
+
+declare_clippy_lint! {
+ /// **What it does:** Checks the doc comments of publicly visible functions that
+ /// return a `Result` type and warns if there is no `# Errors` section.
+ ///
+ /// **Why is this bad?** Documenting the type of errors that can be returned from a
+ /// function can help callers write code to handle the errors appropriately.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Examples:**
+ ///
+ /// Since the following function returns a `Result` it has an `# Errors` section in
+ /// its doc comment:
+ ///
+ /// ```rust
+ ///# use std::io;
+ /// /// # Errors
+ /// ///
+ /// /// Will return `Err` if `filename` does not exist or the user does not have
+ /// /// permission to read it.
+ /// pub fn read(filename: String) -> io::Result {
+ /// unimplemented!();
+ /// }
+ /// ```
+ pub MISSING_ERRORS_DOC,
+ pedantic,
+ "`pub fn` returns `Result` without `# Errors` in doc comment"
+}
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for `fn main() { .. }` in doctests
+ ///
+ /// **Why is this bad?** The test can be shorter (and likely more readable)
+ /// if the `fn main()` is left implicit.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Examples:**
+ /// ``````rust
+ /// /// An example of a doctest with a `main()` function
+ /// ///
+ /// /// # Examples
+ /// ///
+ /// /// ```
+ /// /// fn main() {
+ /// /// // this needs not be in an `fn`
+ /// /// }
+ /// /// ```
+ /// fn needless_main() {
+ /// unimplemented!();
+ /// }
+ /// ``````
+ pub NEEDLESS_DOCTEST_MAIN,
+ style,
+ "presence of `fn main() {` in code examples"
+}
+
+#[allow(clippy::module_name_repetitions)]
+#[derive(Clone)]
+pub struct DocMarkdown {
+ valid_idents: FxHashSet,
+ in_trait_impl: bool,
+}
+
+impl DocMarkdown {
+ pub fn new(valid_idents: FxHashSet) -> Self {
+ Self {
+ valid_idents,
+ in_trait_impl: false,
+ }
+ }
+}
+
+impl_lint_pass!(DocMarkdown => [DOC_MARKDOWN, MISSING_SAFETY_DOC, MISSING_ERRORS_DOC, NEEDLESS_DOCTEST_MAIN]);
+
+impl<'a, 'tcx> LateLintPass<'a, 'tcx> for DocMarkdown {
+ fn check_crate(&mut self, cx: &LateContext<'a, 'tcx>, krate: &'tcx hir::Crate<'_>) {
+ check_attrs(cx, &self.valid_idents, &krate.item.attrs);
+ }
+
+ fn check_item(&mut self, cx: &LateContext<'a, 'tcx>, item: &'tcx hir::Item<'_>) {
+ let headers = check_attrs(cx, &self.valid_idents, &item.attrs);
+ match item.kind {
+ hir::ItemKind::Fn(ref sig, _, body_id) => {
+ if !(is_entrypoint_fn(cx, cx.tcx.hir().local_def_id(item.hir_id).to_def_id())
+ || in_external_macro(cx.tcx.sess, item.span))
+ {
+ lint_for_missing_headers(cx, item.hir_id, item.span, sig, headers, Some(body_id));
+ }
+ },
+ hir::ItemKind::Impl {
+ of_trait: ref trait_ref,
+ ..
+ } => {
+ self.in_trait_impl = trait_ref.is_some();
+ },
+ _ => {},
+ }
+ }
+
+ fn check_item_post(&mut self, _cx: &LateContext<'a, 'tcx>, item: &'tcx hir::Item<'_>) {
+ if let hir::ItemKind::Impl { .. } = item.kind {
+ self.in_trait_impl = false;
+ }
+ }
+
+ fn check_trait_item(&mut self, cx: &LateContext<'a, 'tcx>, item: &'tcx hir::TraitItem<'_>) {
+ let headers = check_attrs(cx, &self.valid_idents, &item.attrs);
+ if let hir::TraitItemKind::Fn(ref sig, ..) = item.kind {
+ if !in_external_macro(cx.tcx.sess, item.span) {
+ lint_for_missing_headers(cx, item.hir_id, item.span, sig, headers, None);
+ }
+ }
+ }
+
+ fn check_impl_item(&mut self, cx: &LateContext<'a, 'tcx>, item: &'tcx hir::ImplItem<'_>) {
+ let headers = check_attrs(cx, &self.valid_idents, &item.attrs);
+ if self.in_trait_impl || in_external_macro(cx.tcx.sess, item.span) {
+ return;
+ }
+ if let hir::ImplItemKind::Fn(ref sig, body_id) = item.kind {
+ lint_for_missing_headers(cx, item.hir_id, item.span, sig, headers, Some(body_id));
+ }
+ }
+}
+
+fn lint_for_missing_headers<'a, 'tcx>(
+ cx: &LateContext<'a, 'tcx>,
+ hir_id: hir::HirId,
+ span: impl Into + Copy,
+ sig: &hir::FnSig<'_>,
+ headers: DocHeaders,
+ body_id: Option,
+) {
+ if !cx.access_levels.is_exported(hir_id) {
+ return; // Private functions do not require doc comments
+ }
+ if !headers.safety && sig.header.unsafety == hir::Unsafety::Unsafe {
+ span_lint(
+ cx,
+ MISSING_SAFETY_DOC,
+ span,
+ "unsafe function's docs miss `# Safety` section",
+ );
+ }
+ if !headers.errors {
+ if is_type_diagnostic_item(cx, return_ty(cx, hir_id), sym!(result_type)) {
+ span_lint(
+ cx,
+ MISSING_ERRORS_DOC,
+ span,
+ "docs for function returning `Result` missing `# Errors` section",
+ );
+ } else {
+ if_chain! {
+ if let Some(body_id) = body_id;
+ if let Some(future) = cx.tcx.lang_items().future_trait();
+ let def_id = cx.tcx.hir().body_owner_def_id(body_id);
+ let mir = cx.tcx.optimized_mir(def_id.to_def_id());
+ let ret_ty = mir.return_ty();
+ if implements_trait(cx, ret_ty, future, &[]);
+ if let ty::Opaque(_, subs) = ret_ty.kind;
+ if let Some(gen) = subs.types().next();
+ if let ty::Generator(_, subs, _) = gen.kind;
+ if is_type_diagnostic_item(cx, subs.as_generator().return_ty(), sym!(result_type));
+ then {
+ span_lint(
+ cx,
+ MISSING_ERRORS_DOC,
+ span,
+ "docs for function returning `Result` missing `# Errors` section",
+ );
+ }
+ }
+ }
+ }
+}
+
+/// Cleanup documentation decoration (`///` and such).
+///
+/// We can't use `rustc_ast::attr::AttributeMethods::with_desugared_doc` or
+/// `rustc_ast::parse::lexer::comments::strip_doc_comment_decoration` because we
+/// need to keep track of
+/// the spans but this function is inspired from the later.
+#[allow(clippy::cast_possible_truncation)]
+#[must_use]
+pub fn strip_doc_comment_decoration(comment: &str, span: Span) -> (String, Vec<(usize, Span)>) {
+ // one-line comments lose their prefix
+ const ONELINERS: &[&str] = &["///!", "///", "//!", "//"];
+ for prefix in ONELINERS {
+ if comment.starts_with(*prefix) {
+ let doc = &comment[prefix.len()..];
+ let mut doc = doc.to_owned();
+ doc.push('\n');
+ return (
+ doc.to_owned(),
+ vec![(doc.len(), span.with_lo(span.lo() + BytePos(prefix.len() as u32)))],
+ );
+ }
+ }
+
+ if comment.starts_with("/*") {
+ let doc = &comment[3..comment.len() - 2];
+ let mut sizes = vec![];
+ let mut contains_initial_stars = false;
+ for line in doc.lines() {
+ let offset = line.as_ptr() as usize - comment.as_ptr() as usize;
+ debug_assert_eq!(offset as u32 as usize, offset);
+ contains_initial_stars |= line.trim_start().starts_with('*');
+ // +1 for the newline
+ sizes.push((line.len() + 1, span.with_lo(span.lo() + BytePos(offset as u32))));
+ }
+ if !contains_initial_stars {
+ return (doc.to_string(), sizes);
+ }
+ // remove the initial '*'s if any
+ let mut no_stars = String::with_capacity(doc.len());
+ for line in doc.lines() {
+ let mut chars = line.chars();
+ while let Some(c) = chars.next() {
+ if c.is_whitespace() {
+ no_stars.push(c);
+ } else {
+ no_stars.push(if c == '*' { ' ' } else { c });
+ break;
+ }
+ }
+ no_stars.push_str(chars.as_str());
+ no_stars.push('\n');
+ }
+ return (no_stars, sizes);
+ }
+
+ panic!("not a doc-comment: {}", comment);
+}
+
+#[derive(Copy, Clone)]
+struct DocHeaders {
+ safety: bool,
+ errors: bool,
+}
+
+fn check_attrs<'a>(cx: &LateContext<'_, '_>, valid_idents: &FxHashSet, attrs: &'a [Attribute]) -> DocHeaders {
+ let mut doc = String::new();
+ let mut spans = vec![];
+
+ for attr in attrs {
+ if let AttrKind::DocComment(ref comment) = attr.kind {
+ let comment = comment.to_string();
+ let (comment, current_spans) = strip_doc_comment_decoration(&comment, attr.span);
+ spans.extend_from_slice(¤t_spans);
+ doc.push_str(&comment);
+ } else if attr.check_name(sym!(doc)) {
+ // ignore mix of sugared and non-sugared doc
+ // don't trigger the safety or errors check
+ return DocHeaders {
+ safety: true,
+ errors: true,
+ };
+ }
+ }
+
+ let mut current = 0;
+ for &mut (ref mut offset, _) in &mut spans {
+ let offset_copy = *offset;
+ *offset = current;
+ current += offset_copy;
+ }
+
+ if doc.is_empty() {
+ return DocHeaders {
+ safety: false,
+ errors: false,
+ };
+ }
+
+ let parser = pulldown_cmark::Parser::new(&doc).into_offset_iter();
+ // Iterate over all `Events` and combine consecutive events into one
+ let events = parser.coalesce(|previous, current| {
+ use pulldown_cmark::Event::Text;
+
+ let previous_range = previous.1;
+ let current_range = current.1;
+
+ match (previous.0, current.0) {
+ (Text(previous), Text(current)) => {
+ let mut previous = previous.to_string();
+ previous.push_str(¤t);
+ Ok((Text(previous.into()), previous_range))
+ },
+ (previous, current) => Err(((previous, previous_range), (current, current_range))),
+ }
+ });
+ check_doc(cx, valid_idents, events, &spans)
+}
+
+const RUST_CODE: &[&str] = &["rust", "no_run", "should_panic", "compile_fail", "edition2018"];
+
+fn check_doc<'a, Events: Iterator
- , Range)>>(
+ cx: &LateContext<'_, '_>,
+ valid_idents: &FxHashSet,
+ events: Events,
+ spans: &[(usize, Span)],
+) -> DocHeaders {
+ // true if a safety header was found
+ use pulldown_cmark::CodeBlockKind;
+ use pulldown_cmark::Event::{
+ Code, End, FootnoteReference, HardBreak, Html, Rule, SoftBreak, Start, TaskListMarker, Text,
+ };
+ use pulldown_cmark::Tag::{CodeBlock, Heading, Link};
+
+ let mut headers = DocHeaders {
+ safety: false,
+ errors: false,
+ };
+ let mut in_code = false;
+ let mut in_link = None;
+ let mut in_heading = false;
+ let mut is_rust = false;
+ for (event, range) in events {
+ match event {
+ Start(CodeBlock(ref kind)) => {
+ in_code = true;
+ if let CodeBlockKind::Fenced(lang) = kind {
+ is_rust =
+ lang.is_empty() || !lang.contains("ignore") && lang.split(',').any(|i| RUST_CODE.contains(&i));
+ }
+ },
+ End(CodeBlock(_)) => {
+ in_code = false;
+ is_rust = false;
+ },
+ Start(Link(_, url, _)) => in_link = Some(url),
+ End(Link(..)) => in_link = None,
+ Start(Heading(_)) => in_heading = true,
+ End(Heading(_)) => in_heading = false,
+ Start(_tag) | End(_tag) => (), // We don't care about other tags
+ Html(_html) => (), // HTML is weird, just ignore it
+ SoftBreak | HardBreak | TaskListMarker(_) | Code(_) | Rule => (),
+ FootnoteReference(text) | Text(text) => {
+ if Some(&text) == in_link.as_ref() {
+ // Probably a link of the form ``
+ // Which are represented as a link to "http://example.com" with
+ // text "http://example.com" by pulldown-cmark
+ continue;
+ }
+ headers.safety |= in_heading && text.trim() == "Safety";
+ headers.errors |= in_heading && text.trim() == "Errors";
+ let index = match spans.binary_search_by(|c| c.0.cmp(&range.start)) {
+ Ok(o) => o,
+ Err(e) => e - 1,
+ };
+ let (begin, span) = spans[index];
+ if in_code {
+ if is_rust {
+ check_code(cx, &text, span);
+ }
+ } else {
+ // Adjust for the beginning of the current `Event`
+ let span = span.with_lo(span.lo() + BytePos::from_usize(range.start - begin));
+
+ check_text(cx, valid_idents, &text, span);
+ }
+ },
+ }
+ }
+ headers
+}
+
+static LEAVE_MAIN_PATTERNS: &[&str] = &["static", "fn main() {}", "extern crate", "async fn main() {"];
+
+fn check_code(cx: &LateContext<'_, '_>, text: &str, span: Span) {
+ if text.contains("fn main() {") && !LEAVE_MAIN_PATTERNS.iter().any(|p| text.contains(p)) {
+ span_lint(cx, NEEDLESS_DOCTEST_MAIN, span, "needless `fn main` in doctest");
+ }
+}
+
+fn check_text(cx: &LateContext<'_, '_>, valid_idents: &FxHashSet, text: &str, span: Span) {
+ for word in text.split(|c: char| c.is_whitespace() || c == '\'') {
+ // Trim punctuation as in `some comment (see foo::bar).`
+ // ^^
+ // Or even as in `_foo bar_` which is emphasized.
+ let word = word.trim_matches(|c: char| !c.is_alphanumeric());
+
+ if valid_idents.contains(word) {
+ continue;
+ }
+
+ // Adjust for the current word
+ let offset = word.as_ptr() as usize - text.as_ptr() as usize;
+ let span = Span::new(
+ span.lo() + BytePos::from_usize(offset),
+ span.lo() + BytePos::from_usize(offset + word.len()),
+ span.ctxt(),
+ );
+
+ check_word(cx, word, span);
+ }
+}
+
+fn check_word(cx: &LateContext<'_, '_>, word: &str, span: Span) {
+ /// Checks if a string is camel-case, i.e., contains at least two uppercase
+ /// letters (`Clippy` is ok) and one lower-case letter (`NASA` is ok).
+ /// Plurals are also excluded (`IDs` is ok).
+ fn is_camel_case(s: &str) -> bool {
+ if s.starts_with(|c: char| c.is_digit(10)) {
+ return false;
+ }
+
+ let s = if s.ends_with('s') { &s[..s.len() - 1] } else { s };
+
+ s.chars().all(char::is_alphanumeric)
+ && s.chars().filter(|&c| c.is_uppercase()).take(2).count() > 1
+ && s.chars().filter(|&c| c.is_lowercase()).take(1).count() > 0
+ }
+
+ fn has_underscore(s: &str) -> bool {
+ s != "_" && !s.contains("\\_") && s.contains('_')
+ }
+
+ fn has_hyphen(s: &str) -> bool {
+ s != "-" && s.contains('-')
+ }
+
+ if let Ok(url) = Url::parse(word) {
+ // try to get around the fact that `foo::bar` parses as a valid URL
+ if !url.cannot_be_a_base() {
+ span_lint(
+ cx,
+ DOC_MARKDOWN,
+ span,
+ "you should put bare URLs between `<`/`>` or make a proper Markdown link",
+ );
+
+ return;
+ }
+ }
+
+ // We assume that mixed-case words are not meant to be put inside bacticks. (Issue #2343)
+ if has_underscore(word) && has_hyphen(word) {
+ return;
+ }
+
+ if has_underscore(word) || word.contains("::") || is_camel_case(word) {
+ span_lint(
+ cx,
+ DOC_MARKDOWN,
+ span,
+ &format!("you should put `{}` between ticks in the documentation", word),
+ );
+ }
+}
diff --git a/src/tools/clippy/clippy_lints/src/double_comparison.rs b/src/tools/clippy/clippy_lints/src/double_comparison.rs
new file mode 100644
index 00000000000..44f85d1ea6e
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/double_comparison.rs
@@ -0,0 +1,95 @@
+//! Lint on unnecessary double comparisons. Some examples:
+
+use rustc_errors::Applicability;
+use rustc_hir::{BinOpKind, Expr, ExprKind};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::source_map::Span;
+
+use crate::utils::{snippet_with_applicability, span_lint_and_sugg, SpanlessEq};
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for double comparisons that could be simplified to a single expression.
+ ///
+ ///
+ /// **Why is this bad?** Readability.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```rust
+ /// # let x = 1;
+ /// # let y = 2;
+ /// if x == y || x < y {}
+ /// ```
+ ///
+ /// Could be written as:
+ ///
+ /// ```rust
+ /// # let x = 1;
+ /// # let y = 2;
+ /// if x <= y {}
+ /// ```
+ pub DOUBLE_COMPARISONS,
+ complexity,
+ "unnecessary double comparisons that can be simplified"
+}
+
+declare_lint_pass!(DoubleComparisons => [DOUBLE_COMPARISONS]);
+
+impl<'a, 'tcx> DoubleComparisons {
+ #[allow(clippy::similar_names)]
+ fn check_binop(cx: &LateContext<'a, 'tcx>, op: BinOpKind, lhs: &'tcx Expr<'_>, rhs: &'tcx Expr<'_>, span: Span) {
+ let (lkind, llhs, lrhs, rkind, rlhs, rrhs) = match (&lhs.kind, &rhs.kind) {
+ (ExprKind::Binary(lb, llhs, lrhs), ExprKind::Binary(rb, rlhs, rrhs)) => {
+ (lb.node, llhs, lrhs, rb.node, rlhs, rrhs)
+ },
+ _ => return,
+ };
+ let mut spanless_eq = SpanlessEq::new(cx).ignore_fn();
+ if !(spanless_eq.eq_expr(&llhs, &rlhs) && spanless_eq.eq_expr(&lrhs, &rrhs)) {
+ return;
+ }
+ macro_rules! lint_double_comparison {
+ ($op:tt) => {{
+ let mut applicability = Applicability::MachineApplicable;
+ let lhs_str = snippet_with_applicability(cx, llhs.span, "", &mut applicability);
+ let rhs_str = snippet_with_applicability(cx, lrhs.span, "", &mut applicability);
+ let sugg = format!("{} {} {}", lhs_str, stringify!($op), rhs_str);
+ span_lint_and_sugg(
+ cx,
+ DOUBLE_COMPARISONS,
+ span,
+ "This binary expression can be simplified",
+ "try",
+ sugg,
+ applicability,
+ );
+ }};
+ }
+ #[rustfmt::skip]
+ match (op, lkind, rkind) {
+ (BinOpKind::Or, BinOpKind::Eq, BinOpKind::Lt) | (BinOpKind::Or, BinOpKind::Lt, BinOpKind::Eq) => {
+ lint_double_comparison!(<=)
+ },
+ (BinOpKind::Or, BinOpKind::Eq, BinOpKind::Gt) | (BinOpKind::Or, BinOpKind::Gt, BinOpKind::Eq) => {
+ lint_double_comparison!(>=)
+ },
+ (BinOpKind::Or, BinOpKind::Lt, BinOpKind::Gt) | (BinOpKind::Or, BinOpKind::Gt, BinOpKind::Lt) => {
+ lint_double_comparison!(!=)
+ },
+ (BinOpKind::And, BinOpKind::Le, BinOpKind::Ge) | (BinOpKind::And, BinOpKind::Ge, BinOpKind::Le) => {
+ lint_double_comparison!(==)
+ },
+ _ => (),
+ };
+ }
+}
+
+impl<'a, 'tcx> LateLintPass<'a, 'tcx> for DoubleComparisons {
+ fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr<'_>) {
+ if let ExprKind::Binary(ref kind, ref lhs, ref rhs) = expr.kind {
+ Self::check_binop(cx, kind.node, lhs, rhs, expr.span);
+ }
+ }
+}
diff --git a/src/tools/clippy/clippy_lints/src/double_parens.rs b/src/tools/clippy/clippy_lints/src/double_parens.rs
new file mode 100644
index 00000000000..7f2ff8b9b26
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/double_parens.rs
@@ -0,0 +1,75 @@
+use crate::utils::span_lint;
+use rustc_ast::ast::{Expr, ExprKind};
+use rustc_lint::{EarlyContext, EarlyLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for unnecessary double parentheses.
+ ///
+ /// **Why is this bad?** This makes code harder to read and might indicate a
+ /// mistake.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```rust
+ /// # fn foo(bar: usize) {}
+ /// ((0));
+ /// foo((0));
+ /// ((1, 2));
+ /// ```
+ pub DOUBLE_PARENS,
+ complexity,
+ "Warn on unnecessary double parentheses"
+}
+
+declare_lint_pass!(DoubleParens => [DOUBLE_PARENS]);
+
+impl EarlyLintPass for DoubleParens {
+ fn check_expr(&mut self, cx: &EarlyContext<'_>, expr: &Expr) {
+ if expr.span.from_expansion() {
+ return;
+ }
+
+ match expr.kind {
+ ExprKind::Paren(ref in_paren) => match in_paren.kind {
+ ExprKind::Paren(_) | ExprKind::Tup(_) => {
+ span_lint(
+ cx,
+ DOUBLE_PARENS,
+ expr.span,
+ "Consider removing unnecessary double parentheses",
+ );
+ },
+ _ => {},
+ },
+ ExprKind::Call(_, ref params) => {
+ if params.len() == 1 {
+ let param = ¶ms[0];
+ if let ExprKind::Paren(_) = param.kind {
+ span_lint(
+ cx,
+ DOUBLE_PARENS,
+ param.span,
+ "Consider removing unnecessary double parentheses",
+ );
+ }
+ }
+ },
+ ExprKind::MethodCall(_, ref params) => {
+ if params.len() == 2 {
+ let param = ¶ms[1];
+ if let ExprKind::Paren(_) = param.kind {
+ span_lint(
+ cx,
+ DOUBLE_PARENS,
+ param.span,
+ "Consider removing unnecessary double parentheses",
+ );
+ }
+ }
+ },
+ _ => {},
+ }
+ }
+}
diff --git a/src/tools/clippy/clippy_lints/src/drop_bounds.rs b/src/tools/clippy/clippy_lints/src/drop_bounds.rs
new file mode 100644
index 00000000000..f4966808279
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/drop_bounds.rs
@@ -0,0 +1,69 @@
+use crate::utils::{match_def_path, paths, span_lint};
+use if_chain::if_chain;
+use rustc_hir::{GenericBound, GenericParam, WhereBoundPredicate, WherePredicate};
+use rustc_lint::LateLintPass;
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for generics with `std::ops::Drop` as bounds.
+ ///
+ /// **Why is this bad?** `Drop` bounds do not really accomplish anything.
+ /// A type may have compiler-generated drop glue without implementing the
+ /// `Drop` trait itself. The `Drop` trait also only has one method,
+ /// `Drop::drop`, and that function is by fiat not callable in user code.
+ /// So there is really no use case for using `Drop` in trait bounds.
+ ///
+ /// The most likely use case of a drop bound is to distinguish between types
+ /// that have destructors and types that don't. Combined with specialization,
+ /// a naive coder would write an implementation that assumed a type could be
+ /// trivially dropped, then write a specialization for `T: Drop` that actually
+ /// calls the destructor. Except that doing so is not correct; String, for
+ /// example, doesn't actually implement Drop, but because String contains a
+ /// Vec, assuming it can be trivially dropped will leak memory.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```rust
+ /// fn foo() {}
+ /// ```
+ pub DROP_BOUNDS,
+ correctness,
+ "Bounds of the form `T: Drop` are useless"
+}
+
+const DROP_BOUNDS_SUMMARY: &str = "Bounds of the form `T: Drop` are useless. \
+ Use `std::mem::needs_drop` to detect if a type has drop glue.";
+
+declare_lint_pass!(DropBounds => [DROP_BOUNDS]);
+
+impl<'a, 'tcx> LateLintPass<'a, 'tcx> for DropBounds {
+ fn check_generic_param(&mut self, cx: &rustc_lint::LateContext<'a, 'tcx>, p: &'tcx GenericParam<'_>) {
+ for bound in p.bounds.iter() {
+ lint_bound(cx, bound);
+ }
+ }
+ fn check_where_predicate(&mut self, cx: &rustc_lint::LateContext<'a, 'tcx>, p: &'tcx WherePredicate<'_>) {
+ if let WherePredicate::BoundPredicate(WhereBoundPredicate { bounds, .. }) = p {
+ for bound in *bounds {
+ lint_bound(cx, bound);
+ }
+ }
+ }
+}
+
+fn lint_bound<'a, 'tcx>(cx: &rustc_lint::LateContext<'a, 'tcx>, bound: &'tcx GenericBound<'_>) {
+ if_chain! {
+ if let GenericBound::Trait(t, _) = bound;
+ if let Some(def_id) = t.trait_ref.path.res.opt_def_id();
+ if match_def_path(cx, def_id, &paths::DROP_TRAIT);
+ then {
+ span_lint(
+ cx,
+ DROP_BOUNDS,
+ t.span,
+ DROP_BOUNDS_SUMMARY
+ );
+ }
+ }
+}
diff --git a/src/tools/clippy/clippy_lints/src/drop_forget_ref.rs b/src/tools/clippy/clippy_lints/src/drop_forget_ref.rs
new file mode 100644
index 00000000000..9de9056c140
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/drop_forget_ref.rs
@@ -0,0 +1,160 @@
+use crate::utils::{is_copy, match_def_path, paths, qpath_res, span_lint_and_note};
+use if_chain::if_chain;
+use rustc_hir::{Expr, ExprKind};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty;
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for calls to `std::mem::drop` with a reference
+ /// instead of an owned value.
+ ///
+ /// **Why is this bad?** Calling `drop` on a reference will only drop the
+ /// reference itself, which is a no-op. It will not call the `drop` method (from
+ /// the `Drop` trait implementation) on the underlying referenced value, which
+ /// is likely what was intended.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```ignore
+ /// let mut lock_guard = mutex.lock();
+ /// std::mem::drop(&lock_guard) // Should have been drop(lock_guard), mutex
+ /// // still locked
+ /// operation_that_requires_mutex_to_be_unlocked();
+ /// ```
+ pub DROP_REF,
+ correctness,
+ "calls to `std::mem::drop` with a reference instead of an owned value"
+}
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for calls to `std::mem::forget` with a reference
+ /// instead of an owned value.
+ ///
+ /// **Why is this bad?** Calling `forget` on a reference will only forget the
+ /// reference itself, which is a no-op. It will not forget the underlying
+ /// referenced
+ /// value, which is likely what was intended.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```rust
+ /// let x = Box::new(1);
+ /// std::mem::forget(&x) // Should have been forget(x), x will still be dropped
+ /// ```
+ pub FORGET_REF,
+ correctness,
+ "calls to `std::mem::forget` with a reference instead of an owned value"
+}
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for calls to `std::mem::drop` with a value
+ /// that derives the Copy trait
+ ///
+ /// **Why is this bad?** Calling `std::mem::drop` [does nothing for types that
+ /// implement Copy](https://doc.rust-lang.org/std/mem/fn.drop.html), since the
+ /// value will be copied and moved into the function on invocation.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```rust
+ /// let x: i32 = 42; // i32 implements Copy
+ /// std::mem::drop(x) // A copy of x is passed to the function, leaving the
+ /// // original unaffected
+ /// ```
+ pub DROP_COPY,
+ correctness,
+ "calls to `std::mem::drop` with a value that implements Copy"
+}
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for calls to `std::mem::forget` with a value that
+ /// derives the Copy trait
+ ///
+ /// **Why is this bad?** Calling `std::mem::forget` [does nothing for types that
+ /// implement Copy](https://doc.rust-lang.org/std/mem/fn.drop.html) since the
+ /// value will be copied and moved into the function on invocation.
+ ///
+ /// An alternative, but also valid, explanation is that Copy types do not
+ /// implement
+ /// the Drop trait, which means they have no destructors. Without a destructor,
+ /// there
+ /// is nothing for `std::mem::forget` to ignore.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```rust
+ /// let x: i32 = 42; // i32 implements Copy
+ /// std::mem::forget(x) // A copy of x is passed to the function, leaving the
+ /// // original unaffected
+ /// ```
+ pub FORGET_COPY,
+ correctness,
+ "calls to `std::mem::forget` with a value that implements Copy"
+}
+
+const DROP_REF_SUMMARY: &str = "calls to `std::mem::drop` with a reference instead of an owned value. \
+ Dropping a reference does nothing.";
+const FORGET_REF_SUMMARY: &str = "calls to `std::mem::forget` with a reference instead of an owned value. \
+ Forgetting a reference does nothing.";
+const DROP_COPY_SUMMARY: &str = "calls to `std::mem::drop` with a value that implements `Copy`. \
+ Dropping a copy leaves the original intact.";
+const FORGET_COPY_SUMMARY: &str = "calls to `std::mem::forget` with a value that implements `Copy`. \
+ Forgetting a copy leaves the original intact.";
+
+declare_lint_pass!(DropForgetRef => [DROP_REF, FORGET_REF, DROP_COPY, FORGET_COPY]);
+
+impl<'a, 'tcx> LateLintPass<'a, 'tcx> for DropForgetRef {
+ fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr<'_>) {
+ if_chain! {
+ if let ExprKind::Call(ref path, ref args) = expr.kind;
+ if let ExprKind::Path(ref qpath) = path.kind;
+ if args.len() == 1;
+ if let Some(def_id) = qpath_res(cx, qpath, path.hir_id).opt_def_id();
+ then {
+ let lint;
+ let msg;
+ let arg = &args[0];
+ let arg_ty = cx.tables.expr_ty(arg);
+
+ if let ty::Ref(..) = arg_ty.kind {
+ if match_def_path(cx, def_id, &paths::DROP) {
+ lint = DROP_REF;
+ msg = DROP_REF_SUMMARY.to_string();
+ } else if match_def_path(cx, def_id, &paths::MEM_FORGET) {
+ lint = FORGET_REF;
+ msg = FORGET_REF_SUMMARY.to_string();
+ } else {
+ return;
+ }
+ span_lint_and_note(cx,
+ lint,
+ expr.span,
+ &msg,
+ Some(arg.span),
+ &format!("argument has type `{}`", arg_ty));
+ } else if is_copy(cx, arg_ty) {
+ if match_def_path(cx, def_id, &paths::DROP) {
+ lint = DROP_COPY;
+ msg = DROP_COPY_SUMMARY.to_string();
+ } else if match_def_path(cx, def_id, &paths::MEM_FORGET) {
+ lint = FORGET_COPY;
+ msg = FORGET_COPY_SUMMARY.to_string();
+ } else {
+ return;
+ }
+ span_lint_and_note(cx,
+ lint,
+ expr.span,
+ &msg,
+ Some(arg.span),
+ &format!("argument has type {}", arg_ty));
+ }
+ }
+ }
+ }
+}
diff --git a/src/tools/clippy/clippy_lints/src/duration_subsec.rs b/src/tools/clippy/clippy_lints/src/duration_subsec.rs
new file mode 100644
index 00000000000..b35a8facf8b
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/duration_subsec.rs
@@ -0,0 +1,65 @@
+use if_chain::if_chain;
+use rustc_errors::Applicability;
+use rustc_hir::{BinOpKind, Expr, ExprKind};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::source_map::Spanned;
+
+use crate::consts::{constant, Constant};
+use crate::utils::paths;
+use crate::utils::{match_type, snippet_with_applicability, span_lint_and_sugg, walk_ptrs_ty};
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for calculation of subsecond microseconds or milliseconds
+ /// from other `Duration` methods.
+ ///
+ /// **Why is this bad?** It's more concise to call `Duration::subsec_micros()` or
+ /// `Duration::subsec_millis()` than to calculate them.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```rust
+ /// # use std::time::Duration;
+ /// let dur = Duration::new(5, 0);
+ /// let _micros = dur.subsec_nanos() / 1_000;
+ /// let _millis = dur.subsec_nanos() / 1_000_000;
+ /// ```
+ pub DURATION_SUBSEC,
+ complexity,
+ "checks for calculation of subsecond microseconds or milliseconds"
+}
+
+declare_lint_pass!(DurationSubsec => [DURATION_SUBSEC]);
+
+impl<'a, 'tcx> LateLintPass<'a, 'tcx> for DurationSubsec {
+ fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr<'_>) {
+ if_chain! {
+ if let ExprKind::Binary(Spanned { node: BinOpKind::Div, .. }, ref left, ref right) = expr.kind;
+ if let ExprKind::MethodCall(ref method_path, _ , ref args) = left.kind;
+ if match_type(cx, walk_ptrs_ty(cx.tables.expr_ty(&args[0])), &paths::DURATION);
+ if let Some((Constant::Int(divisor), _)) = constant(cx, cx.tables, right);
+ then {
+ let suggested_fn = match (method_path.ident.as_str().as_ref(), divisor) {
+ ("subsec_micros", 1_000) | ("subsec_nanos", 1_000_000) => "subsec_millis",
+ ("subsec_nanos", 1_000) => "subsec_micros",
+ _ => return,
+ };
+ let mut applicability = Applicability::MachineApplicable;
+ span_lint_and_sugg(
+ cx,
+ DURATION_SUBSEC,
+ expr.span,
+ &format!("Calling `{}()` is more concise than this calculation", suggested_fn),
+ "try",
+ format!(
+ "{}.{}()",
+ snippet_with_applicability(cx, args[0].span, "_", &mut applicability),
+ suggested_fn
+ ),
+ applicability,
+ );
+ }
+ }
+ }
+}
diff --git a/src/tools/clippy/clippy_lints/src/else_if_without_else.rs b/src/tools/clippy/clippy_lints/src/else_if_without_else.rs
new file mode 100644
index 00000000000..95123e6ff6f
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/else_if_without_else.rs
@@ -0,0 +1,72 @@
+//! Lint on if expressions with an else if, but without a final else branch.
+
+use rustc_ast::ast::{Expr, ExprKind};
+use rustc_lint::{EarlyContext, EarlyLintPass, LintContext};
+use rustc_middle::lint::in_external_macro;
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+
+use crate::utils::span_lint_and_help;
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for usage of if expressions with an `else if` branch,
+ /// but without a final `else` branch.
+ ///
+ /// **Why is this bad?** Some coding guidelines require this (e.g., MISRA-C:2004 Rule 14.10).
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```rust
+ /// # fn a() {}
+ /// # fn b() {}
+ /// # let x: i32 = 1;
+ /// if x.is_positive() {
+ /// a();
+ /// } else if x.is_negative() {
+ /// b();
+ /// }
+ /// ```
+ ///
+ /// Could be written:
+ ///
+ /// ```rust
+ /// # fn a() {}
+ /// # fn b() {}
+ /// # let x: i32 = 1;
+ /// if x.is_positive() {
+ /// a();
+ /// } else if x.is_negative() {
+ /// b();
+ /// } else {
+ /// // We don't care about zero.
+ /// }
+ /// ```
+ pub ELSE_IF_WITHOUT_ELSE,
+ restriction,
+ "`if` expression with an `else if`, but without a final `else` branch"
+}
+
+declare_lint_pass!(ElseIfWithoutElse => [ELSE_IF_WITHOUT_ELSE]);
+
+impl EarlyLintPass for ElseIfWithoutElse {
+ fn check_expr(&mut self, cx: &EarlyContext<'_>, mut item: &Expr) {
+ if in_external_macro(cx.sess(), item.span) {
+ return;
+ }
+
+ while let ExprKind::If(_, _, Some(ref els)) = item.kind {
+ if let ExprKind::If(_, _, None) = els.kind {
+ span_lint_and_help(
+ cx,
+ ELSE_IF_WITHOUT_ELSE,
+ els.span,
+ "`if` expression with an `else if`, but without a final `else`",
+ None,
+ "add an `else` block here",
+ );
+ }
+
+ item = els;
+ }
+ }
+}
diff --git a/src/tools/clippy/clippy_lints/src/empty_enum.rs b/src/tools/clippy/clippy_lints/src/empty_enum.rs
new file mode 100644
index 00000000000..3bfef6f4bed
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/empty_enum.rs
@@ -0,0 +1,60 @@
+//! lint when there is an enum with no variants
+
+use crate::utils::span_lint_and_help;
+use rustc_hir::{Item, ItemKind};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for `enum`s with no variants.
+ ///
+ /// **Why is this bad?** If you want to introduce a type which
+ /// can't be instantiated, you should use `!` (the never type),
+ /// or a wrapper around it, because `!` has more extensive
+ /// compiler support (type inference, etc...) and wrappers
+ /// around it are the conventional way to define an uninhabited type.
+ /// For further information visit [never type documentation](https://doc.rust-lang.org/std/primitive.never.html)
+ ///
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ ///
+ /// Bad:
+ /// ```rust
+ /// enum Test {}
+ /// ```
+ ///
+ /// Good:
+ /// ```rust
+ /// #![feature(never_type)]
+ ///
+ /// struct Test(!);
+ /// ```
+ pub EMPTY_ENUM,
+ pedantic,
+ "enum with no variants"
+}
+
+declare_lint_pass!(EmptyEnum => [EMPTY_ENUM]);
+
+impl<'a, 'tcx> LateLintPass<'a, 'tcx> for EmptyEnum {
+ fn check_item(&mut self, cx: &LateContext<'_, '_>, item: &Item<'_>) {
+ let did = cx.tcx.hir().local_def_id(item.hir_id);
+ if let ItemKind::Enum(..) = item.kind {
+ let ty = cx.tcx.type_of(did);
+ let adt = ty.ty_adt_def().expect("already checked whether this is an enum");
+ if adt.variants.is_empty() {
+ span_lint_and_help(
+ cx,
+ EMPTY_ENUM,
+ item.span,
+ "enum with no variants",
+ None,
+ "consider using the uninhabited type `!` (never type) or a wrapper \
+ around it to introduce a type which can't be instantiated",
+ );
+ }
+ }
+ }
+}
diff --git a/src/tools/clippy/clippy_lints/src/entry.rs b/src/tools/clippy/clippy_lints/src/entry.rs
new file mode 100644
index 00000000000..7b332c761a0
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/entry.rs
@@ -0,0 +1,187 @@
+use crate::utils::SpanlessEq;
+use crate::utils::{get_item_name, higher, is_type_diagnostic_item, match_type, paths, snippet, snippet_opt};
+use crate::utils::{snippet_with_applicability, span_lint_and_then, walk_ptrs_ty};
+use if_chain::if_chain;
+use rustc_errors::Applicability;
+use rustc_hir::intravisit::{walk_expr, NestedVisitorMap, Visitor};
+use rustc_hir::{BorrowKind, Expr, ExprKind, UnOp};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::hir::map::Map;
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::source_map::Span;
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for uses of `contains_key` + `insert` on `HashMap`
+ /// or `BTreeMap`.
+ ///
+ /// **Why is this bad?** Using `entry` is more efficient.
+ ///
+ /// **Known problems:** Some false negatives, eg.:
+ /// ```rust
+ /// # use std::collections::HashMap;
+ /// # let mut map = HashMap::new();
+ /// # let v = 1;
+ /// # let k = 1;
+ /// if !map.contains_key(&k) {
+ /// map.insert(k.clone(), v);
+ /// }
+ /// ```
+ ///
+ /// **Example:**
+ /// ```rust
+ /// # use std::collections::HashMap;
+ /// # let mut map = HashMap::new();
+ /// # let k = 1;
+ /// # let v = 1;
+ /// if !map.contains_key(&k) {
+ /// map.insert(k, v);
+ /// }
+ /// ```
+ /// can both be rewritten as:
+ /// ```rust
+ /// # use std::collections::HashMap;
+ /// # let mut map = HashMap::new();
+ /// # let k = 1;
+ /// # let v = 1;
+ /// map.entry(k).or_insert(v);
+ /// ```
+ pub MAP_ENTRY,
+ perf,
+ "use of `contains_key` followed by `insert` on a `HashMap` or `BTreeMap`"
+}
+
+declare_lint_pass!(HashMapPass => [MAP_ENTRY]);
+
+impl<'a, 'tcx> LateLintPass<'a, 'tcx> for HashMapPass {
+ fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr<'_>) {
+ if let Some((ref check, ref then_block, ref else_block)) = higher::if_block(&expr) {
+ if let ExprKind::Unary(UnOp::UnNot, ref check) = check.kind {
+ if let Some((ty, map, key)) = check_cond(cx, check) {
+ // in case of `if !m.contains_key(&k) { m.insert(k, v); }`
+ // we can give a better error message
+ let sole_expr = {
+ else_block.is_none()
+ && if let ExprKind::Block(ref then_block, _) = then_block.kind {
+ (then_block.expr.is_some() as usize) + then_block.stmts.len() == 1
+ } else {
+ true
+ }
+ // XXXManishearth we can also check for if/else blocks containing `None`.
+ };
+
+ let mut visitor = InsertVisitor {
+ cx,
+ span: expr.span,
+ ty,
+ map,
+ key,
+ sole_expr,
+ };
+
+ walk_expr(&mut visitor, &**then_block);
+ }
+ } else if let Some(ref else_block) = *else_block {
+ if let Some((ty, map, key)) = check_cond(cx, check) {
+ let mut visitor = InsertVisitor {
+ cx,
+ span: expr.span,
+ ty,
+ map,
+ key,
+ sole_expr: false,
+ };
+
+ walk_expr(&mut visitor, else_block);
+ }
+ }
+ }
+ }
+}
+
+fn check_cond<'a, 'tcx, 'b>(
+ cx: &'a LateContext<'a, 'tcx>,
+ check: &'b Expr<'b>,
+) -> Option<(&'static str, &'b Expr<'b>, &'b Expr<'b>)> {
+ if_chain! {
+ if let ExprKind::MethodCall(ref path, _, ref params) = check.kind;
+ if params.len() >= 2;
+ if path.ident.name == sym!(contains_key);
+ if let ExprKind::AddrOf(BorrowKind::Ref, _, ref key) = params[1].kind;
+ then {
+ let map = ¶ms[0];
+ let obj_ty = walk_ptrs_ty(cx.tables.expr_ty(map));
+
+ return if match_type(cx, obj_ty, &paths::BTREEMAP) {
+ Some(("BTreeMap", map, key))
+ }
+ else if is_type_diagnostic_item(cx, obj_ty, sym!(hashmap_type)) {
+ Some(("HashMap", map, key))
+ }
+ else {
+ None
+ };
+ }
+ }
+
+ None
+}
+
+struct InsertVisitor<'a, 'tcx, 'b> {
+ cx: &'a LateContext<'a, 'tcx>,
+ span: Span,
+ ty: &'static str,
+ map: &'b Expr<'b>,
+ key: &'b Expr<'b>,
+ sole_expr: bool,
+}
+
+impl<'a, 'tcx, 'b> Visitor<'tcx> for InsertVisitor<'a, 'tcx, 'b> {
+ type Map = Map<'tcx>;
+
+ fn visit_expr(&mut self, expr: &'tcx Expr<'_>) {
+ if_chain! {
+ if let ExprKind::MethodCall(ref path, _, ref params) = expr.kind;
+ if params.len() == 3;
+ if path.ident.name == sym!(insert);
+ if get_item_name(self.cx, self.map) == get_item_name(self.cx, ¶ms[0]);
+ if SpanlessEq::new(self.cx).eq_expr(self.key, ¶ms[1]);
+ if snippet_opt(self.cx, self.map.span) == snippet_opt(self.cx, params[0].span);
+ then {
+ span_lint_and_then(self.cx, MAP_ENTRY, self.span,
+ &format!("usage of `contains_key` followed by `insert` on a `{}`", self.ty), |diag| {
+ if self.sole_expr {
+ let mut app = Applicability::MachineApplicable;
+ let help = format!("{}.entry({}).or_insert({});",
+ snippet_with_applicability(self.cx, self.map.span, "map", &mut app),
+ snippet_with_applicability(self.cx, params[1].span, "..", &mut app),
+ snippet_with_applicability(self.cx, params[2].span, "..", &mut app));
+
+ diag.span_suggestion(
+ self.span,
+ "consider using",
+ help,
+ Applicability::MachineApplicable, // snippet
+ );
+ }
+ else {
+ let help = format!("consider using `{}.entry({})`",
+ snippet(self.cx, self.map.span, "map"),
+ snippet(self.cx, params[1].span, ".."));
+
+ diag.span_label(
+ self.span,
+ &help,
+ );
+ }
+ });
+ }
+ }
+
+ if !self.sole_expr {
+ walk_expr(self, expr);
+ }
+ }
+ fn nested_visit_map(&mut self) -> NestedVisitorMap {
+ NestedVisitorMap::None
+ }
+}
diff --git a/src/tools/clippy/clippy_lints/src/enum_clike.rs b/src/tools/clippy/clippy_lints/src/enum_clike.rs
new file mode 100644
index 00000000000..a1fed3fb6e2
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/enum_clike.rs
@@ -0,0 +1,82 @@
+//! lint on C-like enums that are `repr(isize/usize)` and have values that
+//! don't fit into an `i32`
+
+use crate::consts::{miri_to_const, Constant};
+use crate::utils::span_lint;
+use rustc_ast::ast::{IntTy, UintTy};
+use rustc_hir::{Item, ItemKind};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty;
+use rustc_middle::ty::util::IntTypeExt;
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use std::convert::TryFrom;
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for C-like enumerations that are
+ /// `repr(isize/usize)` and have values that don't fit into an `i32`.
+ ///
+ /// **Why is this bad?** This will truncate the variant value on 32 bit
+ /// architectures, but works fine on 64 bit.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```rust
+ /// # #[cfg(target_pointer_width = "64")]
+ /// #[repr(usize)]
+ /// enum NonPortable {
+ /// X = 0x1_0000_0000,
+ /// Y = 0,
+ /// }
+ /// ```
+ pub ENUM_CLIKE_UNPORTABLE_VARIANT,
+ correctness,
+ "C-like enums that are `repr(isize/usize)` and have values that don't fit into an `i32`"
+}
+
+declare_lint_pass!(UnportableVariant => [ENUM_CLIKE_UNPORTABLE_VARIANT]);
+
+impl<'a, 'tcx> LateLintPass<'a, 'tcx> for UnportableVariant {
+ #[allow(clippy::cast_possible_truncation, clippy::cast_possible_wrap, clippy::cast_sign_loss)]
+ fn check_item(&mut self, cx: &LateContext<'a, 'tcx>, item: &'tcx Item<'_>) {
+ if cx.tcx.data_layout.pointer_size.bits() != 64 {
+ return;
+ }
+ if let ItemKind::Enum(def, _) = &item.kind {
+ for var in def.variants {
+ if let Some(anon_const) = &var.disr_expr {
+ let def_id = cx.tcx.hir().body_owner_def_id(anon_const.body);
+ let mut ty = cx.tcx.type_of(def_id.to_def_id());
+ let constant = cx
+ .tcx
+ .const_eval_poly(def_id.to_def_id())
+ .ok()
+ .map(|val| rustc_middle::ty::Const::from_value(cx.tcx, val, ty));
+ if let Some(Constant::Int(val)) = constant.and_then(miri_to_const) {
+ if let ty::Adt(adt, _) = ty.kind {
+ if adt.is_enum() {
+ ty = adt.repr.discr_type().to_ty(cx.tcx);
+ }
+ }
+ match ty.kind {
+ ty::Int(IntTy::Isize) => {
+ let val = ((val as i128) << 64) >> 64;
+ if i32::try_from(val).is_ok() {
+ continue;
+ }
+ },
+ ty::Uint(UintTy::Usize) if val > u128::from(u32::max_value()) => {},
+ _ => continue,
+ }
+ span_lint(
+ cx,
+ ENUM_CLIKE_UNPORTABLE_VARIANT,
+ var.span,
+ "Clike enum variant discriminant is not portable to 32-bit targets",
+ );
+ };
+ }
+ }
+ }
+ }
+}
diff --git a/src/tools/clippy/clippy_lints/src/enum_variants.rs b/src/tools/clippy/clippy_lints/src/enum_variants.rs
new file mode 100644
index 00000000000..a5871cf0cd4
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/enum_variants.rs
@@ -0,0 +1,305 @@
+//! lint on enum variants that are prefixed or suffixed by the same characters
+
+use crate::utils::{camel_case, is_present_in_source};
+use crate::utils::{span_lint, span_lint_and_help};
+use rustc_ast::ast::{EnumDef, Item, ItemKind, VisibilityKind};
+use rustc_lint::{EarlyContext, EarlyLintPass, Lint};
+use rustc_session::{declare_tool_lint, impl_lint_pass};
+use rustc_span::source_map::Span;
+use rustc_span::symbol::Symbol;
+
+declare_clippy_lint! {
+ /// **What it does:** Detects enumeration variants that are prefixed or suffixed
+ /// by the same characters.
+ ///
+ /// **Why is this bad?** Enumeration variant names should specify their variant,
+ /// not repeat the enumeration name.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```rust
+ /// enum Cake {
+ /// BlackForestCake,
+ /// HummingbirdCake,
+ /// BattenbergCake,
+ /// }
+ /// ```
+ pub ENUM_VARIANT_NAMES,
+ style,
+ "enums where all variants share a prefix/postfix"
+}
+
+declare_clippy_lint! {
+ /// **What it does:** Detects enumeration variants that are prefixed or suffixed
+ /// by the same characters.
+ ///
+ /// **Why is this bad?** Enumeration variant names should specify their variant,
+ /// not repeat the enumeration name.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```rust
+ /// enum Cake {
+ /// BlackForestCake,
+ /// HummingbirdCake,
+ /// BattenbergCake,
+ /// }
+ /// ```
+ pub PUB_ENUM_VARIANT_NAMES,
+ pedantic,
+ "enums where all variants share a prefix/postfix"
+}
+
+declare_clippy_lint! {
+ /// **What it does:** Detects type names that are prefixed or suffixed by the
+ /// containing module's name.
+ ///
+ /// **Why is this bad?** It requires the user to type the module name twice.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```rust
+ /// mod cake {
+ /// struct BlackForestCake;
+ /// }
+ /// ```
+ pub MODULE_NAME_REPETITIONS,
+ pedantic,
+ "type names prefixed/postfixed with their containing module's name"
+}
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for modules that have the same name as their
+ /// parent module
+ ///
+ /// **Why is this bad?** A typical beginner mistake is to have `mod foo;` and
+ /// again `mod foo { ..
+ /// }` in `foo.rs`.
+ /// The expectation is that items inside the inner `mod foo { .. }` are then
+ /// available
+ /// through `foo::x`, but they are only available through
+ /// `foo::foo::x`.
+ /// If this is done on purpose, it would be better to choose a more
+ /// representative module name.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```ignore
+ /// // lib.rs
+ /// mod foo;
+ /// // foo.rs
+ /// mod foo {
+ /// ...
+ /// }
+ /// ```
+ pub MODULE_INCEPTION,
+ style,
+ "modules that have the same name as their parent module"
+}
+
+pub struct EnumVariantNames {
+ modules: Vec<(Symbol, String)>,
+ threshold: u64,
+}
+
+impl EnumVariantNames {
+ #[must_use]
+ pub fn new(threshold: u64) -> Self {
+ Self {
+ modules: Vec::new(),
+ threshold,
+ }
+ }
+}
+
+impl_lint_pass!(EnumVariantNames => [
+ ENUM_VARIANT_NAMES,
+ PUB_ENUM_VARIANT_NAMES,
+ MODULE_NAME_REPETITIONS,
+ MODULE_INCEPTION
+]);
+
+/// Returns the number of chars that match from the start
+#[must_use]
+fn partial_match(pre: &str, name: &str) -> usize {
+ let mut name_iter = name.chars();
+ let _ = name_iter.next_back(); // make sure the name is never fully matched
+ pre.chars().zip(name_iter).take_while(|&(l, r)| l == r).count()
+}
+
+/// Returns the number of chars that match from the end
+#[must_use]
+fn partial_rmatch(post: &str, name: &str) -> usize {
+ let mut name_iter = name.chars();
+ let _ = name_iter.next(); // make sure the name is never fully matched
+ post.chars()
+ .rev()
+ .zip(name_iter.rev())
+ .take_while(|&(l, r)| l == r)
+ .count()
+}
+
+fn check_variant(
+ cx: &EarlyContext<'_>,
+ threshold: u64,
+ def: &EnumDef,
+ item_name: &str,
+ item_name_chars: usize,
+ span: Span,
+ lint: &'static Lint,
+) {
+ if (def.variants.len() as u64) < threshold {
+ return;
+ }
+ for var in &def.variants {
+ let name = var.ident.name.as_str();
+ if partial_match(item_name, &name) == item_name_chars
+ && name.chars().nth(item_name_chars).map_or(false, |c| !c.is_lowercase())
+ && name.chars().nth(item_name_chars + 1).map_or(false, |c| !c.is_numeric())
+ {
+ span_lint(cx, lint, var.span, "Variant name starts with the enum's name");
+ }
+ if partial_rmatch(item_name, &name) == item_name_chars {
+ span_lint(cx, lint, var.span, "Variant name ends with the enum's name");
+ }
+ }
+ let first = &def.variants[0].ident.name.as_str();
+ let mut pre = &first[..camel_case::until(&*first)];
+ let mut post = &first[camel_case::from(&*first)..];
+ for var in &def.variants {
+ let name = var.ident.name.as_str();
+
+ let pre_match = partial_match(pre, &name);
+ pre = &pre[..pre_match];
+ let pre_camel = camel_case::until(pre);
+ pre = &pre[..pre_camel];
+ while let Some((next, last)) = name[pre.len()..].chars().zip(pre.chars().rev()).next() {
+ if next.is_numeric() {
+ return;
+ }
+ if next.is_lowercase() {
+ let last = pre.len() - last.len_utf8();
+ let last_camel = camel_case::until(&pre[..last]);
+ pre = &pre[..last_camel];
+ } else {
+ break;
+ }
+ }
+
+ let post_match = partial_rmatch(post, &name);
+ let post_end = post.len() - post_match;
+ post = &post[post_end..];
+ let post_camel = camel_case::from(post);
+ post = &post[post_camel..];
+ }
+ let (what, value) = match (pre.is_empty(), post.is_empty()) {
+ (true, true) => return,
+ (false, _) => ("pre", pre),
+ (true, false) => ("post", post),
+ };
+ span_lint_and_help(
+ cx,
+ lint,
+ span,
+ &format!("All variants have the same {}fix: `{}`", what, value),
+ None,
+ &format!(
+ "remove the {}fixes and use full paths to \
+ the variants instead of glob imports",
+ what
+ ),
+ );
+}
+
+#[must_use]
+fn to_camel_case(item_name: &str) -> String {
+ let mut s = String::new();
+ let mut up = true;
+ for c in item_name.chars() {
+ if c.is_uppercase() {
+ // we only turn snake case text into CamelCase
+ return item_name.to_string();
+ }
+ if c == '_' {
+ up = true;
+ continue;
+ }
+ if up {
+ up = false;
+ s.extend(c.to_uppercase());
+ } else {
+ s.push(c);
+ }
+ }
+ s
+}
+
+impl EarlyLintPass for EnumVariantNames {
+ fn check_item_post(&mut self, _cx: &EarlyContext<'_>, _item: &Item) {
+ let last = self.modules.pop();
+ assert!(last.is_some());
+ }
+
+ #[allow(clippy::similar_names)]
+ fn check_item(&mut self, cx: &EarlyContext<'_>, item: &Item) {
+ let item_name = item.ident.name.as_str();
+ let item_name_chars = item_name.chars().count();
+ let item_camel = to_camel_case(&item_name);
+ if !item.span.from_expansion() && is_present_in_source(cx, item.span) {
+ if let Some(&(ref mod_name, ref mod_camel)) = self.modules.last() {
+ // constants don't have surrounding modules
+ if !mod_camel.is_empty() {
+ if mod_name == &item.ident.name {
+ if let ItemKind::Mod(..) = item.kind {
+ span_lint(
+ cx,
+ MODULE_INCEPTION,
+ item.span,
+ "module has the same name as its containing module",
+ );
+ }
+ }
+ if item.vis.node.is_pub() {
+ let matching = partial_match(mod_camel, &item_camel);
+ let rmatching = partial_rmatch(mod_camel, &item_camel);
+ let nchars = mod_camel.chars().count();
+
+ let is_word_beginning = |c: char| c == '_' || c.is_uppercase() || c.is_numeric();
+
+ if matching == nchars {
+ match item_camel.chars().nth(nchars) {
+ Some(c) if is_word_beginning(c) => span_lint(
+ cx,
+ MODULE_NAME_REPETITIONS,
+ item.span,
+ "item name starts with its containing module's name",
+ ),
+ _ => (),
+ }
+ }
+ if rmatching == nchars {
+ span_lint(
+ cx,
+ MODULE_NAME_REPETITIONS,
+ item.span,
+ "item name ends with its containing module's name",
+ );
+ }
+ }
+ }
+ }
+ }
+ if let ItemKind::Enum(ref def, _) = item.kind {
+ let lint = match item.vis.node {
+ VisibilityKind::Public => PUB_ENUM_VARIANT_NAMES,
+ _ => ENUM_VARIANT_NAMES,
+ };
+ check_variant(cx, self.threshold, def, &item_name, item_name_chars, item.span, lint);
+ }
+ self.modules.push((item.ident.name, item_camel));
+ }
+}
diff --git a/src/tools/clippy/clippy_lints/src/eq_op.rs b/src/tools/clippy/clippy_lints/src/eq_op.rs
new file mode 100644
index 00000000000..098d47bdd40
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/eq_op.rs
@@ -0,0 +1,229 @@
+use crate::utils::{
+ implements_trait, in_macro, is_copy, multispan_sugg, snippet, span_lint, span_lint_and_then, SpanlessEq,
+};
+use rustc_errors::Applicability;
+use rustc_hir::{BinOp, BinOpKind, BorrowKind, Expr, ExprKind};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for equal operands to comparison, logical and
+ /// bitwise, difference and division binary operators (`==`, `>`, etc., `&&`,
+ /// `||`, `&`, `|`, `^`, `-` and `/`).
+ ///
+ /// **Why is this bad?** This is usually just a typo or a copy and paste error.
+ ///
+ /// **Known problems:** False negatives: We had some false positives regarding
+ /// calls (notably [racer](https://github.com/phildawes/racer) had one instance
+ /// of `x.pop() && x.pop()`), so we removed matching any function or method
+ /// calls. We may introduce a whitelist of known pure functions in the future.
+ ///
+ /// **Example:**
+ /// ```rust
+ /// # let x = 1;
+ /// if x + 1 == x + 1 {}
+ /// ```
+ pub EQ_OP,
+ correctness,
+ "equal operands on both sides of a comparison or bitwise combination (e.g., `x == x`)"
+}
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for arguments to `==` which have their address
+ /// taken to satisfy a bound
+ /// and suggests to dereference the other argument instead
+ ///
+ /// **Why is this bad?** It is more idiomatic to dereference the other argument.
+ ///
+ /// **Known problems:** None
+ ///
+ /// **Example:**
+ /// ```ignore
+ /// &x == y
+ /// ```
+ pub OP_REF,
+ style,
+ "taking a reference to satisfy the type constraints on `==`"
+}
+
+declare_lint_pass!(EqOp => [EQ_OP, OP_REF]);
+
+impl<'a, 'tcx> LateLintPass<'a, 'tcx> for EqOp {
+ #[allow(clippy::similar_names, clippy::too_many_lines)]
+ fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, e: &'tcx Expr<'_>) {
+ if let ExprKind::Binary(op, ref left, ref right) = e.kind {
+ if e.span.from_expansion() {
+ return;
+ }
+ let macro_with_not_op = |expr_kind: &ExprKind<'_>| {
+ if let ExprKind::Unary(_, ref expr) = *expr_kind {
+ in_macro(expr.span)
+ } else {
+ false
+ }
+ };
+ if macro_with_not_op(&left.kind) || macro_with_not_op(&right.kind) {
+ return;
+ }
+ if is_valid_operator(op) && SpanlessEq::new(cx).ignore_fn().eq_expr(left, right) {
+ span_lint(
+ cx,
+ EQ_OP,
+ e.span,
+ &format!("equal expressions as operands to `{}`", op.node.as_str()),
+ );
+ return;
+ }
+ let (trait_id, requires_ref) = match op.node {
+ BinOpKind::Add => (cx.tcx.lang_items().add_trait(), false),
+ BinOpKind::Sub => (cx.tcx.lang_items().sub_trait(), false),
+ BinOpKind::Mul => (cx.tcx.lang_items().mul_trait(), false),
+ BinOpKind::Div => (cx.tcx.lang_items().div_trait(), false),
+ BinOpKind::Rem => (cx.tcx.lang_items().rem_trait(), false),
+ // don't lint short circuiting ops
+ BinOpKind::And | BinOpKind::Or => return,
+ BinOpKind::BitXor => (cx.tcx.lang_items().bitxor_trait(), false),
+ BinOpKind::BitAnd => (cx.tcx.lang_items().bitand_trait(), false),
+ BinOpKind::BitOr => (cx.tcx.lang_items().bitor_trait(), false),
+ BinOpKind::Shl => (cx.tcx.lang_items().shl_trait(), false),
+ BinOpKind::Shr => (cx.tcx.lang_items().shr_trait(), false),
+ BinOpKind::Ne | BinOpKind::Eq => (cx.tcx.lang_items().eq_trait(), true),
+ BinOpKind::Lt | BinOpKind::Le | BinOpKind::Ge | BinOpKind::Gt => {
+ (cx.tcx.lang_items().partial_ord_trait(), true)
+ },
+ };
+ if let Some(trait_id) = trait_id {
+ #[allow(clippy::match_same_arms)]
+ match (&left.kind, &right.kind) {
+ // do not suggest to dereference literals
+ (&ExprKind::Lit(..), _) | (_, &ExprKind::Lit(..)) => {},
+ // &foo == &bar
+ (&ExprKind::AddrOf(BorrowKind::Ref, _, ref l), &ExprKind::AddrOf(BorrowKind::Ref, _, ref r)) => {
+ let lty = cx.tables.expr_ty(l);
+ let rty = cx.tables.expr_ty(r);
+ let lcpy = is_copy(cx, lty);
+ let rcpy = is_copy(cx, rty);
+ // either operator autorefs or both args are copyable
+ if (requires_ref || (lcpy && rcpy)) && implements_trait(cx, lty, trait_id, &[rty.into()]) {
+ span_lint_and_then(
+ cx,
+ OP_REF,
+ e.span,
+ "needlessly taken reference of both operands",
+ |diag| {
+ let lsnip = snippet(cx, l.span, "...").to_string();
+ let rsnip = snippet(cx, r.span, "...").to_string();
+ multispan_sugg(
+ diag,
+ "use the values directly".to_string(),
+ vec![(left.span, lsnip), (right.span, rsnip)],
+ );
+ },
+ )
+ } else if lcpy
+ && !rcpy
+ && implements_trait(cx, lty, trait_id, &[cx.tables.expr_ty(right).into()])
+ {
+ span_lint_and_then(
+ cx,
+ OP_REF,
+ e.span,
+ "needlessly taken reference of left operand",
+ |diag| {
+ let lsnip = snippet(cx, l.span, "...").to_string();
+ diag.span_suggestion(
+ left.span,
+ "use the left value directly",
+ lsnip,
+ Applicability::MaybeIncorrect, // FIXME #2597
+ );
+ },
+ )
+ } else if !lcpy
+ && rcpy
+ && implements_trait(cx, cx.tables.expr_ty(left), trait_id, &[rty.into()])
+ {
+ span_lint_and_then(
+ cx,
+ OP_REF,
+ e.span,
+ "needlessly taken reference of right operand",
+ |diag| {
+ let rsnip = snippet(cx, r.span, "...").to_string();
+ diag.span_suggestion(
+ right.span,
+ "use the right value directly",
+ rsnip,
+ Applicability::MaybeIncorrect, // FIXME #2597
+ );
+ },
+ )
+ }
+ },
+ // &foo == bar
+ (&ExprKind::AddrOf(BorrowKind::Ref, _, ref l), _) => {
+ let lty = cx.tables.expr_ty(l);
+ let lcpy = is_copy(cx, lty);
+ if (requires_ref || lcpy)
+ && implements_trait(cx, lty, trait_id, &[cx.tables.expr_ty(right).into()])
+ {
+ span_lint_and_then(
+ cx,
+ OP_REF,
+ e.span,
+ "needlessly taken reference of left operand",
+ |diag| {
+ let lsnip = snippet(cx, l.span, "...").to_string();
+ diag.span_suggestion(
+ left.span,
+ "use the left value directly",
+ lsnip,
+ Applicability::MaybeIncorrect, // FIXME #2597
+ );
+ },
+ )
+ }
+ },
+ // foo == &bar
+ (_, &ExprKind::AddrOf(BorrowKind::Ref, _, ref r)) => {
+ let rty = cx.tables.expr_ty(r);
+ let rcpy = is_copy(cx, rty);
+ if (requires_ref || rcpy)
+ && implements_trait(cx, cx.tables.expr_ty(left), trait_id, &[rty.into()])
+ {
+ span_lint_and_then(cx, OP_REF, e.span, "taken reference of right operand", |diag| {
+ let rsnip = snippet(cx, r.span, "...").to_string();
+ diag.span_suggestion(
+ right.span,
+ "use the right value directly",
+ rsnip,
+ Applicability::MaybeIncorrect, // FIXME #2597
+ );
+ })
+ }
+ },
+ _ => {},
+ }
+ }
+ }
+ }
+}
+
+fn is_valid_operator(op: BinOp) -> bool {
+ match op.node {
+ BinOpKind::Sub
+ | BinOpKind::Div
+ | BinOpKind::Eq
+ | BinOpKind::Lt
+ | BinOpKind::Le
+ | BinOpKind::Gt
+ | BinOpKind::Ge
+ | BinOpKind::Ne
+ | BinOpKind::And
+ | BinOpKind::Or
+ | BinOpKind::BitXor
+ | BinOpKind::BitAnd
+ | BinOpKind::BitOr => true,
+ _ => false,
+ }
+}
diff --git a/src/tools/clippy/clippy_lints/src/erasing_op.rs b/src/tools/clippy/clippy_lints/src/erasing_op.rs
new file mode 100644
index 00000000000..3ff0506e28d
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/erasing_op.rs
@@ -0,0 +1,59 @@
+use rustc_hir::{BinOpKind, Expr, ExprKind};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::source_map::Span;
+
+use crate::consts::{constant_simple, Constant};
+use crate::utils::span_lint;
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for erasing operations, e.g., `x * 0`.
+ ///
+ /// **Why is this bad?** The whole expression can be replaced by zero.
+ /// This is most likely not the intended outcome and should probably be
+ /// corrected
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```rust
+ /// let x = 1;
+ /// 0 / x;
+ /// 0 * x;
+ /// x & 0;
+ /// ```
+ pub ERASING_OP,
+ correctness,
+ "using erasing operations, e.g., `x * 0` or `y & 0`"
+}
+
+declare_lint_pass!(ErasingOp => [ERASING_OP]);
+
+impl<'a, 'tcx> LateLintPass<'a, 'tcx> for ErasingOp {
+ fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, e: &'tcx Expr<'_>) {
+ if e.span.from_expansion() {
+ return;
+ }
+ if let ExprKind::Binary(ref cmp, ref left, ref right) = e.kind {
+ match cmp.node {
+ BinOpKind::Mul | BinOpKind::BitAnd => {
+ check(cx, left, e.span);
+ check(cx, right, e.span);
+ },
+ BinOpKind::Div => check(cx, left, e.span),
+ _ => (),
+ }
+ }
+ }
+}
+
+fn check(cx: &LateContext<'_, '_>, e: &Expr<'_>, span: Span) {
+ if let Some(Constant::Int(0)) = constant_simple(cx, cx.tables, e) {
+ span_lint(
+ cx,
+ ERASING_OP,
+ span,
+ "this operation will always return zero. This is likely not the intended outcome",
+ );
+ }
+}
diff --git a/src/tools/clippy/clippy_lints/src/escape.rs b/src/tools/clippy/clippy_lints/src/escape.rs
new file mode 100644
index 00000000000..1ec60a0e6e6
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/escape.rs
@@ -0,0 +1,164 @@
+use rustc_hir::intravisit;
+use rustc_hir::{self, Body, FnDecl, HirId, HirIdSet, ItemKind, Node};
+use rustc_infer::infer::TyCtxtInferExt;
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty::{self, Ty};
+use rustc_session::{declare_tool_lint, impl_lint_pass};
+use rustc_span::source_map::Span;
+use rustc_target::abi::LayoutOf;
+use rustc_typeck::expr_use_visitor::{ConsumeMode, Delegate, ExprUseVisitor, Place, PlaceBase};
+
+use crate::utils::span_lint;
+
+#[derive(Copy, Clone)]
+pub struct BoxedLocal {
+ pub too_large_for_stack: u64,
+}
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for usage of `Box` where an unboxed `T` would
+ /// work fine.
+ ///
+ /// **Why is this bad?** This is an unnecessary allocation, and bad for
+ /// performance. It is only necessary to allocate if you wish to move the box
+ /// into something.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```rust
+ /// # fn foo(bar: usize) {}
+ /// let x = Box::new(1);
+ /// foo(*x);
+ /// println!("{}", *x);
+ /// ```
+ pub BOXED_LOCAL,
+ perf,
+ "using `Box` where unnecessary"
+}
+
+fn is_non_trait_box(ty: Ty<'_>) -> bool {
+ ty.is_box() && !ty.boxed_ty().is_trait()
+}
+
+struct EscapeDelegate<'a, 'tcx> {
+ cx: &'a LateContext<'a, 'tcx>,
+ set: HirIdSet,
+ too_large_for_stack: u64,
+}
+
+impl_lint_pass!(BoxedLocal => [BOXED_LOCAL]);
+
+impl<'a, 'tcx> LateLintPass<'a, 'tcx> for BoxedLocal {
+ fn check_fn(
+ &mut self,
+ cx: &LateContext<'a, 'tcx>,
+ _: intravisit::FnKind<'tcx>,
+ _: &'tcx FnDecl<'_>,
+ body: &'tcx Body<'_>,
+ _: Span,
+ hir_id: HirId,
+ ) {
+ // If the method is an impl for a trait, don't warn.
+ let parent_id = cx.tcx.hir().get_parent_item(hir_id);
+ let parent_node = cx.tcx.hir().find(parent_id);
+
+ if let Some(Node::Item(item)) = parent_node {
+ if let ItemKind::Impl { of_trait: Some(_), .. } = item.kind {
+ return;
+ }
+ }
+
+ let mut v = EscapeDelegate {
+ cx,
+ set: HirIdSet::default(),
+ too_large_for_stack: self.too_large_for_stack,
+ };
+
+ let fn_def_id = cx.tcx.hir().local_def_id(hir_id);
+ cx.tcx.infer_ctxt().enter(|infcx| {
+ ExprUseVisitor::new(&mut v, &infcx, fn_def_id, cx.param_env, cx.tables).consume_body(body);
+ });
+
+ for node in v.set {
+ span_lint(
+ cx,
+ BOXED_LOCAL,
+ cx.tcx.hir().span(node),
+ "local variable doesn't need to be boxed here",
+ );
+ }
+ }
+}
+
+// TODO: Replace with Map::is_argument(..) when it's fixed
+fn is_argument(map: rustc_middle::hir::map::Map<'_>, id: HirId) -> bool {
+ match map.find(id) {
+ Some(Node::Binding(_)) => (),
+ _ => return false,
+ }
+
+ match map.find(map.get_parent_node(id)) {
+ Some(Node::Param(_)) => true,
+ _ => false,
+ }
+}
+
+impl<'a, 'tcx> Delegate<'tcx> for EscapeDelegate<'a, 'tcx> {
+ fn consume(&mut self, cmt: &Place<'tcx>, mode: ConsumeMode) {
+ if cmt.projections.is_empty() {
+ if let PlaceBase::Local(lid) = cmt.base {
+ if let ConsumeMode::Move = mode {
+ // moved out or in. clearly can't be localized
+ self.set.remove(&lid);
+ }
+ let map = &self.cx.tcx.hir();
+ if let Some(Node::Binding(_)) = map.find(cmt.hir_id) {
+ if self.set.contains(&lid) {
+ // let y = x where x is known
+ // remove x, insert y
+ self.set.insert(cmt.hir_id);
+ self.set.remove(&lid);
+ }
+ }
+ }
+ }
+ }
+
+ fn borrow(&mut self, cmt: &Place<'tcx>, _: ty::BorrowKind) {
+ if cmt.projections.is_empty() {
+ if let PlaceBase::Local(lid) = cmt.base {
+ self.set.remove(&lid);
+ }
+ }
+ }
+
+ fn mutate(&mut self, cmt: &Place<'tcx>) {
+ if cmt.projections.is_empty() {
+ let map = &self.cx.tcx.hir();
+ if is_argument(*map, cmt.hir_id) {
+ // Skip closure arguments
+ let parent_id = map.get_parent_node(cmt.hir_id);
+ if let Some(Node::Expr(..)) = map.find(map.get_parent_node(parent_id)) {
+ return;
+ }
+
+ if is_non_trait_box(cmt.ty) && !self.is_large_box(cmt.ty) {
+ self.set.insert(cmt.hir_id);
+ }
+ return;
+ }
+ }
+ }
+}
+
+impl<'a, 'tcx> EscapeDelegate<'a, 'tcx> {
+ fn is_large_box(&self, ty: Ty<'tcx>) -> bool {
+ // Large types need to be boxed to avoid stack overflows.
+ if ty.is_box() {
+ self.cx.layout_of(ty.boxed_ty()).map_or(0, |l| l.size.bytes()) > self.too_large_for_stack
+ } else {
+ false
+ }
+ }
+}
diff --git a/src/tools/clippy/clippy_lints/src/eta_reduction.rs b/src/tools/clippy/clippy_lints/src/eta_reduction.rs
new file mode 100644
index 00000000000..e3e1136b676
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/eta_reduction.rs
@@ -0,0 +1,227 @@
+use if_chain::if_chain;
+use rustc_errors::Applicability;
+use rustc_hir::{def_id, Expr, ExprKind, Param, PatKind, QPath};
+use rustc_lint::{LateContext, LateLintPass, LintContext};
+use rustc_middle::lint::in_external_macro;
+use rustc_middle::ty::{self, Ty};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+
+use crate::utils::{
+ implements_trait, is_adjusted, iter_input_pats, snippet_opt, span_lint_and_sugg, span_lint_and_then,
+ type_is_unsafe_function,
+};
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for closures which just call another function where
+ /// the function can be called directly. `unsafe` functions or calls where types
+ /// get adjusted are ignored.
+ ///
+ /// **Why is this bad?** Needlessly creating a closure adds code for no benefit
+ /// and gives the optimizer more work.
+ ///
+ /// **Known problems:** If creating the closure inside the closure has a side-
+ /// effect then moving the closure creation out will change when that side-
+ /// effect runs.
+ /// See rust-lang/rust-clippy#1439 for more details.
+ ///
+ /// **Example:**
+ /// ```rust,ignore
+ /// xs.map(|x| foo(x))
+ /// ```
+ /// where `foo(_)` is a plain function that takes the exact argument type of
+ /// `x`.
+ pub REDUNDANT_CLOSURE,
+ style,
+ "redundant closures, i.e., `|a| foo(a)` (which can be written as just `foo`)"
+}
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for closures which only invoke a method on the closure
+ /// argument and can be replaced by referencing the method directly.
+ ///
+ /// **Why is this bad?** It's unnecessary to create the closure.
+ ///
+ /// **Known problems:** rust-lang/rust-clippy#3071, rust-lang/rust-clippy#4002,
+ /// rust-lang/rust-clippy#3942
+ ///
+ ///
+ /// **Example:**
+ /// ```rust,ignore
+ /// Some('a').map(|s| s.to_uppercase());
+ /// ```
+ /// may be rewritten as
+ /// ```rust,ignore
+ /// Some('a').map(char::to_uppercase);
+ /// ```
+ pub REDUNDANT_CLOSURE_FOR_METHOD_CALLS,
+ pedantic,
+ "redundant closures for method calls"
+}
+
+declare_lint_pass!(EtaReduction => [REDUNDANT_CLOSURE, REDUNDANT_CLOSURE_FOR_METHOD_CALLS]);
+
+impl<'a, 'tcx> LateLintPass<'a, 'tcx> for EtaReduction {
+ fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr<'_>) {
+ if in_external_macro(cx.sess(), expr.span) {
+ return;
+ }
+
+ match expr.kind {
+ ExprKind::Call(_, args) | ExprKind::MethodCall(_, _, args) => {
+ for arg in args {
+ check_closure(cx, arg)
+ }
+ },
+ _ => (),
+ }
+ }
+}
+
+fn check_closure(cx: &LateContext<'_, '_>, expr: &Expr<'_>) {
+ if let ExprKind::Closure(_, ref decl, eid, _, _) = expr.kind {
+ let body = cx.tcx.hir().body(eid);
+ let ex = &body.value;
+
+ if_chain!(
+ if let ExprKind::Call(ref caller, ref args) = ex.kind;
+
+ if let ExprKind::Path(_) = caller.kind;
+
+ // Not the same number of arguments, there is no way the closure is the same as the function return;
+ if args.len() == decl.inputs.len();
+
+ // Are the expression or the arguments type-adjusted? Then we need the closure
+ if !(is_adjusted(cx, ex) || args.iter().any(|arg| is_adjusted(cx, arg)));
+
+ let fn_ty = cx.tables.expr_ty(caller);
+
+ if matches!(fn_ty.kind, ty::FnDef(_, _) | ty::FnPtr(_) | ty::Closure(_, _));
+
+ if !type_is_unsafe_function(cx, fn_ty);
+
+ if compare_inputs(&mut iter_input_pats(decl, body), &mut args.iter());
+
+ then {
+ span_lint_and_then(cx, REDUNDANT_CLOSURE, expr.span, "redundant closure found", |diag| {
+ if let Some(snippet) = snippet_opt(cx, caller.span) {
+ diag.span_suggestion(
+ expr.span,
+ "remove closure as shown",
+ snippet,
+ Applicability::MachineApplicable,
+ );
+ }
+ });
+ }
+ );
+
+ if_chain!(
+ if let ExprKind::MethodCall(ref path, _, ref args) = ex.kind;
+
+ // Not the same number of arguments, there is no way the closure is the same as the function return;
+ if args.len() == decl.inputs.len();
+
+ // Are the expression or the arguments type-adjusted? Then we need the closure
+ if !(is_adjusted(cx, ex) || args.iter().skip(1).any(|arg| is_adjusted(cx, arg)));
+
+ let method_def_id = cx.tables.type_dependent_def_id(ex.hir_id).unwrap();
+ if !type_is_unsafe_function(cx, cx.tcx.type_of(method_def_id));
+
+ if compare_inputs(&mut iter_input_pats(decl, body), &mut args.iter());
+
+ if let Some(name) = get_ufcs_type_name(cx, method_def_id, &args[0]);
+
+ then {
+ span_lint_and_sugg(
+ cx,
+ REDUNDANT_CLOSURE_FOR_METHOD_CALLS,
+ expr.span,
+ "redundant closure found",
+ "remove closure as shown",
+ format!("{}::{}", name, path.ident.name),
+ Applicability::MachineApplicable,
+ );
+ }
+ );
+ }
+}
+
+/// Tries to determine the type for universal function call to be used instead of the closure
+fn get_ufcs_type_name(cx: &LateContext<'_, '_>, method_def_id: def_id::DefId, self_arg: &Expr<'_>) -> Option {
+ let expected_type_of_self = &cx.tcx.fn_sig(method_def_id).inputs_and_output().skip_binder()[0];
+ let actual_type_of_self = &cx.tables.node_type(self_arg.hir_id);
+
+ if let Some(trait_id) = cx.tcx.trait_of_item(method_def_id) {
+ if match_borrow_depth(expected_type_of_self, &actual_type_of_self)
+ && implements_trait(cx, actual_type_of_self, trait_id, &[])
+ {
+ return Some(cx.tcx.def_path_str(trait_id));
+ }
+ }
+
+ cx.tcx.impl_of_method(method_def_id).and_then(|_| {
+ //a type may implicitly implement other type's methods (e.g. Deref)
+ if match_types(expected_type_of_self, &actual_type_of_self) {
+ return Some(get_type_name(cx, &actual_type_of_self));
+ }
+ None
+ })
+}
+
+fn match_borrow_depth(lhs: Ty<'_>, rhs: Ty<'_>) -> bool {
+ match (&lhs.kind, &rhs.kind) {
+ (ty::Ref(_, t1, mut1), ty::Ref(_, t2, mut2)) => mut1 == mut2 && match_borrow_depth(&t1, &t2),
+ (l, r) => match (l, r) {
+ (ty::Ref(_, _, _), _) | (_, ty::Ref(_, _, _)) => false,
+ (_, _) => true,
+ },
+ }
+}
+
+fn match_types(lhs: Ty<'_>, rhs: Ty<'_>) -> bool {
+ match (&lhs.kind, &rhs.kind) {
+ (ty::Bool, ty::Bool)
+ | (ty::Char, ty::Char)
+ | (ty::Int(_), ty::Int(_))
+ | (ty::Uint(_), ty::Uint(_))
+ | (ty::Str, ty::Str) => true,
+ (ty::Ref(_, t1, mut1), ty::Ref(_, t2, mut2)) => mut1 == mut2 && match_types(t1, t2),
+ (ty::Array(t1, _), ty::Array(t2, _)) | (ty::Slice(t1), ty::Slice(t2)) => match_types(t1, t2),
+ (ty::Adt(def1, _), ty::Adt(def2, _)) => def1 == def2,
+ (_, _) => false,
+ }
+}
+
+fn get_type_name(cx: &LateContext<'_, '_>, ty: Ty<'_>) -> String {
+ match ty.kind {
+ ty::Adt(t, _) => cx.tcx.def_path_str(t.did),
+ ty::Ref(_, r, _) => get_type_name(cx, &r),
+ _ => ty.to_string(),
+ }
+}
+
+fn compare_inputs(
+ closure_inputs: &mut dyn Iterator
- >,
+ call_args: &mut dyn Iterator
- >,
+) -> bool {
+ for (closure_input, function_arg) in closure_inputs.zip(call_args) {
+ if let PatKind::Binding(_, _, ident, _) = closure_input.pat.kind {
+ // XXXManishearth Should I be checking the binding mode here?
+ if let ExprKind::Path(QPath::Resolved(None, ref p)) = function_arg.kind {
+ if p.segments.len() != 1 {
+ // If it's a proper path, it can't be a local variable
+ return false;
+ }
+ if p.segments[0].ident.name != ident.name {
+ // The two idents should be the same
+ return false;
+ }
+ } else {
+ return false;
+ }
+ } else {
+ return false;
+ }
+ }
+ true
+}
diff --git a/src/tools/clippy/clippy_lints/src/eval_order_dependence.rs b/src/tools/clippy/clippy_lints/src/eval_order_dependence.rs
new file mode 100644
index 00000000000..5206266ccf2
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/eval_order_dependence.rs
@@ -0,0 +1,355 @@
+use crate::utils::{get_parent_expr, span_lint, span_lint_and_note};
+use if_chain::if_chain;
+use rustc_hir::intravisit::{walk_expr, NestedVisitorMap, Visitor};
+use rustc_hir::{def, BinOpKind, Block, Expr, ExprKind, Guard, HirId, Local, Node, QPath, Stmt, StmtKind};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::hir::map::Map;
+use rustc_middle::ty;
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for a read and a write to the same variable where
+ /// whether the read occurs before or after the write depends on the evaluation
+ /// order of sub-expressions.
+ ///
+ /// **Why is this bad?** It is often confusing to read. In addition, the
+ /// sub-expression evaluation order for Rust is not well documented.
+ ///
+ /// **Known problems:** Code which intentionally depends on the evaluation
+ /// order, or which is correct for any evaluation order.
+ ///
+ /// **Example:**
+ /// ```rust
+ /// let mut x = 0;
+ /// let a = {
+ /// x = 1;
+ /// 1
+ /// } + x;
+ /// // Unclear whether a is 1 or 2.
+ /// ```
+ pub EVAL_ORDER_DEPENDENCE,
+ complexity,
+ "whether a variable read occurs before a write depends on sub-expression evaluation order"
+}
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for diverging calls that are not match arms or
+ /// statements.
+ ///
+ /// **Why is this bad?** It is often confusing to read. In addition, the
+ /// sub-expression evaluation order for Rust is not well documented.
+ ///
+ /// **Known problems:** Someone might want to use `some_bool || panic!()` as a
+ /// shorthand.
+ ///
+ /// **Example:**
+ /// ```rust,no_run
+ /// # fn b() -> bool { true }
+ /// # fn c() -> bool { true }
+ /// let a = b() || panic!() || c();
+ /// // `c()` is dead, `panic!()` is only called if `b()` returns `false`
+ /// let x = (a, b, c, panic!());
+ /// // can simply be replaced by `panic!()`
+ /// ```
+ pub DIVERGING_SUB_EXPRESSION,
+ complexity,
+ "whether an expression contains a diverging sub expression"
+}
+
+declare_lint_pass!(EvalOrderDependence => [EVAL_ORDER_DEPENDENCE, DIVERGING_SUB_EXPRESSION]);
+
+impl<'a, 'tcx> LateLintPass<'a, 'tcx> for EvalOrderDependence {
+ fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr<'_>) {
+ // Find a write to a local variable.
+ match expr.kind {
+ ExprKind::Assign(ref lhs, ..) | ExprKind::AssignOp(_, ref lhs, _) => {
+ if let ExprKind::Path(ref qpath) = lhs.kind {
+ if let QPath::Resolved(_, ref path) = *qpath {
+ if path.segments.len() == 1 {
+ if let def::Res::Local(var) = cx.tables.qpath_res(qpath, lhs.hir_id) {
+ let mut visitor = ReadVisitor {
+ cx,
+ var,
+ write_expr: expr,
+ last_expr: expr,
+ };
+ check_for_unsequenced_reads(&mut visitor);
+ }
+ }
+ }
+ }
+ },
+ _ => {},
+ }
+ }
+ fn check_stmt(&mut self, cx: &LateContext<'a, 'tcx>, stmt: &'tcx Stmt<'_>) {
+ match stmt.kind {
+ StmtKind::Local(ref local) => {
+ if let Local { init: Some(ref e), .. } = **local {
+ DivergenceVisitor { cx }.visit_expr(e);
+ }
+ },
+ StmtKind::Expr(ref e) | StmtKind::Semi(ref e) => DivergenceVisitor { cx }.maybe_walk_expr(e),
+ StmtKind::Item(..) => {},
+ }
+ }
+}
+
+struct DivergenceVisitor<'a, 'tcx> {
+ cx: &'a LateContext<'a, 'tcx>,
+}
+
+impl<'a, 'tcx> DivergenceVisitor<'a, 'tcx> {
+ fn maybe_walk_expr(&mut self, e: &'tcx Expr<'_>) {
+ match e.kind {
+ ExprKind::Closure(..) => {},
+ ExprKind::Match(ref e, arms, _) => {
+ self.visit_expr(e);
+ for arm in arms {
+ if let Some(Guard::If(if_expr)) = arm.guard {
+ self.visit_expr(if_expr)
+ }
+ // make sure top level arm expressions aren't linted
+ self.maybe_walk_expr(&*arm.body);
+ }
+ },
+ _ => walk_expr(self, e),
+ }
+ }
+ fn report_diverging_sub_expr(&mut self, e: &Expr<'_>) {
+ span_lint(self.cx, DIVERGING_SUB_EXPRESSION, e.span, "sub-expression diverges");
+ }
+}
+
+impl<'a, 'tcx> Visitor<'tcx> for DivergenceVisitor<'a, 'tcx> {
+ type Map = Map<'tcx>;
+
+ fn visit_expr(&mut self, e: &'tcx Expr<'_>) {
+ match e.kind {
+ ExprKind::Continue(_) | ExprKind::Break(_, _) | ExprKind::Ret(_) => self.report_diverging_sub_expr(e),
+ ExprKind::Call(ref func, _) => {
+ let typ = self.cx.tables.expr_ty(func);
+ match typ.kind {
+ ty::FnDef(..) | ty::FnPtr(_) => {
+ let sig = typ.fn_sig(self.cx.tcx);
+ if let ty::Never = self.cx.tcx.erase_late_bound_regions(&sig).output().kind {
+ self.report_diverging_sub_expr(e);
+ }
+ },
+ _ => {},
+ }
+ },
+ ExprKind::MethodCall(..) => {
+ let borrowed_table = self.cx.tables;
+ if borrowed_table.expr_ty(e).is_never() {
+ self.report_diverging_sub_expr(e);
+ }
+ },
+ _ => {
+ // do not lint expressions referencing objects of type `!`, as that required a
+ // diverging expression
+ // to begin with
+ },
+ }
+ self.maybe_walk_expr(e);
+ }
+ fn visit_block(&mut self, _: &'tcx Block<'_>) {
+ // don't continue over blocks, LateLintPass already does that
+ }
+ fn nested_visit_map(&mut self) -> NestedVisitorMap {
+ NestedVisitorMap::None
+ }
+}
+
+/// Walks up the AST from the given write expression (`vis.write_expr`) looking
+/// for reads to the same variable that are unsequenced relative to the write.
+///
+/// This means reads for which there is a common ancestor between the read and
+/// the write such that
+///
+/// * evaluating the ancestor necessarily evaluates both the read and the write (for example, `&x`
+/// and `|| x = 1` don't necessarily evaluate `x`), and
+///
+/// * which one is evaluated first depends on the order of sub-expression evaluation. Blocks, `if`s,
+/// loops, `match`es, and the short-circuiting logical operators are considered to have a defined
+/// evaluation order.
+///
+/// When such a read is found, the lint is triggered.
+fn check_for_unsequenced_reads(vis: &mut ReadVisitor<'_, '_>) {
+ let map = &vis.cx.tcx.hir();
+ let mut cur_id = vis.write_expr.hir_id;
+ loop {
+ let parent_id = map.get_parent_node(cur_id);
+ if parent_id == cur_id {
+ break;
+ }
+ let parent_node = match map.find(parent_id) {
+ Some(parent) => parent,
+ None => break,
+ };
+
+ let stop_early = match parent_node {
+ Node::Expr(expr) => check_expr(vis, expr),
+ Node::Stmt(stmt) => check_stmt(vis, stmt),
+ Node::Item(_) => {
+ // We reached the top of the function, stop.
+ break;
+ },
+ _ => StopEarly::KeepGoing,
+ };
+ match stop_early {
+ StopEarly::Stop => break,
+ StopEarly::KeepGoing => {},
+ }
+
+ cur_id = parent_id;
+ }
+}
+
+/// Whether to stop early for the loop in `check_for_unsequenced_reads`. (If
+/// `check_expr` weren't an independent function, this would be unnecessary and
+/// we could just use `break`).
+enum StopEarly {
+ KeepGoing,
+ Stop,
+}
+
+fn check_expr<'a, 'tcx>(vis: &mut ReadVisitor<'a, 'tcx>, expr: &'tcx Expr<'_>) -> StopEarly {
+ if expr.hir_id == vis.last_expr.hir_id {
+ return StopEarly::KeepGoing;
+ }
+
+ match expr.kind {
+ ExprKind::Array(_)
+ | ExprKind::Tup(_)
+ | ExprKind::MethodCall(..)
+ | ExprKind::Call(_, _)
+ | ExprKind::Assign(..)
+ | ExprKind::Index(_, _)
+ | ExprKind::Repeat(_, _)
+ | ExprKind::Struct(_, _, _) => {
+ walk_expr(vis, expr);
+ },
+ ExprKind::Binary(op, _, _) | ExprKind::AssignOp(op, _, _) => {
+ if op.node == BinOpKind::And || op.node == BinOpKind::Or {
+ // x && y and x || y always evaluate x first, so these are
+ // strictly sequenced.
+ } else {
+ walk_expr(vis, expr);
+ }
+ },
+ ExprKind::Closure(_, _, _, _, _) => {
+ // Either
+ //
+ // * `var` is defined in the closure body, in which case we've reached the top of the enclosing
+ // function and can stop, or
+ //
+ // * `var` is captured by the closure, in which case, because evaluating a closure does not evaluate
+ // its body, we don't necessarily have a write, so we need to stop to avoid generating false
+ // positives.
+ //
+ // This is also the only place we need to stop early (grrr).
+ return StopEarly::Stop;
+ },
+ // All other expressions either have only one child or strictly
+ // sequence the evaluation order of their sub-expressions.
+ _ => {},
+ }
+
+ vis.last_expr = expr;
+
+ StopEarly::KeepGoing
+}
+
+fn check_stmt<'a, 'tcx>(vis: &mut ReadVisitor<'a, 'tcx>, stmt: &'tcx Stmt<'_>) -> StopEarly {
+ match stmt.kind {
+ StmtKind::Expr(ref expr) | StmtKind::Semi(ref expr) => check_expr(vis, expr),
+ // If the declaration is of a local variable, check its initializer
+ // expression if it has one. Otherwise, keep going.
+ StmtKind::Local(ref local) => local
+ .init
+ .as_ref()
+ .map_or(StopEarly::KeepGoing, |expr| check_expr(vis, expr)),
+ _ => StopEarly::KeepGoing,
+ }
+}
+
+/// A visitor that looks for reads from a variable.
+struct ReadVisitor<'a, 'tcx> {
+ cx: &'a LateContext<'a, 'tcx>,
+ /// The ID of the variable we're looking for.
+ var: HirId,
+ /// The expressions where the write to the variable occurred (for reporting
+ /// in the lint).
+ write_expr: &'tcx Expr<'tcx>,
+ /// The last (highest in the AST) expression we've checked, so we know not
+ /// to recheck it.
+ last_expr: &'tcx Expr<'tcx>,
+}
+
+impl<'a, 'tcx> Visitor<'tcx> for ReadVisitor<'a, 'tcx> {
+ type Map = Map<'tcx>;
+
+ fn visit_expr(&mut self, expr: &'tcx Expr<'_>) {
+ if expr.hir_id == self.last_expr.hir_id {
+ return;
+ }
+
+ match expr.kind {
+ ExprKind::Path(ref qpath) => {
+ if_chain! {
+ if let QPath::Resolved(None, ref path) = *qpath;
+ if path.segments.len() == 1;
+ if let def::Res::Local(local_id) = self.cx.tables.qpath_res(qpath, expr.hir_id);
+ if local_id == self.var;
+ // Check that this is a read, not a write.
+ if !is_in_assignment_position(self.cx, expr);
+ then {
+ span_lint_and_note(
+ self.cx,
+ EVAL_ORDER_DEPENDENCE,
+ expr.span,
+ "unsequenced read of a variable",
+ Some(self.write_expr.span),
+ "whether read occurs before this write depends on evaluation order"
+ );
+ }
+ }
+ }
+ // We're about to descend a closure. Since we don't know when (or
+ // if) the closure will be evaluated, any reads in it might not
+ // occur here (or ever). Like above, bail to avoid false positives.
+ ExprKind::Closure(_, _, _, _, _) |
+
+ // We want to avoid a false positive when a variable name occurs
+ // only to have its address taken, so we stop here. Technically,
+ // this misses some weird cases, eg.
+ //
+ // ```rust
+ // let mut x = 0;
+ // let a = foo(&{x = 1; x}, x);
+ // ```
+ //
+ // TODO: fix this
+ ExprKind::AddrOf(_, _, _) => {
+ return;
+ }
+ _ => {}
+ }
+
+ walk_expr(self, expr);
+ }
+ fn nested_visit_map(&mut self) -> NestedVisitorMap {
+ NestedVisitorMap::None
+ }
+}
+
+/// Returns `true` if `expr` is the LHS of an assignment, like `expr = ...`.
+fn is_in_assignment_position(cx: &LateContext<'_, '_>, expr: &Expr<'_>) -> bool {
+ if let Some(parent) = get_parent_expr(cx, expr) {
+ if let ExprKind::Assign(ref lhs, ..) = parent.kind {
+ return lhs.hir_id == expr.hir_id;
+ }
+ }
+ false
+}
diff --git a/src/tools/clippy/clippy_lints/src/excessive_bools.rs b/src/tools/clippy/clippy_lints/src/excessive_bools.rs
new file mode 100644
index 00000000000..82ca4baacb7
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/excessive_bools.rs
@@ -0,0 +1,176 @@
+use crate::utils::{attr_by_name, in_macro, match_path_ast, span_lint_and_help};
+use rustc_ast::ast::{AssocItemKind, Extern, FnSig, Item, ItemKind, Ty, TyKind};
+use rustc_lint::{EarlyContext, EarlyLintPass};
+use rustc_session::{declare_tool_lint, impl_lint_pass};
+use rustc_span::Span;
+
+use std::convert::TryInto;
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for excessive
+ /// use of bools in structs.
+ ///
+ /// **Why is this bad?** Excessive bools in a struct
+ /// is often a sign that it's used as a state machine,
+ /// which is much better implemented as an enum.
+ /// If it's not the case, excessive bools usually benefit
+ /// from refactoring into two-variant enums for better
+ /// readability and API.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// Bad:
+ /// ```rust
+ /// struct S {
+ /// is_pending: bool,
+ /// is_processing: bool,
+ /// is_finished: bool,
+ /// }
+ /// ```
+ ///
+ /// Good:
+ /// ```rust
+ /// enum S {
+ /// Pending,
+ /// Processing,
+ /// Finished,
+ /// }
+ /// ```
+ pub STRUCT_EXCESSIVE_BOOLS,
+ pedantic,
+ "using too many bools in a struct"
+}
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for excessive use of
+ /// bools in function definitions.
+ ///
+ /// **Why is this bad?** Calls to such functions
+ /// are confusing and error prone, because it's
+ /// hard to remember argument order and you have
+ /// no type system support to back you up. Using
+ /// two-variant enums instead of bools often makes
+ /// API easier to use.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// Bad:
+ /// ```rust,ignore
+ /// fn f(is_round: bool, is_hot: bool) { ... }
+ /// ```
+ ///
+ /// Good:
+ /// ```rust,ignore
+ /// enum Shape {
+ /// Round,
+ /// Spiky,
+ /// }
+ ///
+ /// enum Temperature {
+ /// Hot,
+ /// IceCold,
+ /// }
+ ///
+ /// fn f(shape: Shape, temperature: Temperature) { ... }
+ /// ```
+ pub FN_PARAMS_EXCESSIVE_BOOLS,
+ pedantic,
+ "using too many bools in function parameters"
+}
+
+pub struct ExcessiveBools {
+ max_struct_bools: u64,
+ max_fn_params_bools: u64,
+}
+
+impl ExcessiveBools {
+ #[must_use]
+ pub fn new(max_struct_bools: u64, max_fn_params_bools: u64) -> Self {
+ Self {
+ max_struct_bools,
+ max_fn_params_bools,
+ }
+ }
+
+ fn check_fn_sig(&self, cx: &EarlyContext<'_>, fn_sig: &FnSig, span: Span) {
+ match fn_sig.header.ext {
+ Extern::Implicit | Extern::Explicit(_) => return,
+ Extern::None => (),
+ }
+
+ let fn_sig_bools = fn_sig
+ .decl
+ .inputs
+ .iter()
+ .filter(|param| is_bool_ty(¶m.ty))
+ .count()
+ .try_into()
+ .unwrap();
+ if self.max_fn_params_bools < fn_sig_bools {
+ span_lint_and_help(
+ cx,
+ FN_PARAMS_EXCESSIVE_BOOLS,
+ span,
+ &format!("more than {} bools in function parameters", self.max_fn_params_bools),
+ None,
+ "consider refactoring bools into two-variant enums",
+ );
+ }
+ }
+}
+
+impl_lint_pass!(ExcessiveBools => [STRUCT_EXCESSIVE_BOOLS, FN_PARAMS_EXCESSIVE_BOOLS]);
+
+fn is_bool_ty(ty: &Ty) -> bool {
+ if let TyKind::Path(None, path) = &ty.kind {
+ return match_path_ast(path, &["bool"]);
+ }
+ false
+}
+
+impl EarlyLintPass for ExcessiveBools {
+ fn check_item(&mut self, cx: &EarlyContext<'_>, item: &Item) {
+ if in_macro(item.span) {
+ return;
+ }
+ match &item.kind {
+ ItemKind::Struct(variant_data, _) => {
+ if attr_by_name(&item.attrs, "repr").is_some() {
+ return;
+ }
+
+ let struct_bools = variant_data
+ .fields()
+ .iter()
+ .filter(|field| is_bool_ty(&field.ty))
+ .count()
+ .try_into()
+ .unwrap();
+ if self.max_struct_bools < struct_bools {
+ span_lint_and_help(
+ cx,
+ STRUCT_EXCESSIVE_BOOLS,
+ item.span,
+ &format!("more than {} bools in a struct", self.max_struct_bools),
+ None,
+ "consider using a state machine or refactoring bools into two-variant enums",
+ );
+ }
+ },
+ ItemKind::Impl {
+ of_trait: None, items, ..
+ }
+ | ItemKind::Trait(_, _, _, _, items) => {
+ for item in items {
+ if let AssocItemKind::Fn(_, fn_sig, _, _) = &item.kind {
+ self.check_fn_sig(cx, fn_sig, item.span);
+ }
+ }
+ },
+ ItemKind::Fn(_, fn_sig, _, _) => self.check_fn_sig(cx, fn_sig, item.span),
+ _ => (),
+ }
+ }
+}
diff --git a/src/tools/clippy/clippy_lints/src/exit.rs b/src/tools/clippy/clippy_lints/src/exit.rs
new file mode 100644
index 00000000000..621d56185a9
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/exit.rs
@@ -0,0 +1,47 @@
+use crate::utils::{is_entrypoint_fn, match_def_path, paths, qpath_res, span_lint};
+use if_chain::if_chain;
+use rustc_hir::{Expr, ExprKind, Item, ItemKind, Node};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+
+declare_clippy_lint! {
+ /// **What it does:** `exit()` terminates the program and doesn't provide a
+ /// stack trace.
+ ///
+ /// **Why is this bad?** Ideally a program is terminated by finishing
+ /// the main function.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```ignore
+ /// std::process::exit(0)
+ /// ```
+ pub EXIT,
+ restriction,
+ "`std::process::exit` is called, terminating the program"
+}
+
+declare_lint_pass!(Exit => [EXIT]);
+
+impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Exit {
+ fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, e: &'tcx Expr<'_>) {
+ if_chain! {
+ if let ExprKind::Call(ref path_expr, ref _args) = e.kind;
+ if let ExprKind::Path(ref path) = path_expr.kind;
+ if let Some(def_id) = qpath_res(cx, path, path_expr.hir_id).opt_def_id();
+ if match_def_path(cx, def_id, &paths::EXIT);
+ then {
+ let parent = cx.tcx.hir().get_parent_item(e.hir_id);
+ if let Some(Node::Item(Item{kind: ItemKind::Fn(..), ..})) = cx.tcx.hir().find(parent) {
+ // If the next item up is a function we check if it is an entry point
+ // and only then emit a linter warning
+ let def_id = cx.tcx.hir().local_def_id(parent);
+ if !is_entrypoint_fn(cx, def_id.to_def_id()) {
+ span_lint(cx, EXIT, e.span, "usage of `process::exit`");
+ }
+ }
+ }
+ }
+ }
+}
diff --git a/src/tools/clippy/clippy_lints/src/explicit_write.rs b/src/tools/clippy/clippy_lints/src/explicit_write.rs
new file mode 100644
index 00000000000..320121b2771
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/explicit_write.rs
@@ -0,0 +1,149 @@
+use crate::utils::{is_expn_of, match_function_call, paths, span_lint, span_lint_and_sugg};
+use if_chain::if_chain;
+use rustc_ast::ast::LitKind;
+use rustc_errors::Applicability;
+use rustc_hir::{BorrowKind, Expr, ExprKind};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for usage of `write!()` / `writeln()!` which can be
+ /// replaced with `(e)print!()` / `(e)println!()`
+ ///
+ /// **Why is this bad?** Using `(e)println! is clearer and more concise
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```rust
+ /// # use std::io::Write;
+ /// # let bar = "furchtbar";
+ /// // this would be clearer as `eprintln!("foo: {:?}", bar);`
+ /// writeln!(&mut std::io::stderr(), "foo: {:?}", bar).unwrap();
+ /// ```
+ pub EXPLICIT_WRITE,
+ complexity,
+ "using the `write!()` family of functions instead of the `print!()` family of functions, when using the latter would work"
+}
+
+declare_lint_pass!(ExplicitWrite => [EXPLICIT_WRITE]);
+
+impl<'a, 'tcx> LateLintPass<'a, 'tcx> for ExplicitWrite {
+ fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr<'_>) {
+ if_chain! {
+ // match call to unwrap
+ if let ExprKind::MethodCall(ref unwrap_fun, _, ref unwrap_args) = expr.kind;
+ if unwrap_fun.ident.name == sym!(unwrap);
+ // match call to write_fmt
+ if !unwrap_args.is_empty();
+ if let ExprKind::MethodCall(ref write_fun, _, write_args) =
+ unwrap_args[0].kind;
+ if write_fun.ident.name == sym!(write_fmt);
+ // match calls to std::io::stdout() / std::io::stderr ()
+ if !write_args.is_empty();
+ if let Some(dest_name) = if match_function_call(cx, &write_args[0], &paths::STDOUT).is_some() {
+ Some("stdout")
+ } else if match_function_call(cx, &write_args[0], &paths::STDERR).is_some() {
+ Some("stderr")
+ } else {
+ None
+ };
+ then {
+ let write_span = unwrap_args[0].span;
+ let calling_macro =
+ // ordering is important here, since `writeln!` uses `write!` internally
+ if is_expn_of(write_span, "writeln").is_some() {
+ Some("writeln")
+ } else if is_expn_of(write_span, "write").is_some() {
+ Some("write")
+ } else {
+ None
+ };
+ let prefix = if dest_name == "stderr" {
+ "e"
+ } else {
+ ""
+ };
+
+ // We need to remove the last trailing newline from the string because the
+ // underlying `fmt::write` function doesn't know whether `println!` or `print!` was
+ // used.
+ if let Some(mut write_output) = write_output_string(write_args) {
+ if write_output.ends_with('\n') {
+ write_output.pop();
+ }
+
+ if let Some(macro_name) = calling_macro {
+ span_lint_and_sugg(
+ cx,
+ EXPLICIT_WRITE,
+ expr.span,
+ &format!(
+ "use of `{}!({}(), ...).unwrap()`",
+ macro_name,
+ dest_name
+ ),
+ "try this",
+ format!("{}{}!(\"{}\")", prefix, macro_name.replace("write", "print"), write_output.escape_default()),
+ Applicability::MachineApplicable
+ );
+ } else {
+ span_lint_and_sugg(
+ cx,
+ EXPLICIT_WRITE,
+ expr.span,
+ &format!("use of `{}().write_fmt(...).unwrap()`", dest_name),
+ "try this",
+ format!("{}print!(\"{}\")", prefix, write_output.escape_default()),
+ Applicability::MachineApplicable
+ );
+ }
+ } else {
+ // We don't have a proper suggestion
+ if let Some(macro_name) = calling_macro {
+ span_lint(
+ cx,
+ EXPLICIT_WRITE,
+ expr.span,
+ &format!(
+ "use of `{}!({}(), ...).unwrap()`. Consider using `{}{}!` instead",
+ macro_name,
+ dest_name,
+ prefix,
+ macro_name.replace("write", "print")
+ )
+ );
+ } else {
+ span_lint(
+ cx,
+ EXPLICIT_WRITE,
+ expr.span,
+ &format!("use of `{}().write_fmt(...).unwrap()`. Consider using `{}print!` instead", dest_name, prefix),
+ );
+ }
+ }
+
+ }
+ }
+ }
+}
+
+// Extract the output string from the given `write_args`.
+fn write_output_string(write_args: &[Expr<'_>]) -> Option {
+ if_chain! {
+ // Obtain the string that should be printed
+ if write_args.len() > 1;
+ if let ExprKind::Call(_, ref output_args) = write_args[1].kind;
+ if !output_args.is_empty();
+ if let ExprKind::AddrOf(BorrowKind::Ref, _, ref output_string_expr) = output_args[0].kind;
+ if let ExprKind::Array(ref string_exprs) = output_string_expr.kind;
+ // we only want to provide an automatic suggestion for simple (non-format) strings
+ if string_exprs.len() == 1;
+ if let ExprKind::Lit(ref lit) = string_exprs[0].kind;
+ if let LitKind::Str(ref write_output, _) = lit.node;
+ then {
+ return Some(write_output.to_string())
+ }
+ }
+ None
+}
diff --git a/src/tools/clippy/clippy_lints/src/fallible_impl_from.rs b/src/tools/clippy/clippy_lints/src/fallible_impl_from.rs
new file mode 100644
index 00000000000..17639cc2a06
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/fallible_impl_from.rs
@@ -0,0 +1,130 @@
+use crate::utils::paths::{BEGIN_PANIC, BEGIN_PANIC_FMT, FROM_TRAIT};
+use crate::utils::{
+ is_expn_of, is_type_diagnostic_item, match_def_path, method_chain_args, span_lint_and_then, walk_ptrs_ty,
+};
+use if_chain::if_chain;
+use rustc_hir as hir;
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::hir::map::Map;
+use rustc_middle::ty;
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::Span;
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for impls of `From<..>` that contain `panic!()` or `unwrap()`
+ ///
+ /// **Why is this bad?** `TryFrom` should be used if there's a possibility of failure.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```rust
+ /// struct Foo(i32);
+ /// impl From for Foo {
+ /// fn from(s: String) -> Self {
+ /// Foo(s.parse().unwrap())
+ /// }
+ /// }
+ /// ```
+ pub FALLIBLE_IMPL_FROM,
+ nursery,
+ "Warn on impls of `From<..>` that contain `panic!()` or `unwrap()`"
+}
+
+declare_lint_pass!(FallibleImplFrom => [FALLIBLE_IMPL_FROM]);
+
+impl<'a, 'tcx> LateLintPass<'a, 'tcx> for FallibleImplFrom {
+ fn check_item(&mut self, cx: &LateContext<'a, 'tcx>, item: &'tcx hir::Item<'_>) {
+ // check for `impl From for ..`
+ let impl_def_id = cx.tcx.hir().local_def_id(item.hir_id);
+ if_chain! {
+ if let hir::ItemKind::Impl{ items: impl_items, .. } = item.kind;
+ if let Some(impl_trait_ref) = cx.tcx.impl_trait_ref(impl_def_id);
+ if match_def_path(cx, impl_trait_ref.def_id, &FROM_TRAIT);
+ then {
+ lint_impl_body(cx, item.span, impl_items);
+ }
+ }
+ }
+}
+
+fn lint_impl_body<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, impl_span: Span, impl_items: &[hir::ImplItemRef<'_>]) {
+ use rustc_hir::intravisit::{self, NestedVisitorMap, Visitor};
+ use rustc_hir::{Expr, ExprKind, ImplItemKind, QPath};
+
+ struct FindPanicUnwrap<'a, 'tcx> {
+ lcx: &'a LateContext<'a, 'tcx>,
+ tables: &'tcx ty::TypeckTables<'tcx>,
+ result: Vec,
+ }
+
+ impl<'a, 'tcx> Visitor<'tcx> for FindPanicUnwrap<'a, 'tcx> {
+ type Map = Map<'tcx>;
+
+ fn visit_expr(&mut self, expr: &'tcx Expr<'_>) {
+ // check for `begin_panic`
+ if_chain! {
+ if let ExprKind::Call(ref func_expr, _) = expr.kind;
+ if let ExprKind::Path(QPath::Resolved(_, ref path)) = func_expr.kind;
+ if let Some(path_def_id) = path.res.opt_def_id();
+ if match_def_path(self.lcx, path_def_id, &BEGIN_PANIC) ||
+ match_def_path(self.lcx, path_def_id, &BEGIN_PANIC_FMT);
+ if is_expn_of(expr.span, "unreachable").is_none();
+ then {
+ self.result.push(expr.span);
+ }
+ }
+
+ // check for `unwrap`
+ if let Some(arglists) = method_chain_args(expr, &["unwrap"]) {
+ let reciever_ty = walk_ptrs_ty(self.tables.expr_ty(&arglists[0][0]));
+ if is_type_diagnostic_item(self.lcx, reciever_ty, sym!(option_type))
+ || is_type_diagnostic_item(self.lcx, reciever_ty, sym!(result_type))
+ {
+ self.result.push(expr.span);
+ }
+ }
+
+ // and check sub-expressions
+ intravisit::walk_expr(self, expr);
+ }
+
+ fn nested_visit_map(&mut self) -> NestedVisitorMap {
+ NestedVisitorMap::None
+ }
+ }
+
+ for impl_item in impl_items {
+ if_chain! {
+ if impl_item.ident.name == sym!(from);
+ if let ImplItemKind::Fn(_, body_id) =
+ cx.tcx.hir().impl_item(impl_item.id).kind;
+ then {
+ // check the body for `begin_panic` or `unwrap`
+ let body = cx.tcx.hir().body(body_id);
+ let impl_item_def_id = cx.tcx.hir().local_def_id(impl_item.id.hir_id);
+ let mut fpu = FindPanicUnwrap {
+ lcx: cx,
+ tables: cx.tcx.typeck_tables_of(impl_item_def_id),
+ result: Vec::new(),
+ };
+ fpu.visit_expr(&body.value);
+
+ // if we've found one, lint
+ if !fpu.result.is_empty() {
+ span_lint_and_then(
+ cx,
+ FALLIBLE_IMPL_FROM,
+ impl_span,
+ "consider implementing `TryFrom` instead",
+ move |diag| {
+ diag.help(
+ "`From` is intended for infallible conversions only. \
+ Use `TryFrom` if there's a possibility for the conversion to fail.");
+ diag.span_note(fpu.result, "potential failure(s)");
+ });
+ }
+ }
+ }
+ }
+}
diff --git a/src/tools/clippy/clippy_lints/src/float_literal.rs b/src/tools/clippy/clippy_lints/src/float_literal.rs
new file mode 100644
index 00000000000..3a52b1d3fc2
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/float_literal.rs
@@ -0,0 +1,182 @@
+use crate::utils::{numeric_literal, span_lint_and_sugg};
+use if_chain::if_chain;
+use rustc_ast::ast::{FloatTy, LitFloatType, LitKind};
+use rustc_errors::Applicability;
+use rustc_hir as hir;
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty;
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use std::fmt;
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for float literals with a precision greater
+ /// than that supported by the underlying type.
+ ///
+ /// **Why is this bad?** Rust will truncate the literal silently.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ ///
+ /// ```rust
+ /// // Bad
+ /// let v: f32 = 0.123_456_789_9;
+ /// println!("{}", v); // 0.123_456_789
+ ///
+ /// // Good
+ /// let v: f64 = 0.123_456_789_9;
+ /// println!("{}", v); // 0.123_456_789_9
+ /// ```
+ pub EXCESSIVE_PRECISION,
+ style,
+ "excessive precision for float literal"
+}
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for whole number float literals that
+ /// cannot be represented as the underlying type without loss.
+ ///
+ /// **Why is this bad?** Rust will silently lose precision during
+ /// conversion to a float.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ ///
+ /// ```rust
+ /// // Bad
+ /// let _: f32 = 16_777_217.0; // 16_777_216.0
+ ///
+ /// // Good
+ /// let _: f32 = 16_777_216.0;
+ /// let _: f64 = 16_777_217.0;
+ /// ```
+ pub LOSSY_FLOAT_LITERAL,
+ restriction,
+ "lossy whole number float literals"
+}
+
+declare_lint_pass!(FloatLiteral => [EXCESSIVE_PRECISION, LOSSY_FLOAT_LITERAL]);
+
+impl<'a, 'tcx> LateLintPass<'a, 'tcx> for FloatLiteral {
+ fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx hir::Expr<'_>) {
+ if_chain! {
+ let ty = cx.tables.expr_ty(expr);
+ if let ty::Float(fty) = ty.kind;
+ if let hir::ExprKind::Lit(ref lit) = expr.kind;
+ if let LitKind::Float(sym, lit_float_ty) = lit.node;
+ then {
+ let sym_str = sym.as_str();
+ let formatter = FloatFormat::new(&sym_str);
+ // Try to bail out if the float is for sure fine.
+ // If its within the 2 decimal digits of being out of precision we
+ // check if the parsed representation is the same as the string
+ // since we'll need the truncated string anyway.
+ let digits = count_digits(&sym_str);
+ let max = max_digits(fty);
+ let type_suffix = match lit_float_ty {
+ LitFloatType::Suffixed(FloatTy::F32) => Some("f32"),
+ LitFloatType::Suffixed(FloatTy::F64) => Some("f64"),
+ _ => None
+ };
+ let (is_whole, mut float_str) = match fty {
+ FloatTy::F32 => {
+ let value = sym_str.parse::().unwrap();
+
+ (value.fract() == 0.0, formatter.format(value))
+ },
+ FloatTy::F64 => {
+ let value = sym_str.parse::().unwrap();
+
+ (value.fract() == 0.0, formatter.format(value))
+ },
+ };
+
+ if is_whole && !sym_str.contains(|c| c == 'e' || c == 'E') {
+ // Normalize the literal by stripping the fractional portion
+ if sym_str.split('.').next().unwrap() != float_str {
+ // If the type suffix is missing the suggestion would be
+ // incorrectly interpreted as an integer so adding a `.0`
+ // suffix to prevent that.
+ if type_suffix.is_none() {
+ float_str.push_str(".0");
+ }
+
+ span_lint_and_sugg(
+ cx,
+ LOSSY_FLOAT_LITERAL,
+ expr.span,
+ "literal cannot be represented as the underlying type without loss of precision",
+ "consider changing the type or replacing it with",
+ numeric_literal::format(&float_str, type_suffix, true),
+ Applicability::MachineApplicable,
+ );
+ }
+ } else if digits > max as usize && sym_str != float_str {
+ span_lint_and_sugg(
+ cx,
+ EXCESSIVE_PRECISION,
+ expr.span,
+ "float has excessive precision",
+ "consider changing the type or truncating it to",
+ numeric_literal::format(&float_str, type_suffix, true),
+ Applicability::MachineApplicable,
+ );
+ }
+ }
+ }
+ }
+}
+
+#[must_use]
+fn max_digits(fty: FloatTy) -> u32 {
+ match fty {
+ FloatTy::F32 => f32::DIGITS,
+ FloatTy::F64 => f64::DIGITS,
+ }
+}
+
+/// Counts the digits excluding leading zeros
+#[must_use]
+fn count_digits(s: &str) -> usize {
+ // Note that s does not contain the f32/64 suffix, and underscores have been stripped
+ s.chars()
+ .filter(|c| *c != '-' && *c != '.')
+ .take_while(|c| *c != 'e' && *c != 'E')
+ .fold(0, |count, c| {
+ // leading zeros
+ if c == '0' && count == 0 {
+ count
+ } else {
+ count + 1
+ }
+ })
+}
+
+enum FloatFormat {
+ LowerExp,
+ UpperExp,
+ Normal,
+}
+impl FloatFormat {
+ #[must_use]
+ fn new(s: &str) -> Self {
+ s.chars()
+ .find_map(|x| match x {
+ 'e' => Some(Self::LowerExp),
+ 'E' => Some(Self::UpperExp),
+ _ => None,
+ })
+ .unwrap_or(Self::Normal)
+ }
+ fn format(&self, f: T) -> String
+ where
+ T: fmt::UpperExp + fmt::LowerExp + fmt::Display,
+ {
+ match self {
+ Self::LowerExp => format!("{:e}", f),
+ Self::UpperExp => format!("{:E}", f),
+ Self::Normal => format!("{}", f),
+ }
+ }
+}
diff --git a/src/tools/clippy/clippy_lints/src/floating_point_arithmetic.rs b/src/tools/clippy/clippy_lints/src/floating_point_arithmetic.rs
new file mode 100644
index 00000000000..86317fb8bd5
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/floating_point_arithmetic.rs
@@ -0,0 +1,503 @@
+use crate::consts::{
+ constant, constant_simple, Constant,
+ Constant::{F32, F64},
+};
+use crate::utils::{higher, numeric_literal, span_lint_and_sugg, sugg, SpanlessEq};
+use if_chain::if_chain;
+use rustc_errors::Applicability;
+use rustc_hir::{BinOpKind, Expr, ExprKind, UnOp};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty;
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::source_map::Spanned;
+
+use rustc_ast::ast;
+use std::f32::consts as f32_consts;
+use std::f64::consts as f64_consts;
+use sugg::Sugg;
+
+declare_clippy_lint! {
+ /// **What it does:** Looks for floating-point expressions that
+ /// can be expressed using built-in methods to improve accuracy
+ /// at the cost of performance.
+ ///
+ /// **Why is this bad?** Negatively impacts accuracy.
+ ///
+ /// **Known problems:** None
+ ///
+ /// **Example:**
+ ///
+ /// ```rust
+ ///
+ /// let a = 3f32;
+ /// let _ = a.powf(1.0 / 3.0);
+ /// let _ = (1.0 + a).ln();
+ /// let _ = a.exp() - 1.0;
+ /// ```
+ ///
+ /// is better expressed as
+ ///
+ /// ```rust
+ ///
+ /// let a = 3f32;
+ /// let _ = a.cbrt();
+ /// let _ = a.ln_1p();
+ /// let _ = a.exp_m1();
+ /// ```
+ pub IMPRECISE_FLOPS,
+ nursery,
+ "usage of imprecise floating point operations"
+}
+
+declare_clippy_lint! {
+ /// **What it does:** Looks for floating-point expressions that
+ /// can be expressed using built-in methods to improve both
+ /// accuracy and performance.
+ ///
+ /// **Why is this bad?** Negatively impacts accuracy and performance.
+ ///
+ /// **Known problems:** None
+ ///
+ /// **Example:**
+ ///
+ /// ```rust
+ /// use std::f32::consts::E;
+ ///
+ /// let a = 3f32;
+ /// let _ = (2f32).powf(a);
+ /// let _ = E.powf(a);
+ /// let _ = a.powf(1.0 / 2.0);
+ /// let _ = a.log(2.0);
+ /// let _ = a.log(10.0);
+ /// let _ = a.log(E);
+ /// let _ = a.powf(2.0);
+ /// let _ = a * 2.0 + 4.0;
+ /// let _ = if a < 0.0 {
+ /// -a
+ /// } else {
+ /// a
+ /// };
+ /// let _ = if a < 0.0 {
+ /// a
+ /// } else {
+ /// -a
+ /// };
+ /// ```
+ ///
+ /// is better expressed as
+ ///
+ /// ```rust
+ /// use std::f32::consts::E;
+ ///
+ /// let a = 3f32;
+ /// let _ = a.exp2();
+ /// let _ = a.exp();
+ /// let _ = a.sqrt();
+ /// let _ = a.log2();
+ /// let _ = a.log10();
+ /// let _ = a.ln();
+ /// let _ = a.powi(2);
+ /// let _ = a.mul_add(2.0, 4.0);
+ /// let _ = a.abs();
+ /// let _ = -a.abs();
+ /// ```
+ pub SUBOPTIMAL_FLOPS,
+ nursery,
+ "usage of sub-optimal floating point operations"
+}
+
+declare_lint_pass!(FloatingPointArithmetic => [
+ IMPRECISE_FLOPS,
+ SUBOPTIMAL_FLOPS
+]);
+
+// Returns the specialized log method for a given base if base is constant
+// and is one of 2, 10 and e
+fn get_specialized_log_method(cx: &LateContext<'_, '_>, base: &Expr<'_>) -> Option<&'static str> {
+ if let Some((value, _)) = constant(cx, cx.tables, base) {
+ if F32(2.0) == value || F64(2.0) == value {
+ return Some("log2");
+ } else if F32(10.0) == value || F64(10.0) == value {
+ return Some("log10");
+ } else if F32(f32_consts::E) == value || F64(f64_consts::E) == value {
+ return Some("ln");
+ }
+ }
+
+ None
+}
+
+// Adds type suffixes and parenthesis to method receivers if necessary
+fn prepare_receiver_sugg<'a>(cx: &LateContext<'_, '_>, mut expr: &'a Expr<'a>) -> Sugg<'a> {
+ let mut suggestion = Sugg::hir(cx, expr, "..");
+
+ if let ExprKind::Unary(UnOp::UnNeg, inner_expr) = &expr.kind {
+ expr = &inner_expr;
+ }
+
+ if_chain! {
+ // if the expression is a float literal and it is unsuffixed then
+ // add a suffix so the suggestion is valid and unambiguous
+ if let ty::Float(float_ty) = cx.tables.expr_ty(expr).kind;
+ if let ExprKind::Lit(lit) = &expr.kind;
+ if let ast::LitKind::Float(sym, ast::LitFloatType::Unsuffixed) = lit.node;
+ then {
+ let op = format!(
+ "{}{}{}",
+ suggestion,
+ // Check for float literals without numbers following the decimal
+ // separator such as `2.` and adds a trailing zero
+ if sym.as_str().ends_with('.') {
+ "0"
+ } else {
+ ""
+ },
+ float_ty.name_str()
+ ).into();
+
+ suggestion = match suggestion {
+ Sugg::MaybeParen(_) => Sugg::MaybeParen(op),
+ _ => Sugg::NonParen(op)
+ };
+ }
+ }
+
+ suggestion.maybe_par()
+}
+
+fn check_log_base(cx: &LateContext<'_, '_>, expr: &Expr<'_>, args: &[Expr<'_>]) {
+ if let Some(method) = get_specialized_log_method(cx, &args[1]) {
+ span_lint_and_sugg(
+ cx,
+ SUBOPTIMAL_FLOPS,
+ expr.span,
+ "logarithm for bases 2, 10 and e can be computed more accurately",
+ "consider using",
+ format!("{}.{}()", Sugg::hir(cx, &args[0], ".."), method),
+ Applicability::MachineApplicable,
+ );
+ }
+}
+
+// TODO: Lint expressions of the form `(x + y).ln()` where y > 1 and
+// suggest usage of `(x + (y - 1)).ln_1p()` instead
+fn check_ln1p(cx: &LateContext<'_, '_>, expr: &Expr<'_>, args: &[Expr<'_>]) {
+ if let ExprKind::Binary(
+ Spanned {
+ node: BinOpKind::Add, ..
+ },
+ lhs,
+ rhs,
+ ) = &args[0].kind
+ {
+ let recv = match (constant(cx, cx.tables, lhs), constant(cx, cx.tables, rhs)) {
+ (Some((value, _)), _) if F32(1.0) == value || F64(1.0) == value => rhs,
+ (_, Some((value, _))) if F32(1.0) == value || F64(1.0) == value => lhs,
+ _ => return,
+ };
+
+ span_lint_and_sugg(
+ cx,
+ IMPRECISE_FLOPS,
+ expr.span,
+ "ln(1 + x) can be computed more accurately",
+ "consider using",
+ format!("{}.ln_1p()", prepare_receiver_sugg(cx, recv)),
+ Applicability::MachineApplicable,
+ );
+ }
+}
+
+// Returns an integer if the float constant is a whole number and it can be
+// converted to an integer without loss of precision. For now we only check
+// ranges [-16777215, 16777216) for type f32 as whole number floats outside
+// this range are lossy and ambiguous.
+#[allow(clippy::cast_possible_truncation)]
+fn get_integer_from_float_constant(value: &Constant) -> Option {
+ match value {
+ F32(num) if num.fract() == 0.0 => {
+ if (-16_777_215.0..16_777_216.0).contains(num) {
+ Some(num.round() as i32)
+ } else {
+ None
+ }
+ },
+ F64(num) if num.fract() == 0.0 => {
+ if (-2_147_483_648.0..2_147_483_648.0).contains(num) {
+ Some(num.round() as i32)
+ } else {
+ None
+ }
+ },
+ _ => None,
+ }
+}
+
+fn check_powf(cx: &LateContext<'_, '_>, expr: &Expr<'_>, args: &[Expr<'_>]) {
+ // Check receiver
+ if let Some((value, _)) = constant(cx, cx.tables, &args[0]) {
+ let method = if F32(f32_consts::E) == value || F64(f64_consts::E) == value {
+ "exp"
+ } else if F32(2.0) == value || F64(2.0) == value {
+ "exp2"
+ } else {
+ return;
+ };
+
+ span_lint_and_sugg(
+ cx,
+ SUBOPTIMAL_FLOPS,
+ expr.span,
+ "exponent for bases 2 and e can be computed more accurately",
+ "consider using",
+ format!("{}.{}()", prepare_receiver_sugg(cx, &args[1]), method),
+ Applicability::MachineApplicable,
+ );
+ }
+
+ // Check argument
+ if let Some((value, _)) = constant(cx, cx.tables, &args[1]) {
+ let (lint, help, suggestion) = if F32(1.0 / 2.0) == value || F64(1.0 / 2.0) == value {
+ (
+ SUBOPTIMAL_FLOPS,
+ "square-root of a number can be computed more efficiently and accurately",
+ format!("{}.sqrt()", Sugg::hir(cx, &args[0], "..")),
+ )
+ } else if F32(1.0 / 3.0) == value || F64(1.0 / 3.0) == value {
+ (
+ IMPRECISE_FLOPS,
+ "cube-root of a number can be computed more accurately",
+ format!("{}.cbrt()", Sugg::hir(cx, &args[0], "..")),
+ )
+ } else if let Some(exponent) = get_integer_from_float_constant(&value) {
+ (
+ SUBOPTIMAL_FLOPS,
+ "exponentiation with integer powers can be computed more efficiently",
+ format!(
+ "{}.powi({})",
+ Sugg::hir(cx, &args[0], ".."),
+ numeric_literal::format(&exponent.to_string(), None, false)
+ ),
+ )
+ } else {
+ return;
+ };
+
+ span_lint_and_sugg(
+ cx,
+ lint,
+ expr.span,
+ help,
+ "consider using",
+ suggestion,
+ Applicability::MachineApplicable,
+ );
+ }
+}
+
+// TODO: Lint expressions of the form `x.exp() - y` where y > 1
+// and suggest usage of `x.exp_m1() - (y - 1)` instead
+fn check_expm1(cx: &LateContext<'_, '_>, expr: &Expr<'_>) {
+ if_chain! {
+ if let ExprKind::Binary(Spanned { node: BinOpKind::Sub, .. }, ref lhs, ref rhs) = expr.kind;
+ if cx.tables.expr_ty(lhs).is_floating_point();
+ if let Some((value, _)) = constant(cx, cx.tables, rhs);
+ if F32(1.0) == value || F64(1.0) == value;
+ if let ExprKind::MethodCall(ref path, _, ref method_args) = lhs.kind;
+ if cx.tables.expr_ty(&method_args[0]).is_floating_point();
+ if path.ident.name.as_str() == "exp";
+ then {
+ span_lint_and_sugg(
+ cx,
+ IMPRECISE_FLOPS,
+ expr.span,
+ "(e.pow(x) - 1) can be computed more accurately",
+ "consider using",
+ format!(
+ "{}.exp_m1()",
+ Sugg::hir(cx, &method_args[0], "..")
+ ),
+ Applicability::MachineApplicable,
+ );
+ }
+ }
+}
+
+fn is_float_mul_expr<'a>(cx: &LateContext<'_, '_>, expr: &'a Expr<'a>) -> Option<(&'a Expr<'a>, &'a Expr<'a>)> {
+ if_chain! {
+ if let ExprKind::Binary(Spanned { node: BinOpKind::Mul, .. }, ref lhs, ref rhs) = &expr.kind;
+ if cx.tables.expr_ty(lhs).is_floating_point();
+ if cx.tables.expr_ty(rhs).is_floating_point();
+ then {
+ return Some((lhs, rhs));
+ }
+ }
+
+ None
+}
+
+// TODO: Fix rust-lang/rust-clippy#4735
+fn check_mul_add(cx: &LateContext<'_, '_>, expr: &Expr<'_>) {
+ if let ExprKind::Binary(
+ Spanned {
+ node: BinOpKind::Add, ..
+ },
+ lhs,
+ rhs,
+ ) = &expr.kind
+ {
+ let (recv, arg1, arg2) = if let Some((inner_lhs, inner_rhs)) = is_float_mul_expr(cx, lhs) {
+ (inner_lhs, inner_rhs, rhs)
+ } else if let Some((inner_lhs, inner_rhs)) = is_float_mul_expr(cx, rhs) {
+ (inner_lhs, inner_rhs, lhs)
+ } else {
+ return;
+ };
+
+ span_lint_and_sugg(
+ cx,
+ SUBOPTIMAL_FLOPS,
+ expr.span,
+ "multiply and add expressions can be calculated more efficiently and accurately",
+ "consider using",
+ format!(
+ "{}.mul_add({}, {})",
+ prepare_receiver_sugg(cx, recv),
+ Sugg::hir(cx, arg1, ".."),
+ Sugg::hir(cx, arg2, ".."),
+ ),
+ Applicability::MachineApplicable,
+ );
+ }
+}
+
+/// Returns true iff expr is an expression which tests whether or not
+/// test is positive or an expression which tests whether or not test
+/// is nonnegative.
+/// Used for check-custom-abs function below
+fn is_testing_positive(cx: &LateContext<'_, '_>, expr: &Expr<'_>, test: &Expr<'_>) -> bool {
+ if let ExprKind::Binary(Spanned { node: op, .. }, left, right) = expr.kind {
+ match op {
+ BinOpKind::Gt | BinOpKind::Ge => is_zero(cx, right) && are_exprs_equal(cx, left, test),
+ BinOpKind::Lt | BinOpKind::Le => is_zero(cx, left) && are_exprs_equal(cx, right, test),
+ _ => false,
+ }
+ } else {
+ false
+ }
+}
+
+/// See [`is_testing_positive`]
+fn is_testing_negative(cx: &LateContext<'_, '_>, expr: &Expr<'_>, test: &Expr<'_>) -> bool {
+ if let ExprKind::Binary(Spanned { node: op, .. }, left, right) = expr.kind {
+ match op {
+ BinOpKind::Gt | BinOpKind::Ge => is_zero(cx, left) && are_exprs_equal(cx, right, test),
+ BinOpKind::Lt | BinOpKind::Le => is_zero(cx, right) && are_exprs_equal(cx, left, test),
+ _ => false,
+ }
+ } else {
+ false
+ }
+}
+
+fn are_exprs_equal(cx: &LateContext<'_, '_>, expr1: &Expr<'_>, expr2: &Expr<'_>) -> bool {
+ SpanlessEq::new(cx).ignore_fn().eq_expr(expr1, expr2)
+}
+
+/// Returns true iff expr is some zero literal
+fn is_zero(cx: &LateContext<'_, '_>, expr: &Expr<'_>) -> bool {
+ match constant_simple(cx, cx.tables, expr) {
+ Some(Constant::Int(i)) => i == 0,
+ Some(Constant::F32(f)) => f == 0.0,
+ Some(Constant::F64(f)) => f == 0.0,
+ _ => false,
+ }
+}
+
+/// If the two expressions are negations of each other, then it returns
+/// a tuple, in which the first element is true iff expr1 is the
+/// positive expressions, and the second element is the positive
+/// one of the two expressions
+/// If the two expressions are not negations of each other, then it
+/// returns None.
+fn are_negated<'a>(cx: &LateContext<'_, '_>, expr1: &'a Expr<'a>, expr2: &'a Expr<'a>) -> Option<(bool, &'a Expr<'a>)> {
+ if let ExprKind::Unary(UnOp::UnNeg, expr1_negated) = &expr1.kind {
+ if are_exprs_equal(cx, expr1_negated, expr2) {
+ return Some((false, expr2));
+ }
+ }
+ if let ExprKind::Unary(UnOp::UnNeg, expr2_negated) = &expr2.kind {
+ if are_exprs_equal(cx, expr1, expr2_negated) {
+ return Some((true, expr1));
+ }
+ }
+ None
+}
+
+fn check_custom_abs(cx: &LateContext<'_, '_>, expr: &Expr<'_>) {
+ if_chain! {
+ if let Some((cond, body, Some(else_body))) = higher::if_block(&expr);
+ if let ExprKind::Block(block, _) = body.kind;
+ if block.stmts.is_empty();
+ if let Some(if_body_expr) = block.expr;
+ if let ExprKind::Block(else_block, _) = else_body.kind;
+ if else_block.stmts.is_empty();
+ if let Some(else_body_expr) = else_block.expr;
+ if let Some((if_expr_positive, body)) = are_negated(cx, if_body_expr, else_body_expr);
+ then {
+ let positive_abs_sugg = (
+ "manual implementation of `abs` method",
+ format!("{}.abs()", Sugg::hir(cx, body, "..")),
+ );
+ let negative_abs_sugg = (
+ "manual implementation of negation of `abs` method",
+ format!("-{}.abs()", Sugg::hir(cx, body, "..")),
+ );
+ let sugg = if is_testing_positive(cx, cond, body) {
+ if if_expr_positive {
+ positive_abs_sugg
+ } else {
+ negative_abs_sugg
+ }
+ } else if is_testing_negative(cx, cond, body) {
+ if if_expr_positive {
+ negative_abs_sugg
+ } else {
+ positive_abs_sugg
+ }
+ } else {
+ return;
+ };
+ span_lint_and_sugg(
+ cx,
+ SUBOPTIMAL_FLOPS,
+ expr.span,
+ sugg.0,
+ "try",
+ sugg.1,
+ Applicability::MachineApplicable,
+ );
+ }
+ }
+}
+
+impl<'a, 'tcx> LateLintPass<'a, 'tcx> for FloatingPointArithmetic {
+ fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr<'_>) {
+ if let ExprKind::MethodCall(ref path, _, args) = &expr.kind {
+ let recv_ty = cx.tables.expr_ty(&args[0]);
+
+ if recv_ty.is_floating_point() {
+ match &*path.ident.name.as_str() {
+ "ln" => check_ln1p(cx, expr, args),
+ "log" => check_log_base(cx, expr, args),
+ "powf" => check_powf(cx, expr, args),
+ _ => {},
+ }
+ }
+ } else {
+ check_expm1(cx, expr);
+ check_mul_add(cx, expr);
+ check_custom_abs(cx, expr);
+ }
+ }
+}
diff --git a/src/tools/clippy/clippy_lints/src/format.rs b/src/tools/clippy/clippy_lints/src/format.rs
new file mode 100644
index 00000000000..5b092526ce4
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/format.rs
@@ -0,0 +1,200 @@
+use crate::utils::paths;
+use crate::utils::{
+ is_expn_of, is_type_diagnostic_item, last_path_segment, match_def_path, match_function_call, snippet,
+ span_lint_and_then, walk_ptrs_ty,
+};
+use if_chain::if_chain;
+use rustc_ast::ast::LitKind;
+use rustc_errors::Applicability;
+use rustc_hir::{Arm, BorrowKind, Expr, ExprKind, MatchSource, PatKind};
+use rustc_lint::{LateContext, LateLintPass, LintContext};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::source_map::Span;
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for the use of `format!("string literal with no
+ /// argument")` and `format!("{}", foo)` where `foo` is a string.
+ ///
+ /// **Why is this bad?** There is no point of doing that. `format!("foo")` can
+ /// be replaced by `"foo".to_owned()` if you really need a `String`. The even
+ /// worse `&format!("foo")` is often encountered in the wild. `format!("{}",
+ /// foo)` can be replaced by `foo.clone()` if `foo: String` or `foo.to_owned()`
+ /// if `foo: &str`.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Examples:**
+ /// ```rust
+ /// # let foo = "foo";
+ /// format!("foo");
+ /// format!("{}", foo);
+ /// ```
+ pub USELESS_FORMAT,
+ complexity,
+ "useless use of `format!`"
+}
+
+declare_lint_pass!(UselessFormat => [USELESS_FORMAT]);
+
+impl<'a, 'tcx> LateLintPass<'a, 'tcx> for UselessFormat {
+ fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr<'_>) {
+ let span = match is_expn_of(expr.span, "format") {
+ Some(s) if !s.from_expansion() => s,
+ _ => return,
+ };
+
+ // Operate on the only argument of `alloc::fmt::format`.
+ if let Some(sugg) = on_new_v1(cx, expr) {
+ span_useless_format(cx, span, "consider using `.to_string()`", sugg);
+ } else if let Some(sugg) = on_new_v1_fmt(cx, expr) {
+ span_useless_format(cx, span, "consider using `.to_string()`", sugg);
+ }
+ }
+}
+
+fn span_useless_format(cx: &T, span: Span, help: &str, mut sugg: String) {
+ let to_replace = span.source_callsite();
+
+ // The callsite span contains the statement semicolon for some reason.
+ let snippet = snippet(cx, to_replace, "..");
+ if snippet.ends_with(';') {
+ sugg.push(';');
+ }
+
+ span_lint_and_then(cx, USELESS_FORMAT, span, "useless use of `format!`", |diag| {
+ diag.span_suggestion(
+ to_replace,
+ help,
+ sugg,
+ Applicability::MachineApplicable, // snippet
+ );
+ });
+}
+
+fn on_argumentv1_new<'a, 'tcx>(
+ cx: &LateContext<'a, 'tcx>,
+ expr: &'tcx Expr<'_>,
+ arms: &'tcx [Arm<'_>],
+) -> Option {
+ if_chain! {
+ if let ExprKind::AddrOf(BorrowKind::Ref, _, ref format_args) = expr.kind;
+ if let ExprKind::Array(ref elems) = arms[0].body.kind;
+ if elems.len() == 1;
+ if let Some(args) = match_function_call(cx, &elems[0], &paths::FMT_ARGUMENTV1_NEW);
+ // matches `core::fmt::Display::fmt`
+ if args.len() == 2;
+ if let ExprKind::Path(ref qpath) = args[1].kind;
+ if let Some(did) = cx.tables.qpath_res(qpath, args[1].hir_id).opt_def_id();
+ if match_def_path(cx, did, &paths::DISPLAY_FMT_METHOD);
+ // check `(arg0,)` in match block
+ if let PatKind::Tuple(ref pats, None) = arms[0].pat.kind;
+ if pats.len() == 1;
+ then {
+ let ty = walk_ptrs_ty(cx.tables.pat_ty(&pats[0]));
+ if ty.kind != rustc_middle::ty::Str && !is_type_diagnostic_item(cx, ty, sym!(string_type)) {
+ return None;
+ }
+ if let ExprKind::Lit(ref lit) = format_args.kind {
+ if let LitKind::Str(ref s, _) = lit.node {
+ return Some(format!("{:?}.to_string()", s.as_str()));
+ }
+ } else {
+ let snip = snippet(cx, format_args.span, "");
+ if let ExprKind::MethodCall(ref path, _, _) = format_args.kind {
+ if path.ident.name == sym!(to_string) {
+ return Some(format!("{}", snip));
+ }
+ } else if let ExprKind::Binary(..) = format_args.kind {
+ return Some(format!("{}", snip));
+ }
+ return Some(format!("{}.to_string()", snip));
+ }
+ }
+ }
+ None
+}
+
+fn on_new_v1<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr<'_>) -> Option {
+ if_chain! {
+ if let Some(args) = match_function_call(cx, expr, &paths::FMT_ARGUMENTS_NEW_V1);
+ if args.len() == 2;
+ // Argument 1 in `new_v1()`
+ if let ExprKind::AddrOf(BorrowKind::Ref, _, ref arr) = args[0].kind;
+ if let ExprKind::Array(ref pieces) = arr.kind;
+ if pieces.len() == 1;
+ if let ExprKind::Lit(ref lit) = pieces[0].kind;
+ if let LitKind::Str(ref s, _) = lit.node;
+ // Argument 2 in `new_v1()`
+ if let ExprKind::AddrOf(BorrowKind::Ref, _, ref arg1) = args[1].kind;
+ if let ExprKind::Match(ref matchee, ref arms, MatchSource::Normal) = arg1.kind;
+ if arms.len() == 1;
+ if let ExprKind::Tup(ref tup) = matchee.kind;
+ then {
+ // `format!("foo")` expansion contains `match () { () => [], }`
+ if tup.is_empty() {
+ return Some(format!("{:?}.to_string()", s.as_str()));
+ } else if s.as_str().is_empty() {
+ return on_argumentv1_new(cx, &tup[0], arms);
+ }
+ }
+ }
+ None
+}
+
+fn on_new_v1_fmt<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr<'_>) -> Option {
+ if_chain! {
+ if let Some(args) = match_function_call(cx, expr, &paths::FMT_ARGUMENTS_NEW_V1_FORMATTED);
+ if args.len() == 3;
+ if check_unformatted(&args[2]);
+ // Argument 1 in `new_v1_formatted()`
+ if let ExprKind::AddrOf(BorrowKind::Ref, _, ref arr) = args[0].kind;
+ if let ExprKind::Array(ref pieces) = arr.kind;
+ if pieces.len() == 1;
+ if let ExprKind::Lit(ref lit) = pieces[0].kind;
+ if let LitKind::Str(..) = lit.node;
+ // Argument 2 in `new_v1_formatted()`
+ if let ExprKind::AddrOf(BorrowKind::Ref, _, ref arg1) = args[1].kind;
+ if let ExprKind::Match(ref matchee, ref arms, MatchSource::Normal) = arg1.kind;
+ if arms.len() == 1;
+ if let ExprKind::Tup(ref tup) = matchee.kind;
+ then {
+ return on_argumentv1_new(cx, &tup[0], arms);
+ }
+ }
+ None
+}
+
+/// Checks if the expression matches
+/// ```rust,ignore
+/// &[_ {
+/// format: _ {
+/// width: _::Implied,
+/// precision: _::Implied,
+/// ...
+/// },
+/// ...,
+/// }]
+/// ```
+fn check_unformatted(expr: &Expr<'_>) -> bool {
+ if_chain! {
+ if let ExprKind::AddrOf(BorrowKind::Ref, _, ref expr) = expr.kind;
+ if let ExprKind::Array(ref exprs) = expr.kind;
+ if exprs.len() == 1;
+ // struct `core::fmt::rt::v1::Argument`
+ if let ExprKind::Struct(_, ref fields, _) = exprs[0].kind;
+ if let Some(format_field) = fields.iter().find(|f| f.ident.name == sym!(format));
+ // struct `core::fmt::rt::v1::FormatSpec`
+ if let ExprKind::Struct(_, ref fields, _) = format_field.expr.kind;
+ if let Some(precision_field) = fields.iter().find(|f| f.ident.name == sym!(precision));
+ if let ExprKind::Path(ref precision_path) = precision_field.expr.kind;
+ if last_path_segment(precision_path).ident.name == sym!(Implied);
+ if let Some(width_field) = fields.iter().find(|f| f.ident.name == sym!(width));
+ if let ExprKind::Path(ref width_qpath) = width_field.expr.kind;
+ if last_path_segment(width_qpath).ident.name == sym!(Implied);
+ then {
+ return true;
+ }
+ }
+
+ false
+}
diff --git a/src/tools/clippy/clippy_lints/src/formatting.rs b/src/tools/clippy/clippy_lints/src/formatting.rs
new file mode 100644
index 00000000000..eb4b7a826f2
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/formatting.rs
@@ -0,0 +1,326 @@
+use crate::utils::{differing_macro_contexts, snippet_opt, span_lint_and_help, span_lint_and_note};
+use if_chain::if_chain;
+use rustc_ast::ast::{BinOpKind, Block, Expr, ExprKind, StmtKind, UnOp};
+use rustc_lint::{EarlyContext, EarlyLintPass};
+use rustc_middle::lint::in_external_macro;
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::source_map::Span;
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for use of the non-existent `=*`, `=!` and `=-`
+ /// operators.
+ ///
+ /// **Why is this bad?** This is either a typo of `*=`, `!=` or `-=` or
+ /// confusing.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```rust,ignore
+ /// a =- 42; // confusing, should it be `a -= 42` or `a = -42`?
+ /// ```
+ pub SUSPICIOUS_ASSIGNMENT_FORMATTING,
+ style,
+ "suspicious formatting of `*=`, `-=` or `!=`"
+}
+
+declare_clippy_lint! {
+ /// **What it does:** Checks the formatting of a unary operator on the right hand side
+ /// of a binary operator. It lints if there is no space between the binary and unary operators,
+ /// but there is a space between the unary and its operand.
+ ///
+ /// **Why is this bad?** This is either a typo in the binary operator or confusing.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```rust,ignore
+ /// if foo <- 30 { // this should be `foo < -30` but looks like a different operator
+ /// }
+ ///
+ /// if foo &&! bar { // this should be `foo && !bar` but looks like a different operator
+ /// }
+ /// ```
+ pub SUSPICIOUS_UNARY_OP_FORMATTING,
+ style,
+ "suspicious formatting of unary `-` or `!` on the RHS of a BinOp"
+}
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for formatting of `else`. It lints if the `else`
+ /// is followed immediately by a newline or the `else` seems to be missing.
+ ///
+ /// **Why is this bad?** This is probably some refactoring remnant, even if the
+ /// code is correct, it might look confusing.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```rust,ignore
+ /// if foo {
+ /// } { // looks like an `else` is missing here
+ /// }
+ ///
+ /// if foo {
+ /// } if bar { // looks like an `else` is missing here
+ /// }
+ ///
+ /// if foo {
+ /// } else
+ ///
+ /// { // this is the `else` block of the previous `if`, but should it be?
+ /// }
+ ///
+ /// if foo {
+ /// } else
+ ///
+ /// if bar { // this is the `else` block of the previous `if`, but should it be?
+ /// }
+ /// ```
+ pub SUSPICIOUS_ELSE_FORMATTING,
+ style,
+ "suspicious formatting of `else`"
+}
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for possible missing comma in an array. It lints if
+ /// an array element is a binary operator expression and it lies on two lines.
+ ///
+ /// **Why is this bad?** This could lead to unexpected results.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```rust,ignore
+ /// let a = &[
+ /// -1, -2, -3 // <= no comma here
+ /// -4, -5, -6
+ /// ];
+ /// ```
+ pub POSSIBLE_MISSING_COMMA,
+ correctness,
+ "possible missing comma in array"
+}
+
+declare_lint_pass!(Formatting => [
+ SUSPICIOUS_ASSIGNMENT_FORMATTING,
+ SUSPICIOUS_UNARY_OP_FORMATTING,
+ SUSPICIOUS_ELSE_FORMATTING,
+ POSSIBLE_MISSING_COMMA
+]);
+
+impl EarlyLintPass for Formatting {
+ fn check_block(&mut self, cx: &EarlyContext<'_>, block: &Block) {
+ for w in block.stmts.windows(2) {
+ match (&w[0].kind, &w[1].kind) {
+ (&StmtKind::Expr(ref first), &StmtKind::Expr(ref second))
+ | (&StmtKind::Expr(ref first), &StmtKind::Semi(ref second)) => {
+ check_missing_else(cx, first, second);
+ },
+ _ => (),
+ }
+ }
+ }
+
+ fn check_expr(&mut self, cx: &EarlyContext<'_>, expr: &Expr) {
+ check_assign(cx, expr);
+ check_unop(cx, expr);
+ check_else(cx, expr);
+ check_array(cx, expr);
+ }
+}
+
+/// Implementation of the `SUSPICIOUS_ASSIGNMENT_FORMATTING` lint.
+fn check_assign(cx: &EarlyContext<'_>, expr: &Expr) {
+ if let ExprKind::Assign(ref lhs, ref rhs, _) = expr.kind {
+ if !differing_macro_contexts(lhs.span, rhs.span) && !lhs.span.from_expansion() {
+ let eq_span = lhs.span.between(rhs.span);
+ if let ExprKind::Unary(op, ref sub_rhs) = rhs.kind {
+ if let Some(eq_snippet) = snippet_opt(cx, eq_span) {
+ let op = UnOp::to_string(op);
+ let eqop_span = lhs.span.between(sub_rhs.span);
+ if eq_snippet.ends_with('=') {
+ span_lint_and_note(
+ cx,
+ SUSPICIOUS_ASSIGNMENT_FORMATTING,
+ eqop_span,
+ &format!(
+ "this looks like you are trying to use `.. {op}= ..`, but you \
+ really are doing `.. = ({op} ..)`",
+ op = op
+ ),
+ None,
+ &format!("to remove this lint, use either `{op}=` or `= {op}`", op = op),
+ );
+ }
+ }
+ }
+ }
+ }
+}
+
+/// Implementation of the `SUSPICIOUS_UNARY_OP_FORMATTING` lint.
+fn check_unop(cx: &EarlyContext<'_>, expr: &Expr) {
+ if_chain! {
+ if let ExprKind::Binary(ref binop, ref lhs, ref rhs) = expr.kind;
+ if !differing_macro_contexts(lhs.span, rhs.span) && !lhs.span.from_expansion();
+ // span between BinOp LHS and RHS
+ let binop_span = lhs.span.between(rhs.span);
+ // if RHS is a UnOp
+ if let ExprKind::Unary(op, ref un_rhs) = rhs.kind;
+ // from UnOp operator to UnOp operand
+ let unop_operand_span = rhs.span.until(un_rhs.span);
+ if let Some(binop_snippet) = snippet_opt(cx, binop_span);
+ if let Some(unop_operand_snippet) = snippet_opt(cx, unop_operand_span);
+ let binop_str = BinOpKind::to_string(&binop.node);
+ // no space after BinOp operator and space after UnOp operator
+ if binop_snippet.ends_with(binop_str) && unop_operand_snippet.ends_with(' ');
+ then {
+ let unop_str = UnOp::to_string(op);
+ let eqop_span = lhs.span.between(un_rhs.span);
+ span_lint_and_help(
+ cx,
+ SUSPICIOUS_UNARY_OP_FORMATTING,
+ eqop_span,
+ &format!(
+ "by not having a space between `{binop}` and `{unop}` it looks like \
+ `{binop}{unop}` is a single operator",
+ binop = binop_str,
+ unop = unop_str
+ ),
+ None,
+ &format!(
+ "put a space between `{binop}` and `{unop}` and remove the space after `{unop}`",
+ binop = binop_str,
+ unop = unop_str
+ ),
+ );
+ }
+ }
+}
+
+/// Implementation of the `SUSPICIOUS_ELSE_FORMATTING` lint for weird `else`.
+fn check_else(cx: &EarlyContext<'_>, expr: &Expr) {
+ if_chain! {
+ if let ExprKind::If(_, then, Some(else_)) = &expr.kind;
+ if is_block(else_) || is_if(else_);
+ if !differing_macro_contexts(then.span, else_.span);
+ if !then.span.from_expansion() && !in_external_macro(cx.sess, expr.span);
+
+ // workaround for rust-lang/rust#43081
+ if expr.span.lo().0 != 0 && expr.span.hi().0 != 0;
+
+ // this will be a span from the closing ‘}’ of the “then” block (excluding) to
+ // the “if” of the “else if” block (excluding)
+ let else_span = then.span.between(else_.span);
+
+ // the snippet should look like " else \n " with maybe comments anywhere
+ // it’s bad when there is a ‘\n’ after the “else”
+ if let Some(else_snippet) = snippet_opt(cx, else_span);
+ if let Some(else_pos) = else_snippet.find("else");
+ if else_snippet[else_pos..].contains('\n');
+ let else_desc = if is_if(else_) { "if" } else { "{..}" };
+
+ then {
+ span_lint_and_note(
+ cx,
+ SUSPICIOUS_ELSE_FORMATTING,
+ else_span,
+ &format!("this is an `else {}` but the formatting might hide it", else_desc),
+ None,
+ &format!(
+ "to remove this lint, remove the `else` or remove the new line between \
+ `else` and `{}`",
+ else_desc,
+ ),
+ );
+ }
+ }
+}
+
+#[must_use]
+fn has_unary_equivalent(bin_op: BinOpKind) -> bool {
+ // &, *, -
+ bin_op == BinOpKind::And || bin_op == BinOpKind::Mul || bin_op == BinOpKind::Sub
+}
+
+fn indentation(cx: &EarlyContext<'_>, span: Span) -> usize {
+ cx.sess.source_map().lookup_char_pos(span.lo()).col.0
+}
+
+/// Implementation of the `POSSIBLE_MISSING_COMMA` lint for array
+fn check_array(cx: &EarlyContext<'_>, expr: &Expr) {
+ if let ExprKind::Array(ref array) = expr.kind {
+ for element in array {
+ if_chain! {
+ if let ExprKind::Binary(ref op, ref lhs, _) = element.kind;
+ if has_unary_equivalent(op.node) && !differing_macro_contexts(lhs.span, op.span);
+ let space_span = lhs.span.between(op.span);
+ if let Some(space_snippet) = snippet_opt(cx, space_span);
+ let lint_span = lhs.span.with_lo(lhs.span.hi());
+ if space_snippet.contains('\n');
+ if indentation(cx, op.span) <= indentation(cx, lhs.span);
+ then {
+ span_lint_and_note(
+ cx,
+ POSSIBLE_MISSING_COMMA,
+ lint_span,
+ "possibly missing a comma here",
+ None,
+ "to remove this lint, add a comma or write the expr in a single line",
+ );
+ }
+ }
+ }
+ }
+}
+
+fn check_missing_else(cx: &EarlyContext<'_>, first: &Expr, second: &Expr) {
+ if !differing_macro_contexts(first.span, second.span)
+ && !first.span.from_expansion()
+ && is_if(first)
+ && (is_block(second) || is_if(second))
+ {
+ // where the else would be
+ let else_span = first.span.between(second.span);
+
+ if let Some(else_snippet) = snippet_opt(cx, else_span) {
+ if !else_snippet.contains('\n') {
+ let (looks_like, next_thing) = if is_if(second) {
+ ("an `else if`", "the second `if`")
+ } else {
+ ("an `else {..}`", "the next block")
+ };
+
+ span_lint_and_note(
+ cx,
+ SUSPICIOUS_ELSE_FORMATTING,
+ else_span,
+ &format!("this looks like {} but the `else` is missing", looks_like),
+ None,
+ &format!(
+ "to remove this lint, add the missing `else` or add a new line before {}",
+ next_thing,
+ ),
+ );
+ }
+ }
+ }
+}
+
+fn is_block(expr: &Expr) -> bool {
+ if let ExprKind::Block(..) = expr.kind {
+ true
+ } else {
+ false
+ }
+}
+
+/// Check if the expression is an `if` or `if let`
+fn is_if(expr: &Expr) -> bool {
+ if let ExprKind::If(..) = expr.kind {
+ true
+ } else {
+ false
+ }
+}
diff --git a/src/tools/clippy/clippy_lints/src/functions.rs b/src/tools/clippy/clippy_lints/src/functions.rs
new file mode 100644
index 00000000000..c24a24733d7
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/functions.rs
@@ -0,0 +1,661 @@
+use crate::utils::{
+ attr_by_name, attrs::is_proc_macro, is_must_use_ty, is_trait_impl_item, iter_input_pats, match_def_path,
+ must_use_attr, qpath_res, return_ty, snippet, snippet_opt, span_lint, span_lint_and_help, span_lint_and_then,
+ trait_ref_of_method, type_is_unsafe_function,
+};
+use rustc_ast::ast::Attribute;
+use rustc_data_structures::fx::FxHashSet;
+use rustc_errors::Applicability;
+use rustc_hir as hir;
+use rustc_hir::intravisit;
+use rustc_hir::{def::Res, def_id::DefId};
+use rustc_lint::{LateContext, LateLintPass, LintContext};
+use rustc_middle::hir::map::Map;
+use rustc_middle::lint::in_external_macro;
+use rustc_middle::ty::{self, Ty};
+use rustc_session::{declare_tool_lint, impl_lint_pass};
+use rustc_span::source_map::Span;
+use rustc_target::spec::abi::Abi;
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for functions with too many parameters.
+ ///
+ /// **Why is this bad?** Functions with lots of parameters are considered bad
+ /// style and reduce readability (“what does the 5th parameter mean?”). Consider
+ /// grouping some parameters into a new type.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```rust
+ /// # struct Color;
+ /// fn foo(x: u32, y: u32, name: &str, c: Color, w: f32, h: f32, a: f32, b: f32) {
+ /// // ..
+ /// }
+ /// ```
+ pub TOO_MANY_ARGUMENTS,
+ complexity,
+ "functions with too many arguments"
+}
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for functions with a large amount of lines.
+ ///
+ /// **Why is this bad?** Functions with a lot of lines are harder to understand
+ /// due to having to look at a larger amount of code to understand what the
+ /// function is doing. Consider splitting the body of the function into
+ /// multiple functions.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ``` rust
+ /// fn im_too_long() {
+ /// println!("");
+ /// // ... 100 more LoC
+ /// println!("");
+ /// }
+ /// ```
+ pub TOO_MANY_LINES,
+ pedantic,
+ "functions with too many lines"
+}
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for public functions that dereference raw pointer
+ /// arguments but are not marked unsafe.
+ ///
+ /// **Why is this bad?** The function should probably be marked `unsafe`, since
+ /// for an arbitrary raw pointer, there is no way of telling for sure if it is
+ /// valid.
+ ///
+ /// **Known problems:**
+ ///
+ /// * It does not check functions recursively so if the pointer is passed to a
+ /// private non-`unsafe` function which does the dereferencing, the lint won't
+ /// trigger.
+ /// * It only checks for arguments whose type are raw pointers, not raw pointers
+ /// got from an argument in some other way (`fn foo(bar: &[*const u8])` or
+ /// `some_argument.get_raw_ptr()`).
+ ///
+ /// **Example:**
+ /// ```rust
+ /// pub fn foo(x: *const u8) {
+ /// println!("{}", unsafe { *x });
+ /// }
+ /// ```
+ pub NOT_UNSAFE_PTR_ARG_DEREF,
+ correctness,
+ "public functions dereferencing raw pointer arguments but not marked `unsafe`"
+}
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for a [`#[must_use]`] attribute on
+ /// unit-returning functions and methods.
+ ///
+ /// [`#[must_use]`]: https://doc.rust-lang.org/reference/attributes/diagnostics.html#the-must_use-attribute
+ ///
+ /// **Why is this bad?** Unit values are useless. The attribute is likely
+ /// a remnant of a refactoring that removed the return type.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Examples:**
+ /// ```rust
+ /// #[must_use]
+ /// fn useless() { }
+ /// ```
+ pub MUST_USE_UNIT,
+ style,
+ "`#[must_use]` attribute on a unit-returning function / method"
+}
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for a [`#[must_use]`] attribute without
+ /// further information on functions and methods that return a type already
+ /// marked as `#[must_use]`.
+ ///
+ /// [`#[must_use]`]: https://doc.rust-lang.org/reference/attributes/diagnostics.html#the-must_use-attribute
+ ///
+ /// **Why is this bad?** The attribute isn't needed. Not using the result
+ /// will already be reported. Alternatively, one can add some text to the
+ /// attribute to improve the lint message.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Examples:**
+ /// ```rust
+ /// #[must_use]
+ /// fn double_must_use() -> Result<(), ()> {
+ /// unimplemented!();
+ /// }
+ /// ```
+ pub DOUBLE_MUST_USE,
+ style,
+ "`#[must_use]` attribute on a `#[must_use]`-returning function / method"
+}
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for public functions that have no
+ /// [`#[must_use]`] attribute, but return something not already marked
+ /// must-use, have no mutable arg and mutate no statics.
+ ///
+ /// [`#[must_use]`]: https://doc.rust-lang.org/reference/attributes/diagnostics.html#the-must_use-attribute
+ ///
+ /// **Why is this bad?** Not bad at all, this lint just shows places where
+ /// you could add the attribute.
+ ///
+ /// **Known problems:** The lint only checks the arguments for mutable
+ /// types without looking if they are actually changed. On the other hand,
+ /// it also ignores a broad range of potentially interesting side effects,
+ /// because we cannot decide whether the programmer intends the function to
+ /// be called for the side effect or the result. Expect many false
+ /// positives. At least we don't lint if the result type is unit or already
+ /// `#[must_use]`.
+ ///
+ /// **Examples:**
+ /// ```rust
+ /// // this could be annotated with `#[must_use]`.
+ /// fn id(t: T) -> T { t }
+ /// ```
+ pub MUST_USE_CANDIDATE,
+ pedantic,
+ "function or method that could take a `#[must_use]` attribute"
+}
+
+#[derive(Copy, Clone)]
+pub struct Functions {
+ threshold: u64,
+ max_lines: u64,
+}
+
+impl Functions {
+ pub fn new(threshold: u64, max_lines: u64) -> Self {
+ Self { threshold, max_lines }
+ }
+}
+
+impl_lint_pass!(Functions => [
+ TOO_MANY_ARGUMENTS,
+ TOO_MANY_LINES,
+ NOT_UNSAFE_PTR_ARG_DEREF,
+ MUST_USE_UNIT,
+ DOUBLE_MUST_USE,
+ MUST_USE_CANDIDATE,
+]);
+
+impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Functions {
+ fn check_fn(
+ &mut self,
+ cx: &LateContext<'a, 'tcx>,
+ kind: intravisit::FnKind<'tcx>,
+ decl: &'tcx hir::FnDecl<'_>,
+ body: &'tcx hir::Body<'_>,
+ span: Span,
+ hir_id: hir::HirId,
+ ) {
+ let unsafety = match kind {
+ intravisit::FnKind::ItemFn(_, _, hir::FnHeader { unsafety, .. }, _, _) => unsafety,
+ intravisit::FnKind::Method(_, sig, _, _) => sig.header.unsafety,
+ intravisit::FnKind::Closure(_) => return,
+ };
+
+ // don't warn for implementations, it's not their fault
+ if !is_trait_impl_item(cx, hir_id) {
+ // don't lint extern functions decls, it's not their fault either
+ match kind {
+ intravisit::FnKind::Method(
+ _,
+ &hir::FnSig {
+ header: hir::FnHeader { abi: Abi::Rust, .. },
+ ..
+ },
+ _,
+ _,
+ )
+ | intravisit::FnKind::ItemFn(_, _, hir::FnHeader { abi: Abi::Rust, .. }, _, _) => {
+ self.check_arg_number(cx, decl, span.with_hi(decl.output.span().hi()))
+ },
+ _ => {},
+ }
+ }
+
+ Self::check_raw_ptr(cx, unsafety, decl, body, hir_id);
+ self.check_line_number(cx, span, body);
+ }
+
+ fn check_item(&mut self, cx: &LateContext<'a, 'tcx>, item: &'tcx hir::Item<'_>) {
+ let attr = must_use_attr(&item.attrs);
+ if let hir::ItemKind::Fn(ref sig, ref _generics, ref body_id) = item.kind {
+ if let Some(attr) = attr {
+ let fn_header_span = item.span.with_hi(sig.decl.output.span().hi());
+ check_needless_must_use(cx, &sig.decl, item.hir_id, item.span, fn_header_span, attr);
+ return;
+ }
+ if cx.access_levels.is_exported(item.hir_id)
+ && !is_proc_macro(&item.attrs)
+ && attr_by_name(&item.attrs, "no_mangle").is_none()
+ {
+ check_must_use_candidate(
+ cx,
+ &sig.decl,
+ cx.tcx.hir().body(*body_id),
+ item.span,
+ item.hir_id,
+ item.span.with_hi(sig.decl.output.span().hi()),
+ "this function could have a `#[must_use]` attribute",
+ );
+ }
+ }
+ }
+
+ fn check_impl_item(&mut self, cx: &LateContext<'a, 'tcx>, item: &'tcx hir::ImplItem<'_>) {
+ if let hir::ImplItemKind::Fn(ref sig, ref body_id) = item.kind {
+ let attr = must_use_attr(&item.attrs);
+ if let Some(attr) = attr {
+ let fn_header_span = item.span.with_hi(sig.decl.output.span().hi());
+ check_needless_must_use(cx, &sig.decl, item.hir_id, item.span, fn_header_span, attr);
+ } else if cx.access_levels.is_exported(item.hir_id)
+ && !is_proc_macro(&item.attrs)
+ && trait_ref_of_method(cx, item.hir_id).is_none()
+ {
+ check_must_use_candidate(
+ cx,
+ &sig.decl,
+ cx.tcx.hir().body(*body_id),
+ item.span,
+ item.hir_id,
+ item.span.with_hi(sig.decl.output.span().hi()),
+ "this method could have a `#[must_use]` attribute",
+ );
+ }
+ }
+ }
+
+ fn check_trait_item(&mut self, cx: &LateContext<'a, 'tcx>, item: &'tcx hir::TraitItem<'_>) {
+ if let hir::TraitItemKind::Fn(ref sig, ref eid) = item.kind {
+ // don't lint extern functions decls, it's not their fault
+ if sig.header.abi == Abi::Rust {
+ self.check_arg_number(cx, &sig.decl, item.span.with_hi(sig.decl.output.span().hi()));
+ }
+
+ let attr = must_use_attr(&item.attrs);
+ if let Some(attr) = attr {
+ let fn_header_span = item.span.with_hi(sig.decl.output.span().hi());
+ check_needless_must_use(cx, &sig.decl, item.hir_id, item.span, fn_header_span, attr);
+ }
+ if let hir::TraitFn::Provided(eid) = *eid {
+ let body = cx.tcx.hir().body(eid);
+ Self::check_raw_ptr(cx, sig.header.unsafety, &sig.decl, body, item.hir_id);
+
+ if attr.is_none() && cx.access_levels.is_exported(item.hir_id) && !is_proc_macro(&item.attrs) {
+ check_must_use_candidate(
+ cx,
+ &sig.decl,
+ body,
+ item.span,
+ item.hir_id,
+ item.span.with_hi(sig.decl.output.span().hi()),
+ "this method could have a `#[must_use]` attribute",
+ );
+ }
+ }
+ }
+ }
+}
+
+impl<'a, 'tcx> Functions {
+ fn check_arg_number(self, cx: &LateContext<'_, '_>, decl: &hir::FnDecl<'_>, fn_span: Span) {
+ let args = decl.inputs.len() as u64;
+ if args > self.threshold {
+ span_lint(
+ cx,
+ TOO_MANY_ARGUMENTS,
+ fn_span,
+ &format!("this function has too many arguments ({}/{})", args, self.threshold),
+ );
+ }
+ }
+
+ fn check_line_number(self, cx: &LateContext<'_, '_>, span: Span, body: &'tcx hir::Body<'_>) {
+ if in_external_macro(cx.sess(), span) {
+ return;
+ }
+
+ let code_snippet = snippet(cx, body.value.span, "..");
+ let mut line_count: u64 = 0;
+ let mut in_comment = false;
+ let mut code_in_line;
+
+ // Skip the surrounding function decl.
+ let start_brace_idx = code_snippet.find('{').map_or(0, |i| i + 1);
+ let end_brace_idx = code_snippet.rfind('}').unwrap_or_else(|| code_snippet.len());
+ let function_lines = code_snippet[start_brace_idx..end_brace_idx].lines();
+
+ for mut line in function_lines {
+ code_in_line = false;
+ loop {
+ line = line.trim_start();
+ if line.is_empty() {
+ break;
+ }
+ if in_comment {
+ match line.find("*/") {
+ Some(i) => {
+ line = &line[i + 2..];
+ in_comment = false;
+ continue;
+ },
+ None => break,
+ }
+ } else {
+ let multi_idx = line.find("/*").unwrap_or_else(|| line.len());
+ let single_idx = line.find("//").unwrap_or_else(|| line.len());
+ code_in_line |= multi_idx > 0 && single_idx > 0;
+ // Implies multi_idx is below line.len()
+ if multi_idx < single_idx {
+ line = &line[multi_idx + 2..];
+ in_comment = true;
+ continue;
+ }
+ break;
+ }
+ }
+ if code_in_line {
+ line_count += 1;
+ }
+ }
+
+ if line_count > self.max_lines {
+ span_lint(cx, TOO_MANY_LINES, span, "This function has a large number of lines.")
+ }
+ }
+
+ fn check_raw_ptr(
+ cx: &LateContext<'a, 'tcx>,
+ unsafety: hir::Unsafety,
+ decl: &'tcx hir::FnDecl<'_>,
+ body: &'tcx hir::Body<'_>,
+ hir_id: hir::HirId,
+ ) {
+ let expr = &body.value;
+ if unsafety == hir::Unsafety::Normal && cx.access_levels.is_exported(hir_id) {
+ let raw_ptrs = iter_input_pats(decl, body)
+ .zip(decl.inputs.iter())
+ .filter_map(|(arg, ty)| raw_ptr_arg(arg, ty))
+ .collect::>();
+
+ if !raw_ptrs.is_empty() {
+ let tables = cx.tcx.body_tables(body.id());
+ let mut v = DerefVisitor {
+ cx,
+ ptrs: raw_ptrs,
+ tables,
+ };
+
+ intravisit::walk_expr(&mut v, expr);
+ }
+ }
+ }
+}
+
+fn check_needless_must_use(
+ cx: &LateContext<'_, '_>,
+ decl: &hir::FnDecl<'_>,
+ item_id: hir::HirId,
+ item_span: Span,
+ fn_header_span: Span,
+ attr: &Attribute,
+) {
+ if in_external_macro(cx.sess(), item_span) {
+ return;
+ }
+ if returns_unit(decl) {
+ span_lint_and_then(
+ cx,
+ MUST_USE_UNIT,
+ fn_header_span,
+ "this unit-returning function has a `#[must_use]` attribute",
+ |diag| {
+ diag.span_suggestion(
+ attr.span,
+ "remove the attribute",
+ "".into(),
+ Applicability::MachineApplicable,
+ );
+ },
+ );
+ } else if !attr.is_value_str() && is_must_use_ty(cx, return_ty(cx, item_id)) {
+ span_lint_and_help(
+ cx,
+ DOUBLE_MUST_USE,
+ fn_header_span,
+ "this function has an empty `#[must_use]` attribute, but returns a type already marked as `#[must_use]`",
+ None,
+ "either add some descriptive text or remove the attribute",
+ );
+ }
+}
+
+fn check_must_use_candidate<'a, 'tcx>(
+ cx: &LateContext<'a, 'tcx>,
+ decl: &'tcx hir::FnDecl<'_>,
+ body: &'tcx hir::Body<'_>,
+ item_span: Span,
+ item_id: hir::HirId,
+ fn_span: Span,
+ msg: &str,
+) {
+ if has_mutable_arg(cx, body)
+ || mutates_static(cx, body)
+ || in_external_macro(cx.sess(), item_span)
+ || returns_unit(decl)
+ || !cx.access_levels.is_exported(item_id)
+ || is_must_use_ty(cx, return_ty(cx, item_id))
+ {
+ return;
+ }
+ span_lint_and_then(cx, MUST_USE_CANDIDATE, fn_span, msg, |diag| {
+ if let Some(snippet) = snippet_opt(cx, fn_span) {
+ diag.span_suggestion(
+ fn_span,
+ "add the attribute",
+ format!("#[must_use] {}", snippet),
+ Applicability::MachineApplicable,
+ );
+ }
+ });
+}
+
+fn returns_unit(decl: &hir::FnDecl<'_>) -> bool {
+ match decl.output {
+ hir::FnRetTy::DefaultReturn(_) => true,
+ hir::FnRetTy::Return(ref ty) => match ty.kind {
+ hir::TyKind::Tup(ref tys) => tys.is_empty(),
+ hir::TyKind::Never => true,
+ _ => false,
+ },
+ }
+}
+
+fn has_mutable_arg(cx: &LateContext<'_, '_>, body: &hir::Body<'_>) -> bool {
+ let mut tys = FxHashSet::default();
+ body.params.iter().any(|param| is_mutable_pat(cx, ¶m.pat, &mut tys))
+}
+
+fn is_mutable_pat(cx: &LateContext<'_, '_>, pat: &hir::Pat<'_>, tys: &mut FxHashSet) -> bool {
+ if let hir::PatKind::Wild = pat.kind {
+ return false; // ignore `_` patterns
+ }
+ let def_id = pat.hir_id.owner.to_def_id();
+ if cx.tcx.has_typeck_tables(def_id) {
+ is_mutable_ty(
+ cx,
+ &cx.tcx.typeck_tables_of(def_id.expect_local()).pat_ty(pat),
+ pat.span,
+ tys,
+ )
+ } else {
+ false
+ }
+}
+
+static KNOWN_WRAPPER_TYS: &[&[&str]] = &[&["alloc", "rc", "Rc"], &["std", "sync", "Arc"]];
+
+fn is_mutable_ty<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, ty: Ty<'tcx>, span: Span, tys: &mut FxHashSet) -> bool {
+ match ty.kind {
+ // primitive types are never mutable
+ ty::Bool | ty::Char | ty::Int(_) | ty::Uint(_) | ty::Float(_) | ty::Str => false,
+ ty::Adt(ref adt, ref substs) => {
+ tys.insert(adt.did) && !ty.is_freeze(cx.tcx, cx.param_env, span)
+ || KNOWN_WRAPPER_TYS.iter().any(|path| match_def_path(cx, adt.did, path))
+ && substs.types().any(|ty| is_mutable_ty(cx, ty, span, tys))
+ },
+ ty::Tuple(ref substs) => substs.types().any(|ty| is_mutable_ty(cx, ty, span, tys)),
+ ty::Array(ty, _) | ty::Slice(ty) => is_mutable_ty(cx, ty, span, tys),
+ ty::RawPtr(ty::TypeAndMut { ty, mutbl }) | ty::Ref(_, ty, mutbl) => {
+ mutbl == hir::Mutability::Mut || is_mutable_ty(cx, ty, span, tys)
+ },
+ // calling something constitutes a side effect, so return true on all callables
+ // also never calls need not be used, so return true for them, too
+ _ => true,
+ }
+}
+
+fn raw_ptr_arg(arg: &hir::Param<'_>, ty: &hir::Ty<'_>) -> Option {
+ if let (&hir::PatKind::Binding(_, id, _, _), &hir::TyKind::Ptr(_)) = (&arg.pat.kind, &ty.kind) {
+ Some(id)
+ } else {
+ None
+ }
+}
+
+struct DerefVisitor<'a, 'tcx> {
+ cx: &'a LateContext<'a, 'tcx>,
+ ptrs: FxHashSet,
+ tables: &'a ty::TypeckTables<'tcx>,
+}
+
+impl<'a, 'tcx> intravisit::Visitor<'tcx> for DerefVisitor<'a, 'tcx> {
+ type Map = Map<'tcx>;
+
+ fn visit_expr(&mut self, expr: &'tcx hir::Expr<'_>) {
+ match expr.kind {
+ hir::ExprKind::Call(ref f, args) => {
+ let ty = self.tables.expr_ty(f);
+
+ if type_is_unsafe_function(self.cx, ty) {
+ for arg in args {
+ self.check_arg(arg);
+ }
+ }
+ },
+ hir::ExprKind::MethodCall(_, _, args) => {
+ let def_id = self.tables.type_dependent_def_id(expr.hir_id).unwrap();
+ let base_type = self.cx.tcx.type_of(def_id);
+
+ if type_is_unsafe_function(self.cx, base_type) {
+ for arg in args {
+ self.check_arg(arg);
+ }
+ }
+ },
+ hir::ExprKind::Unary(hir::UnOp::UnDeref, ref ptr) => self.check_arg(ptr),
+ _ => (),
+ }
+
+ intravisit::walk_expr(self, expr);
+ }
+
+ fn nested_visit_map(&mut self) -> intravisit::NestedVisitorMap {
+ intravisit::NestedVisitorMap::None
+ }
+}
+
+impl<'a, 'tcx> DerefVisitor<'a, 'tcx> {
+ fn check_arg(&self, ptr: &hir::Expr<'_>) {
+ if let hir::ExprKind::Path(ref qpath) = ptr.kind {
+ if let Res::Local(id) = qpath_res(self.cx, qpath, ptr.hir_id) {
+ if self.ptrs.contains(&id) {
+ span_lint(
+ self.cx,
+ NOT_UNSAFE_PTR_ARG_DEREF,
+ ptr.span,
+ "this public function dereferences a raw pointer but is not marked `unsafe`",
+ );
+ }
+ }
+ }
+ }
+}
+
+struct StaticMutVisitor<'a, 'tcx> {
+ cx: &'a LateContext<'a, 'tcx>,
+ mutates_static: bool,
+}
+
+impl<'a, 'tcx> intravisit::Visitor<'tcx> for StaticMutVisitor<'a, 'tcx> {
+ type Map = Map<'tcx>;
+
+ fn visit_expr(&mut self, expr: &'tcx hir::Expr<'_>) {
+ use hir::ExprKind::{AddrOf, Assign, AssignOp, Call, MethodCall};
+
+ if self.mutates_static {
+ return;
+ }
+ match expr.kind {
+ Call(_, args) | MethodCall(_, _, args) => {
+ let mut tys = FxHashSet::default();
+ for arg in args {
+ let def_id = arg.hir_id.owner.to_def_id();
+ if self.cx.tcx.has_typeck_tables(def_id)
+ && is_mutable_ty(
+ self.cx,
+ self.cx.tcx.typeck_tables_of(def_id.expect_local()).expr_ty(arg),
+ arg.span,
+ &mut tys,
+ )
+ && is_mutated_static(self.cx, arg)
+ {
+ self.mutates_static = true;
+ return;
+ }
+ tys.clear();
+ }
+ },
+ Assign(ref target, ..) | AssignOp(_, ref target, _) | AddrOf(_, hir::Mutability::Mut, ref target) => {
+ self.mutates_static |= is_mutated_static(self.cx, target)
+ },
+ _ => {},
+ }
+ }
+
+ fn nested_visit_map(&mut self) -> intravisit::NestedVisitorMap {
+ intravisit::NestedVisitorMap::None
+ }
+}
+
+fn is_mutated_static(cx: &LateContext<'_, '_>, e: &hir::Expr<'_>) -> bool {
+ use hir::ExprKind::{Field, Index, Path};
+
+ match e.kind {
+ Path(ref qpath) => {
+ if let Res::Local(_) = qpath_res(cx, qpath, e.hir_id) {
+ false
+ } else {
+ true
+ }
+ },
+ Field(ref inner, _) | Index(ref inner, _) => is_mutated_static(cx, inner),
+ _ => false,
+ }
+}
+
+fn mutates_static<'a, 'tcx>(cx: &'a LateContext<'a, 'tcx>, body: &'tcx hir::Body<'_>) -> bool {
+ let mut v = StaticMutVisitor {
+ cx,
+ mutates_static: false,
+ };
+ intravisit::walk_expr(&mut v, &body.value);
+ v.mutates_static
+}
diff --git a/src/tools/clippy/clippy_lints/src/future_not_send.rs b/src/tools/clippy/clippy_lints/src/future_not_send.rs
new file mode 100644
index 00000000000..704a95ec0a0
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/future_not_send.rs
@@ -0,0 +1,110 @@
+use crate::utils;
+use rustc_hir::intravisit::FnKind;
+use rustc_hir::{Body, FnDecl, HirId};
+use rustc_infer::infer::TyCtxtInferExt;
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty::{Opaque, Predicate::Trait, ToPolyTraitRef};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::{sym, Span};
+use rustc_trait_selection::traits::error_reporting::suggestions::InferCtxtExt;
+use rustc_trait_selection::traits::{self, FulfillmentError, TraitEngine};
+
+declare_clippy_lint! {
+ /// **What it does:** This lint requires Future implementations returned from
+ /// functions and methods to implement the `Send` marker trait. It is mostly
+ /// used by library authors (public and internal) that target an audience where
+ /// multithreaded executors are likely to be used for running these Futures.
+ ///
+ /// **Why is this bad?** A Future implementation captures some state that it
+ /// needs to eventually produce its final value. When targeting a multithreaded
+ /// executor (which is the norm on non-embedded devices) this means that this
+ /// state may need to be transported to other threads, in other words the
+ /// whole Future needs to implement the `Send` marker trait. If it does not,
+ /// then the resulting Future cannot be submitted to a thread pool in the
+ /// end user’s code.
+ ///
+ /// Especially for generic functions it can be confusing to leave the
+ /// discovery of this problem to the end user: the reported error location
+ /// will be far from its cause and can in many cases not even be fixed without
+ /// modifying the library where the offending Future implementation is
+ /// produced.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ ///
+ /// ```rust
+ /// async fn not_send(bytes: std::rc::Rc<[u8]>) {}
+ /// ```
+ /// Use instead:
+ /// ```rust
+ /// async fn is_send(bytes: std::sync::Arc<[u8]>) {}
+ /// ```
+ pub FUTURE_NOT_SEND,
+ nursery,
+ "public Futures must be Send"
+}
+
+declare_lint_pass!(FutureNotSend => [FUTURE_NOT_SEND]);
+
+impl<'a, 'tcx> LateLintPass<'a, 'tcx> for FutureNotSend {
+ fn check_fn(
+ &mut self,
+ cx: &LateContext<'a, 'tcx>,
+ kind: FnKind<'tcx>,
+ decl: &'tcx FnDecl<'tcx>,
+ _: &'tcx Body<'tcx>,
+ _: Span,
+ hir_id: HirId,
+ ) {
+ if let FnKind::Closure(_) = kind {
+ return;
+ }
+ let ret_ty = utils::return_ty(cx, hir_id);
+ if let Opaque(id, subst) = ret_ty.kind {
+ let preds = cx.tcx.predicates_of(id).instantiate(cx.tcx, subst);
+ let mut is_future = false;
+ for p in preds.predicates {
+ if let Some(trait_ref) = p.to_opt_poly_trait_ref() {
+ if Some(trait_ref.def_id()) == cx.tcx.lang_items().future_trait() {
+ is_future = true;
+ break;
+ }
+ }
+ }
+ if is_future {
+ let send_trait = cx.tcx.get_diagnostic_item(sym::send_trait).unwrap();
+ let span = decl.output.span();
+ let send_result = cx.tcx.infer_ctxt().enter(|infcx| {
+ let cause = traits::ObligationCause::misc(span, hir_id);
+ let mut fulfillment_cx = traits::FulfillmentContext::new();
+ fulfillment_cx.register_bound(&infcx, cx.param_env, ret_ty, send_trait, cause);
+ fulfillment_cx.select_all_or_error(&infcx)
+ });
+ if let Err(send_errors) = send_result {
+ utils::span_lint_and_then(
+ cx,
+ FUTURE_NOT_SEND,
+ span,
+ "future cannot be sent between threads safely",
+ |db| {
+ cx.tcx.infer_ctxt().enter(|infcx| {
+ for FulfillmentError { obligation, .. } in send_errors {
+ infcx.maybe_note_obligation_cause_for_async_await(db, &obligation);
+ if let Trait(trait_pred, _) = obligation.predicate {
+ let trait_ref = trait_pred.to_poly_trait_ref();
+ db.note(&*format!(
+ "`{}` doesn't implement `{}`",
+ trait_ref.self_ty(),
+ trait_ref.print_only_trait_path(),
+ ));
+ }
+ }
+ })
+ },
+ );
+ }
+ }
+ }
+ }
+}
diff --git a/src/tools/clippy/clippy_lints/src/get_last_with_len.rs b/src/tools/clippy/clippy_lints/src/get_last_with_len.rs
new file mode 100644
index 00000000000..c32e0a2290d
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/get_last_with_len.rs
@@ -0,0 +1,103 @@
+//! lint on using `x.get(x.len() - 1)` instead of `x.last()`
+
+use crate::utils::{is_type_diagnostic_item, snippet_with_applicability, span_lint_and_sugg, SpanlessEq};
+use if_chain::if_chain;
+use rustc_ast::ast::LitKind;
+use rustc_errors::Applicability;
+use rustc_hir::{BinOpKind, Expr, ExprKind};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::source_map::Spanned;
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for using `x.get(x.len() - 1)` instead of
+ /// `x.last()`.
+ ///
+ /// **Why is this bad?** Using `x.last()` is easier to read and has the same
+ /// result.
+ ///
+ /// Note that using `x[x.len() - 1]` is semantically different from
+ /// `x.last()`. Indexing into the array will panic on out-of-bounds
+ /// accesses, while `x.get()` and `x.last()` will return `None`.
+ ///
+ /// There is another lint (get_unwrap) that covers the case of using
+ /// `x.get(index).unwrap()` instead of `x[index]`.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ ///
+ /// ```rust
+ /// // Bad
+ /// let x = vec![2, 3, 5];
+ /// let last_element = x.get(x.len() - 1);
+ ///
+ /// // Good
+ /// let x = vec![2, 3, 5];
+ /// let last_element = x.last();
+ /// ```
+ pub GET_LAST_WITH_LEN,
+ complexity,
+ "Using `x.get(x.len() - 1)` when `x.last()` is correct and simpler"
+}
+
+declare_lint_pass!(GetLastWithLen => [GET_LAST_WITH_LEN]);
+
+impl<'a, 'tcx> LateLintPass<'a, 'tcx> for GetLastWithLen {
+ fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr<'_>) {
+ if_chain! {
+ // Is a method call
+ if let ExprKind::MethodCall(ref path, _, ref args) = expr.kind;
+
+ // Method name is "get"
+ if path.ident.name == sym!(get);
+
+ // Argument 0 (the struct we're calling the method on) is a vector
+ if let Some(struct_calling_on) = args.get(0);
+ let struct_ty = cx.tables.expr_ty(struct_calling_on);
+ if is_type_diagnostic_item(cx, struct_ty, sym!(vec_type));
+
+ // Argument to "get" is a subtraction
+ if let Some(get_index_arg) = args.get(1);
+ if let ExprKind::Binary(
+ Spanned {
+ node: BinOpKind::Sub,
+ ..
+ },
+ lhs,
+ rhs,
+ ) = &get_index_arg.kind;
+
+ // LHS of subtraction is "x.len()"
+ if let ExprKind::MethodCall(arg_lhs_path, _, lhs_args) = &lhs.kind;
+ if arg_lhs_path.ident.name == sym!(len);
+ if let Some(arg_lhs_struct) = lhs_args.get(0);
+
+ // The two vectors referenced (x in x.get(...) and in x.len())
+ if SpanlessEq::new(cx).eq_expr(struct_calling_on, arg_lhs_struct);
+
+ // RHS of subtraction is 1
+ if let ExprKind::Lit(rhs_lit) = &rhs.kind;
+ if let LitKind::Int(1, ..) = rhs_lit.node;
+
+ then {
+ let mut applicability = Applicability::MachineApplicable;
+ let vec_name = snippet_with_applicability(
+ cx,
+ struct_calling_on.span, "vec",
+ &mut applicability,
+ );
+
+ span_lint_and_sugg(
+ cx,
+ GET_LAST_WITH_LEN,
+ expr.span,
+ &format!("accessing last element with `{0}.get({0}.len() - 1)`", vec_name),
+ "try",
+ format!("{}.last()", vec_name),
+ applicability,
+ );
+ }
+ }
+ }
+}
diff --git a/src/tools/clippy/clippy_lints/src/identity_conversion.rs b/src/tools/clippy/clippy_lints/src/identity_conversion.rs
new file mode 100644
index 00000000000..33a9478f058
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/identity_conversion.rs
@@ -0,0 +1,124 @@
+use crate::utils::{
+ match_def_path, match_trait_method, paths, same_tys, snippet, snippet_with_macro_callsite, span_lint_and_sugg,
+};
+use rustc_errors::Applicability;
+use rustc_hir::{Expr, ExprKind, HirId, MatchSource};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_tool_lint, impl_lint_pass};
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for always-identical `Into`/`From`/`IntoIter` conversions.
+ ///
+ /// **Why is this bad?** Redundant code.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```rust
+ /// // format!() returns a `String`
+ /// let s: String = format!("hello").into();
+ /// ```
+ pub IDENTITY_CONVERSION,
+ complexity,
+ "using always-identical `Into`/`From`/`IntoIter` conversions"
+}
+
+#[derive(Default)]
+pub struct IdentityConversion {
+ try_desugar_arm: Vec,
+}
+
+impl_lint_pass!(IdentityConversion => [IDENTITY_CONVERSION]);
+
+impl<'a, 'tcx> LateLintPass<'a, 'tcx> for IdentityConversion {
+ fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, e: &'tcx Expr<'_>) {
+ if e.span.from_expansion() {
+ return;
+ }
+
+ if Some(&e.hir_id) == self.try_desugar_arm.last() {
+ return;
+ }
+
+ match e.kind {
+ ExprKind::Match(_, ref arms, MatchSource::TryDesugar) => {
+ let e = match arms[0].body.kind {
+ ExprKind::Ret(Some(ref e)) | ExprKind::Break(_, Some(ref e)) => e,
+ _ => return,
+ };
+ if let ExprKind::Call(_, ref args) = e.kind {
+ self.try_desugar_arm.push(args[0].hir_id);
+ }
+ },
+
+ ExprKind::MethodCall(ref name, .., ref args) => {
+ if match_trait_method(cx, e, &paths::INTO) && &*name.ident.as_str() == "into" {
+ let a = cx.tables.expr_ty(e);
+ let b = cx.tables.expr_ty(&args[0]);
+ if same_tys(cx, a, b) {
+ let sugg = snippet_with_macro_callsite(cx, args[0].span, "").to_string();
+
+ span_lint_and_sugg(
+ cx,
+ IDENTITY_CONVERSION,
+ e.span,
+ "identical conversion",
+ "consider removing `.into()`",
+ sugg,
+ Applicability::MachineApplicable, // snippet
+ );
+ }
+ }
+ if match_trait_method(cx, e, &paths::INTO_ITERATOR) && &*name.ident.as_str() == "into_iter" {
+ let a = cx.tables.expr_ty(e);
+ let b = cx.tables.expr_ty(&args[0]);
+ if same_tys(cx, a, b) {
+ let sugg = snippet(cx, args[0].span, "").into_owned();
+ span_lint_and_sugg(
+ cx,
+ IDENTITY_CONVERSION,
+ e.span,
+ "identical conversion",
+ "consider removing `.into_iter()`",
+ sugg,
+ Applicability::MachineApplicable, // snippet
+ );
+ }
+ }
+ },
+
+ ExprKind::Call(ref path, ref args) => {
+ if let ExprKind::Path(ref qpath) = path.kind {
+ if let Some(def_id) = cx.tables.qpath_res(qpath, path.hir_id).opt_def_id() {
+ if match_def_path(cx, def_id, &paths::FROM_FROM) {
+ let a = cx.tables.expr_ty(e);
+ let b = cx.tables.expr_ty(&args[0]);
+ if same_tys(cx, a, b) {
+ let sugg = snippet(cx, args[0].span.source_callsite(), "").into_owned();
+ let sugg_msg =
+ format!("consider removing `{}()`", snippet(cx, path.span, "From::from"));
+ span_lint_and_sugg(
+ cx,
+ IDENTITY_CONVERSION,
+ e.span,
+ "identical conversion",
+ &sugg_msg,
+ sugg,
+ Applicability::MachineApplicable, // snippet
+ );
+ }
+ }
+ }
+ }
+ },
+
+ _ => {},
+ }
+ }
+
+ fn check_expr_post(&mut self, _: &LateContext<'a, 'tcx>, e: &'tcx Expr<'_>) {
+ if Some(&e.hir_id) == self.try_desugar_arm.last() {
+ self.try_desugar_arm.pop();
+ }
+ }
+}
diff --git a/src/tools/clippy/clippy_lints/src/identity_op.rs b/src/tools/clippy/clippy_lints/src/identity_op.rs
new file mode 100644
index 00000000000..088e4ab1921
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/identity_op.rs
@@ -0,0 +1,82 @@
+use rustc_hir::{BinOpKind, Expr, ExprKind};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty;
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::source_map::Span;
+
+use crate::consts::{constant_simple, Constant};
+use crate::utils::{clip, snippet, span_lint, unsext};
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for identity operations, e.g., `x + 0`.
+ ///
+ /// **Why is this bad?** This code can be removed without changing the
+ /// meaning. So it just obscures what's going on. Delete it mercilessly.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```rust
+ /// # let x = 1;
+ /// x / 1 + 0 * 1 - 0 | 0;
+ /// ```
+ pub IDENTITY_OP,
+ complexity,
+ "using identity operations, e.g., `x + 0` or `y / 1`"
+}
+
+declare_lint_pass!(IdentityOp => [IDENTITY_OP]);
+
+impl<'a, 'tcx> LateLintPass<'a, 'tcx> for IdentityOp {
+ fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, e: &'tcx Expr<'_>) {
+ if e.span.from_expansion() {
+ return;
+ }
+ if let ExprKind::Binary(ref cmp, ref left, ref right) = e.kind {
+ match cmp.node {
+ BinOpKind::Add | BinOpKind::BitOr | BinOpKind::BitXor => {
+ check(cx, left, 0, e.span, right.span);
+ check(cx, right, 0, e.span, left.span);
+ },
+ BinOpKind::Shl | BinOpKind::Shr | BinOpKind::Sub => check(cx, right, 0, e.span, left.span),
+ BinOpKind::Mul => {
+ check(cx, left, 1, e.span, right.span);
+ check(cx, right, 1, e.span, left.span);
+ },
+ BinOpKind::Div => check(cx, right, 1, e.span, left.span),
+ BinOpKind::BitAnd => {
+ check(cx, left, -1, e.span, right.span);
+ check(cx, right, -1, e.span, left.span);
+ },
+ _ => (),
+ }
+ }
+ }
+}
+
+#[allow(clippy::cast_possible_wrap)]
+fn check(cx: &LateContext<'_, '_>, e: &Expr<'_>, m: i8, span: Span, arg: Span) {
+ if let Some(Constant::Int(v)) = constant_simple(cx, cx.tables, e) {
+ let check = match cx.tables.expr_ty(e).kind {
+ ty::Int(ity) => unsext(cx.tcx, -1_i128, ity),
+ ty::Uint(uty) => clip(cx.tcx, !0, uty),
+ _ => return,
+ };
+ if match m {
+ 0 => v == 0,
+ -1 => v == check,
+ 1 => v == 1,
+ _ => unreachable!(),
+ } {
+ span_lint(
+ cx,
+ IDENTITY_OP,
+ span,
+ &format!(
+ "the operation is ineffective. Consider reducing it to `{}`",
+ snippet(cx, arg, "..")
+ ),
+ );
+ }
+ }
+}
diff --git a/src/tools/clippy/clippy_lints/src/if_let_mutex.rs b/src/tools/clippy/clippy_lints/src/if_let_mutex.rs
new file mode 100644
index 00000000000..ae92a96d163
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/if_let_mutex.rs
@@ -0,0 +1,160 @@
+use crate::utils::{is_type_diagnostic_item, span_lint_and_help, SpanlessEq};
+use if_chain::if_chain;
+use rustc_hir::intravisit::{self as visit, NestedVisitorMap, Visitor};
+use rustc_hir::{Expr, ExprKind, MatchSource};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::hir::map::Map;
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for `Mutex::lock` calls in `if let` expression
+ /// with lock calls in any of the else blocks.
+ ///
+ /// **Why is this bad?** The Mutex lock remains held for the whole
+ /// `if let ... else` block and deadlocks.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ ///
+ /// ```rust,ignore
+ /// if let Ok(thing) = mutex.lock() {
+ /// do_thing();
+ /// } else {
+ /// mutex.lock();
+ /// }
+ /// ```
+ /// Should be written
+ /// ```rust,ignore
+ /// let locked = mutex.lock();
+ /// if let Ok(thing) = locked {
+ /// do_thing(thing);
+ /// } else {
+ /// use_locked(locked);
+ /// }
+ /// ```
+ pub IF_LET_MUTEX,
+ correctness,
+ "locking a `Mutex` in an `if let` block can cause deadlocks"
+}
+
+declare_lint_pass!(IfLetMutex => [IF_LET_MUTEX]);
+
+impl LateLintPass<'_, '_> for IfLetMutex {
+ fn check_expr(&mut self, cx: &LateContext<'_, '_>, ex: &'_ Expr<'_>) {
+ let mut arm_visit = ArmVisitor {
+ mutex_lock_called: false,
+ found_mutex: None,
+ cx,
+ };
+ let mut op_visit = OppVisitor {
+ mutex_lock_called: false,
+ found_mutex: None,
+ cx,
+ };
+ if let ExprKind::Match(
+ ref op,
+ ref arms,
+ MatchSource::IfLetDesugar {
+ contains_else_clause: true,
+ },
+ ) = ex.kind
+ {
+ op_visit.visit_expr(op);
+ if op_visit.mutex_lock_called {
+ for arm in *arms {
+ arm_visit.visit_arm(arm);
+ }
+
+ if arm_visit.mutex_lock_called && arm_visit.same_mutex(cx, op_visit.found_mutex.unwrap()) {
+ span_lint_and_help(
+ cx,
+ IF_LET_MUTEX,
+ ex.span,
+ "calling `Mutex::lock` inside the scope of another `Mutex::lock` causes a deadlock",
+ None,
+ "move the lock call outside of the `if let ...` expression",
+ );
+ }
+ }
+ }
+ }
+}
+
+/// Checks if `Mutex::lock` is called in the `if let _ = expr.
+pub struct OppVisitor<'tcx, 'l> {
+ mutex_lock_called: bool,
+ found_mutex: Option<&'tcx Expr<'tcx>>,
+ cx: &'tcx LateContext<'tcx, 'l>,
+}
+
+impl<'tcx, 'l> Visitor<'tcx> for OppVisitor<'tcx, 'l> {
+ type Map = Map<'tcx>;
+
+ fn visit_expr(&mut self, expr: &'tcx Expr<'_>) {
+ if_chain! {
+ if let Some(mutex) = is_mutex_lock_call(self.cx, expr);
+ then {
+ self.found_mutex = Some(mutex);
+ self.mutex_lock_called = true;
+ return;
+ }
+ }
+ visit::walk_expr(self, expr);
+ }
+
+ fn nested_visit_map(&mut self) -> NestedVisitorMap {
+ NestedVisitorMap::None
+ }
+}
+
+/// Checks if `Mutex::lock` is called in any of the branches.
+pub struct ArmVisitor<'tcx, 'l> {
+ mutex_lock_called: bool,
+ found_mutex: Option<&'tcx Expr<'tcx>>,
+ cx: &'tcx LateContext<'tcx, 'l>,
+}
+
+impl<'tcx, 'l> Visitor<'tcx> for ArmVisitor<'tcx, 'l> {
+ type Map = Map<'tcx>;
+
+ fn visit_expr(&mut self, expr: &'tcx Expr<'tcx>) {
+ if_chain! {
+ if let Some(mutex) = is_mutex_lock_call(self.cx, expr);
+ then {
+ self.found_mutex = Some(mutex);
+ self.mutex_lock_called = true;
+ return;
+ }
+ }
+ visit::walk_expr(self, expr);
+ }
+
+ fn nested_visit_map(&mut self) -> NestedVisitorMap {
+ NestedVisitorMap::None
+ }
+}
+
+impl<'tcx, 'l> ArmVisitor<'tcx, 'l> {
+ fn same_mutex(&self, cx: &LateContext<'_, '_>, op_mutex: &Expr<'_>) -> bool {
+ if let Some(arm_mutex) = self.found_mutex {
+ SpanlessEq::new(cx).eq_expr(op_mutex, arm_mutex)
+ } else {
+ false
+ }
+ }
+}
+
+fn is_mutex_lock_call<'a>(cx: &LateContext<'a, '_>, expr: &'a Expr<'_>) -> Option<&'a Expr<'a>> {
+ if_chain! {
+ if let ExprKind::MethodCall(path, _span, args) = &expr.kind;
+ if path.ident.to_string() == "lock";
+ let ty = cx.tables.expr_ty(&args[0]);
+ if is_type_diagnostic_item(cx, ty, sym!(mutex_type));
+ then {
+ Some(&args[0])
+ } else {
+ None
+ }
+ }
+}
diff --git a/src/tools/clippy/clippy_lints/src/if_let_some_result.rs b/src/tools/clippy/clippy_lints/src/if_let_some_result.rs
new file mode 100644
index 00000000000..9b13f760924
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/if_let_some_result.rs
@@ -0,0 +1,72 @@
+use crate::utils::{is_type_diagnostic_item, method_chain_args, snippet_with_applicability, span_lint_and_sugg};
+use if_chain::if_chain;
+use rustc_errors::Applicability;
+use rustc_hir::{Expr, ExprKind, MatchSource, PatKind, QPath};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+
+declare_clippy_lint! {
+ /// **What it does:*** Checks for unnecessary `ok()` in if let.
+ ///
+ /// **Why is this bad?** Calling `ok()` in if let is unnecessary, instead match
+ /// on `Ok(pat)`
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```ignore
+ /// for i in iter {
+ /// if let Some(value) = i.parse().ok() {
+ /// vec.push(value)
+ /// }
+ /// }
+ /// ```
+ /// Could be written:
+ ///
+ /// ```ignore
+ /// for i in iter {
+ /// if let Ok(value) = i.parse() {
+ /// vec.push(value)
+ /// }
+ /// }
+ /// ```
+ pub IF_LET_SOME_RESULT,
+ style,
+ "usage of `ok()` in `if let Some(pat)` statements is unnecessary, match on `Ok(pat)` instead"
+}
+
+declare_lint_pass!(OkIfLet => [IF_LET_SOME_RESULT]);
+
+impl<'a, 'tcx> LateLintPass<'a, 'tcx> for OkIfLet {
+ fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr<'_>) {
+ if_chain! { //begin checking variables
+ if let ExprKind::Match(ref op, ref body, source) = expr.kind; //test if expr is a match
+ if let MatchSource::IfLetDesugar { .. } = source; //test if it is an If Let
+ if let ExprKind::MethodCall(_, ok_span, ref result_types) = op.kind; //check is expr.ok() has type Result.ok()
+ if let PatKind::TupleStruct(QPath::Resolved(_, ref x), ref y, _) = body[0].pat.kind; //get operation
+ if method_chain_args(op, &["ok"]).is_some(); //test to see if using ok() methoduse std::marker::Sized;
+ if is_type_diagnostic_item(cx, cx.tables.expr_ty(&result_types[0]), sym!(result_type));
+ if rustc_hir_pretty::to_string(rustc_hir_pretty::NO_ANN, |s| s.print_path(x, false)) == "Some";
+
+ then {
+ let mut applicability = Applicability::MachineApplicable;
+ let some_expr_string = snippet_with_applicability(cx, y[0].span, "", &mut applicability);
+ let trimmed_ok = snippet_with_applicability(cx, op.span.until(ok_span), "", &mut applicability);
+ let sugg = format!(
+ "if let Ok({}) = {}",
+ some_expr_string,
+ trimmed_ok.trim().trim_end_matches('.'),
+ );
+ span_lint_and_sugg(
+ cx,
+ IF_LET_SOME_RESULT,
+ expr.span.with_hi(op.span.hi()),
+ "Matching on `Some` with `ok()` is redundant",
+ &format!("Consider matching on `Ok({})` and removing the call to `ok` instead", some_expr_string),
+ sugg,
+ applicability,
+ );
+ }
+ }
+ }
+}
diff --git a/src/tools/clippy/clippy_lints/src/if_not_else.rs b/src/tools/clippy/clippy_lints/src/if_not_else.rs
new file mode 100644
index 00000000000..c11e291f98e
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/if_not_else.rs
@@ -0,0 +1,83 @@
+//! lint on if branches that could be swapped so no `!` operation is necessary
+//! on the condition
+
+use rustc_ast::ast::{BinOpKind, Expr, ExprKind, UnOp};
+use rustc_lint::{EarlyContext, EarlyLintPass, LintContext};
+use rustc_middle::lint::in_external_macro;
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+
+use crate::utils::span_lint_and_help;
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for usage of `!` or `!=` in an if condition with an
+ /// else branch.
+ ///
+ /// **Why is this bad?** Negations reduce the readability of statements.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```rust
+ /// # let v: Vec = vec![];
+ /// # fn a() {}
+ /// # fn b() {}
+ /// if !v.is_empty() {
+ /// a()
+ /// } else {
+ /// b()
+ /// }
+ /// ```
+ ///
+ /// Could be written:
+ ///
+ /// ```rust
+ /// # let v: Vec = vec![];
+ /// # fn a() {}
+ /// # fn b() {}
+ /// if v.is_empty() {
+ /// b()
+ /// } else {
+ /// a()
+ /// }
+ /// ```
+ pub IF_NOT_ELSE,
+ pedantic,
+ "`if` branches that could be swapped so no negation operation is necessary on the condition"
+}
+
+declare_lint_pass!(IfNotElse => [IF_NOT_ELSE]);
+
+impl EarlyLintPass for IfNotElse {
+ fn check_expr(&mut self, cx: &EarlyContext<'_>, item: &Expr) {
+ if in_external_macro(cx.sess(), item.span) {
+ return;
+ }
+ if let ExprKind::If(ref cond, _, Some(ref els)) = item.kind {
+ if let ExprKind::Block(..) = els.kind {
+ match cond.kind {
+ ExprKind::Unary(UnOp::Not, _) => {
+ span_lint_and_help(
+ cx,
+ IF_NOT_ELSE,
+ item.span,
+ "Unnecessary boolean `not` operation",
+ None,
+ "remove the `!` and swap the blocks of the `if`/`else`",
+ );
+ },
+ ExprKind::Binary(ref kind, _, _) if kind.node == BinOpKind::Ne => {
+ span_lint_and_help(
+ cx,
+ IF_NOT_ELSE,
+ item.span,
+ "Unnecessary `!=` operation",
+ None,
+ "change to `==` and swap the blocks of the `if`/`else`",
+ );
+ },
+ _ => (),
+ }
+ }
+ }
+ }
+}
diff --git a/src/tools/clippy/clippy_lints/src/implicit_return.rs b/src/tools/clippy/clippy_lints/src/implicit_return.rs
new file mode 100644
index 00000000000..c4308fd26a3
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/implicit_return.rs
@@ -0,0 +1,150 @@
+use crate::utils::{
+ fn_has_unsatisfiable_preds, match_def_path,
+ paths::{BEGIN_PANIC, BEGIN_PANIC_FMT},
+ snippet_opt, span_lint_and_then,
+};
+use if_chain::if_chain;
+use rustc_errors::Applicability;
+use rustc_hir::intravisit::FnKind;
+use rustc_hir::{Body, Expr, ExprKind, FnDecl, HirId, MatchSource, StmtKind};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::source_map::Span;
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for missing return statements at the end of a block.
+ ///
+ /// **Why is this bad?** Actually omitting the return keyword is idiomatic Rust code. Programmers
+ /// coming from other languages might prefer the expressiveness of `return`. It's possible to miss
+ /// the last returning statement because the only difference is a missing `;`. Especially in bigger
+ /// code with multiple return paths having a `return` keyword makes it easier to find the
+ /// corresponding statements.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```rust
+ /// fn foo(x: usize) -> usize {
+ /// x
+ /// }
+ /// ```
+ /// add return
+ /// ```rust
+ /// fn foo(x: usize) -> usize {
+ /// return x;
+ /// }
+ /// ```
+ pub IMPLICIT_RETURN,
+ restriction,
+ "use a return statement like `return expr` instead of an expression"
+}
+
+declare_lint_pass!(ImplicitReturn => [IMPLICIT_RETURN]);
+
+static LINT_BREAK: &str = "change `break` to `return` as shown";
+static LINT_RETURN: &str = "add `return` as shown";
+
+fn lint(cx: &LateContext<'_, '_>, outer_span: Span, inner_span: Span, msg: &str) {
+ let outer_span = outer_span.source_callsite();
+ let inner_span = inner_span.source_callsite();
+
+ span_lint_and_then(cx, IMPLICIT_RETURN, outer_span, "missing `return` statement", |diag| {
+ if let Some(snippet) = snippet_opt(cx, inner_span) {
+ diag.span_suggestion(
+ outer_span,
+ msg,
+ format!("return {}", snippet),
+ Applicability::MachineApplicable,
+ );
+ }
+ });
+}
+
+fn expr_match(cx: &LateContext<'_, '_>, expr: &Expr<'_>) {
+ match expr.kind {
+ // loops could be using `break` instead of `return`
+ ExprKind::Block(block, ..) | ExprKind::Loop(block, ..) => {
+ if let Some(expr) = &block.expr {
+ expr_match(cx, expr);
+ }
+ // only needed in the case of `break` with `;` at the end
+ else if let Some(stmt) = block.stmts.last() {
+ if_chain! {
+ if let StmtKind::Semi(expr, ..) = &stmt.kind;
+ // make sure it's a break, otherwise we want to skip
+ if let ExprKind::Break(.., break_expr) = &expr.kind;
+ if let Some(break_expr) = break_expr;
+ then {
+ lint(cx, expr.span, break_expr.span, LINT_BREAK);
+ }
+ }
+ }
+ },
+ // use `return` instead of `break`
+ ExprKind::Break(.., break_expr) => {
+ if let Some(break_expr) = break_expr {
+ lint(cx, expr.span, break_expr.span, LINT_BREAK);
+ }
+ },
+ ExprKind::Match(.., arms, source) => {
+ let check_all_arms = match source {
+ MatchSource::IfLetDesugar {
+ contains_else_clause: has_else,
+ } => has_else,
+ _ => true,
+ };
+
+ if check_all_arms {
+ for arm in arms {
+ expr_match(cx, &arm.body);
+ }
+ } else {
+ expr_match(cx, &arms.first().expect("`if let` doesn't have a single arm").body);
+ }
+ },
+ // skip if it already has a return statement
+ ExprKind::Ret(..) => (),
+ // make sure it's not a call that panics
+ ExprKind::Call(expr, ..) => {
+ if_chain! {
+ if let ExprKind::Path(qpath) = &expr.kind;
+ if let Some(path_def_id) = cx.tables.qpath_res(qpath, expr.hir_id).opt_def_id();
+ if match_def_path(cx, path_def_id, &BEGIN_PANIC) ||
+ match_def_path(cx, path_def_id, &BEGIN_PANIC_FMT);
+ then { }
+ else {
+ lint(cx, expr.span, expr.span, LINT_RETURN)
+ }
+ }
+ },
+ // everything else is missing `return`
+ _ => lint(cx, expr.span, expr.span, LINT_RETURN),
+ }
+}
+
+impl<'a, 'tcx> LateLintPass<'a, 'tcx> for ImplicitReturn {
+ fn check_fn(
+ &mut self,
+ cx: &LateContext<'a, 'tcx>,
+ _: FnKind<'tcx>,
+ _: &'tcx FnDecl<'_>,
+ body: &'tcx Body<'_>,
+ span: Span,
+ _: HirId,
+ ) {
+ let def_id = cx.tcx.hir().body_owner_def_id(body.id());
+
+ // Building MIR for `fn`s with unsatisfiable preds results in ICE.
+ if fn_has_unsatisfiable_preds(cx, def_id.to_def_id()) {
+ return;
+ }
+
+ let mir = cx.tcx.optimized_mir(def_id.to_def_id());
+
+ // checking return type through MIR, HIR is not able to determine inferred closure return types
+ // make sure it's not a macro
+ if !mir.return_ty().is_unit() && !span.from_expansion() {
+ expr_match(cx, &body.value);
+ }
+ }
+}
diff --git a/src/tools/clippy/clippy_lints/src/implicit_saturating_sub.rs b/src/tools/clippy/clippy_lints/src/implicit_saturating_sub.rs
new file mode 100644
index 00000000000..155a93de4fa
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/implicit_saturating_sub.rs
@@ -0,0 +1,173 @@
+use crate::utils::{higher, in_macro, match_qpath, span_lint_and_sugg, SpanlessEq};
+use if_chain::if_chain;
+use rustc_ast::ast::LitKind;
+use rustc_errors::Applicability;
+use rustc_hir::{BinOpKind, Expr, ExprKind, QPath, StmtKind};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for implicit saturating subtraction.
+ ///
+ /// **Why is this bad?** Simplicity and readability. Instead we can easily use an builtin function.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ ///
+ /// ```rust
+ /// let end: u32 = 10;
+ /// let start: u32 = 5;
+ ///
+ /// let mut i: u32 = end - start;
+ ///
+ /// // Bad
+ /// if i != 0 {
+ /// i -= 1;
+ /// }
+ /// ```
+ /// Use instead:
+ /// ```rust
+ /// let end: u32 = 10;
+ /// let start: u32 = 5;
+ ///
+ /// let mut i: u32 = end - start;
+ ///
+ /// // Good
+ /// i = i.saturating_sub(1);
+ /// ```
+ pub IMPLICIT_SATURATING_SUB,
+ pedantic,
+ "Perform saturating subtraction instead of implicitly checking lower bound of data type"
+}
+
+declare_lint_pass!(ImplicitSaturatingSub => [IMPLICIT_SATURATING_SUB]);
+
+impl<'a, 'tcx> LateLintPass<'a, 'tcx> for ImplicitSaturatingSub {
+ fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr<'tcx>) {
+ if in_macro(expr.span) {
+ return;
+ }
+ if_chain! {
+ if let Some((ref cond, ref then, None)) = higher::if_block(&expr);
+
+ // Check if the conditional expression is a binary operation
+ if let ExprKind::Binary(ref cond_op, ref cond_left, ref cond_right) = cond.kind;
+
+ // Ensure that the binary operator is >, != and <
+ if BinOpKind::Ne == cond_op.node || BinOpKind::Gt == cond_op.node || BinOpKind::Lt == cond_op.node;
+
+ // Check if the true condition block has only one statement
+ if let ExprKind::Block(ref block, _) = then.kind;
+ if block.stmts.len() == 1 && block.expr.is_none();
+
+ // Check if assign operation is done
+ if let StmtKind::Semi(ref e) = block.stmts[0].kind;
+ if let Some(target) = subtracts_one(cx, e);
+
+ // Extracting out the variable name
+ if let ExprKind::Path(ref assign_path) = target.kind;
+ if let QPath::Resolved(_, ref ares_path) = assign_path;
+
+ then {
+ // Handle symmetric conditions in the if statement
+ let (cond_var, cond_num_val) = if SpanlessEq::new(cx).eq_expr(cond_left, target) {
+ if BinOpKind::Gt == cond_op.node || BinOpKind::Ne == cond_op.node {
+ (cond_left, cond_right)
+ } else {
+ return;
+ }
+ } else if SpanlessEq::new(cx).eq_expr(cond_right, target) {
+ if BinOpKind::Lt == cond_op.node || BinOpKind::Ne == cond_op.node {
+ (cond_right, cond_left)
+ } else {
+ return;
+ }
+ } else {
+ return;
+ };
+
+ // Check if the variable in the condition statement is an integer
+ if !cx.tables.expr_ty(cond_var).is_integral() {
+ return;
+ }
+
+ // Get the variable name
+ let var_name = ares_path.segments[0].ident.name.as_str();
+ const INT_TYPES: [&str; 5] = ["i8", "i16", "i32", "i64", "i128"];
+
+ match cond_num_val.kind {
+ ExprKind::Lit(ref cond_lit) => {
+ // Check if the constant is zero
+ if let LitKind::Int(0, _) = cond_lit.node {
+ if cx.tables.expr_ty(cond_left).is_signed() {
+ } else {
+ print_lint_and_sugg(cx, &var_name, expr);
+ };
+ }
+ },
+ ExprKind::Path(ref cond_num_path) => {
+ if INT_TYPES.iter().any(|int_type| match_qpath(cond_num_path, &[int_type, "MIN"])) {
+ print_lint_and_sugg(cx, &var_name, expr);
+ };
+ },
+ ExprKind::Call(ref func, _) => {
+ if let ExprKind::Path(ref cond_num_path) = func.kind {
+ if INT_TYPES.iter().any(|int_type| match_qpath(cond_num_path, &[int_type, "min_value"])) {
+ print_lint_and_sugg(cx, &var_name, expr);
+ }
+ };
+ },
+ _ => (),
+ }
+ }
+ }
+ }
+}
+
+fn subtracts_one<'a>(cx: &LateContext<'_, '_>, expr: &Expr<'a>) -> Option<&'a Expr<'a>> {
+ match expr.kind {
+ ExprKind::AssignOp(ref op1, ref target, ref value) => {
+ if_chain! {
+ if BinOpKind::Sub == op1.node;
+ // Check if literal being subtracted is one
+ if let ExprKind::Lit(ref lit1) = value.kind;
+ if let LitKind::Int(1, _) = lit1.node;
+ then {
+ Some(target)
+ } else {
+ None
+ }
+ }
+ },
+ ExprKind::Assign(ref target, ref value, _) => {
+ if_chain! {
+ if let ExprKind::Binary(ref op1, ref left1, ref right1) = value.kind;
+ if BinOpKind::Sub == op1.node;
+
+ if SpanlessEq::new(cx).eq_expr(left1, target);
+
+ if let ExprKind::Lit(ref lit1) = right1.kind;
+ if let LitKind::Int(1, _) = lit1.node;
+ then {
+ Some(target)
+ } else {
+ None
+ }
+ }
+ },
+ _ => None,
+ }
+}
+
+fn print_lint_and_sugg(cx: &LateContext<'_, '_>, var_name: &str, expr: &Expr<'_>) {
+ span_lint_and_sugg(
+ cx,
+ IMPLICIT_SATURATING_SUB,
+ expr.span,
+ "Implicitly performing saturating subtraction",
+ "try",
+ format!("{} = {}.saturating_sub({});", var_name, var_name, 1.to_string()),
+ Applicability::MachineApplicable,
+ );
+}
diff --git a/src/tools/clippy/clippy_lints/src/indexing_slicing.rs b/src/tools/clippy/clippy_lints/src/indexing_slicing.rs
new file mode 100644
index 00000000000..c5808dd540b
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/indexing_slicing.rs
@@ -0,0 +1,193 @@
+//! lint on indexing and slicing operations
+
+use crate::consts::{constant, Constant};
+use crate::utils::{higher, span_lint, span_lint_and_help};
+use rustc_ast::ast::RangeLimits;
+use rustc_hir::{Expr, ExprKind};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty;
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for out of bounds array indexing with a constant
+ /// index.
+ ///
+ /// **Why is this bad?** This will always panic at runtime.
+ ///
+ /// **Known problems:** Hopefully none.
+ ///
+ /// **Example:**
+ /// ```no_run
+ /// # #![allow(const_err)]
+ /// let x = [1, 2, 3, 4];
+ ///
+ /// // Bad
+ /// x[9];
+ /// &x[2..9];
+ ///
+ /// // Good
+ /// x[0];
+ /// x[3];
+ /// ```
+ pub OUT_OF_BOUNDS_INDEXING,
+ correctness,
+ "out of bounds constant indexing"
+}
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for usage of indexing or slicing. Arrays are special cases, this lint
+ /// does report on arrays if we can tell that slicing operations are in bounds and does not
+ /// lint on constant `usize` indexing on arrays because that is handled by rustc's `const_err` lint.
+ ///
+ /// **Why is this bad?** Indexing and slicing can panic at runtime and there are
+ /// safe alternatives.
+ ///
+ /// **Known problems:** Hopefully none.
+ ///
+ /// **Example:**
+ /// ```rust,no_run
+ /// // Vector
+ /// let x = vec![0; 5];
+ ///
+ /// // Bad
+ /// x[2];
+ /// &x[2..100];
+ /// &x[2..];
+ /// &x[..100];
+ ///
+ /// // Good
+ /// x.get(2);
+ /// x.get(2..100);
+ /// x.get(2..);
+ /// x.get(..100);
+ ///
+ /// // Array
+ /// let y = [0, 1, 2, 3];
+ ///
+ /// // Bad
+ /// &y[10..100];
+ /// &y[10..];
+ /// &y[..100];
+ ///
+ /// // Good
+ /// &y[2..];
+ /// &y[..2];
+ /// &y[0..3];
+ /// y.get(10);
+ /// y.get(10..100);
+ /// y.get(10..);
+ /// y.get(..100);
+ /// ```
+ pub INDEXING_SLICING,
+ restriction,
+ "indexing/slicing usage"
+}
+
+declare_lint_pass!(IndexingSlicing => [INDEXING_SLICING, OUT_OF_BOUNDS_INDEXING]);
+
+impl<'a, 'tcx> LateLintPass<'a, 'tcx> for IndexingSlicing {
+ fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr<'_>) {
+ if let ExprKind::Index(ref array, ref index) = &expr.kind {
+ let ty = cx.tables.expr_ty(array);
+ if let Some(range) = higher::range(cx, index) {
+ // Ranged indexes, i.e., &x[n..m], &x[n..], &x[..n] and &x[..]
+ if let ty::Array(_, s) = ty.kind {
+ let size: u128 = if let Some(size) = s.try_eval_usize(cx.tcx, cx.param_env) {
+ size.into()
+ } else {
+ return;
+ };
+
+ let const_range = to_const_range(cx, range, size);
+
+ if let (Some(start), _) = const_range {
+ if start > size {
+ span_lint(
+ cx,
+ OUT_OF_BOUNDS_INDEXING,
+ range.start.map_or(expr.span, |start| start.span),
+ "range is out of bounds",
+ );
+ return;
+ }
+ }
+
+ if let (_, Some(end)) = const_range {
+ if end > size {
+ span_lint(
+ cx,
+ OUT_OF_BOUNDS_INDEXING,
+ range.end.map_or(expr.span, |end| end.span),
+ "range is out of bounds",
+ );
+ return;
+ }
+ }
+
+ if let (Some(_), Some(_)) = const_range {
+ // early return because both start and end are constants
+ // and we have proven above that they are in bounds
+ return;
+ }
+ }
+
+ let help_msg = match (range.start, range.end) {
+ (None, Some(_)) => "Consider using `.get(..n)`or `.get_mut(..n)` instead",
+ (Some(_), None) => "Consider using `.get(n..)` or .get_mut(n..)` instead",
+ (Some(_), Some(_)) => "Consider using `.get(n..m)` or `.get_mut(n..m)` instead",
+ (None, None) => return, // [..] is ok.
+ };
+
+ span_lint_and_help(cx, INDEXING_SLICING, expr.span, "slicing may panic.", None, help_msg);
+ } else {
+ // Catchall non-range index, i.e., [n] or [n << m]
+ if let ty::Array(..) = ty.kind {
+ // Index is a constant uint.
+ if let Some(..) = constant(cx, cx.tables, index) {
+ // Let rustc's `const_err` lint handle constant `usize` indexing on arrays.
+ return;
+ }
+ }
+
+ span_lint_and_help(
+ cx,
+ INDEXING_SLICING,
+ expr.span,
+ "indexing may panic.",
+ None,
+ "Consider using `.get(n)` or `.get_mut(n)` instead",
+ );
+ }
+ }
+ }
+}
+
+/// Returns a tuple of options with the start and end (exclusive) values of
+/// the range. If the start or end is not constant, None is returned.
+fn to_const_range<'a, 'tcx>(
+ cx: &LateContext<'a, 'tcx>,
+ range: higher::Range<'_>,
+ array_size: u128,
+) -> (Option, Option) {
+ let s = range.start.map(|expr| constant(cx, cx.tables, expr).map(|(c, _)| c));
+ let start = match s {
+ Some(Some(Constant::Int(x))) => Some(x),
+ Some(_) => None,
+ None => Some(0),
+ };
+
+ let e = range.end.map(|expr| constant(cx, cx.tables, expr).map(|(c, _)| c));
+ let end = match e {
+ Some(Some(Constant::Int(x))) => {
+ if range.limits == RangeLimits::Closed {
+ Some(x + 1)
+ } else {
+ Some(x)
+ }
+ },
+ Some(_) => None,
+ None => Some(array_size),
+ };
+
+ (start, end)
+}
diff --git a/src/tools/clippy/clippy_lints/src/infinite_iter.rs b/src/tools/clippy/clippy_lints/src/infinite_iter.rs
new file mode 100644
index 00000000000..cd989c0ea6f
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/infinite_iter.rs
@@ -0,0 +1,253 @@
+use rustc_hir::{BorrowKind, Expr, ExprKind};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+
+use crate::utils::{get_trait_def_id, higher, implements_trait, match_qpath, match_type, paths, span_lint};
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for iteration that is guaranteed to be infinite.
+ ///
+ /// **Why is this bad?** While there may be places where this is acceptable
+ /// (e.g., in event streams), in most cases this is simply an error.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```no_run
+ /// use std::iter;
+ ///
+ /// iter::repeat(1_u8).collect::>();
+ /// ```
+ pub INFINITE_ITER,
+ correctness,
+ "infinite iteration"
+}
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for iteration that may be infinite.
+ ///
+ /// **Why is this bad?** While there may be places where this is acceptable
+ /// (e.g., in event streams), in most cases this is simply an error.
+ ///
+ /// **Known problems:** The code may have a condition to stop iteration, but
+ /// this lint is not clever enough to analyze it.
+ ///
+ /// **Example:**
+ /// ```rust
+ /// let infinite_iter = 0..;
+ /// [0..].iter().zip(infinite_iter.take_while(|x| *x > 5));
+ /// ```
+ pub MAYBE_INFINITE_ITER,
+ pedantic,
+ "possible infinite iteration"
+}
+
+declare_lint_pass!(InfiniteIter => [INFINITE_ITER, MAYBE_INFINITE_ITER]);
+
+impl<'a, 'tcx> LateLintPass<'a, 'tcx> for InfiniteIter {
+ fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr<'_>) {
+ let (lint, msg) = match complete_infinite_iter(cx, expr) {
+ Infinite => (INFINITE_ITER, "infinite iteration detected"),
+ MaybeInfinite => (MAYBE_INFINITE_ITER, "possible infinite iteration detected"),
+ Finite => {
+ return;
+ },
+ };
+ span_lint(cx, lint, expr.span, msg)
+ }
+}
+
+#[derive(Copy, Clone, Debug, PartialEq, Eq)]
+enum Finiteness {
+ Infinite,
+ MaybeInfinite,
+ Finite,
+}
+
+use self::Finiteness::{Finite, Infinite, MaybeInfinite};
+
+impl Finiteness {
+ #[must_use]
+ fn and(self, b: Self) -> Self {
+ match (self, b) {
+ (Finite, _) | (_, Finite) => Finite,
+ (MaybeInfinite, _) | (_, MaybeInfinite) => MaybeInfinite,
+ _ => Infinite,
+ }
+ }
+
+ #[must_use]
+ fn or(self, b: Self) -> Self {
+ match (self, b) {
+ (Infinite, _) | (_, Infinite) => Infinite,
+ (MaybeInfinite, _) | (_, MaybeInfinite) => MaybeInfinite,
+ _ => Finite,
+ }
+ }
+}
+
+impl From for Finiteness {
+ #[must_use]
+ fn from(b: bool) -> Self {
+ if b {
+ Infinite
+ } else {
+ Finite
+ }
+ }
+}
+
+/// This tells us what to look for to know if the iterator returned by
+/// this method is infinite
+#[derive(Copy, Clone)]
+enum Heuristic {
+ /// infinite no matter what
+ Always,
+ /// infinite if the first argument is
+ First,
+ /// infinite if any of the supplied arguments is
+ Any,
+ /// infinite if all of the supplied arguments are
+ All,
+}
+
+use self::Heuristic::{All, Always, Any, First};
+
+/// a slice of (method name, number of args, heuristic, bounds) tuples
+/// that will be used to determine whether the method in question
+/// returns an infinite or possibly infinite iterator. The finiteness
+/// is an upper bound, e.g., some methods can return a possibly
+/// infinite iterator at worst, e.g., `take_while`.
+const HEURISTICS: [(&str, usize, Heuristic, Finiteness); 19] = [
+ ("zip", 2, All, Infinite),
+ ("chain", 2, Any, Infinite),
+ ("cycle", 1, Always, Infinite),
+ ("map", 2, First, Infinite),
+ ("by_ref", 1, First, Infinite),
+ ("cloned", 1, First, Infinite),
+ ("rev", 1, First, Infinite),
+ ("inspect", 1, First, Infinite),
+ ("enumerate", 1, First, Infinite),
+ ("peekable", 2, First, Infinite),
+ ("fuse", 1, First, Infinite),
+ ("skip", 2, First, Infinite),
+ ("skip_while", 1, First, Infinite),
+ ("filter", 2, First, Infinite),
+ ("filter_map", 2, First, Infinite),
+ ("flat_map", 2, First, Infinite),
+ ("unzip", 1, First, Infinite),
+ ("take_while", 2, First, MaybeInfinite),
+ ("scan", 3, First, MaybeInfinite),
+];
+
+fn is_infinite(cx: &LateContext<'_, '_>, expr: &Expr<'_>) -> Finiteness {
+ match expr.kind {
+ ExprKind::MethodCall(ref method, _, ref args) => {
+ for &(name, len, heuristic, cap) in &HEURISTICS {
+ if method.ident.name.as_str() == name && args.len() == len {
+ return (match heuristic {
+ Always => Infinite,
+ First => is_infinite(cx, &args[0]),
+ Any => is_infinite(cx, &args[0]).or(is_infinite(cx, &args[1])),
+ All => is_infinite(cx, &args[0]).and(is_infinite(cx, &args[1])),
+ })
+ .and(cap);
+ }
+ }
+ if method.ident.name == sym!(flat_map) && args.len() == 2 {
+ if let ExprKind::Closure(_, _, body_id, _, _) = args[1].kind {
+ let body = cx.tcx.hir().body(body_id);
+ return is_infinite(cx, &body.value);
+ }
+ }
+ Finite
+ },
+ ExprKind::Block(ref block, _) => block.expr.as_ref().map_or(Finite, |e| is_infinite(cx, e)),
+ ExprKind::Box(ref e) | ExprKind::AddrOf(BorrowKind::Ref, _, ref e) => is_infinite(cx, e),
+ ExprKind::Call(ref path, _) => {
+ if let ExprKind::Path(ref qpath) = path.kind {
+ match_qpath(qpath, &paths::REPEAT).into()
+ } else {
+ Finite
+ }
+ },
+ ExprKind::Struct(..) => higher::range(cx, expr).map_or(false, |r| r.end.is_none()).into(),
+ _ => Finite,
+ }
+}
+
+/// the names and argument lengths of methods that *may* exhaust their
+/// iterators
+const POSSIBLY_COMPLETING_METHODS: [(&str, usize); 6] = [
+ ("find", 2),
+ ("rfind", 2),
+ ("position", 2),
+ ("rposition", 2),
+ ("any", 2),
+ ("all", 2),
+];
+
+/// the names and argument lengths of methods that *always* exhaust
+/// their iterators
+const COMPLETING_METHODS: [(&str, usize); 12] = [
+ ("count", 1),
+ ("fold", 3),
+ ("for_each", 2),
+ ("partition", 2),
+ ("max", 1),
+ ("max_by", 2),
+ ("max_by_key", 2),
+ ("min", 1),
+ ("min_by", 2),
+ ("min_by_key", 2),
+ ("sum", 1),
+ ("product", 1),
+];
+
+/// the paths of types that are known to be infinitely allocating
+const INFINITE_COLLECTORS: [&[&str]; 8] = [
+ &paths::BINARY_HEAP,
+ &paths::BTREEMAP,
+ &paths::BTREESET,
+ &paths::HASHMAP,
+ &paths::HASHSET,
+ &paths::LINKED_LIST,
+ &paths::VEC,
+ &paths::VEC_DEQUE,
+];
+
+fn complete_infinite_iter(cx: &LateContext<'_, '_>, expr: &Expr<'_>) -> Finiteness {
+ match expr.kind {
+ ExprKind::MethodCall(ref method, _, ref args) => {
+ for &(name, len) in &COMPLETING_METHODS {
+ if method.ident.name.as_str() == name && args.len() == len {
+ return is_infinite(cx, &args[0]);
+ }
+ }
+ for &(name, len) in &POSSIBLY_COMPLETING_METHODS {
+ if method.ident.name.as_str() == name && args.len() == len {
+ return MaybeInfinite.and(is_infinite(cx, &args[0]));
+ }
+ }
+ if method.ident.name == sym!(last) && args.len() == 1 {
+ let not_double_ended = get_trait_def_id(cx, &paths::DOUBLE_ENDED_ITERATOR)
+ .map_or(false, |id| !implements_trait(cx, cx.tables.expr_ty(&args[0]), id, &[]));
+ if not_double_ended {
+ return is_infinite(cx, &args[0]);
+ }
+ } else if method.ident.name == sym!(collect) {
+ let ty = cx.tables.expr_ty(expr);
+ if INFINITE_COLLECTORS.iter().any(|path| match_type(cx, ty, path)) {
+ return is_infinite(cx, &args[0]);
+ }
+ }
+ },
+ ExprKind::Binary(op, ref l, ref r) => {
+ if op.node.is_comparison() {
+ return is_infinite(cx, l).and(is_infinite(cx, r)).and(MaybeInfinite);
+ }
+ }, // TODO: ExprKind::Loop + Match
+ _ => (),
+ }
+ Finite
+}
diff --git a/src/tools/clippy/clippy_lints/src/inherent_impl.rs b/src/tools/clippy/clippy_lints/src/inherent_impl.rs
new file mode 100644
index 00000000000..7e2975ac2ae
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/inherent_impl.rs
@@ -0,0 +1,94 @@
+//! lint on inherent implementations
+
+use crate::utils::{in_macro, span_lint_and_then};
+use rustc_data_structures::fx::FxHashMap;
+use rustc_hir::{def_id, Crate, Item, ItemKind};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_tool_lint, impl_lint_pass};
+use rustc_span::Span;
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for multiple inherent implementations of a struct
+ ///
+ /// **Why is this bad?** Splitting the implementation of a type makes the code harder to navigate.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```rust
+ /// struct X;
+ /// impl X {
+ /// fn one() {}
+ /// }
+ /// impl X {
+ /// fn other() {}
+ /// }
+ /// ```
+ ///
+ /// Could be written:
+ ///
+ /// ```rust
+ /// struct X;
+ /// impl X {
+ /// fn one() {}
+ /// fn other() {}
+ /// }
+ /// ```
+ pub MULTIPLE_INHERENT_IMPL,
+ restriction,
+ "Multiple inherent impl that could be grouped"
+}
+
+#[allow(clippy::module_name_repetitions)]
+#[derive(Default)]
+pub struct MultipleInherentImpl {
+ impls: FxHashMap,
+}
+
+impl_lint_pass!(MultipleInherentImpl => [MULTIPLE_INHERENT_IMPL]);
+
+impl<'a, 'tcx> LateLintPass<'a, 'tcx> for MultipleInherentImpl {
+ fn check_item(&mut self, _: &LateContext<'a, 'tcx>, item: &'tcx Item<'_>) {
+ if let ItemKind::Impl {
+ ref generics,
+ of_trait: None,
+ ..
+ } = item.kind
+ {
+ // Remember for each inherent implementation encoutered its span and generics
+ // but filter out implementations that have generic params (type or lifetime)
+ // or are derived from a macro
+ if !in_macro(item.span) && generics.params.is_empty() {
+ self.impls.insert(item.hir_id.owner.to_def_id(), item.span);
+ }
+ }
+ }
+
+ fn check_crate_post(&mut self, cx: &LateContext<'a, 'tcx>, krate: &'tcx Crate<'_>) {
+ if let Some(item) = krate.items.values().next() {
+ // Retrieve all inherent implementations from the crate, grouped by type
+ for impls in cx
+ .tcx
+ .crate_inherent_impls(item.hir_id.owner.to_def_id().krate)
+ .inherent_impls
+ .values()
+ {
+ // Filter out implementations that have generic params (type or lifetime)
+ let mut impl_spans = impls.iter().filter_map(|impl_def| self.impls.get(impl_def));
+ if let Some(initial_span) = impl_spans.next() {
+ impl_spans.for_each(|additional_span| {
+ span_lint_and_then(
+ cx,
+ MULTIPLE_INHERENT_IMPL,
+ *additional_span,
+ "Multiple implementations of this structure",
+ |diag| {
+ diag.span_note(*initial_span, "First implementation here");
+ },
+ )
+ })
+ }
+ }
+ }
+ }
+}
diff --git a/src/tools/clippy/clippy_lints/src/inherent_to_string.rs b/src/tools/clippy/clippy_lints/src/inherent_to_string.rs
new file mode 100644
index 00000000000..289628a2752
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/inherent_to_string.rs
@@ -0,0 +1,156 @@
+use if_chain::if_chain;
+use rustc_hir::{ImplItem, ImplItemKind};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+
+use crate::utils::{
+ get_trait_def_id, implements_trait, is_type_diagnostic_item, paths, return_ty, span_lint_and_help,
+ trait_ref_of_method, walk_ptrs_ty,
+};
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for the definition of inherent methods with a signature of `to_string(&self) -> String`.
+ ///
+ /// **Why is this bad?** This method is also implicitly defined if a type implements the `Display` trait. As the functionality of `Display` is much more versatile, it should be preferred.
+ ///
+ /// **Known problems:** None
+ ///
+ /// ** Example:**
+ ///
+ /// ```rust
+ /// // Bad
+ /// pub struct A;
+ ///
+ /// impl A {
+ /// pub fn to_string(&self) -> String {
+ /// "I am A".to_string()
+ /// }
+ /// }
+ /// ```
+ ///
+ /// ```rust
+ /// // Good
+ /// use std::fmt;
+ ///
+ /// pub struct A;
+ ///
+ /// impl fmt::Display for A {
+ /// fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+ /// write!(f, "I am A")
+ /// }
+ /// }
+ /// ```
+ pub INHERENT_TO_STRING,
+ style,
+ "type implements inherent method `to_string()`, but should instead implement the `Display` trait"
+}
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for the definition of inherent methods with a signature of `to_string(&self) -> String` and if the type implementing this method also implements the `Display` trait.
+ ///
+ /// **Why is this bad?** This method is also implicitly defined if a type implements the `Display` trait. The less versatile inherent method will then shadow the implementation introduced by `Display`.
+ ///
+ /// **Known problems:** None
+ ///
+ /// ** Example:**
+ ///
+ /// ```rust
+ /// // Bad
+ /// use std::fmt;
+ ///
+ /// pub struct A;
+ ///
+ /// impl A {
+ /// pub fn to_string(&self) -> String {
+ /// "I am A".to_string()
+ /// }
+ /// }
+ ///
+ /// impl fmt::Display for A {
+ /// fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+ /// write!(f, "I am A, too")
+ /// }
+ /// }
+ /// ```
+ ///
+ /// ```rust
+ /// // Good
+ /// use std::fmt;
+ ///
+ /// pub struct A;
+ ///
+ /// impl fmt::Display for A {
+ /// fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+ /// write!(f, "I am A")
+ /// }
+ /// }
+ /// ```
+ pub INHERENT_TO_STRING_SHADOW_DISPLAY,
+ correctness,
+ "type implements inherent method `to_string()`, which gets shadowed by the implementation of the `Display` trait"
+}
+
+declare_lint_pass!(InherentToString => [INHERENT_TO_STRING, INHERENT_TO_STRING_SHADOW_DISPLAY]);
+
+impl<'a, 'tcx> LateLintPass<'a, 'tcx> for InherentToString {
+ fn check_impl_item(&mut self, cx: &LateContext<'a, 'tcx>, impl_item: &'tcx ImplItem<'_>) {
+ if impl_item.span.from_expansion() {
+ return;
+ }
+
+ if_chain! {
+ // Check if item is a method, called to_string and has a parameter 'self'
+ if let ImplItemKind::Fn(ref signature, _) = impl_item.kind;
+ if impl_item.ident.name.as_str() == "to_string";
+ let decl = &signature.decl;
+ if decl.implicit_self.has_implicit_self();
+ if decl.inputs.len() == 1;
+
+ // Check if return type is String
+ if is_type_diagnostic_item(cx, return_ty(cx, impl_item.hir_id), sym!(string_type));
+
+ // Filters instances of to_string which are required by a trait
+ if trait_ref_of_method(cx, impl_item.hir_id).is_none();
+
+ then {
+ show_lint(cx, impl_item);
+ }
+ }
+ }
+}
+
+fn show_lint(cx: &LateContext<'_, '_>, item: &ImplItem<'_>) {
+ let display_trait_id = get_trait_def_id(cx, &paths::DISPLAY_TRAIT).expect("Failed to get trait ID of `Display`!");
+
+ // Get the real type of 'self'
+ let fn_def_id = cx.tcx.hir().local_def_id(item.hir_id);
+ let self_type = cx.tcx.fn_sig(fn_def_id).input(0);
+ let self_type = walk_ptrs_ty(self_type.skip_binder());
+
+ // Emit either a warning or an error
+ if implements_trait(cx, self_type, display_trait_id, &[]) {
+ span_lint_and_help(
+ cx,
+ INHERENT_TO_STRING_SHADOW_DISPLAY,
+ item.span,
+ &format!(
+ "type `{}` implements inherent method `to_string(&self) -> String` which shadows the implementation of `Display`",
+ self_type.to_string()
+ ),
+ None,
+ &format!("remove the inherent method from type `{}`", self_type.to_string())
+ );
+ } else {
+ span_lint_and_help(
+ cx,
+ INHERENT_TO_STRING,
+ item.span,
+ &format!(
+ "implementation of inherent method `to_string(&self) -> String` for type `{}`",
+ self_type.to_string()
+ ),
+ None,
+ &format!("implement trait `Display` for type `{}` instead", self_type.to_string()),
+ );
+ }
+}
diff --git a/src/tools/clippy/clippy_lints/src/inline_fn_without_body.rs b/src/tools/clippy/clippy_lints/src/inline_fn_without_body.rs
new file mode 100644
index 00000000000..1ebfb3c8162
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/inline_fn_without_body.rs
@@ -0,0 +1,57 @@
+//! checks for `#[inline]` on trait methods without bodies
+
+use crate::utils::span_lint_and_then;
+use crate::utils::sugg::DiagnosticBuilderExt;
+use rustc_ast::ast::{Attribute, Name};
+use rustc_errors::Applicability;
+use rustc_hir::{TraitFn, TraitItem, TraitItemKind};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for `#[inline]` on trait methods without bodies
+ ///
+ /// **Why is this bad?** Only implementations of trait methods may be inlined.
+ /// The inline attribute is ignored for trait methods without bodies.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```rust
+ /// trait Animal {
+ /// #[inline]
+ /// fn name(&self) -> &'static str;
+ /// }
+ /// ```
+ pub INLINE_FN_WITHOUT_BODY,
+ correctness,
+ "use of `#[inline]` on trait methods without bodies"
+}
+
+declare_lint_pass!(InlineFnWithoutBody => [INLINE_FN_WITHOUT_BODY]);
+
+impl<'a, 'tcx> LateLintPass<'a, 'tcx> for InlineFnWithoutBody {
+ fn check_trait_item(&mut self, cx: &LateContext<'a, 'tcx>, item: &'tcx TraitItem<'_>) {
+ if let TraitItemKind::Fn(_, TraitFn::Required(_)) = item.kind {
+ check_attrs(cx, item.ident.name, &item.attrs);
+ }
+ }
+}
+
+fn check_attrs(cx: &LateContext<'_, '_>, name: Name, attrs: &[Attribute]) {
+ for attr in attrs {
+ if !attr.check_name(sym!(inline)) {
+ continue;
+ }
+
+ span_lint_and_then(
+ cx,
+ INLINE_FN_WITHOUT_BODY,
+ attr.span,
+ &format!("use of `#[inline]` on trait method `{}` which has no body", name),
+ |diag| {
+ diag.suggest_remove_item(cx, attr.span, "remove", Applicability::MachineApplicable);
+ },
+ );
+ }
+}
diff --git a/src/tools/clippy/clippy_lints/src/int_plus_one.rs b/src/tools/clippy/clippy_lints/src/int_plus_one.rs
new file mode 100644
index 00000000000..d5dbd495680
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/int_plus_one.rs
@@ -0,0 +1,172 @@
+//! lint on blocks unnecessarily using >= with a + 1 or - 1
+
+use rustc_ast::ast::{BinOpKind, Expr, ExprKind, Lit, LitKind};
+use rustc_errors::Applicability;
+use rustc_lint::{EarlyContext, EarlyLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+
+use crate::utils::{snippet_opt, span_lint_and_sugg};
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for usage of `x >= y + 1` or `x - 1 >= y` (and `<=`) in a block
+ ///
+ ///
+ /// **Why is this bad?** Readability -- better to use `> y` instead of `>= y + 1`.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```rust
+ /// # let x = 1;
+ /// # let y = 1;
+ /// if x >= y + 1 {}
+ /// ```
+ ///
+ /// Could be written as:
+ ///
+ /// ```rust
+ /// # let x = 1;
+ /// # let y = 1;
+ /// if x > y {}
+ /// ```
+ pub INT_PLUS_ONE,
+ complexity,
+ "instead of using `x >= y + 1`, use `x > y`"
+}
+
+declare_lint_pass!(IntPlusOne => [INT_PLUS_ONE]);
+
+// cases:
+// BinOpKind::Ge
+// x >= y + 1
+// x - 1 >= y
+//
+// BinOpKind::Le
+// x + 1 <= y
+// x <= y - 1
+
+#[derive(Copy, Clone)]
+enum Side {
+ LHS,
+ RHS,
+}
+
+impl IntPlusOne {
+ #[allow(clippy::cast_sign_loss)]
+ fn check_lit(lit: &Lit, target_value: i128) -> bool {
+ if let LitKind::Int(value, ..) = lit.kind {
+ return value == (target_value as u128);
+ }
+ false
+ }
+
+ fn check_binop(cx: &EarlyContext<'_>, binop: BinOpKind, lhs: &Expr, rhs: &Expr) -> Option {
+ match (binop, &lhs.kind, &rhs.kind) {
+ // case where `x - 1 >= ...` or `-1 + x >= ...`
+ (BinOpKind::Ge, &ExprKind::Binary(ref lhskind, ref lhslhs, ref lhsrhs), _) => {
+ match (lhskind.node, &lhslhs.kind, &lhsrhs.kind) {
+ // `-1 + x`
+ (BinOpKind::Add, &ExprKind::Lit(ref lit), _) if Self::check_lit(lit, -1) => {
+ Self::generate_recommendation(cx, binop, lhsrhs, rhs, Side::LHS)
+ },
+ // `x - 1`
+ (BinOpKind::Sub, _, &ExprKind::Lit(ref lit)) if Self::check_lit(lit, 1) => {
+ Self::generate_recommendation(cx, binop, lhslhs, rhs, Side::LHS)
+ },
+ _ => None,
+ }
+ },
+ // case where `... >= y + 1` or `... >= 1 + y`
+ (BinOpKind::Ge, _, &ExprKind::Binary(ref rhskind, ref rhslhs, ref rhsrhs))
+ if rhskind.node == BinOpKind::Add =>
+ {
+ match (&rhslhs.kind, &rhsrhs.kind) {
+ // `y + 1` and `1 + y`
+ (&ExprKind::Lit(ref lit), _) if Self::check_lit(lit, 1) => {
+ Self::generate_recommendation(cx, binop, rhsrhs, lhs, Side::RHS)
+ },
+ (_, &ExprKind::Lit(ref lit)) if Self::check_lit(lit, 1) => {
+ Self::generate_recommendation(cx, binop, rhslhs, lhs, Side::RHS)
+ },
+ _ => None,
+ }
+ }
+ // case where `x + 1 <= ...` or `1 + x <= ...`
+ (BinOpKind::Le, &ExprKind::Binary(ref lhskind, ref lhslhs, ref lhsrhs), _)
+ if lhskind.node == BinOpKind::Add =>
+ {
+ match (&lhslhs.kind, &lhsrhs.kind) {
+ // `1 + x` and `x + 1`
+ (&ExprKind::Lit(ref lit), _) if Self::check_lit(lit, 1) => {
+ Self::generate_recommendation(cx, binop, lhsrhs, rhs, Side::LHS)
+ },
+ (_, &ExprKind::Lit(ref lit)) if Self::check_lit(lit, 1) => {
+ Self::generate_recommendation(cx, binop, lhslhs, rhs, Side::LHS)
+ },
+ _ => None,
+ }
+ }
+ // case where `... >= y - 1` or `... >= -1 + y`
+ (BinOpKind::Le, _, &ExprKind::Binary(ref rhskind, ref rhslhs, ref rhsrhs)) => {
+ match (rhskind.node, &rhslhs.kind, &rhsrhs.kind) {
+ // `-1 + y`
+ (BinOpKind::Add, &ExprKind::Lit(ref lit), _) if Self::check_lit(lit, -1) => {
+ Self::generate_recommendation(cx, binop, rhsrhs, lhs, Side::RHS)
+ },
+ // `y - 1`
+ (BinOpKind::Sub, _, &ExprKind::Lit(ref lit)) if Self::check_lit(lit, 1) => {
+ Self::generate_recommendation(cx, binop, rhslhs, lhs, Side::RHS)
+ },
+ _ => None,
+ }
+ },
+ _ => None,
+ }
+ }
+
+ fn generate_recommendation(
+ cx: &EarlyContext<'_>,
+ binop: BinOpKind,
+ node: &Expr,
+ other_side: &Expr,
+ side: Side,
+ ) -> Option {
+ let binop_string = match binop {
+ BinOpKind::Ge => ">",
+ BinOpKind::Le => "<",
+ _ => return None,
+ };
+ if let Some(snippet) = snippet_opt(cx, node.span) {
+ if let Some(other_side_snippet) = snippet_opt(cx, other_side.span) {
+ let rec = match side {
+ Side::LHS => Some(format!("{} {} {}", snippet, binop_string, other_side_snippet)),
+ Side::RHS => Some(format!("{} {} {}", other_side_snippet, binop_string, snippet)),
+ };
+ return rec;
+ }
+ }
+ None
+ }
+
+ fn emit_warning(cx: &EarlyContext<'_>, block: &Expr, recommendation: String) {
+ span_lint_and_sugg(
+ cx,
+ INT_PLUS_ONE,
+ block.span,
+ "Unnecessary `>= y + 1` or `x - 1 >=`",
+ "change it to",
+ recommendation,
+ Applicability::MachineApplicable, // snippet
+ );
+ }
+}
+
+impl EarlyLintPass for IntPlusOne {
+ fn check_expr(&mut self, cx: &EarlyContext<'_>, item: &Expr) {
+ if let ExprKind::Binary(ref kind, ref lhs, ref rhs) = item.kind {
+ if let Some(ref rec) = Self::check_binop(cx, kind.node, lhs, rhs) {
+ Self::emit_warning(cx, item, rec.clone());
+ }
+ }
+ }
+}
diff --git a/src/tools/clippy/clippy_lints/src/integer_division.rs b/src/tools/clippy/clippy_lints/src/integer_division.rs
new file mode 100644
index 00000000000..fe34d33fe65
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/integer_division.rs
@@ -0,0 +1,56 @@
+use crate::utils::span_lint_and_help;
+use if_chain::if_chain;
+use rustc_hir as hir;
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for division of integers
+ ///
+ /// **Why is this bad?** When outside of some very specific algorithms,
+ /// integer division is very often a mistake because it discards the
+ /// remainder.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```rust
+ /// fn main() {
+ /// let x = 3 / 2;
+ /// println!("{}", x);
+ /// }
+ /// ```
+ pub INTEGER_DIVISION,
+ restriction,
+ "integer division may cause loss of precision"
+}
+
+declare_lint_pass!(IntegerDivision => [INTEGER_DIVISION]);
+
+impl<'a, 'tcx> LateLintPass<'a, 'tcx> for IntegerDivision {
+ fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx hir::Expr<'_>) {
+ if is_integer_division(cx, expr) {
+ span_lint_and_help(
+ cx,
+ INTEGER_DIVISION,
+ expr.span,
+ "integer division",
+ None,
+ "division of integers may cause loss of precision. consider using floats.",
+ );
+ }
+ }
+}
+
+fn is_integer_division<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, expr: &'tcx hir::Expr<'_>) -> bool {
+ if_chain! {
+ if let hir::ExprKind::Binary(binop, left, right) = &expr.kind;
+ if let hir::BinOpKind::Div = &binop.node;
+ then {
+ let (left_ty, right_ty) = (cx.tables.expr_ty(left), cx.tables.expr_ty(right));
+ return left_ty.is_integral() && right_ty.is_integral();
+ }
+ }
+
+ false
+}
diff --git a/src/tools/clippy/clippy_lints/src/items_after_statements.rs b/src/tools/clippy/clippy_lints/src/items_after_statements.rs
new file mode 100644
index 00000000000..e7062b7c16b
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/items_after_statements.rs
@@ -0,0 +1,71 @@
+//! lint when items are used after statements
+
+use crate::utils::span_lint;
+use rustc_ast::ast::{Block, ItemKind, StmtKind};
+use rustc_lint::{EarlyContext, EarlyLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for items declared after some statement in a block.
+ ///
+ /// **Why is this bad?** Items live for the entire scope they are declared
+ /// in. But statements are processed in order. This might cause confusion as
+ /// it's hard to figure out which item is meant in a statement.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```rust
+ /// fn foo() {
+ /// println!("cake");
+ /// }
+ ///
+ /// fn main() {
+ /// foo(); // prints "foo"
+ /// fn foo() {
+ /// println!("foo");
+ /// }
+ /// foo(); // prints "foo"
+ /// }
+ /// ```
+ pub ITEMS_AFTER_STATEMENTS,
+ pedantic,
+ "blocks where an item comes after a statement"
+}
+
+declare_lint_pass!(ItemsAfterStatements => [ITEMS_AFTER_STATEMENTS]);
+
+impl EarlyLintPass for ItemsAfterStatements {
+ fn check_block(&mut self, cx: &EarlyContext<'_>, item: &Block) {
+ if item.span.from_expansion() {
+ return;
+ }
+
+ // skip initial items
+ let stmts = item
+ .stmts
+ .iter()
+ .map(|stmt| &stmt.kind)
+ .skip_while(|s| matches!(**s, StmtKind::Item(..)));
+
+ // lint on all further items
+ for stmt in stmts {
+ if let StmtKind::Item(ref it) = *stmt {
+ if it.span.from_expansion() {
+ return;
+ }
+ if let ItemKind::MacroDef(..) = it.kind {
+ // do not lint `macro_rules`, but continue processing further statements
+ continue;
+ }
+ span_lint(
+ cx,
+ ITEMS_AFTER_STATEMENTS,
+ it.span,
+ "adding items after statements is confusing, since items exist from the \
+ start of the scope",
+ );
+ }
+ }
+ }
+}
diff --git a/src/tools/clippy/clippy_lints/src/large_const_arrays.rs b/src/tools/clippy/clippy_lints/src/large_const_arrays.rs
new file mode 100644
index 00000000000..c9e12fc535e
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/large_const_arrays.rs
@@ -0,0 +1,85 @@
+use crate::rustc_target::abi::LayoutOf;
+use crate::utils::span_lint_and_then;
+use if_chain::if_chain;
+use rustc_errors::Applicability;
+use rustc_hir::{Item, ItemKind};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::mir::interpret::ConstValue;
+use rustc_middle::ty::{self, ConstKind};
+use rustc_session::{declare_tool_lint, impl_lint_pass};
+use rustc_span::{BytePos, Pos, Span};
+use rustc_typeck::hir_ty_to_ty;
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for large `const` arrays that should
+ /// be defined as `static` instead.
+ ///
+ /// **Why is this bad?** Performance: const variables are inlined upon use.
+ /// Static items result in only one instance and has a fixed location in memory.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```rust,ignore
+ /// // Bad
+ /// pub const a = [0u32; 1_000_000];
+ ///
+ /// // Good
+ /// pub static a = [0u32; 1_000_000];
+ /// ```
+ pub LARGE_CONST_ARRAYS,
+ perf,
+ "large non-scalar const array may cause performance overhead"
+}
+
+pub struct LargeConstArrays {
+ maximum_allowed_size: u64,
+}
+
+impl LargeConstArrays {
+ #[must_use]
+ pub fn new(maximum_allowed_size: u64) -> Self {
+ Self { maximum_allowed_size }
+ }
+}
+
+impl_lint_pass!(LargeConstArrays => [LARGE_CONST_ARRAYS]);
+
+impl<'a, 'tcx> LateLintPass<'a, 'tcx> for LargeConstArrays {
+ fn check_item(&mut self, cx: &LateContext<'a, 'tcx>, item: &'tcx Item<'_>) {
+ if_chain! {
+ if !item.span.from_expansion();
+ if let ItemKind::Const(hir_ty, _) = &item.kind;
+ let ty = hir_ty_to_ty(cx.tcx, hir_ty);
+ if let ty::Array(element_type, cst) = ty.kind;
+ if let ConstKind::Value(val) = cst.val;
+ if let ConstValue::Scalar(element_count) = val;
+ if let Ok(element_count) = element_count.to_machine_usize(&cx.tcx);
+ if let Ok(element_size) = cx.layout_of(element_type).map(|l| l.size.bytes());
+ if self.maximum_allowed_size < element_count * element_size;
+
+ then {
+ let hi_pos = item.ident.span.lo() - BytePos::from_usize(1);
+ let sugg_span = Span::new(
+ hi_pos - BytePos::from_usize("const".len()),
+ hi_pos,
+ item.span.ctxt(),
+ );
+ span_lint_and_then(
+ cx,
+ LARGE_CONST_ARRAYS,
+ item.span,
+ "large array defined as const",
+ |diag| {
+ diag.span_suggestion(
+ sugg_span,
+ "make this a static item",
+ "static".to_string(),
+ Applicability::MachineApplicable,
+ );
+ }
+ );
+ }
+ }
+ }
+}
diff --git a/src/tools/clippy/clippy_lints/src/large_enum_variant.rs b/src/tools/clippy/clippy_lints/src/large_enum_variant.rs
new file mode 100644
index 00000000000..5bc3234e325
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/large_enum_variant.rs
@@ -0,0 +1,134 @@
+//! lint when there is a large size difference between variants on an enum
+
+use crate::utils::{snippet_opt, span_lint_and_then};
+use rustc_errors::Applicability;
+use rustc_hir::{Item, ItemKind, VariantData};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_tool_lint, impl_lint_pass};
+use rustc_target::abi::LayoutOf;
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for large size differences between variants on
+ /// `enum`s.
+ ///
+ /// **Why is this bad?** Enum size is bounded by the largest variant. Having a
+ /// large variant can penalize the memory layout of that enum.
+ ///
+ /// **Known problems:** This lint obviously cannot take the distribution of
+ /// variants in your running program into account. It is possible that the
+ /// smaller variants make up less than 1% of all instances, in which case
+ /// the overhead is negligible and the boxing is counter-productive. Always
+ /// measure the change this lint suggests.
+ ///
+ /// **Example:**
+ ///
+ /// ```rust
+ /// // Bad
+ /// enum Test {
+ /// A(i32),
+ /// B([i32; 8000]),
+ /// }
+ ///
+ /// // Possibly better
+ /// enum Test2 {
+ /// A(i32),
+ /// B(Box<[i32; 8000]>),
+ /// }
+ /// ```
+ pub LARGE_ENUM_VARIANT,
+ perf,
+ "large size difference between variants on an enum"
+}
+
+#[derive(Copy, Clone)]
+pub struct LargeEnumVariant {
+ maximum_size_difference_allowed: u64,
+}
+
+impl LargeEnumVariant {
+ #[must_use]
+ pub fn new(maximum_size_difference_allowed: u64) -> Self {
+ Self {
+ maximum_size_difference_allowed,
+ }
+ }
+}
+
+impl_lint_pass!(LargeEnumVariant => [LARGE_ENUM_VARIANT]);
+
+impl<'a, 'tcx> LateLintPass<'a, 'tcx> for LargeEnumVariant {
+ fn check_item(&mut self, cx: &LateContext<'_, '_>, item: &Item<'_>) {
+ let did = cx.tcx.hir().local_def_id(item.hir_id);
+ if let ItemKind::Enum(ref def, _) = item.kind {
+ let ty = cx.tcx.type_of(did);
+ let adt = ty.ty_adt_def().expect("already checked whether this is an enum");
+
+ let mut largest_variant: Option<(_, _)> = None;
+ let mut second_variant: Option<(_, _)> = None;
+
+ for (i, variant) in adt.variants.iter().enumerate() {
+ let size: u64 = variant
+ .fields
+ .iter()
+ .filter_map(|f| {
+ let ty = cx.tcx.type_of(f.did);
+ // don't count generics by filtering out everything
+ // that does not have a layout
+ cx.layout_of(ty).ok().map(|l| l.size.bytes())
+ })
+ .sum();
+
+ let grouped = (size, (i, variant));
+
+ if grouped.0 >= largest_variant.map_or(0, |x| x.0) {
+ second_variant = largest_variant;
+ largest_variant = Some(grouped);
+ }
+ }
+
+ if let (Some(largest), Some(second)) = (largest_variant, second_variant) {
+ let difference = largest.0 - second.0;
+
+ if difference > self.maximum_size_difference_allowed {
+ let (i, variant) = largest.1;
+
+ let help_text = "consider boxing the large fields to reduce the total size of the enum";
+ span_lint_and_then(
+ cx,
+ LARGE_ENUM_VARIANT,
+ def.variants[i].span,
+ "large size difference between variants",
+ |diag| {
+ diag.span_label(
+ def.variants[(largest.1).0].span,
+ &format!("this variant is {} bytes", largest.0),
+ );
+ diag.span_note(
+ def.variants[(second.1).0].span,
+ &format!("and the second-largest variant is {} bytes:", second.0),
+ );
+ if variant.fields.len() == 1 {
+ let span = match def.variants[i].data {
+ VariantData::Struct(ref fields, ..) | VariantData::Tuple(ref fields, ..) => {
+ fields[0].ty.span
+ },
+ VariantData::Unit(..) => unreachable!(),
+ };
+ if let Some(snip) = snippet_opt(cx, span) {
+ diag.span_suggestion(
+ span,
+ help_text,
+ format!("Box<{}>", snip),
+ Applicability::MaybeIncorrect,
+ );
+ return;
+ }
+ }
+ diag.span_help(def.variants[i].span, help_text);
+ },
+ );
+ }
+ }
+ }
+ }
+}
diff --git a/src/tools/clippy/clippy_lints/src/large_stack_arrays.rs b/src/tools/clippy/clippy_lints/src/large_stack_arrays.rs
new file mode 100644
index 00000000000..deb57db1678
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/large_stack_arrays.rs
@@ -0,0 +1,69 @@
+use rustc_hir::{Expr, ExprKind};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::mir::interpret::ConstValue;
+use rustc_middle::ty::{self, ConstKind};
+use rustc_session::{declare_tool_lint, impl_lint_pass};
+
+use if_chain::if_chain;
+
+use crate::rustc_target::abi::LayoutOf;
+use crate::utils::{snippet, span_lint_and_help};
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for local arrays that may be too large.
+ ///
+ /// **Why is this bad?** Large local arrays may cause stack overflow.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```rust,ignore
+ /// let a = [0u32; 1_000_000];
+ /// ```
+ pub LARGE_STACK_ARRAYS,
+ pedantic,
+ "allocating large arrays on stack may cause stack overflow"
+}
+
+pub struct LargeStackArrays {
+ maximum_allowed_size: u64,
+}
+
+impl LargeStackArrays {
+ #[must_use]
+ pub fn new(maximum_allowed_size: u64) -> Self {
+ Self { maximum_allowed_size }
+ }
+}
+
+impl_lint_pass!(LargeStackArrays => [LARGE_STACK_ARRAYS]);
+
+impl<'a, 'tcx> LateLintPass<'a, 'tcx> for LargeStackArrays {
+ fn check_expr(&mut self, cx: &LateContext<'_, '_>, expr: &Expr<'_>) {
+ if_chain! {
+ if let ExprKind::Repeat(_, _) = expr.kind;
+ if let ty::Array(element_type, cst) = cx.tables.expr_ty(expr).kind;
+ if let ConstKind::Value(val) = cst.val;
+ if let ConstValue::Scalar(element_count) = val;
+ if let Ok(element_count) = element_count.to_machine_usize(&cx.tcx);
+ if let Ok(element_size) = cx.layout_of(element_type).map(|l| l.size.bytes());
+ if self.maximum_allowed_size < element_count * element_size;
+ then {
+ span_lint_and_help(
+ cx,
+ LARGE_STACK_ARRAYS,
+ expr.span,
+ &format!(
+ "allocating a local array larger than {} bytes",
+ self.maximum_allowed_size
+ ),
+ None,
+ &format!(
+ "consider allocating on the heap with `vec!{}.into_boxed_slice()`",
+ snippet(cx, expr.span, "[...]")
+ ),
+ );
+ }
+ }
+ }
+}
diff --git a/src/tools/clippy/clippy_lints/src/len_zero.rs b/src/tools/clippy/clippy_lints/src/len_zero.rs
new file mode 100644
index 00000000000..1d86ca9696f
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/len_zero.rs
@@ -0,0 +1,304 @@
+use crate::utils::{get_item_name, snippet_with_applicability, span_lint, span_lint_and_sugg, walk_ptrs_ty};
+use rustc_ast::ast::{LitKind, Name};
+use rustc_data_structures::fx::FxHashSet;
+use rustc_errors::Applicability;
+use rustc_hir::def_id::DefId;
+use rustc_hir::{AssocItemKind, BinOpKind, Expr, ExprKind, ImplItemRef, Item, ItemKind, TraitItemRef};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty;
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::source_map::{Span, Spanned};
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for getting the length of something via `.len()`
+ /// just to compare to zero, and suggests using `.is_empty()` where applicable.
+ ///
+ /// **Why is this bad?** Some structures can answer `.is_empty()` much faster
+ /// than calculating their length. So it is good to get into the habit of using
+ /// `.is_empty()`, and having it is cheap.
+ /// Besides, it makes the intent clearer than a manual comparison in some contexts.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```ignore
+ /// if x.len() == 0 {
+ /// ..
+ /// }
+ /// if y.len() != 0 {
+ /// ..
+ /// }
+ /// ```
+ /// instead use
+ /// ```ignore
+ /// if x.is_empty() {
+ /// ..
+ /// }
+ /// if !y.is_empty() {
+ /// ..
+ /// }
+ /// ```
+ pub LEN_ZERO,
+ style,
+ "checking `.len() == 0` or `.len() > 0` (or similar) when `.is_empty()` could be used instead"
+}
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for items that implement `.len()` but not
+ /// `.is_empty()`.
+ ///
+ /// **Why is this bad?** It is good custom to have both methods, because for
+ /// some data structures, asking about the length will be a costly operation,
+ /// whereas `.is_empty()` can usually answer in constant time. Also it used to
+ /// lead to false positives on the [`len_zero`](#len_zero) lint – currently that
+ /// lint will ignore such entities.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```ignore
+ /// impl X {
+ /// pub fn len(&self) -> usize {
+ /// ..
+ /// }
+ /// }
+ /// ```
+ pub LEN_WITHOUT_IS_EMPTY,
+ style,
+ "traits or impls with a public `len` method but no corresponding `is_empty` method"
+}
+
+declare_lint_pass!(LenZero => [LEN_ZERO, LEN_WITHOUT_IS_EMPTY]);
+
+impl<'a, 'tcx> LateLintPass<'a, 'tcx> for LenZero {
+ fn check_item(&mut self, cx: &LateContext<'a, 'tcx>, item: &'tcx Item<'_>) {
+ if item.span.from_expansion() {
+ return;
+ }
+
+ match item.kind {
+ ItemKind::Trait(_, _, _, _, ref trait_items) => check_trait_items(cx, item, trait_items),
+ ItemKind::Impl {
+ of_trait: None,
+ items: ref impl_items,
+ ..
+ } => check_impl_items(cx, item, impl_items),
+ _ => (),
+ }
+ }
+
+ fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr<'_>) {
+ if expr.span.from_expansion() {
+ return;
+ }
+
+ if let ExprKind::Binary(Spanned { node: cmp, .. }, ref left, ref right) = expr.kind {
+ match cmp {
+ BinOpKind::Eq => {
+ check_cmp(cx, expr.span, left, right, "", 0); // len == 0
+ check_cmp(cx, expr.span, right, left, "", 0); // 0 == len
+ },
+ BinOpKind::Ne => {
+ check_cmp(cx, expr.span, left, right, "!", 0); // len != 0
+ check_cmp(cx, expr.span, right, left, "!", 0); // 0 != len
+ },
+ BinOpKind::Gt => {
+ check_cmp(cx, expr.span, left, right, "!", 0); // len > 0
+ check_cmp(cx, expr.span, right, left, "", 1); // 1 > len
+ },
+ BinOpKind::Lt => {
+ check_cmp(cx, expr.span, left, right, "", 1); // len < 1
+ check_cmp(cx, expr.span, right, left, "!", 0); // 0 < len
+ },
+ BinOpKind::Ge => check_cmp(cx, expr.span, left, right, "!", 1), // len >= 1
+ BinOpKind::Le => check_cmp(cx, expr.span, right, left, "!", 1), // 1 <= len
+ _ => (),
+ }
+ }
+ }
+}
+
+fn check_trait_items(cx: &LateContext<'_, '_>, visited_trait: &Item<'_>, trait_items: &[TraitItemRef]) {
+ fn is_named_self(cx: &LateContext<'_, '_>, item: &TraitItemRef, name: &str) -> bool {
+ item.ident.name.as_str() == name
+ && if let AssocItemKind::Fn { has_self } = item.kind {
+ has_self && {
+ let did = cx.tcx.hir().local_def_id(item.id.hir_id);
+ cx.tcx.fn_sig(did).inputs().skip_binder().len() == 1
+ }
+ } else {
+ false
+ }
+ }
+
+ // fill the set with current and super traits
+ fn fill_trait_set(traitt: DefId, set: &mut FxHashSet, cx: &LateContext<'_, '_>) {
+ if set.insert(traitt) {
+ for supertrait in rustc_trait_selection::traits::supertrait_def_ids(cx.tcx, traitt) {
+ fill_trait_set(supertrait, set, cx);
+ }
+ }
+ }
+
+ if cx.access_levels.is_exported(visited_trait.hir_id) && trait_items.iter().any(|i| is_named_self(cx, i, "len")) {
+ let mut current_and_super_traits = FxHashSet::default();
+ let visited_trait_def_id = cx.tcx.hir().local_def_id(visited_trait.hir_id);
+ fill_trait_set(visited_trait_def_id.to_def_id(), &mut current_and_super_traits, cx);
+
+ let is_empty_method_found = current_and_super_traits
+ .iter()
+ .flat_map(|&i| cx.tcx.associated_items(i).in_definition_order())
+ .any(|i| {
+ i.kind == ty::AssocKind::Fn
+ && i.fn_has_self_parameter
+ && i.ident.name == sym!(is_empty)
+ && cx.tcx.fn_sig(i.def_id).inputs().skip_binder().len() == 1
+ });
+
+ if !is_empty_method_found {
+ span_lint(
+ cx,
+ LEN_WITHOUT_IS_EMPTY,
+ visited_trait.span,
+ &format!(
+ "trait `{}` has a `len` method but no (possibly inherited) `is_empty` method",
+ visited_trait.ident.name
+ ),
+ );
+ }
+ }
+}
+
+fn check_impl_items(cx: &LateContext<'_, '_>, item: &Item<'_>, impl_items: &[ImplItemRef<'_>]) {
+ fn is_named_self(cx: &LateContext<'_, '_>, item: &ImplItemRef<'_>, name: &str) -> bool {
+ item.ident.name.as_str() == name
+ && if let AssocItemKind::Fn { has_self } = item.kind {
+ has_self && {
+ let did = cx.tcx.hir().local_def_id(item.id.hir_id);
+ cx.tcx.fn_sig(did).inputs().skip_binder().len() == 1
+ }
+ } else {
+ false
+ }
+ }
+
+ let is_empty = if let Some(is_empty) = impl_items.iter().find(|i| is_named_self(cx, i, "is_empty")) {
+ if cx.access_levels.is_exported(is_empty.id.hir_id) {
+ return;
+ } else {
+ "a private"
+ }
+ } else {
+ "no corresponding"
+ };
+
+ if let Some(i) = impl_items.iter().find(|i| is_named_self(cx, i, "len")) {
+ if cx.access_levels.is_exported(i.id.hir_id) {
+ let def_id = cx.tcx.hir().local_def_id(item.hir_id);
+ let ty = cx.tcx.type_of(def_id);
+
+ span_lint(
+ cx,
+ LEN_WITHOUT_IS_EMPTY,
+ item.span,
+ &format!(
+ "item `{}` has a public `len` method but {} `is_empty` method",
+ ty, is_empty
+ ),
+ );
+ }
+ }
+}
+
+fn check_cmp(cx: &LateContext<'_, '_>, span: Span, method: &Expr<'_>, lit: &Expr<'_>, op: &str, compare_to: u32) {
+ if let (&ExprKind::MethodCall(ref method_path, _, ref args), &ExprKind::Lit(ref lit)) = (&method.kind, &lit.kind) {
+ // check if we are in an is_empty() method
+ if let Some(name) = get_item_name(cx, method) {
+ if name.as_str() == "is_empty" {
+ return;
+ }
+ }
+
+ check_len(cx, span, method_path.ident.name, args, &lit.node, op, compare_to)
+ }
+}
+
+fn check_len(
+ cx: &LateContext<'_, '_>,
+ span: Span,
+ method_name: Name,
+ args: &[Expr<'_>],
+ lit: &LitKind,
+ op: &str,
+ compare_to: u32,
+) {
+ if let LitKind::Int(lit, _) = *lit {
+ // check if length is compared to the specified number
+ if lit != u128::from(compare_to) {
+ return;
+ }
+
+ if method_name.as_str() == "len" && args.len() == 1 && has_is_empty(cx, &args[0]) {
+ let mut applicability = Applicability::MachineApplicable;
+ span_lint_and_sugg(
+ cx,
+ LEN_ZERO,
+ span,
+ &format!("length comparison to {}", if compare_to == 0 { "zero" } else { "one" }),
+ &format!("using `{}is_empty` is clearer and more explicit", op),
+ format!(
+ "{}{}.is_empty()",
+ op,
+ snippet_with_applicability(cx, args[0].span, "_", &mut applicability)
+ ),
+ applicability,
+ );
+ }
+ }
+}
+
+/// Checks if this type has an `is_empty` method.
+fn has_is_empty(cx: &LateContext<'_, '_>, expr: &Expr<'_>) -> bool {
+ /// Gets an `AssocItem` and return true if it matches `is_empty(self)`.
+ fn is_is_empty(cx: &LateContext<'_, '_>, item: &ty::AssocItem) -> bool {
+ if let ty::AssocKind::Fn = item.kind {
+ if item.ident.name.as_str() == "is_empty" {
+ let sig = cx.tcx.fn_sig(item.def_id);
+ let ty = sig.skip_binder();
+ ty.inputs().len() == 1
+ } else {
+ false
+ }
+ } else {
+ false
+ }
+ }
+
+ /// Checks the inherent impl's items for an `is_empty(self)` method.
+ fn has_is_empty_impl(cx: &LateContext<'_, '_>, id: DefId) -> bool {
+ cx.tcx.inherent_impls(id).iter().any(|imp| {
+ cx.tcx
+ .associated_items(*imp)
+ .in_definition_order()
+ .any(|item| is_is_empty(cx, &item))
+ })
+ }
+
+ let ty = &walk_ptrs_ty(cx.tables.expr_ty(expr));
+ match ty.kind {
+ ty::Dynamic(ref tt, ..) => {
+ if let Some(principal) = tt.principal() {
+ cx.tcx
+ .associated_items(principal.def_id())
+ .in_definition_order()
+ .any(|item| is_is_empty(cx, &item))
+ } else {
+ false
+ }
+ },
+ ty::Projection(ref proj) => has_is_empty_impl(cx, proj.item_def_id),
+ ty::Adt(id, _) => has_is_empty_impl(cx, id.did),
+ ty::Array(..) | ty::Slice(..) | ty::Str => true,
+ _ => false,
+ }
+}
diff --git a/src/tools/clippy/clippy_lints/src/let_if_seq.rs b/src/tools/clippy/clippy_lints/src/let_if_seq.rs
new file mode 100644
index 00000000000..398a3103a03
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/let_if_seq.rs
@@ -0,0 +1,205 @@
+use crate::utils::{higher, qpath_res, snippet, span_lint_and_then};
+use if_chain::if_chain;
+use rustc_errors::Applicability;
+use rustc_hir as hir;
+use rustc_hir::def::Res;
+use rustc_hir::intravisit;
+use rustc_hir::BindingAnnotation;
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::hir::map::Map;
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for variable declarations immediately followed by a
+ /// conditional affectation.
+ ///
+ /// **Why is this bad?** This is not idiomatic Rust.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```rust,ignore
+ /// let foo;
+ ///
+ /// if bar() {
+ /// foo = 42;
+ /// } else {
+ /// foo = 0;
+ /// }
+ ///
+ /// let mut baz = None;
+ ///
+ /// if bar() {
+ /// baz = Some(42);
+ /// }
+ /// ```
+ ///
+ /// should be written
+ ///
+ /// ```rust,ignore
+ /// let foo = if bar() {
+ /// 42
+ /// } else {
+ /// 0
+ /// };
+ ///
+ /// let baz = if bar() {
+ /// Some(42)
+ /// } else {
+ /// None
+ /// };
+ /// ```
+ pub USELESS_LET_IF_SEQ,
+ style,
+ "unidiomatic `let mut` declaration followed by initialization in `if`"
+}
+
+declare_lint_pass!(LetIfSeq => [USELESS_LET_IF_SEQ]);
+
+impl<'a, 'tcx> LateLintPass<'a, 'tcx> for LetIfSeq {
+ fn check_block(&mut self, cx: &LateContext<'a, 'tcx>, block: &'tcx hir::Block<'_>) {
+ let mut it = block.stmts.iter().peekable();
+ while let Some(stmt) = it.next() {
+ if_chain! {
+ if let Some(expr) = it.peek();
+ if let hir::StmtKind::Local(ref local) = stmt.kind;
+ if let hir::PatKind::Binding(mode, canonical_id, ident, None) = local.pat.kind;
+ if let hir::StmtKind::Expr(ref if_) = expr.kind;
+ if let Some((ref cond, ref then, ref else_)) = higher::if_block(&if_);
+ if !used_in_expr(cx, canonical_id, cond);
+ if let hir::ExprKind::Block(ref then, _) = then.kind;
+ if let Some(value) = check_assign(cx, canonical_id, &*then);
+ if !used_in_expr(cx, canonical_id, value);
+ then {
+ let span = stmt.span.to(if_.span);
+
+ let has_interior_mutability = !cx.tables.node_type(canonical_id).is_freeze(
+ cx.tcx,
+ cx.param_env,
+ span
+ );
+ if has_interior_mutability { return; }
+
+ let (default_multi_stmts, default) = if let Some(ref else_) = *else_ {
+ if let hir::ExprKind::Block(ref else_, _) = else_.kind {
+ if let Some(default) = check_assign(cx, canonical_id, else_) {
+ (else_.stmts.len() > 1, default)
+ } else if let Some(ref default) = local.init {
+ (true, &**default)
+ } else {
+ continue;
+ }
+ } else {
+ continue;
+ }
+ } else if let Some(ref default) = local.init {
+ (false, &**default)
+ } else {
+ continue;
+ };
+
+ let mutability = match mode {
+ BindingAnnotation::RefMut | BindingAnnotation::Mutable => " ",
+ _ => "",
+ };
+
+ // FIXME: this should not suggest `mut` if we can detect that the variable is not
+ // use mutably after the `if`
+
+ let sug = format!(
+ "let {mut}{name} = if {cond} {{{then} {value} }} else {{{else} {default} }};",
+ mut=mutability,
+ name=ident.name,
+ cond=snippet(cx, cond.span, "_"),
+ then=if then.stmts.len() > 1 { " ..;" } else { "" },
+ else=if default_multi_stmts { " ..;" } else { "" },
+ value=snippet(cx, value.span, ""),
+ default=snippet(cx, default.span, ""),
+ );
+ span_lint_and_then(cx,
+ USELESS_LET_IF_SEQ,
+ span,
+ "`if _ { .. } else { .. }` is an expression",
+ |diag| {
+ diag.span_suggestion(
+ span,
+ "it is more idiomatic to write",
+ sug,
+ Applicability::HasPlaceholders,
+ );
+ if !mutability.is_empty() {
+ diag.note("you might not need `mut` at all");
+ }
+ });
+ }
+ }
+ }
+ }
+}
+
+struct UsedVisitor<'a, 'tcx> {
+ cx: &'a LateContext<'a, 'tcx>,
+ id: hir::HirId,
+ used: bool,
+}
+
+impl<'a, 'tcx> intravisit::Visitor<'tcx> for UsedVisitor<'a, 'tcx> {
+ type Map = Map<'tcx>;
+
+ fn visit_expr(&mut self, expr: &'tcx hir::Expr<'_>) {
+ if_chain! {
+ if let hir::ExprKind::Path(ref qpath) = expr.kind;
+ if let Res::Local(local_id) = qpath_res(self.cx, qpath, expr.hir_id);
+ if self.id == local_id;
+ then {
+ self.used = true;
+ return;
+ }
+ }
+ intravisit::walk_expr(self, expr);
+ }
+ fn nested_visit_map(&mut self) -> intravisit::NestedVisitorMap {
+ intravisit::NestedVisitorMap::None
+ }
+}
+
+fn check_assign<'a, 'tcx>(
+ cx: &LateContext<'a, 'tcx>,
+ decl: hir::HirId,
+ block: &'tcx hir::Block<'_>,
+) -> Option<&'tcx hir::Expr<'tcx>> {
+ if_chain! {
+ if block.expr.is_none();
+ if let Some(expr) = block.stmts.iter().last();
+ if let hir::StmtKind::Semi(ref expr) = expr.kind;
+ if let hir::ExprKind::Assign(ref var, ref value, _) = expr.kind;
+ if let hir::ExprKind::Path(ref qpath) = var.kind;
+ if let Res::Local(local_id) = qpath_res(cx, qpath, var.hir_id);
+ if decl == local_id;
+ then {
+ let mut v = UsedVisitor {
+ cx,
+ id: decl,
+ used: false,
+ };
+
+ for s in block.stmts.iter().take(block.stmts.len()-1) {
+ intravisit::walk_stmt(&mut v, s);
+
+ if v.used {
+ return None;
+ }
+ }
+
+ return Some(value);
+ }
+ }
+
+ None
+}
+
+fn used_in_expr<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, id: hir::HirId, expr: &'tcx hir::Expr<'_>) -> bool {
+ let mut v = UsedVisitor { cx, id, used: false };
+ intravisit::walk_expr(&mut v, expr);
+ v.used
+}
diff --git a/src/tools/clippy/clippy_lints/src/let_underscore.rs b/src/tools/clippy/clippy_lints/src/let_underscore.rs
new file mode 100644
index 00000000000..710dec8d33f
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/let_underscore.rs
@@ -0,0 +1,119 @@
+use if_chain::if_chain;
+use rustc_hir::{Local, PatKind};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::lint::in_external_macro;
+use rustc_middle::ty::subst::GenericArgKind;
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+
+use crate::utils::{is_must_use_func_call, is_must_use_ty, match_type, paths, span_lint_and_help};
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for `let _ = `
+ /// where expr is #[must_use]
+ ///
+ /// **Why is this bad?** It's better to explicitly
+ /// handle the value of a #[must_use] expr
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```rust
+ /// fn f() -> Result {
+ /// Ok(0)
+ /// }
+ ///
+ /// let _ = f();
+ /// // is_ok() is marked #[must_use]
+ /// let _ = f().is_ok();
+ /// ```
+ pub LET_UNDERSCORE_MUST_USE,
+ restriction,
+ "non-binding let on a `#[must_use]` expression"
+}
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for `let _ = sync_lock`
+ ///
+ /// **Why is this bad?** This statement immediately drops the lock instead of
+ /// extending it's lifetime to the end of the scope, which is often not intended.
+ /// To extend lock lifetime to the end of the scope, use an underscore-prefixed
+ /// name instead (i.e. _lock). If you want to explicitly drop the lock,
+ /// `std::mem::drop` conveys your intention better and is less error-prone.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ ///
+ /// Bad:
+ /// ```rust,ignore
+ /// let _ = mutex.lock();
+ /// ```
+ ///
+ /// Good:
+ /// ```rust,ignore
+ /// let _lock = mutex.lock();
+ /// ```
+ pub LET_UNDERSCORE_LOCK,
+ correctness,
+ "non-binding let on a synchronization lock"
+}
+
+declare_lint_pass!(LetUnderscore => [LET_UNDERSCORE_MUST_USE, LET_UNDERSCORE_LOCK]);
+
+const SYNC_GUARD_PATHS: [&[&str]; 3] = [
+ &paths::MUTEX_GUARD,
+ &paths::RWLOCK_READ_GUARD,
+ &paths::RWLOCK_WRITE_GUARD,
+];
+
+impl<'a, 'tcx> LateLintPass<'a, 'tcx> for LetUnderscore {
+ fn check_local(&mut self, cx: &LateContext<'_, '_>, local: &Local<'_>) {
+ if in_external_macro(cx.tcx.sess, local.span) {
+ return;
+ }
+
+ if_chain! {
+ if let PatKind::Wild = local.pat.kind;
+ if let Some(ref init) = local.init;
+ then {
+ let init_ty = cx.tables.expr_ty(init);
+ let contains_sync_guard = init_ty.walk().any(|inner| match inner.unpack() {
+ GenericArgKind::Type(inner_ty) => {
+ SYNC_GUARD_PATHS.iter().any(|path| match_type(cx, inner_ty, path))
+ },
+
+ GenericArgKind::Lifetime(_) | GenericArgKind::Const(_) => false,
+ });
+ if contains_sync_guard {
+ span_lint_and_help(
+ cx,
+ LET_UNDERSCORE_LOCK,
+ local.span,
+ "non-binding let on a synchronization lock",
+ None,
+ "consider using an underscore-prefixed named \
+ binding or dropping explicitly with `std::mem::drop`"
+ )
+ } else if is_must_use_ty(cx, cx.tables.expr_ty(init)) {
+ span_lint_and_help(
+ cx,
+ LET_UNDERSCORE_MUST_USE,
+ local.span,
+ "non-binding let on an expression with `#[must_use]` type",
+ None,
+ "consider explicitly using expression value"
+ )
+ } else if is_must_use_func_call(cx, init) {
+ span_lint_and_help(
+ cx,
+ LET_UNDERSCORE_MUST_USE,
+ local.span,
+ "non-binding let on a result of a `#[must_use]` function",
+ None,
+ "consider explicitly using function result"
+ )
+ }
+ }
+ }
+ }
+}
diff --git a/src/tools/clippy/clippy_lints/src/lib.rs b/src/tools/clippy/clippy_lints/src/lib.rs
new file mode 100644
index 00000000000..c995be5edc2
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/lib.rs
@@ -0,0 +1,1795 @@
+// error-pattern:cargo-clippy
+
+#![feature(box_syntax)]
+#![feature(box_patterns)]
+#![feature(or_patterns)]
+#![feature(rustc_private)]
+#![feature(stmt_expr_attributes)]
+#![allow(clippy::missing_docs_in_private_items, clippy::must_use_candidate)]
+#![recursion_limit = "512"]
+#![warn(rust_2018_idioms, trivial_casts, trivial_numeric_casts)]
+#![deny(rustc::internal)]
+#![cfg_attr(feature = "deny-warnings", deny(warnings))]
+#![feature(crate_visibility_modifier)]
+#![feature(concat_idents)]
+
+// FIXME: switch to something more ergonomic here, once available.
+// (Currently there is no way to opt into sysroot crates without `extern crate`.)
+#[allow(unused_extern_crates)]
+extern crate fmt_macros;
+#[allow(unused_extern_crates)]
+extern crate rustc_ast;
+#[allow(unused_extern_crates)]
+extern crate rustc_ast_pretty;
+#[allow(unused_extern_crates)]
+extern crate rustc_attr;
+#[allow(unused_extern_crates)]
+extern crate rustc_data_structures;
+#[allow(unused_extern_crates)]
+extern crate rustc_driver;
+#[allow(unused_extern_crates)]
+extern crate rustc_errors;
+#[allow(unused_extern_crates)]
+extern crate rustc_hir;
+#[allow(unused_extern_crates)]
+extern crate rustc_hir_pretty;
+#[allow(unused_extern_crates)]
+extern crate rustc_index;
+#[allow(unused_extern_crates)]
+extern crate rustc_infer;
+#[allow(unused_extern_crates)]
+extern crate rustc_lexer;
+#[allow(unused_extern_crates)]
+extern crate rustc_lint;
+#[allow(unused_extern_crates)]
+extern crate rustc_middle;
+#[allow(unused_extern_crates)]
+extern crate rustc_mir;
+#[allow(unused_extern_crates)]
+extern crate rustc_parse;
+#[allow(unused_extern_crates)]
+extern crate rustc_session;
+#[allow(unused_extern_crates)]
+extern crate rustc_span;
+#[allow(unused_extern_crates)]
+extern crate rustc_target;
+#[allow(unused_extern_crates)]
+extern crate rustc_trait_selection;
+#[allow(unused_extern_crates)]
+extern crate rustc_typeck;
+
+use rustc_data_structures::fx::FxHashSet;
+use rustc_lint::LintId;
+use rustc_session::Session;
+
+/// Macro used to declare a Clippy lint.
+///
+/// Every lint declaration consists of 4 parts:
+///
+/// 1. The documentation, which is used for the website
+/// 2. The `LINT_NAME`. See [lint naming][lint_naming] on lint naming conventions.
+/// 3. The `lint_level`, which is a mapping from *one* of our lint groups to `Allow`, `Warn` or
+/// `Deny`. The lint level here has nothing to do with what lint groups the lint is a part of.
+/// 4. The `description` that contains a short explanation on what's wrong with code where the
+/// lint is triggered.
+///
+/// Currently the categories `style`, `correctness`, `complexity` and `perf` are enabled by default.
+/// As said in the README.md of this repository, if the lint level mapping changes, please update
+/// README.md.
+///
+/// # Example
+///
+/// ```
+/// # #![feature(rustc_private)]
+/// # #[allow(unused_extern_crates)]
+/// # extern crate rustc_middle;
+/// # #[allow(unused_extern_crates)]
+/// # extern crate rustc_session;
+/// # #[macro_use]
+/// # use clippy_lints::declare_clippy_lint;
+/// use rustc_session::declare_tool_lint;
+///
+/// declare_clippy_lint! {
+/// /// **What it does:** Checks for ... (describe what the lint matches).
+/// ///
+/// /// **Why is this bad?** Supply the reason for linting the code.
+/// ///
+/// /// **Known problems:** None. (Or describe where it could go wrong.)
+/// ///
+/// /// **Example:**
+/// ///
+/// /// ```rust
+/// /// // Bad
+/// /// Insert a short example of code that triggers the lint
+/// ///
+/// /// // Good
+/// /// Insert a short example of improved code that doesn't trigger the lint
+/// /// ```
+/// pub LINT_NAME,
+/// pedantic,
+/// "description"
+/// }
+/// ```
+/// [lint_naming]: https://rust-lang.github.io/rfcs/0344-conventions-galore.html#lints
+#[macro_export]
+macro_rules! declare_clippy_lint {
+ { $(#[$attr:meta])* pub $name:tt, style, $description:tt } => {
+ declare_tool_lint! {
+ $(#[$attr])* pub clippy::$name, Warn, $description, report_in_external_macro: true
+ }
+ };
+ { $(#[$attr:meta])* pub $name:tt, correctness, $description:tt } => {
+ declare_tool_lint! {
+ $(#[$attr])* pub clippy::$name, Deny, $description, report_in_external_macro: true
+ }
+ };
+ { $(#[$attr:meta])* pub $name:tt, complexity, $description:tt } => {
+ declare_tool_lint! {
+ $(#[$attr])* pub clippy::$name, Warn, $description, report_in_external_macro: true
+ }
+ };
+ { $(#[$attr:meta])* pub $name:tt, perf, $description:tt } => {
+ declare_tool_lint! {
+ $(#[$attr])* pub clippy::$name, Warn, $description, report_in_external_macro: true
+ }
+ };
+ { $(#[$attr:meta])* pub $name:tt, pedantic, $description:tt } => {
+ declare_tool_lint! {
+ $(#[$attr])* pub clippy::$name, Allow, $description, report_in_external_macro: true
+ }
+ };
+ { $(#[$attr:meta])* pub $name:tt, restriction, $description:tt } => {
+ declare_tool_lint! {
+ $(#[$attr])* pub clippy::$name, Allow, $description, report_in_external_macro: true
+ }
+ };
+ { $(#[$attr:meta])* pub $name:tt, cargo, $description:tt } => {
+ declare_tool_lint! {
+ $(#[$attr])* pub clippy::$name, Allow, $description, report_in_external_macro: true
+ }
+ };
+ { $(#[$attr:meta])* pub $name:tt, nursery, $description:tt } => {
+ declare_tool_lint! {
+ $(#[$attr])* pub clippy::$name, Allow, $description, report_in_external_macro: true
+ }
+ };
+ { $(#[$attr:meta])* pub $name:tt, internal, $description:tt } => {
+ declare_tool_lint! {
+ $(#[$attr])* pub clippy::$name, Allow, $description, report_in_external_macro: true
+ }
+ };
+ { $(#[$attr:meta])* pub $name:tt, internal_warn, $description:tt } => {
+ declare_tool_lint! {
+ $(#[$attr])* pub clippy::$name, Warn, $description, report_in_external_macro: true
+ }
+ };
+}
+
+mod consts;
+#[macro_use]
+mod utils;
+
+// begin lints modules, do not remove this comment, it’s used in `update_lints`
+mod approx_const;
+mod arithmetic;
+mod as_conversions;
+mod assertions_on_constants;
+mod assign_ops;
+mod atomic_ordering;
+mod attrs;
+mod await_holding_lock;
+mod bit_mask;
+mod blacklisted_name;
+mod block_in_if_condition;
+mod booleans;
+mod bytecount;
+mod cargo_common_metadata;
+mod checked_conversions;
+mod cognitive_complexity;
+mod collapsible_if;
+mod comparison_chain;
+mod copies;
+mod copy_iterator;
+mod dbg_macro;
+mod default_trait_access;
+mod dereference;
+mod derive;
+mod doc;
+mod double_comparison;
+mod double_parens;
+mod drop_bounds;
+mod drop_forget_ref;
+mod duration_subsec;
+mod else_if_without_else;
+mod empty_enum;
+mod entry;
+mod enum_clike;
+mod enum_variants;
+mod eq_op;
+mod erasing_op;
+mod escape;
+mod eta_reduction;
+mod eval_order_dependence;
+mod excessive_bools;
+mod exit;
+mod explicit_write;
+mod fallible_impl_from;
+mod float_literal;
+mod floating_point_arithmetic;
+mod format;
+mod formatting;
+mod functions;
+mod future_not_send;
+mod get_last_with_len;
+mod identity_conversion;
+mod identity_op;
+mod if_let_mutex;
+mod if_let_some_result;
+mod if_not_else;
+mod implicit_return;
+mod implicit_saturating_sub;
+mod indexing_slicing;
+mod infinite_iter;
+mod inherent_impl;
+mod inherent_to_string;
+mod inline_fn_without_body;
+mod int_plus_one;
+mod integer_division;
+mod items_after_statements;
+mod large_const_arrays;
+mod large_enum_variant;
+mod large_stack_arrays;
+mod len_zero;
+mod let_if_seq;
+mod let_underscore;
+mod lifetimes;
+mod literal_representation;
+mod loops;
+mod macro_use;
+mod main_recursion;
+mod map_clone;
+mod map_unit_fn;
+mod match_on_vec_items;
+mod matches;
+mod mem_discriminant;
+mod mem_forget;
+mod mem_replace;
+mod methods;
+mod minmax;
+mod misc;
+mod misc_early;
+mod missing_const_for_fn;
+mod missing_doc;
+mod missing_inline;
+mod modulo_arithmetic;
+mod multiple_crate_versions;
+mod mut_key;
+mod mut_mut;
+mod mut_reference;
+mod mutable_debug_assertion;
+mod mutex_atomic;
+mod needless_bool;
+mod needless_borrow;
+mod needless_borrowed_ref;
+mod needless_continue;
+mod needless_pass_by_value;
+mod needless_update;
+mod neg_cmp_op_on_partial_ord;
+mod neg_multiply;
+mod new_without_default;
+mod no_effect;
+mod non_copy_const;
+mod non_expressive_names;
+mod open_options;
+mod option_env_unwrap;
+mod overflow_check_conditional;
+mod panic_unimplemented;
+mod partialeq_ne_impl;
+mod path_buf_push_overwrite;
+mod precedence;
+mod ptr;
+mod ptr_offset_with_cast;
+mod question_mark;
+mod ranges;
+mod redundant_clone;
+mod redundant_field_names;
+mod redundant_pattern_matching;
+mod redundant_pub_crate;
+mod redundant_static_lifetimes;
+mod reference;
+mod regex;
+mod returns;
+mod serde_api;
+mod shadow;
+mod single_component_path_imports;
+mod slow_vector_initialization;
+mod strings;
+mod suspicious_trait_impl;
+mod swap;
+mod tabs_in_doc_comments;
+mod temporary_assignment;
+mod to_digit_is_some;
+mod trait_bounds;
+mod transmute;
+mod transmuting_null;
+mod trivially_copy_pass_by_ref;
+mod try_err;
+mod types;
+mod unicode;
+mod unnamed_address;
+mod unsafe_removed_from_name;
+mod unused_io_amount;
+mod unused_self;
+mod unwrap;
+mod use_self;
+mod vec;
+mod verbose_file_reads;
+mod wildcard_dependencies;
+mod wildcard_imports;
+mod write;
+mod zero_div_zero;
+// end lints modules, do not remove this comment, it’s used in `update_lints`
+
+pub use crate::utils::conf::Conf;
+
+mod reexport {
+ pub use rustc_ast::ast::Name;
+}
+
+/// Register all pre expansion lints
+///
+/// Pre-expansion lints run before any macro expansion has happened.
+///
+/// Note that due to the architecture of the compiler, currently `cfg_attr` attributes on crate
+/// level (i.e `#![cfg_attr(...)]`) will still be expanded even when using a pre-expansion pass.
+///
+/// Used in `./src/driver.rs`.
+pub fn register_pre_expansion_lints(store: &mut rustc_lint::LintStore, conf: &Conf) {
+ store.register_pre_expansion_pass(|| box write::Write::default());
+ store.register_pre_expansion_pass(|| box redundant_field_names::RedundantFieldNames);
+ let single_char_binding_names_threshold = conf.single_char_binding_names_threshold;
+ store.register_pre_expansion_pass(move || box non_expressive_names::NonExpressiveNames {
+ single_char_binding_names_threshold,
+ });
+ store.register_pre_expansion_pass(|| box attrs::EarlyAttributes);
+ store.register_pre_expansion_pass(|| box dbg_macro::DbgMacro);
+}
+
+#[doc(hidden)]
+pub fn read_conf(args: &[rustc_ast::ast::NestedMetaItem], sess: &Session) -> Conf {
+ use std::path::Path;
+ match utils::conf::file_from_args(args) {
+ Ok(file_name) => {
+ // if the user specified a file, it must exist, otherwise default to `clippy.toml` but
+ // do not require the file to exist
+ let file_name = match file_name {
+ Some(file_name) => file_name,
+ None => match utils::conf::lookup_conf_file() {
+ Ok(Some(path)) => path,
+ Ok(None) => return Conf::default(),
+ Err(error) => {
+ sess.struct_err(&format!("error finding Clippy's configuration file: {}", error))
+ .emit();
+ return Conf::default();
+ },
+ },
+ };
+
+ let file_name = if file_name.is_relative() {
+ sess.local_crate_source_file
+ .as_deref()
+ .and_then(Path::parent)
+ .unwrap_or_else(|| Path::new(""))
+ .join(file_name)
+ } else {
+ file_name
+ };
+
+ let (conf, errors) = utils::conf::read(&file_name);
+
+ // all conf errors are non-fatal, we just use the default conf in case of error
+ for error in errors {
+ sess.struct_err(&format!(
+ "error reading Clippy's configuration file `{}`: {}",
+ file_name.display(),
+ error
+ ))
+ .emit();
+ }
+
+ conf
+ },
+ Err((err, span)) => {
+ sess.struct_span_err(span, err)
+ .span_note(span, "Clippy will use default configuration")
+ .emit();
+ Conf::default()
+ },
+ }
+}
+
+/// Register all lints and lint groups with the rustc plugin registry
+///
+/// Used in `./src/driver.rs`.
+#[allow(clippy::too_many_lines)]
+#[rustfmt::skip]
+pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: &Conf) {
+ register_removed_non_tool_lints(store);
+
+ // begin deprecated lints, do not remove this comment, it’s used in `update_lints`
+ store.register_removed(
+ "clippy::should_assert_eq",
+ "`assert!()` will be more flexible with RFC 2011",
+ );
+ store.register_removed(
+ "clippy::extend_from_slice",
+ "`.extend_from_slice(_)` is a faster way to extend a Vec by a slice",
+ );
+ store.register_removed(
+ "clippy::range_step_by_zero",
+ "`iterator.step_by(0)` panics nowadays",
+ );
+ store.register_removed(
+ "clippy::unstable_as_slice",
+ "`Vec::as_slice` has been stabilized in 1.7",
+ );
+ store.register_removed(
+ "clippy::unstable_as_mut_slice",
+ "`Vec::as_mut_slice` has been stabilized in 1.7",
+ );
+ store.register_removed(
+ "clippy::str_to_string",
+ "using `str::to_string` is common even today and specialization will likely happen soon",
+ );
+ store.register_removed(
+ "clippy::string_to_string",
+ "using `string::to_string` is common even today and specialization will likely happen soon",
+ );
+ store.register_removed(
+ "clippy::misaligned_transmute",
+ "this lint has been split into cast_ptr_alignment and transmute_ptr_to_ptr",
+ );
+ store.register_removed(
+ "clippy::assign_ops",
+ "using compound assignment operators (e.g., `+=`) is harmless",
+ );
+ store.register_removed(
+ "clippy::if_let_redundant_pattern_matching",
+ "this lint has been changed to redundant_pattern_matching",
+ );
+ store.register_removed(
+ "clippy::unsafe_vector_initialization",
+ "the replacement suggested by this lint had substantially different behavior",
+ );
+ store.register_removed(
+ "clippy::invalid_ref",
+ "superseded by rustc lint `invalid_value`",
+ );
+ store.register_removed(
+ "clippy::unused_collect",
+ "`collect` has been marked as #[must_use] in rustc and that covers all cases of this lint",
+ );
+ store.register_removed(
+ "clippy::into_iter_on_array",
+ "this lint has been uplifted to rustc and is now called `array_into_iter`",
+ );
+ store.register_removed(
+ "clippy::unused_label",
+ "this lint has been uplifted to rustc and is now called `unused_labels`",
+ );
+ store.register_removed(
+ "clippy::replace_consts",
+ "associated-constants `MIN`/`MAX` of integers are prefer to `{min,max}_value()` and module constants",
+ );
+ // end deprecated lints, do not remove this comment, it’s used in `update_lints`
+
+ // begin register lints, do not remove this comment, it’s used in `update_lints`
+ store.register_lints(&[
+ &approx_const::APPROX_CONSTANT,
+ &arithmetic::FLOAT_ARITHMETIC,
+ &arithmetic::INTEGER_ARITHMETIC,
+ &as_conversions::AS_CONVERSIONS,
+ &assertions_on_constants::ASSERTIONS_ON_CONSTANTS,
+ &assign_ops::ASSIGN_OP_PATTERN,
+ &assign_ops::MISREFACTORED_ASSIGN_OP,
+ &atomic_ordering::INVALID_ATOMIC_ORDERING,
+ &attrs::DEPRECATED_CFG_ATTR,
+ &attrs::DEPRECATED_SEMVER,
+ &attrs::EMPTY_LINE_AFTER_OUTER_ATTR,
+ &attrs::INLINE_ALWAYS,
+ &attrs::MISMATCHED_TARGET_OS,
+ &attrs::UNKNOWN_CLIPPY_LINTS,
+ &attrs::USELESS_ATTRIBUTE,
+ &await_holding_lock::AWAIT_HOLDING_LOCK,
+ &bit_mask::BAD_BIT_MASK,
+ &bit_mask::INEFFECTIVE_BIT_MASK,
+ &bit_mask::VERBOSE_BIT_MASK,
+ &blacklisted_name::BLACKLISTED_NAME,
+ &block_in_if_condition::BLOCK_IN_IF_CONDITION_EXPR,
+ &block_in_if_condition::BLOCK_IN_IF_CONDITION_STMT,
+ &booleans::LOGIC_BUG,
+ &booleans::NONMINIMAL_BOOL,
+ &bytecount::NAIVE_BYTECOUNT,
+ &cargo_common_metadata::CARGO_COMMON_METADATA,
+ &checked_conversions::CHECKED_CONVERSIONS,
+ &cognitive_complexity::COGNITIVE_COMPLEXITY,
+ &collapsible_if::COLLAPSIBLE_IF,
+ &comparison_chain::COMPARISON_CHAIN,
+ &copies::IFS_SAME_COND,
+ &copies::IF_SAME_THEN_ELSE,
+ &copies::MATCH_SAME_ARMS,
+ &copies::SAME_FUNCTIONS_IN_IF_CONDITION,
+ ©_iterator::COPY_ITERATOR,
+ &dbg_macro::DBG_MACRO,
+ &default_trait_access::DEFAULT_TRAIT_ACCESS,
+ &dereference::EXPLICIT_DEREF_METHODS,
+ &derive::DERIVE_HASH_XOR_EQ,
+ &derive::EXPL_IMPL_CLONE_ON_COPY,
+ &derive::UNSAFE_DERIVE_DESERIALIZE,
+ &doc::DOC_MARKDOWN,
+ &doc::MISSING_ERRORS_DOC,
+ &doc::MISSING_SAFETY_DOC,
+ &doc::NEEDLESS_DOCTEST_MAIN,
+ &double_comparison::DOUBLE_COMPARISONS,
+ &double_parens::DOUBLE_PARENS,
+ &drop_bounds::DROP_BOUNDS,
+ &drop_forget_ref::DROP_COPY,
+ &drop_forget_ref::DROP_REF,
+ &drop_forget_ref::FORGET_COPY,
+ &drop_forget_ref::FORGET_REF,
+ &duration_subsec::DURATION_SUBSEC,
+ &else_if_without_else::ELSE_IF_WITHOUT_ELSE,
+ &empty_enum::EMPTY_ENUM,
+ &entry::MAP_ENTRY,
+ &enum_clike::ENUM_CLIKE_UNPORTABLE_VARIANT,
+ &enum_variants::ENUM_VARIANT_NAMES,
+ &enum_variants::MODULE_INCEPTION,
+ &enum_variants::MODULE_NAME_REPETITIONS,
+ &enum_variants::PUB_ENUM_VARIANT_NAMES,
+ &eq_op::EQ_OP,
+ &eq_op::OP_REF,
+ &erasing_op::ERASING_OP,
+ &escape::BOXED_LOCAL,
+ &eta_reduction::REDUNDANT_CLOSURE,
+ &eta_reduction::REDUNDANT_CLOSURE_FOR_METHOD_CALLS,
+ &eval_order_dependence::DIVERGING_SUB_EXPRESSION,
+ &eval_order_dependence::EVAL_ORDER_DEPENDENCE,
+ &excessive_bools::FN_PARAMS_EXCESSIVE_BOOLS,
+ &excessive_bools::STRUCT_EXCESSIVE_BOOLS,
+ &exit::EXIT,
+ &explicit_write::EXPLICIT_WRITE,
+ &fallible_impl_from::FALLIBLE_IMPL_FROM,
+ &float_literal::EXCESSIVE_PRECISION,
+ &float_literal::LOSSY_FLOAT_LITERAL,
+ &floating_point_arithmetic::IMPRECISE_FLOPS,
+ &floating_point_arithmetic::SUBOPTIMAL_FLOPS,
+ &format::USELESS_FORMAT,
+ &formatting::POSSIBLE_MISSING_COMMA,
+ &formatting::SUSPICIOUS_ASSIGNMENT_FORMATTING,
+ &formatting::SUSPICIOUS_ELSE_FORMATTING,
+ &formatting::SUSPICIOUS_UNARY_OP_FORMATTING,
+ &functions::DOUBLE_MUST_USE,
+ &functions::MUST_USE_CANDIDATE,
+ &functions::MUST_USE_UNIT,
+ &functions::NOT_UNSAFE_PTR_ARG_DEREF,
+ &functions::TOO_MANY_ARGUMENTS,
+ &functions::TOO_MANY_LINES,
+ &future_not_send::FUTURE_NOT_SEND,
+ &get_last_with_len::GET_LAST_WITH_LEN,
+ &identity_conversion::IDENTITY_CONVERSION,
+ &identity_op::IDENTITY_OP,
+ &if_let_mutex::IF_LET_MUTEX,
+ &if_let_some_result::IF_LET_SOME_RESULT,
+ &if_not_else::IF_NOT_ELSE,
+ &implicit_return::IMPLICIT_RETURN,
+ &implicit_saturating_sub::IMPLICIT_SATURATING_SUB,
+ &indexing_slicing::INDEXING_SLICING,
+ &indexing_slicing::OUT_OF_BOUNDS_INDEXING,
+ &infinite_iter::INFINITE_ITER,
+ &infinite_iter::MAYBE_INFINITE_ITER,
+ &inherent_impl::MULTIPLE_INHERENT_IMPL,
+ &inherent_to_string::INHERENT_TO_STRING,
+ &inherent_to_string::INHERENT_TO_STRING_SHADOW_DISPLAY,
+ &inline_fn_without_body::INLINE_FN_WITHOUT_BODY,
+ &int_plus_one::INT_PLUS_ONE,
+ &integer_division::INTEGER_DIVISION,
+ &items_after_statements::ITEMS_AFTER_STATEMENTS,
+ &large_const_arrays::LARGE_CONST_ARRAYS,
+ &large_enum_variant::LARGE_ENUM_VARIANT,
+ &large_stack_arrays::LARGE_STACK_ARRAYS,
+ &len_zero::LEN_WITHOUT_IS_EMPTY,
+ &len_zero::LEN_ZERO,
+ &let_if_seq::USELESS_LET_IF_SEQ,
+ &let_underscore::LET_UNDERSCORE_LOCK,
+ &let_underscore::LET_UNDERSCORE_MUST_USE,
+ &lifetimes::EXTRA_UNUSED_LIFETIMES,
+ &lifetimes::NEEDLESS_LIFETIMES,
+ &literal_representation::DECIMAL_LITERAL_REPRESENTATION,
+ &literal_representation::INCONSISTENT_DIGIT_GROUPING,
+ &literal_representation::LARGE_DIGIT_GROUPS,
+ &literal_representation::MISTYPED_LITERAL_SUFFIXES,
+ &literal_representation::UNREADABLE_LITERAL,
+ &loops::EMPTY_LOOP,
+ &loops::EXPLICIT_COUNTER_LOOP,
+ &loops::EXPLICIT_INTO_ITER_LOOP,
+ &loops::EXPLICIT_ITER_LOOP,
+ &loops::FOR_KV_MAP,
+ &loops::FOR_LOOP_OVER_OPTION,
+ &loops::FOR_LOOP_OVER_RESULT,
+ &loops::ITER_NEXT_LOOP,
+ &loops::MANUAL_MEMCPY,
+ &loops::MUT_RANGE_BOUND,
+ &loops::NEEDLESS_COLLECT,
+ &loops::NEEDLESS_RANGE_LOOP,
+ &loops::NEVER_LOOP,
+ &loops::REVERSE_RANGE_LOOP,
+ &loops::WHILE_IMMUTABLE_CONDITION,
+ &loops::WHILE_LET_LOOP,
+ &loops::WHILE_LET_ON_ITERATOR,
+ ¯o_use::MACRO_USE_IMPORTS,
+ &main_recursion::MAIN_RECURSION,
+ &map_clone::MAP_CLONE,
+ &map_unit_fn::OPTION_MAP_UNIT_FN,
+ &map_unit_fn::RESULT_MAP_UNIT_FN,
+ &match_on_vec_items::MATCH_ON_VEC_ITEMS,
+ &matches::INFALLIBLE_DESTRUCTURING_MATCH,
+ &matches::MATCH_AS_REF,
+ &matches::MATCH_BOOL,
+ &matches::MATCH_OVERLAPPING_ARM,
+ &matches::MATCH_REF_PATS,
+ &matches::MATCH_SINGLE_BINDING,
+ &matches::MATCH_WILD_ERR_ARM,
+ &matches::REST_PAT_IN_FULLY_BOUND_STRUCTS,
+ &matches::SINGLE_MATCH,
+ &matches::SINGLE_MATCH_ELSE,
+ &matches::WILDCARD_ENUM_MATCH_ARM,
+ &matches::WILDCARD_IN_OR_PATTERNS,
+ &mem_discriminant::MEM_DISCRIMINANT_NON_ENUM,
+ &mem_forget::MEM_FORGET,
+ &mem_replace::MEM_REPLACE_OPTION_WITH_NONE,
+ &mem_replace::MEM_REPLACE_WITH_DEFAULT,
+ &mem_replace::MEM_REPLACE_WITH_UNINIT,
+ &methods::CHARS_LAST_CMP,
+ &methods::CHARS_NEXT_CMP,
+ &methods::CLONE_DOUBLE_REF,
+ &methods::CLONE_ON_COPY,
+ &methods::CLONE_ON_REF_PTR,
+ &methods::EXPECT_FUN_CALL,
+ &methods::FILETYPE_IS_FILE,
+ &methods::FILTER_MAP,
+ &methods::FILTER_MAP_NEXT,
+ &methods::FILTER_NEXT,
+ &methods::FIND_MAP,
+ &methods::FLAT_MAP_IDENTITY,
+ &methods::GET_UNWRAP,
+ &methods::INEFFICIENT_TO_STRING,
+ &methods::INTO_ITER_ON_REF,
+ &methods::ITERATOR_STEP_BY_ZERO,
+ &methods::ITER_CLONED_COLLECT,
+ &methods::ITER_NTH,
+ &methods::ITER_NTH_ZERO,
+ &methods::ITER_SKIP_NEXT,
+ &methods::MANUAL_SATURATING_ARITHMETIC,
+ &methods::MAP_FLATTEN,
+ &methods::NEW_RET_NO_SELF,
+ &methods::OK_EXPECT,
+ &methods::OPTION_AND_THEN_SOME,
+ &methods::OPTION_AS_REF_DEREF,
+ &methods::OPTION_EXPECT_USED,
+ &methods::OPTION_MAP_OR_NONE,
+ &methods::OPTION_MAP_UNWRAP_OR,
+ &methods::OPTION_MAP_UNWRAP_OR_ELSE,
+ &methods::OPTION_UNWRAP_USED,
+ &methods::OR_FUN_CALL,
+ &methods::RESULT_EXPECT_USED,
+ &methods::RESULT_MAP_OR_INTO_OPTION,
+ &methods::RESULT_MAP_UNWRAP_OR_ELSE,
+ &methods::RESULT_UNWRAP_USED,
+ &methods::SEARCH_IS_SOME,
+ &methods::SHOULD_IMPLEMENT_TRAIT,
+ &methods::SINGLE_CHAR_PATTERN,
+ &methods::SKIP_WHILE_NEXT,
+ &methods::STRING_EXTEND_CHARS,
+ &methods::SUSPICIOUS_MAP,
+ &methods::TEMPORARY_CSTRING_AS_PTR,
+ &methods::UNINIT_ASSUMED_INIT,
+ &methods::UNNECESSARY_FILTER_MAP,
+ &methods::UNNECESSARY_FOLD,
+ &methods::USELESS_ASREF,
+ &methods::WRONG_PUB_SELF_CONVENTION,
+ &methods::WRONG_SELF_CONVENTION,
+ &methods::ZST_OFFSET,
+ &minmax::MIN_MAX,
+ &misc::CMP_NAN,
+ &misc::CMP_OWNED,
+ &misc::FLOAT_CMP,
+ &misc::FLOAT_CMP_CONST,
+ &misc::MODULO_ONE,
+ &misc::SHORT_CIRCUIT_STATEMENT,
+ &misc::TOPLEVEL_REF_ARG,
+ &misc::USED_UNDERSCORE_BINDING,
+ &misc::ZERO_PTR,
+ &misc_early::BUILTIN_TYPE_SHADOW,
+ &misc_early::DOUBLE_NEG,
+ &misc_early::DUPLICATE_UNDERSCORE_ARGUMENT,
+ &misc_early::MIXED_CASE_HEX_LITERALS,
+ &misc_early::REDUNDANT_CLOSURE_CALL,
+ &misc_early::REDUNDANT_PATTERN,
+ &misc_early::UNNEEDED_FIELD_PATTERN,
+ &misc_early::UNNEEDED_WILDCARD_PATTERN,
+ &misc_early::UNSEPARATED_LITERAL_SUFFIX,
+ &misc_early::ZERO_PREFIXED_LITERAL,
+ &missing_const_for_fn::MISSING_CONST_FOR_FN,
+ &missing_doc::MISSING_DOCS_IN_PRIVATE_ITEMS,
+ &missing_inline::MISSING_INLINE_IN_PUBLIC_ITEMS,
+ &modulo_arithmetic::MODULO_ARITHMETIC,
+ &multiple_crate_versions::MULTIPLE_CRATE_VERSIONS,
+ &mut_key::MUTABLE_KEY_TYPE,
+ &mut_mut::MUT_MUT,
+ &mut_reference::UNNECESSARY_MUT_PASSED,
+ &mutable_debug_assertion::DEBUG_ASSERT_WITH_MUT_CALL,
+ &mutex_atomic::MUTEX_ATOMIC,
+ &mutex_atomic::MUTEX_INTEGER,
+ &needless_bool::BOOL_COMPARISON,
+ &needless_bool::NEEDLESS_BOOL,
+ &needless_borrow::NEEDLESS_BORROW,
+ &needless_borrowed_ref::NEEDLESS_BORROWED_REFERENCE,
+ &needless_continue::NEEDLESS_CONTINUE,
+ &needless_pass_by_value::NEEDLESS_PASS_BY_VALUE,
+ &needless_update::NEEDLESS_UPDATE,
+ &neg_cmp_op_on_partial_ord::NEG_CMP_OP_ON_PARTIAL_ORD,
+ &neg_multiply::NEG_MULTIPLY,
+ &new_without_default::NEW_WITHOUT_DEFAULT,
+ &no_effect::NO_EFFECT,
+ &no_effect::UNNECESSARY_OPERATION,
+ &non_copy_const::BORROW_INTERIOR_MUTABLE_CONST,
+ &non_copy_const::DECLARE_INTERIOR_MUTABLE_CONST,
+ &non_expressive_names::JUST_UNDERSCORES_AND_DIGITS,
+ &non_expressive_names::MANY_SINGLE_CHAR_NAMES,
+ &non_expressive_names::SIMILAR_NAMES,
+ &open_options::NONSENSICAL_OPEN_OPTIONS,
+ &option_env_unwrap::OPTION_ENV_UNWRAP,
+ &overflow_check_conditional::OVERFLOW_CHECK_CONDITIONAL,
+ &panic_unimplemented::PANIC,
+ &panic_unimplemented::PANIC_PARAMS,
+ &panic_unimplemented::TODO,
+ &panic_unimplemented::UNIMPLEMENTED,
+ &panic_unimplemented::UNREACHABLE,
+ &partialeq_ne_impl::PARTIALEQ_NE_IMPL,
+ &path_buf_push_overwrite::PATH_BUF_PUSH_OVERWRITE,
+ &precedence::PRECEDENCE,
+ &ptr::CMP_NULL,
+ &ptr::MUT_FROM_REF,
+ &ptr::PTR_ARG,
+ &ptr_offset_with_cast::PTR_OFFSET_WITH_CAST,
+ &question_mark::QUESTION_MARK,
+ &ranges::RANGE_MINUS_ONE,
+ &ranges::RANGE_PLUS_ONE,
+ &ranges::RANGE_ZIP_WITH_LEN,
+ &redundant_clone::REDUNDANT_CLONE,
+ &redundant_field_names::REDUNDANT_FIELD_NAMES,
+ &redundant_pattern_matching::REDUNDANT_PATTERN_MATCHING,
+ &redundant_pub_crate::REDUNDANT_PUB_CRATE,
+ &redundant_static_lifetimes::REDUNDANT_STATIC_LIFETIMES,
+ &reference::DEREF_ADDROF,
+ &reference::REF_IN_DEREF,
+ ®ex::INVALID_REGEX,
+ ®ex::REGEX_MACRO,
+ ®ex::TRIVIAL_REGEX,
+ &returns::LET_AND_RETURN,
+ &returns::NEEDLESS_RETURN,
+ &returns::UNUSED_UNIT,
+ &serde_api::SERDE_API_MISUSE,
+ &shadow::SHADOW_REUSE,
+ &shadow::SHADOW_SAME,
+ &shadow::SHADOW_UNRELATED,
+ &single_component_path_imports::SINGLE_COMPONENT_PATH_IMPORTS,
+ &slow_vector_initialization::SLOW_VECTOR_INITIALIZATION,
+ &strings::STRING_ADD,
+ &strings::STRING_ADD_ASSIGN,
+ &strings::STRING_LIT_AS_BYTES,
+ &suspicious_trait_impl::SUSPICIOUS_ARITHMETIC_IMPL,
+ &suspicious_trait_impl::SUSPICIOUS_OP_ASSIGN_IMPL,
+ &swap::ALMOST_SWAPPED,
+ &swap::MANUAL_SWAP,
+ &tabs_in_doc_comments::TABS_IN_DOC_COMMENTS,
+ &temporary_assignment::TEMPORARY_ASSIGNMENT,
+ &to_digit_is_some::TO_DIGIT_IS_SOME,
+ &trait_bounds::TYPE_REPETITION_IN_BOUNDS,
+ &transmute::CROSSPOINTER_TRANSMUTE,
+ &transmute::TRANSMUTE_BYTES_TO_STR,
+ &transmute::TRANSMUTE_FLOAT_TO_INT,
+ &transmute::TRANSMUTE_INT_TO_BOOL,
+ &transmute::TRANSMUTE_INT_TO_CHAR,
+ &transmute::TRANSMUTE_INT_TO_FLOAT,
+ &transmute::TRANSMUTE_PTR_TO_PTR,
+ &transmute::TRANSMUTE_PTR_TO_REF,
+ &transmute::UNSOUND_COLLECTION_TRANSMUTE,
+ &transmute::USELESS_TRANSMUTE,
+ &transmute::WRONG_TRANSMUTE,
+ &transmuting_null::TRANSMUTING_NULL,
+ &trivially_copy_pass_by_ref::TRIVIALLY_COPY_PASS_BY_REF,
+ &try_err::TRY_ERR,
+ &types::ABSURD_EXTREME_COMPARISONS,
+ &types::BORROWED_BOX,
+ &types::BOX_VEC,
+ &types::CAST_LOSSLESS,
+ &types::CAST_POSSIBLE_TRUNCATION,
+ &types::CAST_POSSIBLE_WRAP,
+ &types::CAST_PRECISION_LOSS,
+ &types::CAST_PTR_ALIGNMENT,
+ &types::CAST_REF_TO_MUT,
+ &types::CAST_SIGN_LOSS,
+ &types::CHAR_LIT_AS_U8,
+ &types::FN_TO_NUMERIC_CAST,
+ &types::FN_TO_NUMERIC_CAST_WITH_TRUNCATION,
+ &types::IMPLICIT_HASHER,
+ &types::INVALID_UPCAST_COMPARISONS,
+ &types::LET_UNIT_VALUE,
+ &types::LINKEDLIST,
+ &types::OPTION_OPTION,
+ &types::REDUNDANT_ALLOCATION,
+ &types::TYPE_COMPLEXITY,
+ &types::UNIT_ARG,
+ &types::UNIT_CMP,
+ &types::UNNECESSARY_CAST,
+ &types::VEC_BOX,
+ &unicode::NON_ASCII_LITERAL,
+ &unicode::UNICODE_NOT_NFC,
+ &unicode::ZERO_WIDTH_SPACE,
+ &unnamed_address::FN_ADDRESS_COMPARISONS,
+ &unnamed_address::VTABLE_ADDRESS_COMPARISONS,
+ &unsafe_removed_from_name::UNSAFE_REMOVED_FROM_NAME,
+ &unused_io_amount::UNUSED_IO_AMOUNT,
+ &unused_self::UNUSED_SELF,
+ &unwrap::PANICKING_UNWRAP,
+ &unwrap::UNNECESSARY_UNWRAP,
+ &use_self::USE_SELF,
+ &utils::internal_lints::CLIPPY_LINTS_INTERNAL,
+ &utils::internal_lints::COLLAPSIBLE_SPAN_LINT_CALLS,
+ &utils::internal_lints::COMPILER_LINT_FUNCTIONS,
+ &utils::internal_lints::DEFAULT_LINT,
+ &utils::internal_lints::LINT_WITHOUT_LINT_PASS,
+ &utils::internal_lints::OUTER_EXPN_EXPN_DATA,
+ &utils::internal_lints::PRODUCE_ICE,
+ &vec::USELESS_VEC,
+ &verbose_file_reads::VERBOSE_FILE_READS,
+ &wildcard_dependencies::WILDCARD_DEPENDENCIES,
+ &wildcard_imports::ENUM_GLOB_USE,
+ &wildcard_imports::WILDCARD_IMPORTS,
+ &write::PRINTLN_EMPTY_STRING,
+ &write::PRINT_LITERAL,
+ &write::PRINT_STDOUT,
+ &write::PRINT_WITH_NEWLINE,
+ &write::USE_DEBUG,
+ &write::WRITELN_EMPTY_STRING,
+ &write::WRITE_LITERAL,
+ &write::WRITE_WITH_NEWLINE,
+ &zero_div_zero::ZERO_DIVIDED_BY_ZERO,
+ ]);
+ // end register lints, do not remove this comment, it’s used in `update_lints`
+
+ store.register_late_pass(|| box await_holding_lock::AwaitHoldingLock);
+ store.register_late_pass(|| box serde_api::SerdeAPI);
+ store.register_late_pass(|| box utils::internal_lints::CompilerLintFunctions::new());
+ store.register_late_pass(|| box utils::internal_lints::LintWithoutLintPass::default());
+ store.register_late_pass(|| box utils::internal_lints::OuterExpnDataPass);
+ store.register_late_pass(|| box utils::inspector::DeepCodeInspector);
+ store.register_late_pass(|| box utils::author::Author);
+ let vec_box_size_threshold = conf.vec_box_size_threshold;
+ store.register_late_pass(move || box types::Types::new(vec_box_size_threshold));
+ store.register_late_pass(|| box booleans::NonminimalBool);
+ store.register_late_pass(|| box eq_op::EqOp);
+ store.register_late_pass(|| box enum_clike::UnportableVariant);
+ store.register_late_pass(|| box float_literal::FloatLiteral);
+ let verbose_bit_mask_threshold = conf.verbose_bit_mask_threshold;
+ store.register_late_pass(move || box bit_mask::BitMask::new(verbose_bit_mask_threshold));
+ store.register_late_pass(|| box ptr::Ptr);
+ store.register_late_pass(|| box needless_bool::NeedlessBool);
+ store.register_late_pass(|| box needless_bool::BoolComparison);
+ store.register_late_pass(|| box approx_const::ApproxConstant);
+ store.register_late_pass(|| box misc::MiscLints);
+ store.register_late_pass(|| box eta_reduction::EtaReduction);
+ store.register_late_pass(|| box identity_op::IdentityOp);
+ store.register_late_pass(|| box erasing_op::ErasingOp);
+ store.register_late_pass(|| box mut_mut::MutMut);
+ store.register_late_pass(|| box mut_reference::UnnecessaryMutPassed);
+ store.register_late_pass(|| box len_zero::LenZero);
+ store.register_late_pass(|| box attrs::Attributes);
+ store.register_late_pass(|| box block_in_if_condition::BlockInIfCondition);
+ store.register_late_pass(|| box unicode::Unicode);
+ store.register_late_pass(|| box strings::StringAdd);
+ store.register_late_pass(|| box implicit_return::ImplicitReturn);
+ store.register_late_pass(|| box implicit_saturating_sub::ImplicitSaturatingSub);
+ store.register_late_pass(|| box methods::Methods);
+ store.register_late_pass(|| box map_clone::MapClone);
+ store.register_late_pass(|| box shadow::Shadow);
+ store.register_late_pass(|| box types::LetUnitValue);
+ store.register_late_pass(|| box types::UnitCmp);
+ store.register_late_pass(|| box loops::Loops);
+ store.register_late_pass(|| box main_recursion::MainRecursion::default());
+ store.register_late_pass(|| box lifetimes::Lifetimes);
+ store.register_late_pass(|| box entry::HashMapPass);
+ store.register_late_pass(|| box ranges::Ranges);
+ store.register_late_pass(|| box types::Casts);
+ let type_complexity_threshold = conf.type_complexity_threshold;
+ store.register_late_pass(move || box types::TypeComplexity::new(type_complexity_threshold));
+ store.register_late_pass(|| box matches::Matches::default());
+ store.register_late_pass(|| box minmax::MinMaxPass);
+ store.register_late_pass(|| box open_options::OpenOptions);
+ store.register_late_pass(|| box zero_div_zero::ZeroDiv);
+ store.register_late_pass(|| box mutex_atomic::Mutex);
+ store.register_late_pass(|| box needless_update::NeedlessUpdate);
+ store.register_late_pass(|| box needless_borrow::NeedlessBorrow::default());
+ store.register_late_pass(|| box needless_borrowed_ref::NeedlessBorrowedRef);
+ store.register_late_pass(|| box no_effect::NoEffect);
+ store.register_late_pass(|| box temporary_assignment::TemporaryAssignment);
+ store.register_late_pass(|| box transmute::Transmute);
+ let cognitive_complexity_threshold = conf.cognitive_complexity_threshold;
+ store.register_late_pass(move || box cognitive_complexity::CognitiveComplexity::new(cognitive_complexity_threshold));
+ let too_large_for_stack = conf.too_large_for_stack;
+ store.register_late_pass(move || box escape::BoxedLocal{too_large_for_stack});
+ store.register_late_pass(|| box panic_unimplemented::PanicUnimplemented);
+ store.register_late_pass(|| box strings::StringLitAsBytes);
+ store.register_late_pass(|| box derive::Derive);
+ store.register_late_pass(|| box types::CharLitAsU8);
+ store.register_late_pass(|| box vec::UselessVec);
+ store.register_late_pass(|| box drop_bounds::DropBounds);
+ store.register_late_pass(|| box get_last_with_len::GetLastWithLen);
+ store.register_late_pass(|| box drop_forget_ref::DropForgetRef);
+ store.register_late_pass(|| box empty_enum::EmptyEnum);
+ store.register_late_pass(|| box types::AbsurdExtremeComparisons);
+ store.register_late_pass(|| box types::InvalidUpcastComparisons);
+ store.register_late_pass(|| box regex::Regex::default());
+ store.register_late_pass(|| box copies::CopyAndPaste);
+ store.register_late_pass(|| box copy_iterator::CopyIterator);
+ store.register_late_pass(|| box format::UselessFormat);
+ store.register_late_pass(|| box swap::Swap);
+ store.register_late_pass(|| box overflow_check_conditional::OverflowCheckConditional);
+ store.register_late_pass(|| box new_without_default::NewWithoutDefault::default());
+ let blacklisted_names = conf.blacklisted_names.iter().cloned().collect::>();
+ store.register_late_pass(move || box blacklisted_name::BlacklistedName::new(blacklisted_names.clone()));
+ let too_many_arguments_threshold1 = conf.too_many_arguments_threshold;
+ let too_many_lines_threshold2 = conf.too_many_lines_threshold;
+ store.register_late_pass(move || box functions::Functions::new(too_many_arguments_threshold1, too_many_lines_threshold2));
+ let doc_valid_idents = conf.doc_valid_idents.iter().cloned().collect::>();
+ store.register_late_pass(move || box doc::DocMarkdown::new(doc_valid_idents.clone()));
+ store.register_late_pass(|| box neg_multiply::NegMultiply);
+ store.register_late_pass(|| box mem_discriminant::MemDiscriminant);
+ store.register_late_pass(|| box mem_forget::MemForget);
+ store.register_late_pass(|| box mem_replace::MemReplace);
+ store.register_late_pass(|| box arithmetic::Arithmetic::default());
+ store.register_late_pass(|| box assign_ops::AssignOps);
+ store.register_late_pass(|| box let_if_seq::LetIfSeq);
+ store.register_late_pass(|| box eval_order_dependence::EvalOrderDependence);
+ store.register_late_pass(|| box missing_doc::MissingDoc::new());
+ store.register_late_pass(|| box missing_inline::MissingInline);
+ store.register_late_pass(|| box if_let_some_result::OkIfLet);
+ store.register_late_pass(|| box redundant_pattern_matching::RedundantPatternMatching);
+ store.register_late_pass(|| box partialeq_ne_impl::PartialEqNeImpl);
+ store.register_late_pass(|| box unused_io_amount::UnusedIoAmount);
+ let enum_variant_size_threshold = conf.enum_variant_size_threshold;
+ store.register_late_pass(move || box large_enum_variant::LargeEnumVariant::new(enum_variant_size_threshold));
+ store.register_late_pass(|| box explicit_write::ExplicitWrite);
+ store.register_late_pass(|| box needless_pass_by_value::NeedlessPassByValue);
+ let trivially_copy_pass_by_ref = trivially_copy_pass_by_ref::TriviallyCopyPassByRef::new(
+ conf.trivial_copy_size_limit,
+ &sess.target,
+ );
+ store.register_late_pass(move || box trivially_copy_pass_by_ref);
+ store.register_late_pass(|| box try_err::TryErr);
+ store.register_late_pass(|| box use_self::UseSelf);
+ store.register_late_pass(|| box bytecount::ByteCount);
+ store.register_late_pass(|| box infinite_iter::InfiniteIter);
+ store.register_late_pass(|| box inline_fn_without_body::InlineFnWithoutBody);
+ store.register_late_pass(|| box identity_conversion::IdentityConversion::default());
+ store.register_late_pass(|| box types::ImplicitHasher);
+ store.register_late_pass(|| box fallible_impl_from::FallibleImplFrom);
+ store.register_late_pass(|| box types::UnitArg);
+ store.register_late_pass(|| box double_comparison::DoubleComparisons);
+ store.register_late_pass(|| box question_mark::QuestionMark);
+ store.register_late_pass(|| box suspicious_trait_impl::SuspiciousImpl);
+ store.register_late_pass(|| box map_unit_fn::MapUnit);
+ store.register_late_pass(|| box inherent_impl::MultipleInherentImpl::default());
+ store.register_late_pass(|| box neg_cmp_op_on_partial_ord::NoNegCompOpForPartialOrd);
+ store.register_late_pass(|| box unwrap::Unwrap);
+ store.register_late_pass(|| box duration_subsec::DurationSubsec);
+ store.register_late_pass(|| box default_trait_access::DefaultTraitAccess);
+ store.register_late_pass(|| box indexing_slicing::IndexingSlicing);
+ store.register_late_pass(|| box non_copy_const::NonCopyConst);
+ store.register_late_pass(|| box ptr_offset_with_cast::PtrOffsetWithCast);
+ store.register_late_pass(|| box redundant_clone::RedundantClone);
+ store.register_late_pass(|| box slow_vector_initialization::SlowVectorInit);
+ store.register_late_pass(|| box types::RefToMut);
+ store.register_late_pass(|| box assertions_on_constants::AssertionsOnConstants);
+ store.register_late_pass(|| box missing_const_for_fn::MissingConstForFn);
+ store.register_late_pass(|| box transmuting_null::TransmutingNull);
+ store.register_late_pass(|| box path_buf_push_overwrite::PathBufPushOverwrite);
+ store.register_late_pass(|| box checked_conversions::CheckedConversions);
+ store.register_late_pass(|| box integer_division::IntegerDivision);
+ store.register_late_pass(|| box inherent_to_string::InherentToString);
+ store.register_late_pass(|| box trait_bounds::TraitBounds);
+ store.register_late_pass(|| box comparison_chain::ComparisonChain);
+ store.register_late_pass(|| box mut_key::MutableKeyType);
+ store.register_late_pass(|| box modulo_arithmetic::ModuloArithmetic);
+ store.register_early_pass(|| box reference::DerefAddrOf);
+ store.register_early_pass(|| box reference::RefInDeref);
+ store.register_early_pass(|| box double_parens::DoubleParens);
+ store.register_early_pass(|| box unsafe_removed_from_name::UnsafeNameRemoval);
+ store.register_early_pass(|| box if_not_else::IfNotElse);
+ store.register_early_pass(|| box else_if_without_else::ElseIfWithoutElse);
+ store.register_early_pass(|| box int_plus_one::IntPlusOne);
+ store.register_early_pass(|| box formatting::Formatting);
+ store.register_early_pass(|| box misc_early::MiscEarlyLints);
+ store.register_early_pass(|| box returns::Return);
+ store.register_early_pass(|| box collapsible_if::CollapsibleIf);
+ store.register_early_pass(|| box items_after_statements::ItemsAfterStatements);
+ store.register_early_pass(|| box precedence::Precedence);
+ store.register_early_pass(|| box needless_continue::NeedlessContinue);
+ store.register_early_pass(|| box redundant_static_lifetimes::RedundantStaticLifetimes);
+ store.register_late_pass(|| box cargo_common_metadata::CargoCommonMetadata);
+ store.register_late_pass(|| box multiple_crate_versions::MultipleCrateVersions);
+ store.register_late_pass(|| box wildcard_dependencies::WildcardDependencies);
+ store.register_early_pass(|| box literal_representation::LiteralDigitGrouping);
+ let literal_representation_threshold = conf.literal_representation_threshold;
+ store.register_early_pass(move || box literal_representation::DecimalLiteralRepresentation::new(literal_representation_threshold));
+ store.register_early_pass(|| box utils::internal_lints::ClippyLintsInternal);
+ let enum_variant_name_threshold = conf.enum_variant_name_threshold;
+ store.register_early_pass(move || box enum_variants::EnumVariantNames::new(enum_variant_name_threshold));
+ store.register_early_pass(|| box tabs_in_doc_comments::TabsInDocComments);
+ store.register_late_pass(|| box unused_self::UnusedSelf);
+ store.register_late_pass(|| box mutable_debug_assertion::DebugAssertWithMutCall);
+ store.register_late_pass(|| box exit::Exit);
+ store.register_late_pass(|| box to_digit_is_some::ToDigitIsSome);
+ let array_size_threshold = conf.array_size_threshold;
+ store.register_late_pass(move || box large_stack_arrays::LargeStackArrays::new(array_size_threshold));
+ store.register_late_pass(move || box large_const_arrays::LargeConstArrays::new(array_size_threshold));
+ store.register_late_pass(move || box floating_point_arithmetic::FloatingPointArithmetic);
+ store.register_early_pass(|| box as_conversions::AsConversions);
+ store.register_early_pass(|| box utils::internal_lints::ProduceIce);
+ store.register_late_pass(|| box let_underscore::LetUnderscore);
+ store.register_late_pass(|| box atomic_ordering::AtomicOrdering);
+ store.register_early_pass(|| box single_component_path_imports::SingleComponentPathImports);
+ let max_fn_params_bools = conf.max_fn_params_bools;
+ let max_struct_bools = conf.max_struct_bools;
+ store.register_early_pass(move || box excessive_bools::ExcessiveBools::new(max_struct_bools, max_fn_params_bools));
+ store.register_early_pass(|| box option_env_unwrap::OptionEnvUnwrap);
+ store.register_late_pass(|| box wildcard_imports::WildcardImports);
+ store.register_early_pass(|| box macro_use::MacroUseImports);
+ store.register_late_pass(|| box verbose_file_reads::VerboseFileReads);
+ store.register_late_pass(|| box redundant_pub_crate::RedundantPubCrate::default());
+ store.register_late_pass(|| box unnamed_address::UnnamedAddress);
+ store.register_late_pass(|| box dereference::Dereferencing);
+ store.register_late_pass(|| box future_not_send::FutureNotSend);
+ store.register_late_pass(|| box utils::internal_lints::CollapsibleCalls);
+ store.register_late_pass(|| box if_let_mutex::IfLetMutex);
+ store.register_late_pass(|| box match_on_vec_items::MatchOnVecItems);
+
+ store.register_group(true, "clippy::restriction", Some("clippy_restriction"), vec![
+ LintId::of(&arithmetic::FLOAT_ARITHMETIC),
+ LintId::of(&arithmetic::INTEGER_ARITHMETIC),
+ LintId::of(&as_conversions::AS_CONVERSIONS),
+ LintId::of(&dbg_macro::DBG_MACRO),
+ LintId::of(&else_if_without_else::ELSE_IF_WITHOUT_ELSE),
+ LintId::of(&exit::EXIT),
+ LintId::of(&float_literal::LOSSY_FLOAT_LITERAL),
+ LintId::of(&implicit_return::IMPLICIT_RETURN),
+ LintId::of(&indexing_slicing::INDEXING_SLICING),
+ LintId::of(&inherent_impl::MULTIPLE_INHERENT_IMPL),
+ LintId::of(&integer_division::INTEGER_DIVISION),
+ LintId::of(&let_underscore::LET_UNDERSCORE_MUST_USE),
+ LintId::of(&literal_representation::DECIMAL_LITERAL_REPRESENTATION),
+ LintId::of(&matches::REST_PAT_IN_FULLY_BOUND_STRUCTS),
+ LintId::of(&matches::WILDCARD_ENUM_MATCH_ARM),
+ LintId::of(&mem_forget::MEM_FORGET),
+ LintId::of(&methods::CLONE_ON_REF_PTR),
+ LintId::of(&methods::FILETYPE_IS_FILE),
+ LintId::of(&methods::GET_UNWRAP),
+ LintId::of(&methods::OPTION_EXPECT_USED),
+ LintId::of(&methods::OPTION_UNWRAP_USED),
+ LintId::of(&methods::RESULT_EXPECT_USED),
+ LintId::of(&methods::RESULT_UNWRAP_USED),
+ LintId::of(&methods::WRONG_PUB_SELF_CONVENTION),
+ LintId::of(&misc::FLOAT_CMP_CONST),
+ LintId::of(&misc_early::UNNEEDED_FIELD_PATTERN),
+ LintId::of(&missing_doc::MISSING_DOCS_IN_PRIVATE_ITEMS),
+ LintId::of(&missing_inline::MISSING_INLINE_IN_PUBLIC_ITEMS),
+ LintId::of(&modulo_arithmetic::MODULO_ARITHMETIC),
+ LintId::of(&panic_unimplemented::PANIC),
+ LintId::of(&panic_unimplemented::TODO),
+ LintId::of(&panic_unimplemented::UNIMPLEMENTED),
+ LintId::of(&panic_unimplemented::UNREACHABLE),
+ LintId::of(&shadow::SHADOW_REUSE),
+ LintId::of(&shadow::SHADOW_SAME),
+ LintId::of(&strings::STRING_ADD),
+ LintId::of(&verbose_file_reads::VERBOSE_FILE_READS),
+ LintId::of(&write::PRINT_STDOUT),
+ LintId::of(&write::USE_DEBUG),
+ ]);
+
+ store.register_group(true, "clippy::pedantic", Some("clippy_pedantic"), vec![
+ LintId::of(&attrs::INLINE_ALWAYS),
+ LintId::of(&await_holding_lock::AWAIT_HOLDING_LOCK),
+ LintId::of(&checked_conversions::CHECKED_CONVERSIONS),
+ LintId::of(&copies::MATCH_SAME_ARMS),
+ LintId::of(&copies::SAME_FUNCTIONS_IN_IF_CONDITION),
+ LintId::of(©_iterator::COPY_ITERATOR),
+ LintId::of(&default_trait_access::DEFAULT_TRAIT_ACCESS),
+ LintId::of(&dereference::EXPLICIT_DEREF_METHODS),
+ LintId::of(&derive::EXPL_IMPL_CLONE_ON_COPY),
+ LintId::of(&derive::UNSAFE_DERIVE_DESERIALIZE),
+ LintId::of(&doc::DOC_MARKDOWN),
+ LintId::of(&doc::MISSING_ERRORS_DOC),
+ LintId::of(&empty_enum::EMPTY_ENUM),
+ LintId::of(&enum_variants::MODULE_NAME_REPETITIONS),
+ LintId::of(&enum_variants::PUB_ENUM_VARIANT_NAMES),
+ LintId::of(&eta_reduction::REDUNDANT_CLOSURE_FOR_METHOD_CALLS),
+ LintId::of(&excessive_bools::FN_PARAMS_EXCESSIVE_BOOLS),
+ LintId::of(&excessive_bools::STRUCT_EXCESSIVE_BOOLS),
+ LintId::of(&functions::MUST_USE_CANDIDATE),
+ LintId::of(&functions::TOO_MANY_LINES),
+ LintId::of(&if_not_else::IF_NOT_ELSE),
+ LintId::of(&implicit_saturating_sub::IMPLICIT_SATURATING_SUB),
+ LintId::of(&infinite_iter::MAYBE_INFINITE_ITER),
+ LintId::of(&items_after_statements::ITEMS_AFTER_STATEMENTS),
+ LintId::of(&large_stack_arrays::LARGE_STACK_ARRAYS),
+ LintId::of(&literal_representation::LARGE_DIGIT_GROUPS),
+ LintId::of(&literal_representation::UNREADABLE_LITERAL),
+ LintId::of(&loops::EXPLICIT_INTO_ITER_LOOP),
+ LintId::of(&loops::EXPLICIT_ITER_LOOP),
+ LintId::of(¯o_use::MACRO_USE_IMPORTS),
+ LintId::of(&matches::MATCH_BOOL),
+ LintId::of(&matches::SINGLE_MATCH_ELSE),
+ LintId::of(&methods::FILTER_MAP),
+ LintId::of(&methods::FILTER_MAP_NEXT),
+ LintId::of(&methods::FIND_MAP),
+ LintId::of(&methods::INEFFICIENT_TO_STRING),
+ LintId::of(&methods::MAP_FLATTEN),
+ LintId::of(&methods::OPTION_MAP_UNWRAP_OR),
+ LintId::of(&methods::OPTION_MAP_UNWRAP_OR_ELSE),
+ LintId::of(&methods::RESULT_MAP_UNWRAP_OR_ELSE),
+ LintId::of(&misc::USED_UNDERSCORE_BINDING),
+ LintId::of(&misc_early::UNSEPARATED_LITERAL_SUFFIX),
+ LintId::of(&mut_mut::MUT_MUT),
+ LintId::of(&needless_continue::NEEDLESS_CONTINUE),
+ LintId::of(&needless_pass_by_value::NEEDLESS_PASS_BY_VALUE),
+ LintId::of(&non_expressive_names::SIMILAR_NAMES),
+ LintId::of(&ranges::RANGE_PLUS_ONE),
+ LintId::of(&shadow::SHADOW_UNRELATED),
+ LintId::of(&strings::STRING_ADD_ASSIGN),
+ LintId::of(&trait_bounds::TYPE_REPETITION_IN_BOUNDS),
+ LintId::of(&trivially_copy_pass_by_ref::TRIVIALLY_COPY_PASS_BY_REF),
+ LintId::of(&types::CAST_LOSSLESS),
+ LintId::of(&types::CAST_POSSIBLE_TRUNCATION),
+ LintId::of(&types::CAST_POSSIBLE_WRAP),
+ LintId::of(&types::CAST_PRECISION_LOSS),
+ LintId::of(&types::CAST_SIGN_LOSS),
+ LintId::of(&types::IMPLICIT_HASHER),
+ LintId::of(&types::INVALID_UPCAST_COMPARISONS),
+ LintId::of(&types::LET_UNIT_VALUE),
+ LintId::of(&types::LINKEDLIST),
+ LintId::of(&types::OPTION_OPTION),
+ LintId::of(&unicode::NON_ASCII_LITERAL),
+ LintId::of(&unicode::UNICODE_NOT_NFC),
+ LintId::of(&unused_self::UNUSED_SELF),
+ LintId::of(&wildcard_imports::ENUM_GLOB_USE),
+ LintId::of(&wildcard_imports::WILDCARD_IMPORTS),
+ ]);
+
+ store.register_group(true, "clippy::internal", Some("clippy_internal"), vec![
+ LintId::of(&utils::internal_lints::CLIPPY_LINTS_INTERNAL),
+ LintId::of(&utils::internal_lints::COLLAPSIBLE_SPAN_LINT_CALLS),
+ LintId::of(&utils::internal_lints::COMPILER_LINT_FUNCTIONS),
+ LintId::of(&utils::internal_lints::DEFAULT_LINT),
+ LintId::of(&utils::internal_lints::LINT_WITHOUT_LINT_PASS),
+ LintId::of(&utils::internal_lints::OUTER_EXPN_EXPN_DATA),
+ LintId::of(&utils::internal_lints::PRODUCE_ICE),
+ ]);
+
+ store.register_group(true, "clippy::all", Some("clippy"), vec![
+ LintId::of(&approx_const::APPROX_CONSTANT),
+ LintId::of(&assertions_on_constants::ASSERTIONS_ON_CONSTANTS),
+ LintId::of(&assign_ops::ASSIGN_OP_PATTERN),
+ LintId::of(&assign_ops::MISREFACTORED_ASSIGN_OP),
+ LintId::of(&atomic_ordering::INVALID_ATOMIC_ORDERING),
+ LintId::of(&attrs::DEPRECATED_CFG_ATTR),
+ LintId::of(&attrs::DEPRECATED_SEMVER),
+ LintId::of(&attrs::MISMATCHED_TARGET_OS),
+ LintId::of(&attrs::UNKNOWN_CLIPPY_LINTS),
+ LintId::of(&attrs::USELESS_ATTRIBUTE),
+ LintId::of(&bit_mask::BAD_BIT_MASK),
+ LintId::of(&bit_mask::INEFFECTIVE_BIT_MASK),
+ LintId::of(&bit_mask::VERBOSE_BIT_MASK),
+ LintId::of(&blacklisted_name::BLACKLISTED_NAME),
+ LintId::of(&block_in_if_condition::BLOCK_IN_IF_CONDITION_EXPR),
+ LintId::of(&block_in_if_condition::BLOCK_IN_IF_CONDITION_STMT),
+ LintId::of(&booleans::LOGIC_BUG),
+ LintId::of(&booleans::NONMINIMAL_BOOL),
+ LintId::of(&bytecount::NAIVE_BYTECOUNT),
+ LintId::of(&collapsible_if::COLLAPSIBLE_IF),
+ LintId::of(&comparison_chain::COMPARISON_CHAIN),
+ LintId::of(&copies::IFS_SAME_COND),
+ LintId::of(&copies::IF_SAME_THEN_ELSE),
+ LintId::of(&derive::DERIVE_HASH_XOR_EQ),
+ LintId::of(&doc::MISSING_SAFETY_DOC),
+ LintId::of(&doc::NEEDLESS_DOCTEST_MAIN),
+ LintId::of(&double_comparison::DOUBLE_COMPARISONS),
+ LintId::of(&double_parens::DOUBLE_PARENS),
+ LintId::of(&drop_bounds::DROP_BOUNDS),
+ LintId::of(&drop_forget_ref::DROP_COPY),
+ LintId::of(&drop_forget_ref::DROP_REF),
+ LintId::of(&drop_forget_ref::FORGET_COPY),
+ LintId::of(&drop_forget_ref::FORGET_REF),
+ LintId::of(&duration_subsec::DURATION_SUBSEC),
+ LintId::of(&entry::MAP_ENTRY),
+ LintId::of(&enum_clike::ENUM_CLIKE_UNPORTABLE_VARIANT),
+ LintId::of(&enum_variants::ENUM_VARIANT_NAMES),
+ LintId::of(&enum_variants::MODULE_INCEPTION),
+ LintId::of(&eq_op::EQ_OP),
+ LintId::of(&eq_op::OP_REF),
+ LintId::of(&erasing_op::ERASING_OP),
+ LintId::of(&escape::BOXED_LOCAL),
+ LintId::of(&eta_reduction::REDUNDANT_CLOSURE),
+ LintId::of(&eval_order_dependence::DIVERGING_SUB_EXPRESSION),
+ LintId::of(&eval_order_dependence::EVAL_ORDER_DEPENDENCE),
+ LintId::of(&explicit_write::EXPLICIT_WRITE),
+ LintId::of(&float_literal::EXCESSIVE_PRECISION),
+ LintId::of(&format::USELESS_FORMAT),
+ LintId::of(&formatting::POSSIBLE_MISSING_COMMA),
+ LintId::of(&formatting::SUSPICIOUS_ASSIGNMENT_FORMATTING),
+ LintId::of(&formatting::SUSPICIOUS_ELSE_FORMATTING),
+ LintId::of(&formatting::SUSPICIOUS_UNARY_OP_FORMATTING),
+ LintId::of(&functions::DOUBLE_MUST_USE),
+ LintId::of(&functions::MUST_USE_UNIT),
+ LintId::of(&functions::NOT_UNSAFE_PTR_ARG_DEREF),
+ LintId::of(&functions::TOO_MANY_ARGUMENTS),
+ LintId::of(&get_last_with_len::GET_LAST_WITH_LEN),
+ LintId::of(&identity_conversion::IDENTITY_CONVERSION),
+ LintId::of(&identity_op::IDENTITY_OP),
+ LintId::of(&if_let_mutex::IF_LET_MUTEX),
+ LintId::of(&if_let_some_result::IF_LET_SOME_RESULT),
+ LintId::of(&indexing_slicing::OUT_OF_BOUNDS_INDEXING),
+ LintId::of(&infinite_iter::INFINITE_ITER),
+ LintId::of(&inherent_to_string::INHERENT_TO_STRING),
+ LintId::of(&inherent_to_string::INHERENT_TO_STRING_SHADOW_DISPLAY),
+ LintId::of(&inline_fn_without_body::INLINE_FN_WITHOUT_BODY),
+ LintId::of(&int_plus_one::INT_PLUS_ONE),
+ LintId::of(&large_const_arrays::LARGE_CONST_ARRAYS),
+ LintId::of(&large_enum_variant::LARGE_ENUM_VARIANT),
+ LintId::of(&len_zero::LEN_WITHOUT_IS_EMPTY),
+ LintId::of(&len_zero::LEN_ZERO),
+ LintId::of(&let_if_seq::USELESS_LET_IF_SEQ),
+ LintId::of(&let_underscore::LET_UNDERSCORE_LOCK),
+ LintId::of(&lifetimes::EXTRA_UNUSED_LIFETIMES),
+ LintId::of(&lifetimes::NEEDLESS_LIFETIMES),
+ LintId::of(&literal_representation::INCONSISTENT_DIGIT_GROUPING),
+ LintId::of(&literal_representation::MISTYPED_LITERAL_SUFFIXES),
+ LintId::of(&loops::EMPTY_LOOP),
+ LintId::of(&loops::EXPLICIT_COUNTER_LOOP),
+ LintId::of(&loops::FOR_KV_MAP),
+ LintId::of(&loops::FOR_LOOP_OVER_OPTION),
+ LintId::of(&loops::FOR_LOOP_OVER_RESULT),
+ LintId::of(&loops::ITER_NEXT_LOOP),
+ LintId::of(&loops::MANUAL_MEMCPY),
+ LintId::of(&loops::MUT_RANGE_BOUND),
+ LintId::of(&loops::NEEDLESS_COLLECT),
+ LintId::of(&loops::NEEDLESS_RANGE_LOOP),
+ LintId::of(&loops::NEVER_LOOP),
+ LintId::of(&loops::REVERSE_RANGE_LOOP),
+ LintId::of(&loops::WHILE_IMMUTABLE_CONDITION),
+ LintId::of(&loops::WHILE_LET_LOOP),
+ LintId::of(&loops::WHILE_LET_ON_ITERATOR),
+ LintId::of(&main_recursion::MAIN_RECURSION),
+ LintId::of(&map_clone::MAP_CLONE),
+ LintId::of(&map_unit_fn::OPTION_MAP_UNIT_FN),
+ LintId::of(&map_unit_fn::RESULT_MAP_UNIT_FN),
+ LintId::of(&match_on_vec_items::MATCH_ON_VEC_ITEMS),
+ LintId::of(&matches::INFALLIBLE_DESTRUCTURING_MATCH),
+ LintId::of(&matches::MATCH_AS_REF),
+ LintId::of(&matches::MATCH_OVERLAPPING_ARM),
+ LintId::of(&matches::MATCH_REF_PATS),
+ LintId::of(&matches::MATCH_SINGLE_BINDING),
+ LintId::of(&matches::MATCH_WILD_ERR_ARM),
+ LintId::of(&matches::SINGLE_MATCH),
+ LintId::of(&matches::WILDCARD_IN_OR_PATTERNS),
+ LintId::of(&mem_discriminant::MEM_DISCRIMINANT_NON_ENUM),
+ LintId::of(&mem_replace::MEM_REPLACE_OPTION_WITH_NONE),
+ LintId::of(&mem_replace::MEM_REPLACE_WITH_DEFAULT),
+ LintId::of(&mem_replace::MEM_REPLACE_WITH_UNINIT),
+ LintId::of(&methods::CHARS_LAST_CMP),
+ LintId::of(&methods::CHARS_NEXT_CMP),
+ LintId::of(&methods::CLONE_DOUBLE_REF),
+ LintId::of(&methods::CLONE_ON_COPY),
+ LintId::of(&methods::EXPECT_FUN_CALL),
+ LintId::of(&methods::FILTER_NEXT),
+ LintId::of(&methods::FLAT_MAP_IDENTITY),
+ LintId::of(&methods::INTO_ITER_ON_REF),
+ LintId::of(&methods::ITERATOR_STEP_BY_ZERO),
+ LintId::of(&methods::ITER_CLONED_COLLECT),
+ LintId::of(&methods::ITER_NTH),
+ LintId::of(&methods::ITER_NTH_ZERO),
+ LintId::of(&methods::ITER_SKIP_NEXT),
+ LintId::of(&methods::MANUAL_SATURATING_ARITHMETIC),
+ LintId::of(&methods::NEW_RET_NO_SELF),
+ LintId::of(&methods::OK_EXPECT),
+ LintId::of(&methods::OPTION_AND_THEN_SOME),
+ LintId::of(&methods::OPTION_AS_REF_DEREF),
+ LintId::of(&methods::OPTION_MAP_OR_NONE),
+ LintId::of(&methods::OR_FUN_CALL),
+ LintId::of(&methods::RESULT_MAP_OR_INTO_OPTION),
+ LintId::of(&methods::SEARCH_IS_SOME),
+ LintId::of(&methods::SHOULD_IMPLEMENT_TRAIT),
+ LintId::of(&methods::SINGLE_CHAR_PATTERN),
+ LintId::of(&methods::SKIP_WHILE_NEXT),
+ LintId::of(&methods::STRING_EXTEND_CHARS),
+ LintId::of(&methods::SUSPICIOUS_MAP),
+ LintId::of(&methods::TEMPORARY_CSTRING_AS_PTR),
+ LintId::of(&methods::UNINIT_ASSUMED_INIT),
+ LintId::of(&methods::UNNECESSARY_FILTER_MAP),
+ LintId::of(&methods::UNNECESSARY_FOLD),
+ LintId::of(&methods::USELESS_ASREF),
+ LintId::of(&methods::WRONG_SELF_CONVENTION),
+ LintId::of(&methods::ZST_OFFSET),
+ LintId::of(&minmax::MIN_MAX),
+ LintId::of(&misc::CMP_NAN),
+ LintId::of(&misc::CMP_OWNED),
+ LintId::of(&misc::FLOAT_CMP),
+ LintId::of(&misc::MODULO_ONE),
+ LintId::of(&misc::SHORT_CIRCUIT_STATEMENT),
+ LintId::of(&misc::TOPLEVEL_REF_ARG),
+ LintId::of(&misc::ZERO_PTR),
+ LintId::of(&misc_early::BUILTIN_TYPE_SHADOW),
+ LintId::of(&misc_early::DOUBLE_NEG),
+ LintId::of(&misc_early::DUPLICATE_UNDERSCORE_ARGUMENT),
+ LintId::of(&misc_early::MIXED_CASE_HEX_LITERALS),
+ LintId::of(&misc_early::REDUNDANT_CLOSURE_CALL),
+ LintId::of(&misc_early::REDUNDANT_PATTERN),
+ LintId::of(&misc_early::UNNEEDED_WILDCARD_PATTERN),
+ LintId::of(&misc_early::ZERO_PREFIXED_LITERAL),
+ LintId::of(&mut_key::MUTABLE_KEY_TYPE),
+ LintId::of(&mut_reference::UNNECESSARY_MUT_PASSED),
+ LintId::of(&mutex_atomic::MUTEX_ATOMIC),
+ LintId::of(&needless_bool::BOOL_COMPARISON),
+ LintId::of(&needless_bool::NEEDLESS_BOOL),
+ LintId::of(&needless_borrowed_ref::NEEDLESS_BORROWED_REFERENCE),
+ LintId::of(&needless_update::NEEDLESS_UPDATE),
+ LintId::of(&neg_cmp_op_on_partial_ord::NEG_CMP_OP_ON_PARTIAL_ORD),
+ LintId::of(&neg_multiply::NEG_MULTIPLY),
+ LintId::of(&new_without_default::NEW_WITHOUT_DEFAULT),
+ LintId::of(&no_effect::NO_EFFECT),
+ LintId::of(&no_effect::UNNECESSARY_OPERATION),
+ LintId::of(&non_copy_const::BORROW_INTERIOR_MUTABLE_CONST),
+ LintId::of(&non_copy_const::DECLARE_INTERIOR_MUTABLE_CONST),
+ LintId::of(&non_expressive_names::JUST_UNDERSCORES_AND_DIGITS),
+ LintId::of(&non_expressive_names::MANY_SINGLE_CHAR_NAMES),
+ LintId::of(&open_options::NONSENSICAL_OPEN_OPTIONS),
+ LintId::of(&option_env_unwrap::OPTION_ENV_UNWRAP),
+ LintId::of(&overflow_check_conditional::OVERFLOW_CHECK_CONDITIONAL),
+ LintId::of(&panic_unimplemented::PANIC_PARAMS),
+ LintId::of(&partialeq_ne_impl::PARTIALEQ_NE_IMPL),
+ LintId::of(&precedence::PRECEDENCE),
+ LintId::of(&ptr::CMP_NULL),
+ LintId::of(&ptr::MUT_FROM_REF),
+ LintId::of(&ptr::PTR_ARG),
+ LintId::of(&ptr_offset_with_cast::PTR_OFFSET_WITH_CAST),
+ LintId::of(&question_mark::QUESTION_MARK),
+ LintId::of(&ranges::RANGE_MINUS_ONE),
+ LintId::of(&ranges::RANGE_ZIP_WITH_LEN),
+ LintId::of(&redundant_clone::REDUNDANT_CLONE),
+ LintId::of(&redundant_field_names::REDUNDANT_FIELD_NAMES),
+ LintId::of(&redundant_pattern_matching::REDUNDANT_PATTERN_MATCHING),
+ LintId::of(&redundant_static_lifetimes::REDUNDANT_STATIC_LIFETIMES),
+ LintId::of(&reference::DEREF_ADDROF),
+ LintId::of(&reference::REF_IN_DEREF),
+ LintId::of(®ex::INVALID_REGEX),
+ LintId::of(®ex::REGEX_MACRO),
+ LintId::of(®ex::TRIVIAL_REGEX),
+ LintId::of(&returns::LET_AND_RETURN),
+ LintId::of(&returns::NEEDLESS_RETURN),
+ LintId::of(&returns::UNUSED_UNIT),
+ LintId::of(&serde_api::SERDE_API_MISUSE),
+ LintId::of(&single_component_path_imports::SINGLE_COMPONENT_PATH_IMPORTS),
+ LintId::of(&slow_vector_initialization::SLOW_VECTOR_INITIALIZATION),
+ LintId::of(&strings::STRING_LIT_AS_BYTES),
+ LintId::of(&suspicious_trait_impl::SUSPICIOUS_ARITHMETIC_IMPL),
+ LintId::of(&suspicious_trait_impl::SUSPICIOUS_OP_ASSIGN_IMPL),
+ LintId::of(&swap::ALMOST_SWAPPED),
+ LintId::of(&swap::MANUAL_SWAP),
+ LintId::of(&tabs_in_doc_comments::TABS_IN_DOC_COMMENTS),
+ LintId::of(&temporary_assignment::TEMPORARY_ASSIGNMENT),
+ LintId::of(&to_digit_is_some::TO_DIGIT_IS_SOME),
+ LintId::of(&transmute::CROSSPOINTER_TRANSMUTE),
+ LintId::of(&transmute::TRANSMUTE_BYTES_TO_STR),
+ LintId::of(&transmute::TRANSMUTE_FLOAT_TO_INT),
+ LintId::of(&transmute::TRANSMUTE_INT_TO_BOOL),
+ LintId::of(&transmute::TRANSMUTE_INT_TO_CHAR),
+ LintId::of(&transmute::TRANSMUTE_INT_TO_FLOAT),
+ LintId::of(&transmute::TRANSMUTE_PTR_TO_PTR),
+ LintId::of(&transmute::TRANSMUTE_PTR_TO_REF),
+ LintId::of(&transmute::UNSOUND_COLLECTION_TRANSMUTE),
+ LintId::of(&transmute::WRONG_TRANSMUTE),
+ LintId::of(&transmuting_null::TRANSMUTING_NULL),
+ LintId::of(&try_err::TRY_ERR),
+ LintId::of(&types::ABSURD_EXTREME_COMPARISONS),
+ LintId::of(&types::BORROWED_BOX),
+ LintId::of(&types::BOX_VEC),
+ LintId::of(&types::CAST_PTR_ALIGNMENT),
+ LintId::of(&types::CAST_REF_TO_MUT),
+ LintId::of(&types::CHAR_LIT_AS_U8),
+ LintId::of(&types::FN_TO_NUMERIC_CAST),
+ LintId::of(&types::FN_TO_NUMERIC_CAST_WITH_TRUNCATION),
+ LintId::of(&types::REDUNDANT_ALLOCATION),
+ LintId::of(&types::TYPE_COMPLEXITY),
+ LintId::of(&types::UNIT_ARG),
+ LintId::of(&types::UNIT_CMP),
+ LintId::of(&types::UNNECESSARY_CAST),
+ LintId::of(&types::VEC_BOX),
+ LintId::of(&unicode::ZERO_WIDTH_SPACE),
+ LintId::of(&unnamed_address::FN_ADDRESS_COMPARISONS),
+ LintId::of(&unnamed_address::VTABLE_ADDRESS_COMPARISONS),
+ LintId::of(&unsafe_removed_from_name::UNSAFE_REMOVED_FROM_NAME),
+ LintId::of(&unused_io_amount::UNUSED_IO_AMOUNT),
+ LintId::of(&unwrap::PANICKING_UNWRAP),
+ LintId::of(&unwrap::UNNECESSARY_UNWRAP),
+ LintId::of(&vec::USELESS_VEC),
+ LintId::of(&write::PRINTLN_EMPTY_STRING),
+ LintId::of(&write::PRINT_LITERAL),
+ LintId::of(&write::PRINT_WITH_NEWLINE),
+ LintId::of(&write::WRITELN_EMPTY_STRING),
+ LintId::of(&write::WRITE_LITERAL),
+ LintId::of(&write::WRITE_WITH_NEWLINE),
+ LintId::of(&zero_div_zero::ZERO_DIVIDED_BY_ZERO),
+ ]);
+
+ store.register_group(true, "clippy::style", Some("clippy_style"), vec![
+ LintId::of(&assertions_on_constants::ASSERTIONS_ON_CONSTANTS),
+ LintId::of(&assign_ops::ASSIGN_OP_PATTERN),
+ LintId::of(&attrs::UNKNOWN_CLIPPY_LINTS),
+ LintId::of(&bit_mask::VERBOSE_BIT_MASK),
+ LintId::of(&blacklisted_name::BLACKLISTED_NAME),
+ LintId::of(&block_in_if_condition::BLOCK_IN_IF_CONDITION_EXPR),
+ LintId::of(&block_in_if_condition::BLOCK_IN_IF_CONDITION_STMT),
+ LintId::of(&collapsible_if::COLLAPSIBLE_IF),
+ LintId::of(&comparison_chain::COMPARISON_CHAIN),
+ LintId::of(&doc::MISSING_SAFETY_DOC),
+ LintId::of(&doc::NEEDLESS_DOCTEST_MAIN),
+ LintId::of(&enum_variants::ENUM_VARIANT_NAMES),
+ LintId::of(&enum_variants::MODULE_INCEPTION),
+ LintId::of(&eq_op::OP_REF),
+ LintId::of(&eta_reduction::REDUNDANT_CLOSURE),
+ LintId::of(&float_literal::EXCESSIVE_PRECISION),
+ LintId::of(&formatting::SUSPICIOUS_ASSIGNMENT_FORMATTING),
+ LintId::of(&formatting::SUSPICIOUS_ELSE_FORMATTING),
+ LintId::of(&formatting::SUSPICIOUS_UNARY_OP_FORMATTING),
+ LintId::of(&functions::DOUBLE_MUST_USE),
+ LintId::of(&functions::MUST_USE_UNIT),
+ LintId::of(&if_let_some_result::IF_LET_SOME_RESULT),
+ LintId::of(&inherent_to_string::INHERENT_TO_STRING),
+ LintId::of(&len_zero::LEN_WITHOUT_IS_EMPTY),
+ LintId::of(&len_zero::LEN_ZERO),
+ LintId::of(&let_if_seq::USELESS_LET_IF_SEQ),
+ LintId::of(&literal_representation::INCONSISTENT_DIGIT_GROUPING),
+ LintId::of(&loops::EMPTY_LOOP),
+ LintId::of(&loops::FOR_KV_MAP),
+ LintId::of(&loops::NEEDLESS_RANGE_LOOP),
+ LintId::of(&loops::WHILE_LET_ON_ITERATOR),
+ LintId::of(&main_recursion::MAIN_RECURSION),
+ LintId::of(&map_clone::MAP_CLONE),
+ LintId::of(&matches::INFALLIBLE_DESTRUCTURING_MATCH),
+ LintId::of(&matches::MATCH_OVERLAPPING_ARM),
+ LintId::of(&matches::MATCH_REF_PATS),
+ LintId::of(&matches::MATCH_WILD_ERR_ARM),
+ LintId::of(&matches::SINGLE_MATCH),
+ LintId::of(&mem_replace::MEM_REPLACE_OPTION_WITH_NONE),
+ LintId::of(&mem_replace::MEM_REPLACE_WITH_DEFAULT),
+ LintId::of(&methods::CHARS_LAST_CMP),
+ LintId::of(&methods::CHARS_NEXT_CMP),
+ LintId::of(&methods::INTO_ITER_ON_REF),
+ LintId::of(&methods::ITER_CLONED_COLLECT),
+ LintId::of(&methods::ITER_NTH_ZERO),
+ LintId::of(&methods::ITER_SKIP_NEXT),
+ LintId::of(&methods::MANUAL_SATURATING_ARITHMETIC),
+ LintId::of(&methods::NEW_RET_NO_SELF),
+ LintId::of(&methods::OK_EXPECT),
+ LintId::of(&methods::OPTION_MAP_OR_NONE),
+ LintId::of(&methods::RESULT_MAP_OR_INTO_OPTION),
+ LintId::of(&methods::SHOULD_IMPLEMENT_TRAIT),
+ LintId::of(&methods::STRING_EXTEND_CHARS),
+ LintId::of(&methods::UNNECESSARY_FOLD),
+ LintId::of(&methods::WRONG_SELF_CONVENTION),
+ LintId::of(&misc::TOPLEVEL_REF_ARG),
+ LintId::of(&misc::ZERO_PTR),
+ LintId::of(&misc_early::BUILTIN_TYPE_SHADOW),
+ LintId::of(&misc_early::DOUBLE_NEG),
+ LintId::of(&misc_early::DUPLICATE_UNDERSCORE_ARGUMENT),
+ LintId::of(&misc_early::MIXED_CASE_HEX_LITERALS),
+ LintId::of(&misc_early::REDUNDANT_PATTERN),
+ LintId::of(&mut_reference::UNNECESSARY_MUT_PASSED),
+ LintId::of(&neg_multiply::NEG_MULTIPLY),
+ LintId::of(&new_without_default::NEW_WITHOUT_DEFAULT),
+ LintId::of(&non_expressive_names::JUST_UNDERSCORES_AND_DIGITS),
+ LintId::of(&non_expressive_names::MANY_SINGLE_CHAR_NAMES),
+ LintId::of(&panic_unimplemented::PANIC_PARAMS),
+ LintId::of(&ptr::CMP_NULL),
+ LintId::of(&ptr::PTR_ARG),
+ LintId::of(&question_mark::QUESTION_MARK),
+ LintId::of(&redundant_field_names::REDUNDANT_FIELD_NAMES),
+ LintId::of(&redundant_pattern_matching::REDUNDANT_PATTERN_MATCHING),
+ LintId::of(&redundant_static_lifetimes::REDUNDANT_STATIC_LIFETIMES),
+ LintId::of(®ex::REGEX_MACRO),
+ LintId::of(®ex::TRIVIAL_REGEX),
+ LintId::of(&returns::LET_AND_RETURN),
+ LintId::of(&returns::NEEDLESS_RETURN),
+ LintId::of(&returns::UNUSED_UNIT),
+ LintId::of(&single_component_path_imports::SINGLE_COMPONENT_PATH_IMPORTS),
+ LintId::of(&strings::STRING_LIT_AS_BYTES),
+ LintId::of(&tabs_in_doc_comments::TABS_IN_DOC_COMMENTS),
+ LintId::of(&to_digit_is_some::TO_DIGIT_IS_SOME),
+ LintId::of(&try_err::TRY_ERR),
+ LintId::of(&types::FN_TO_NUMERIC_CAST),
+ LintId::of(&types::FN_TO_NUMERIC_CAST_WITH_TRUNCATION),
+ LintId::of(&unsafe_removed_from_name::UNSAFE_REMOVED_FROM_NAME),
+ LintId::of(&write::PRINTLN_EMPTY_STRING),
+ LintId::of(&write::PRINT_LITERAL),
+ LintId::of(&write::PRINT_WITH_NEWLINE),
+ LintId::of(&write::WRITELN_EMPTY_STRING),
+ LintId::of(&write::WRITE_LITERAL),
+ LintId::of(&write::WRITE_WITH_NEWLINE),
+ ]);
+
+ store.register_group(true, "clippy::complexity", Some("clippy_complexity"), vec![
+ LintId::of(&assign_ops::MISREFACTORED_ASSIGN_OP),
+ LintId::of(&attrs::DEPRECATED_CFG_ATTR),
+ LintId::of(&booleans::NONMINIMAL_BOOL),
+ LintId::of(&double_comparison::DOUBLE_COMPARISONS),
+ LintId::of(&double_parens::DOUBLE_PARENS),
+ LintId::of(&duration_subsec::DURATION_SUBSEC),
+ LintId::of(&eval_order_dependence::DIVERGING_SUB_EXPRESSION),
+ LintId::of(&eval_order_dependence::EVAL_ORDER_DEPENDENCE),
+ LintId::of(&explicit_write::EXPLICIT_WRITE),
+ LintId::of(&format::USELESS_FORMAT),
+ LintId::of(&functions::TOO_MANY_ARGUMENTS),
+ LintId::of(&get_last_with_len::GET_LAST_WITH_LEN),
+ LintId::of(&identity_conversion::IDENTITY_CONVERSION),
+ LintId::of(&identity_op::IDENTITY_OP),
+ LintId::of(&int_plus_one::INT_PLUS_ONE),
+ LintId::of(&lifetimes::EXTRA_UNUSED_LIFETIMES),
+ LintId::of(&lifetimes::NEEDLESS_LIFETIMES),
+ LintId::of(&loops::EXPLICIT_COUNTER_LOOP),
+ LintId::of(&loops::MUT_RANGE_BOUND),
+ LintId::of(&loops::WHILE_LET_LOOP),
+ LintId::of(&map_unit_fn::OPTION_MAP_UNIT_FN),
+ LintId::of(&map_unit_fn::RESULT_MAP_UNIT_FN),
+ LintId::of(&matches::MATCH_AS_REF),
+ LintId::of(&matches::MATCH_SINGLE_BINDING),
+ LintId::of(&matches::WILDCARD_IN_OR_PATTERNS),
+ LintId::of(&methods::CLONE_ON_COPY),
+ LintId::of(&methods::FILTER_NEXT),
+ LintId::of(&methods::FLAT_MAP_IDENTITY),
+ LintId::of(&methods::OPTION_AND_THEN_SOME),
+ LintId::of(&methods::OPTION_AS_REF_DEREF),
+ LintId::of(&methods::SEARCH_IS_SOME),
+ LintId::of(&methods::SKIP_WHILE_NEXT),
+ LintId::of(&methods::SUSPICIOUS_MAP),
+ LintId::of(&methods::UNNECESSARY_FILTER_MAP),
+ LintId::of(&methods::USELESS_ASREF),
+ LintId::of(&misc::SHORT_CIRCUIT_STATEMENT),
+ LintId::of(&misc_early::REDUNDANT_CLOSURE_CALL),
+ LintId::of(&misc_early::UNNEEDED_WILDCARD_PATTERN),
+ LintId::of(&misc_early::ZERO_PREFIXED_LITERAL),
+ LintId::of(&needless_bool::BOOL_COMPARISON),
+ LintId::of(&needless_bool::NEEDLESS_BOOL),
+ LintId::of(&needless_borrowed_ref::NEEDLESS_BORROWED_REFERENCE),
+ LintId::of(&needless_update::NEEDLESS_UPDATE),
+ LintId::of(&neg_cmp_op_on_partial_ord::NEG_CMP_OP_ON_PARTIAL_ORD),
+ LintId::of(&no_effect::NO_EFFECT),
+ LintId::of(&no_effect::UNNECESSARY_OPERATION),
+ LintId::of(&overflow_check_conditional::OVERFLOW_CHECK_CONDITIONAL),
+ LintId::of(&partialeq_ne_impl::PARTIALEQ_NE_IMPL),
+ LintId::of(&precedence::PRECEDENCE),
+ LintId::of(&ptr_offset_with_cast::PTR_OFFSET_WITH_CAST),
+ LintId::of(&ranges::RANGE_MINUS_ONE),
+ LintId::of(&ranges::RANGE_ZIP_WITH_LEN),
+ LintId::of(&reference::DEREF_ADDROF),
+ LintId::of(&reference::REF_IN_DEREF),
+ LintId::of(&swap::MANUAL_SWAP),
+ LintId::of(&temporary_assignment::TEMPORARY_ASSIGNMENT),
+ LintId::of(&transmute::CROSSPOINTER_TRANSMUTE),
+ LintId::of(&transmute::TRANSMUTE_BYTES_TO_STR),
+ LintId::of(&transmute::TRANSMUTE_FLOAT_TO_INT),
+ LintId::of(&transmute::TRANSMUTE_INT_TO_BOOL),
+ LintId::of(&transmute::TRANSMUTE_INT_TO_CHAR),
+ LintId::of(&transmute::TRANSMUTE_INT_TO_FLOAT),
+ LintId::of(&transmute::TRANSMUTE_PTR_TO_PTR),
+ LintId::of(&transmute::TRANSMUTE_PTR_TO_REF),
+ LintId::of(&types::BORROWED_BOX),
+ LintId::of(&types::CHAR_LIT_AS_U8),
+ LintId::of(&types::TYPE_COMPLEXITY),
+ LintId::of(&types::UNIT_ARG),
+ LintId::of(&types::UNNECESSARY_CAST),
+ LintId::of(&types::VEC_BOX),
+ LintId::of(&unwrap::UNNECESSARY_UNWRAP),
+ LintId::of(&zero_div_zero::ZERO_DIVIDED_BY_ZERO),
+ ]);
+
+ store.register_group(true, "clippy::correctness", Some("clippy_correctness"), vec![
+ LintId::of(&approx_const::APPROX_CONSTANT),
+ LintId::of(&atomic_ordering::INVALID_ATOMIC_ORDERING),
+ LintId::of(&attrs::DEPRECATED_SEMVER),
+ LintId::of(&attrs::MISMATCHED_TARGET_OS),
+ LintId::of(&attrs::USELESS_ATTRIBUTE),
+ LintId::of(&bit_mask::BAD_BIT_MASK),
+ LintId::of(&bit_mask::INEFFECTIVE_BIT_MASK),
+ LintId::of(&booleans::LOGIC_BUG),
+ LintId::of(&copies::IFS_SAME_COND),
+ LintId::of(&copies::IF_SAME_THEN_ELSE),
+ LintId::of(&derive::DERIVE_HASH_XOR_EQ),
+ LintId::of(&drop_bounds::DROP_BOUNDS),
+ LintId::of(&drop_forget_ref::DROP_COPY),
+ LintId::of(&drop_forget_ref::DROP_REF),
+ LintId::of(&drop_forget_ref::FORGET_COPY),
+ LintId::of(&drop_forget_ref::FORGET_REF),
+ LintId::of(&enum_clike::ENUM_CLIKE_UNPORTABLE_VARIANT),
+ LintId::of(&eq_op::EQ_OP),
+ LintId::of(&erasing_op::ERASING_OP),
+ LintId::of(&formatting::POSSIBLE_MISSING_COMMA),
+ LintId::of(&functions::NOT_UNSAFE_PTR_ARG_DEREF),
+ LintId::of(&if_let_mutex::IF_LET_MUTEX),
+ LintId::of(&indexing_slicing::OUT_OF_BOUNDS_INDEXING),
+ LintId::of(&infinite_iter::INFINITE_ITER),
+ LintId::of(&inherent_to_string::INHERENT_TO_STRING_SHADOW_DISPLAY),
+ LintId::of(&inline_fn_without_body::INLINE_FN_WITHOUT_BODY),
+ LintId::of(&let_underscore::LET_UNDERSCORE_LOCK),
+ LintId::of(&literal_representation::MISTYPED_LITERAL_SUFFIXES),
+ LintId::of(&loops::FOR_LOOP_OVER_OPTION),
+ LintId::of(&loops::FOR_LOOP_OVER_RESULT),
+ LintId::of(&loops::ITER_NEXT_LOOP),
+ LintId::of(&loops::NEVER_LOOP),
+ LintId::of(&loops::REVERSE_RANGE_LOOP),
+ LintId::of(&loops::WHILE_IMMUTABLE_CONDITION),
+ LintId::of(&match_on_vec_items::MATCH_ON_VEC_ITEMS),
+ LintId::of(&mem_discriminant::MEM_DISCRIMINANT_NON_ENUM),
+ LintId::of(&mem_replace::MEM_REPLACE_WITH_UNINIT),
+ LintId::of(&methods::CLONE_DOUBLE_REF),
+ LintId::of(&methods::ITERATOR_STEP_BY_ZERO),
+ LintId::of(&methods::TEMPORARY_CSTRING_AS_PTR),
+ LintId::of(&methods::UNINIT_ASSUMED_INIT),
+ LintId::of(&methods::ZST_OFFSET),
+ LintId::of(&minmax::MIN_MAX),
+ LintId::of(&misc::CMP_NAN),
+ LintId::of(&misc::FLOAT_CMP),
+ LintId::of(&misc::MODULO_ONE),
+ LintId::of(&mut_key::MUTABLE_KEY_TYPE),
+ LintId::of(&non_copy_const::BORROW_INTERIOR_MUTABLE_CONST),
+ LintId::of(&non_copy_const::DECLARE_INTERIOR_MUTABLE_CONST),
+ LintId::of(&open_options::NONSENSICAL_OPEN_OPTIONS),
+ LintId::of(&option_env_unwrap::OPTION_ENV_UNWRAP),
+ LintId::of(&ptr::MUT_FROM_REF),
+ LintId::of(®ex::INVALID_REGEX),
+ LintId::of(&serde_api::SERDE_API_MISUSE),
+ LintId::of(&suspicious_trait_impl::SUSPICIOUS_ARITHMETIC_IMPL),
+ LintId::of(&suspicious_trait_impl::SUSPICIOUS_OP_ASSIGN_IMPL),
+ LintId::of(&swap::ALMOST_SWAPPED),
+ LintId::of(&transmute::UNSOUND_COLLECTION_TRANSMUTE),
+ LintId::of(&transmute::WRONG_TRANSMUTE),
+ LintId::of(&transmuting_null::TRANSMUTING_NULL),
+ LintId::of(&types::ABSURD_EXTREME_COMPARISONS),
+ LintId::of(&types::CAST_PTR_ALIGNMENT),
+ LintId::of(&types::CAST_REF_TO_MUT),
+ LintId::of(&types::UNIT_CMP),
+ LintId::of(&unicode::ZERO_WIDTH_SPACE),
+ LintId::of(&unnamed_address::FN_ADDRESS_COMPARISONS),
+ LintId::of(&unnamed_address::VTABLE_ADDRESS_COMPARISONS),
+ LintId::of(&unused_io_amount::UNUSED_IO_AMOUNT),
+ LintId::of(&unwrap::PANICKING_UNWRAP),
+ ]);
+
+ store.register_group(true, "clippy::perf", Some("clippy_perf"), vec![
+ LintId::of(&bytecount::NAIVE_BYTECOUNT),
+ LintId::of(&entry::MAP_ENTRY),
+ LintId::of(&escape::BOXED_LOCAL),
+ LintId::of(&large_const_arrays::LARGE_CONST_ARRAYS),
+ LintId::of(&large_enum_variant::LARGE_ENUM_VARIANT),
+ LintId::of(&loops::MANUAL_MEMCPY),
+ LintId::of(&loops::NEEDLESS_COLLECT),
+ LintId::of(&methods::EXPECT_FUN_CALL),
+ LintId::of(&methods::ITER_NTH),
+ LintId::of(&methods::OR_FUN_CALL),
+ LintId::of(&methods::SINGLE_CHAR_PATTERN),
+ LintId::of(&misc::CMP_OWNED),
+ LintId::of(&mutex_atomic::MUTEX_ATOMIC),
+ LintId::of(&redundant_clone::REDUNDANT_CLONE),
+ LintId::of(&slow_vector_initialization::SLOW_VECTOR_INITIALIZATION),
+ LintId::of(&types::BOX_VEC),
+ LintId::of(&types::REDUNDANT_ALLOCATION),
+ LintId::of(&vec::USELESS_VEC),
+ ]);
+
+ store.register_group(true, "clippy::cargo", Some("clippy_cargo"), vec![
+ LintId::of(&cargo_common_metadata::CARGO_COMMON_METADATA),
+ LintId::of(&multiple_crate_versions::MULTIPLE_CRATE_VERSIONS),
+ LintId::of(&wildcard_dependencies::WILDCARD_DEPENDENCIES),
+ ]);
+
+ store.register_group(true, "clippy::nursery", Some("clippy_nursery"), vec![
+ LintId::of(&attrs::EMPTY_LINE_AFTER_OUTER_ATTR),
+ LintId::of(&cognitive_complexity::COGNITIVE_COMPLEXITY),
+ LintId::of(&fallible_impl_from::FALLIBLE_IMPL_FROM),
+ LintId::of(&floating_point_arithmetic::IMPRECISE_FLOPS),
+ LintId::of(&floating_point_arithmetic::SUBOPTIMAL_FLOPS),
+ LintId::of(&future_not_send::FUTURE_NOT_SEND),
+ LintId::of(&missing_const_for_fn::MISSING_CONST_FOR_FN),
+ LintId::of(&mutable_debug_assertion::DEBUG_ASSERT_WITH_MUT_CALL),
+ LintId::of(&mutex_atomic::MUTEX_INTEGER),
+ LintId::of(&needless_borrow::NEEDLESS_BORROW),
+ LintId::of(&path_buf_push_overwrite::PATH_BUF_PUSH_OVERWRITE),
+ LintId::of(&redundant_pub_crate::REDUNDANT_PUB_CRATE),
+ LintId::of(&transmute::USELESS_TRANSMUTE),
+ LintId::of(&use_self::USE_SELF),
+ ]);
+}
+
+#[rustfmt::skip]
+fn register_removed_non_tool_lints(store: &mut rustc_lint::LintStore) {
+ store.register_removed(
+ "should_assert_eq",
+ "`assert!()` will be more flexible with RFC 2011",
+ );
+ store.register_removed(
+ "extend_from_slice",
+ "`.extend_from_slice(_)` is a faster way to extend a Vec by a slice",
+ );
+ store.register_removed(
+ "range_step_by_zero",
+ "`iterator.step_by(0)` panics nowadays",
+ );
+ store.register_removed(
+ "unstable_as_slice",
+ "`Vec::as_slice` has been stabilized in 1.7",
+ );
+ store.register_removed(
+ "unstable_as_mut_slice",
+ "`Vec::as_mut_slice` has been stabilized in 1.7",
+ );
+ store.register_removed(
+ "str_to_string",
+ "using `str::to_string` is common even today and specialization will likely happen soon",
+ );
+ store.register_removed(
+ "string_to_string",
+ "using `string::to_string` is common even today and specialization will likely happen soon",
+ );
+ store.register_removed(
+ "misaligned_transmute",
+ "this lint has been split into cast_ptr_alignment and transmute_ptr_to_ptr",
+ );
+ store.register_removed(
+ "assign_ops",
+ "using compound assignment operators (e.g., `+=`) is harmless",
+ );
+ store.register_removed(
+ "if_let_redundant_pattern_matching",
+ "this lint has been changed to redundant_pattern_matching",
+ );
+ store.register_removed(
+ "unsafe_vector_initialization",
+ "the replacement suggested by this lint had substantially different behavior",
+ );
+}
+
+/// Register renamed lints.
+///
+/// Used in `./src/driver.rs`.
+pub fn register_renamed(ls: &mut rustc_lint::LintStore) {
+ ls.register_renamed("clippy::stutter", "clippy::module_name_repetitions");
+ ls.register_renamed("clippy::new_without_default_derive", "clippy::new_without_default");
+ ls.register_renamed("clippy::cyclomatic_complexity", "clippy::cognitive_complexity");
+ ls.register_renamed("clippy::const_static_lifetime", "clippy::redundant_static_lifetimes");
+}
+
+// only exists to let the dogfood integration test works.
+// Don't run clippy as an executable directly
+#[allow(dead_code)]
+fn main() {
+ panic!("Please use the cargo-clippy executable");
+}
diff --git a/src/tools/clippy/clippy_lints/src/lifetimes.rs b/src/tools/clippy/clippy_lints/src/lifetimes.rs
new file mode 100644
index 00000000000..d80ad47ab24
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/lifetimes.rs
@@ -0,0 +1,526 @@
+use rustc_data_structures::fx::{FxHashMap, FxHashSet};
+use rustc_hir::def::{DefKind, Res};
+use rustc_hir::intravisit::{
+ walk_fn_decl, walk_generic_param, walk_generics, walk_param_bound, walk_ty, NestedVisitorMap, Visitor,
+};
+use rustc_hir::FnRetTy::Return;
+use rustc_hir::{
+ BodyId, FnDecl, GenericArg, GenericBound, GenericParam, GenericParamKind, Generics, ImplItem, ImplItemKind, Item,
+ ItemKind, Lifetime, LifetimeName, ParamName, QPath, TraitBoundModifier, TraitFn, TraitItem, TraitItemKind, Ty,
+ TyKind, WhereClause, WherePredicate,
+};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::hir::map::Map;
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::source_map::Span;
+use rustc_span::symbol::kw;
+
+use crate::reexport::Name;
+use crate::utils::{in_macro, last_path_segment, span_lint, trait_ref_of_method};
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for lifetime annotations which can be removed by
+ /// relying on lifetime elision.
+ ///
+ /// **Why is this bad?** The additional lifetimes make the code look more
+ /// complicated, while there is nothing out of the ordinary going on. Removing
+ /// them leads to more readable code.
+ ///
+ /// **Known problems:** Potential false negatives: we bail out if the function
+ /// has a `where` clause where lifetimes are mentioned.
+ ///
+ /// **Example:**
+ /// ```rust
+ /// // Bad: unnecessary lifetime annotations
+ /// fn in_and_out<'a>(x: &'a u8, y: u8) -> &'a u8 {
+ /// x
+ /// }
+ ///
+ /// // Good
+ /// fn elided(x: &u8, y: u8) -> &u8 {
+ /// x
+ /// }
+ /// ```
+ pub NEEDLESS_LIFETIMES,
+ complexity,
+ "using explicit lifetimes for references in function arguments when elision rules \
+ would allow omitting them"
+}
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for lifetimes in generics that are never used
+ /// anywhere else.
+ ///
+ /// **Why is this bad?** The additional lifetimes make the code look more
+ /// complicated, while there is nothing out of the ordinary going on. Removing
+ /// them leads to more readable code.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```rust
+ /// // Bad: unnecessary lifetimes
+ /// fn unused_lifetime<'a>(x: u8) {
+ /// // ..
+ /// }
+ ///
+ /// // Good
+ /// fn no_lifetime(x: u8) {
+ /// // ...
+ /// }
+ /// ```
+ pub EXTRA_UNUSED_LIFETIMES,
+ complexity,
+ "unused lifetimes in function definitions"
+}
+
+declare_lint_pass!(Lifetimes => [NEEDLESS_LIFETIMES, EXTRA_UNUSED_LIFETIMES]);
+
+impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Lifetimes {
+ fn check_item(&mut self, cx: &LateContext<'a, 'tcx>, item: &'tcx Item<'_>) {
+ if let ItemKind::Fn(ref sig, ref generics, id) = item.kind {
+ check_fn_inner(cx, &sig.decl, Some(id), generics, item.span, true);
+ }
+ }
+
+ fn check_impl_item(&mut self, cx: &LateContext<'a, 'tcx>, item: &'tcx ImplItem<'_>) {
+ if let ImplItemKind::Fn(ref sig, id) = item.kind {
+ let report_extra_lifetimes = trait_ref_of_method(cx, item.hir_id).is_none();
+ check_fn_inner(
+ cx,
+ &sig.decl,
+ Some(id),
+ &item.generics,
+ item.span,
+ report_extra_lifetimes,
+ );
+ }
+ }
+
+ fn check_trait_item(&mut self, cx: &LateContext<'a, 'tcx>, item: &'tcx TraitItem<'_>) {
+ if let TraitItemKind::Fn(ref sig, ref body) = item.kind {
+ let body = match *body {
+ TraitFn::Required(_) => None,
+ TraitFn::Provided(id) => Some(id),
+ };
+ check_fn_inner(cx, &sig.decl, body, &item.generics, item.span, true);
+ }
+ }
+}
+
+/// The lifetime of a &-reference.
+#[derive(PartialEq, Eq, Hash, Debug)]
+enum RefLt {
+ Unnamed,
+ Static,
+ Named(Name),
+}
+
+fn check_fn_inner<'a, 'tcx>(
+ cx: &LateContext<'a, 'tcx>,
+ decl: &'tcx FnDecl<'_>,
+ body: Option,
+ generics: &'tcx Generics<'_>,
+ span: Span,
+ report_extra_lifetimes: bool,
+) {
+ if in_macro(span) || has_where_lifetimes(cx, &generics.where_clause) {
+ return;
+ }
+
+ let mut bounds_lts = Vec::new();
+ let types = generics.params.iter().filter(|param| match param.kind {
+ GenericParamKind::Type { .. } => true,
+ _ => false,
+ });
+ for typ in types {
+ for bound in typ.bounds {
+ let mut visitor = RefVisitor::new(cx);
+ walk_param_bound(&mut visitor, bound);
+ if visitor.lts.iter().any(|lt| matches!(lt, RefLt::Named(_))) {
+ return;
+ }
+ if let GenericBound::Trait(ref trait_ref, _) = *bound {
+ let params = &trait_ref
+ .trait_ref
+ .path
+ .segments
+ .last()
+ .expect("a path must have at least one segment")
+ .args;
+ if let Some(ref params) = *params {
+ let lifetimes = params.args.iter().filter_map(|arg| match arg {
+ GenericArg::Lifetime(lt) => Some(lt),
+ _ => None,
+ });
+ for bound in lifetimes {
+ if bound.name != LifetimeName::Static && !bound.is_elided() {
+ return;
+ }
+ bounds_lts.push(bound);
+ }
+ }
+ }
+ }
+ }
+ if could_use_elision(cx, decl, body, &generics.params, bounds_lts) {
+ span_lint(
+ cx,
+ NEEDLESS_LIFETIMES,
+ span.with_hi(decl.output.span().hi()),
+ "explicit lifetimes given in parameter types where they could be elided \
+ (or replaced with `'_` if needed by type declaration)",
+ );
+ }
+ if report_extra_lifetimes {
+ self::report_extra_lifetimes(cx, decl, generics);
+ }
+}
+
+fn could_use_elision<'a, 'tcx>(
+ cx: &LateContext<'a, 'tcx>,
+ func: &'tcx FnDecl<'_>,
+ body: Option,
+ named_generics: &'tcx [GenericParam<'_>],
+ bounds_lts: Vec<&'tcx Lifetime>,
+) -> bool {
+ // There are two scenarios where elision works:
+ // * no output references, all input references have different LT
+ // * output references, exactly one input reference with same LT
+ // All lifetimes must be unnamed, 'static or defined without bounds on the
+ // level of the current item.
+
+ // check named LTs
+ let allowed_lts = allowed_lts_from(named_generics);
+
+ // these will collect all the lifetimes for references in arg/return types
+ let mut input_visitor = RefVisitor::new(cx);
+ let mut output_visitor = RefVisitor::new(cx);
+
+ // extract lifetimes in input argument types
+ for arg in func.inputs {
+ input_visitor.visit_ty(arg);
+ }
+ // extract lifetimes in output type
+ if let Return(ref ty) = func.output {
+ output_visitor.visit_ty(ty);
+ }
+
+ let input_lts = match input_visitor.into_vec() {
+ Some(lts) => lts_from_bounds(lts, bounds_lts.into_iter()),
+ None => return false,
+ };
+ let output_lts = match output_visitor.into_vec() {
+ Some(val) => val,
+ None => return false,
+ };
+
+ if let Some(body_id) = body {
+ let mut checker = BodyLifetimeChecker {
+ lifetimes_used_in_body: false,
+ };
+ checker.visit_expr(&cx.tcx.hir().body(body_id).value);
+ if checker.lifetimes_used_in_body {
+ return false;
+ }
+ }
+
+ // check for lifetimes from higher scopes
+ for lt in input_lts.iter().chain(output_lts.iter()) {
+ if !allowed_lts.contains(lt) {
+ return false;
+ }
+ }
+
+ // no input lifetimes? easy case!
+ if input_lts.is_empty() {
+ false
+ } else if output_lts.is_empty() {
+ // no output lifetimes, check distinctness of input lifetimes
+
+ // only unnamed and static, ok
+ let unnamed_and_static = input_lts.iter().all(|lt| *lt == RefLt::Unnamed || *lt == RefLt::Static);
+ if unnamed_and_static {
+ return false;
+ }
+ // we have no output reference, so we only need all distinct lifetimes
+ input_lts.len() == unique_lifetimes(&input_lts)
+ } else {
+ // we have output references, so we need one input reference,
+ // and all output lifetimes must be the same
+ if unique_lifetimes(&output_lts) > 1 {
+ return false;
+ }
+ if input_lts.len() == 1 {
+ match (&input_lts[0], &output_lts[0]) {
+ (&RefLt::Named(n1), &RefLt::Named(n2)) if n1 == n2 => true,
+ (&RefLt::Named(_), &RefLt::Unnamed) => true,
+ _ => false, /* already elided, different named lifetimes
+ * or something static going on */
+ }
+ } else {
+ false
+ }
+ }
+}
+
+fn allowed_lts_from(named_generics: &[GenericParam<'_>]) -> FxHashSet {
+ let mut allowed_lts = FxHashSet::default();
+ for par in named_generics.iter() {
+ if let GenericParamKind::Lifetime { .. } = par.kind {
+ if par.bounds.is_empty() {
+ allowed_lts.insert(RefLt::Named(par.name.ident().name));
+ }
+ }
+ }
+ allowed_lts.insert(RefLt::Unnamed);
+ allowed_lts.insert(RefLt::Static);
+ allowed_lts
+}
+
+fn lts_from_bounds<'a, T: Iterator
- >(mut vec: Vec, bounds_lts: T) -> Vec {
+ for lt in bounds_lts {
+ if lt.name != LifetimeName::Static {
+ vec.push(RefLt::Named(lt.name.ident().name));
+ }
+ }
+
+ vec
+}
+
+/// Number of unique lifetimes in the given vector.
+#[must_use]
+fn unique_lifetimes(lts: &[RefLt]) -> usize {
+ lts.iter().collect::>().len()
+}
+
+/// A visitor usable for `rustc_front::visit::walk_ty()`.
+struct RefVisitor<'a, 'tcx> {
+ cx: &'a LateContext<'a, 'tcx>,
+ lts: Vec,
+ abort: bool,
+}
+
+impl<'v, 't> RefVisitor<'v, 't> {
+ fn new(cx: &'v LateContext<'v, 't>) -> Self {
+ Self {
+ cx,
+ lts: Vec::new(),
+ abort: false,
+ }
+ }
+
+ fn record(&mut self, lifetime: &Option) {
+ if let Some(ref lt) = *lifetime {
+ if lt.name == LifetimeName::Static {
+ self.lts.push(RefLt::Static);
+ } else if let LifetimeName::Param(ParamName::Fresh(_)) = lt.name {
+ // Fresh lifetimes generated should be ignored.
+ } else if lt.is_elided() {
+ self.lts.push(RefLt::Unnamed);
+ } else {
+ self.lts.push(RefLt::Named(lt.name.ident().name));
+ }
+ } else {
+ self.lts.push(RefLt::Unnamed);
+ }
+ }
+
+ fn into_vec(self) -> Option> {
+ if self.abort {
+ None
+ } else {
+ Some(self.lts)
+ }
+ }
+
+ fn collect_anonymous_lifetimes(&mut self, qpath: &QPath<'_>, ty: &Ty<'_>) {
+ if let Some(ref last_path_segment) = last_path_segment(qpath).args {
+ if !last_path_segment.parenthesized
+ && !last_path_segment.args.iter().any(|arg| match arg {
+ GenericArg::Lifetime(_) => true,
+ _ => false,
+ })
+ {
+ let hir_id = ty.hir_id;
+ match self.cx.tables.qpath_res(qpath, hir_id) {
+ Res::Def(DefKind::TyAlias | DefKind::Struct, def_id) => {
+ let generics = self.cx.tcx.generics_of(def_id);
+ for _ in generics.params.as_slice() {
+ self.record(&None);
+ }
+ },
+ Res::Def(DefKind::Trait, def_id) => {
+ let trait_def = self.cx.tcx.trait_def(def_id);
+ for _ in &self.cx.tcx.generics_of(trait_def.def_id).params {
+ self.record(&None);
+ }
+ },
+ _ => (),
+ }
+ }
+ }
+ }
+}
+
+impl<'a, 'tcx> Visitor<'tcx> for RefVisitor<'a, 'tcx> {
+ type Map = Map<'tcx>;
+
+ // for lifetimes as parameters of generics
+ fn visit_lifetime(&mut self, lifetime: &'tcx Lifetime) {
+ self.record(&Some(*lifetime));
+ }
+
+ fn visit_ty(&mut self, ty: &'tcx Ty<'_>) {
+ match ty.kind {
+ TyKind::Rptr(ref lt, _) if lt.is_elided() => {
+ self.record(&None);
+ },
+ TyKind::Path(ref path) => {
+ self.collect_anonymous_lifetimes(path, ty);
+ },
+ TyKind::Def(item, _) => {
+ let map = self.cx.tcx.hir();
+ if let ItemKind::OpaqueTy(ref exist_ty) = map.expect_item(item.id).kind {
+ for bound in exist_ty.bounds {
+ if let GenericBound::Outlives(_) = *bound {
+ self.record(&None);
+ }
+ }
+ } else {
+ unreachable!()
+ }
+ walk_ty(self, ty);
+ },
+ TyKind::TraitObject(bounds, ref lt) => {
+ if !lt.is_elided() {
+ self.abort = true;
+ }
+ for bound in bounds {
+ self.visit_poly_trait_ref(bound, TraitBoundModifier::None);
+ }
+ return;
+ },
+ _ => (),
+ }
+ walk_ty(self, ty);
+ }
+ fn nested_visit_map(&mut self) -> NestedVisitorMap {
+ NestedVisitorMap::None
+ }
+}
+
+/// Are any lifetimes mentioned in the `where` clause? If so, we don't try to
+/// reason about elision.
+fn has_where_lifetimes<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, where_clause: &'tcx WhereClause<'_>) -> bool {
+ for predicate in where_clause.predicates {
+ match *predicate {
+ WherePredicate::RegionPredicate(..) => return true,
+ WherePredicate::BoundPredicate(ref pred) => {
+ // a predicate like F: Trait or F: for<'a> Trait<'a>
+ let mut visitor = RefVisitor::new(cx);
+ // walk the type F, it may not contain LT refs
+ walk_ty(&mut visitor, &pred.bounded_ty);
+ if !visitor.lts.is_empty() {
+ return true;
+ }
+ // if the bounds define new lifetimes, they are fine to occur
+ let allowed_lts = allowed_lts_from(&pred.bound_generic_params);
+ // now walk the bounds
+ for bound in pred.bounds.iter() {
+ walk_param_bound(&mut visitor, bound);
+ }
+ // and check that all lifetimes are allowed
+ match visitor.into_vec() {
+ None => return false,
+ Some(lts) => {
+ for lt in lts {
+ if !allowed_lts.contains(<) {
+ return true;
+ }
+ }
+ },
+ }
+ },
+ WherePredicate::EqPredicate(ref pred) => {
+ let mut visitor = RefVisitor::new(cx);
+ walk_ty(&mut visitor, &pred.lhs_ty);
+ walk_ty(&mut visitor, &pred.rhs_ty);
+ if !visitor.lts.is_empty() {
+ return true;
+ }
+ },
+ }
+ }
+ false
+}
+
+struct LifetimeChecker {
+ map: FxHashMap,
+}
+
+impl<'tcx> Visitor<'tcx> for LifetimeChecker {
+ type Map = Map<'tcx>;
+
+ // for lifetimes as parameters of generics
+ fn visit_lifetime(&mut self, lifetime: &'tcx Lifetime) {
+ self.map.remove(&lifetime.name.ident().name);
+ }
+
+ fn visit_generic_param(&mut self, param: &'tcx GenericParam<'_>) {
+ // don't actually visit `<'a>` or `<'a: 'b>`
+ // we've already visited the `'a` declarations and
+ // don't want to spuriously remove them
+ // `'b` in `'a: 'b` is useless unless used elsewhere in
+ // a non-lifetime bound
+ if let GenericParamKind::Type { .. } = param.kind {
+ walk_generic_param(self, param)
+ }
+ }
+ fn nested_visit_map(&mut self) -> NestedVisitorMap {
+ NestedVisitorMap::None
+ }
+}
+
+fn report_extra_lifetimes<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, func: &'tcx FnDecl<'_>, generics: &'tcx Generics<'_>) {
+ let hs = generics
+ .params
+ .iter()
+ .filter_map(|par| match par.kind {
+ GenericParamKind::Lifetime { .. } => Some((par.name.ident().name, par.span)),
+ _ => None,
+ })
+ .collect();
+ let mut checker = LifetimeChecker { map: hs };
+
+ walk_generics(&mut checker, generics);
+ walk_fn_decl(&mut checker, func);
+
+ for &v in checker.map.values() {
+ span_lint(
+ cx,
+ EXTRA_UNUSED_LIFETIMES,
+ v,
+ "this lifetime isn't used in the function definition",
+ );
+ }
+}
+
+struct BodyLifetimeChecker {
+ lifetimes_used_in_body: bool,
+}
+
+impl<'tcx> Visitor<'tcx> for BodyLifetimeChecker {
+ type Map = Map<'tcx>;
+
+ // for lifetimes as parameters of generics
+ fn visit_lifetime(&mut self, lifetime: &'tcx Lifetime) {
+ if lifetime.name.ident().name != kw::Invalid && lifetime.name.ident().name != kw::StaticLifetime {
+ self.lifetimes_used_in_body = true;
+ }
+ }
+
+ fn nested_visit_map(&mut self) -> NestedVisitorMap {
+ NestedVisitorMap::None
+ }
+}
diff --git a/src/tools/clippy/clippy_lints/src/literal_representation.rs b/src/tools/clippy/clippy_lints/src/literal_representation.rs
new file mode 100644
index 00000000000..ec7c4531ed7
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/literal_representation.rs
@@ -0,0 +1,430 @@
+//! Lints concerned with the grouping of digits with underscores in integral or
+//! floating-point literal expressions.
+
+use crate::utils::{
+ in_macro,
+ numeric_literal::{NumericLiteral, Radix},
+ snippet_opt, span_lint_and_sugg,
+};
+use if_chain::if_chain;
+use rustc_ast::ast::{Expr, ExprKind, Lit, LitKind};
+use rustc_errors::Applicability;
+use rustc_lint::{EarlyContext, EarlyLintPass, LintContext};
+use rustc_middle::lint::in_external_macro;
+use rustc_session::{declare_lint_pass, declare_tool_lint, impl_lint_pass};
+
+declare_clippy_lint! {
+ /// **What it does:** Warns if a long integral or floating-point constant does
+ /// not contain underscores.
+ ///
+ /// **Why is this bad?** Reading long numbers is difficult without separators.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ ///
+ /// ```rust
+ /// let x: u64 = 61864918973511;
+ /// ```
+ pub UNREADABLE_LITERAL,
+ pedantic,
+ "long integer literal without underscores"
+}
+
+declare_clippy_lint! {
+ /// **What it does:** Warns for mistyped suffix in literals
+ ///
+ /// **Why is this bad?** This is most probably a typo
+ ///
+ /// **Known problems:**
+ /// - Recommends a signed suffix, even though the number might be too big and an unsigned
+ /// suffix is required
+ /// - Does not match on `_127` since that is a valid grouping for decimal and octal numbers
+ ///
+ /// **Example:**
+ ///
+ /// ```rust
+ /// 2_32;
+ /// ```
+ pub MISTYPED_LITERAL_SUFFIXES,
+ correctness,
+ "mistyped literal suffix"
+}
+
+declare_clippy_lint! {
+ /// **What it does:** Warns if an integral or floating-point constant is
+ /// grouped inconsistently with underscores.
+ ///
+ /// **Why is this bad?** Readers may incorrectly interpret inconsistently
+ /// grouped digits.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ ///
+ /// ```rust
+ /// let x: u64 = 618_64_9189_73_511;
+ /// ```
+ pub INCONSISTENT_DIGIT_GROUPING,
+ style,
+ "integer literals with digits grouped inconsistently"
+}
+
+declare_clippy_lint! {
+ /// **What it does:** Warns if the digits of an integral or floating-point
+ /// constant are grouped into groups that
+ /// are too large.
+ ///
+ /// **Why is this bad?** Negatively impacts readability.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ ///
+ /// ```rust
+ /// let x: u64 = 6186491_8973511;
+ /// ```
+ pub LARGE_DIGIT_GROUPS,
+ pedantic,
+ "grouping digits into groups that are too large"
+}
+
+declare_clippy_lint! {
+ /// **What it does:** Warns if there is a better representation for a numeric literal.
+ ///
+ /// **Why is this bad?** Especially for big powers of 2 a hexadecimal representation is more
+ /// readable than a decimal representation.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ ///
+ /// `255` => `0xFF`
+ /// `65_535` => `0xFFFF`
+ /// `4_042_322_160` => `0xF0F0_F0F0`
+ pub DECIMAL_LITERAL_REPRESENTATION,
+ restriction,
+ "using decimal representation when hexadecimal would be better"
+}
+
+enum WarningType {
+ UnreadableLiteral,
+ InconsistentDigitGrouping,
+ LargeDigitGroups,
+ DecimalRepresentation,
+ MistypedLiteralSuffix,
+}
+
+impl WarningType {
+ fn display(&self, suggested_format: String, cx: &EarlyContext<'_>, span: rustc_span::Span) {
+ match self {
+ Self::MistypedLiteralSuffix => span_lint_and_sugg(
+ cx,
+ MISTYPED_LITERAL_SUFFIXES,
+ span,
+ "mistyped literal suffix",
+ "did you mean to write",
+ suggested_format,
+ Applicability::MaybeIncorrect,
+ ),
+ Self::UnreadableLiteral => span_lint_and_sugg(
+ cx,
+ UNREADABLE_LITERAL,
+ span,
+ "long literal lacking separators",
+ "consider",
+ suggested_format,
+ Applicability::MachineApplicable,
+ ),
+ Self::LargeDigitGroups => span_lint_and_sugg(
+ cx,
+ LARGE_DIGIT_GROUPS,
+ span,
+ "digit groups should be smaller",
+ "consider",
+ suggested_format,
+ Applicability::MachineApplicable,
+ ),
+ Self::InconsistentDigitGrouping => span_lint_and_sugg(
+ cx,
+ INCONSISTENT_DIGIT_GROUPING,
+ span,
+ "digits grouped inconsistently by underscores",
+ "consider",
+ suggested_format,
+ Applicability::MachineApplicable,
+ ),
+ Self::DecimalRepresentation => span_lint_and_sugg(
+ cx,
+ DECIMAL_LITERAL_REPRESENTATION,
+ span,
+ "integer literal has a better hexadecimal representation",
+ "consider",
+ suggested_format,
+ Applicability::MachineApplicable,
+ ),
+ };
+ }
+}
+
+declare_lint_pass!(LiteralDigitGrouping => [
+ UNREADABLE_LITERAL,
+ INCONSISTENT_DIGIT_GROUPING,
+ LARGE_DIGIT_GROUPS,
+ MISTYPED_LITERAL_SUFFIXES,
+]);
+
+impl EarlyLintPass for LiteralDigitGrouping {
+ fn check_expr(&mut self, cx: &EarlyContext<'_>, expr: &Expr) {
+ if in_external_macro(cx.sess(), expr.span) {
+ return;
+ }
+
+ if let ExprKind::Lit(ref lit) = expr.kind {
+ Self::check_lit(cx, lit)
+ }
+ }
+}
+
+// Length of each UUID hyphenated group in hex digits.
+const UUID_GROUP_LENS: [usize; 5] = [8, 4, 4, 4, 12];
+
+impl LiteralDigitGrouping {
+ fn check_lit(cx: &EarlyContext<'_>, lit: &Lit) {
+ if_chain! {
+ if let Some(src) = snippet_opt(cx, lit.span);
+ if let Some(mut num_lit) = NumericLiteral::from_lit(&src, &lit);
+ then {
+ if !Self::check_for_mistyped_suffix(cx, lit.span, &mut num_lit) {
+ return;
+ }
+
+ if Self::is_literal_uuid_formatted(&mut num_lit) {
+ return;
+ }
+
+ let result = (|| {
+
+ let integral_group_size = Self::get_group_size(num_lit.integer.split('_'))?;
+ if let Some(fraction) = num_lit.fraction {
+ let fractional_group_size = Self::get_group_size(fraction.rsplit('_'))?;
+
+ let consistent = Self::parts_consistent(integral_group_size,
+ fractional_group_size,
+ num_lit.integer.len(),
+ fraction.len());
+ if !consistent {
+ return Err(WarningType::InconsistentDigitGrouping);
+ };
+ }
+ Ok(())
+ })();
+
+
+ if let Err(warning_type) = result {
+ let should_warn = match warning_type {
+ | WarningType::UnreadableLiteral
+ | WarningType::InconsistentDigitGrouping
+ | WarningType::LargeDigitGroups => {
+ !in_macro(lit.span)
+ }
+ WarningType::DecimalRepresentation | WarningType::MistypedLiteralSuffix => {
+ true
+ }
+ };
+ if should_warn {
+ warning_type.display(num_lit.format(), cx, lit.span)
+ }
+ }
+ }
+ }
+ }
+
+ // Returns `false` if the check fails
+ fn check_for_mistyped_suffix(
+ cx: &EarlyContext<'_>,
+ span: rustc_span::Span,
+ num_lit: &mut NumericLiteral<'_>,
+ ) -> bool {
+ if num_lit.suffix.is_some() {
+ return true;
+ }
+
+ let (part, mistyped_suffixes, missing_char) = if let Some((_, exponent)) = &mut num_lit.exponent {
+ (exponent, &["32", "64"][..], 'f')
+ } else if let Some(fraction) = &mut num_lit.fraction {
+ (fraction, &["32", "64"][..], 'f')
+ } else {
+ (&mut num_lit.integer, &["8", "16", "32", "64"][..], 'i')
+ };
+
+ let mut split = part.rsplit('_');
+ let last_group = split.next().expect("At least one group");
+ if split.next().is_some() && mistyped_suffixes.contains(&last_group) {
+ *part = &part[..part.len() - last_group.len()];
+ let mut sugg = num_lit.format();
+ sugg.push('_');
+ sugg.push(missing_char);
+ sugg.push_str(last_group);
+ WarningType::MistypedLiteralSuffix.display(sugg, cx, span);
+ false
+ } else {
+ true
+ }
+ }
+
+ /// Checks whether the numeric literal matches the formatting of a UUID.
+ ///
+ /// Returns `true` if the radix is hexadecimal, and the groups match the
+ /// UUID format of 8-4-4-4-12.
+ fn is_literal_uuid_formatted(num_lit: &mut NumericLiteral<'_>) -> bool {
+ if num_lit.radix != Radix::Hexadecimal {
+ return false;
+ }
+
+ // UUIDs should not have a fraction
+ if num_lit.fraction.is_some() {
+ return false;
+ }
+
+ let group_sizes: Vec = num_lit.integer.split('_').map(str::len).collect();
+ if UUID_GROUP_LENS.len() == group_sizes.len() {
+ UUID_GROUP_LENS.iter().zip(&group_sizes).all(|(&a, &b)| a == b)
+ } else {
+ false
+ }
+ }
+
+ /// Given the sizes of the digit groups of both integral and fractional
+ /// parts, and the length
+ /// of both parts, determine if the digits have been grouped consistently.
+ #[must_use]
+ fn parts_consistent(
+ int_group_size: Option,
+ frac_group_size: Option,
+ int_size: usize,
+ frac_size: usize,
+ ) -> bool {
+ match (int_group_size, frac_group_size) {
+ // No groups on either side of decimal point - trivially consistent.
+ (None, None) => true,
+ // Integral part has grouped digits, fractional part does not.
+ (Some(int_group_size), None) => frac_size <= int_group_size,
+ // Fractional part has grouped digits, integral part does not.
+ (None, Some(frac_group_size)) => int_size <= frac_group_size,
+ // Both parts have grouped digits. Groups should be the same size.
+ (Some(int_group_size), Some(frac_group_size)) => int_group_size == frac_group_size,
+ }
+ }
+
+ /// Returns the size of the digit groups (or None if ungrouped) if successful,
+ /// otherwise returns a `WarningType` for linting.
+ fn get_group_size<'a>(groups: impl Iterator
- ) -> Result, WarningType> {
+ let mut groups = groups.map(str::len);
+
+ let first = groups.next().expect("At least one group");
+
+ if let Some(second) = groups.next() {
+ if !groups.all(|x| x == second) || first > second {
+ Err(WarningType::InconsistentDigitGrouping)
+ } else if second > 4 {
+ Err(WarningType::LargeDigitGroups)
+ } else {
+ Ok(Some(second))
+ }
+ } else if first > 5 {
+ Err(WarningType::UnreadableLiteral)
+ } else {
+ Ok(None)
+ }
+ }
+}
+
+#[allow(clippy::module_name_repetitions)]
+#[derive(Copy, Clone)]
+pub struct DecimalLiteralRepresentation {
+ threshold: u64,
+}
+
+impl_lint_pass!(DecimalLiteralRepresentation => [DECIMAL_LITERAL_REPRESENTATION]);
+
+impl EarlyLintPass for DecimalLiteralRepresentation {
+ fn check_expr(&mut self, cx: &EarlyContext<'_>, expr: &Expr) {
+ if in_external_macro(cx.sess(), expr.span) {
+ return;
+ }
+
+ if let ExprKind::Lit(ref lit) = expr.kind {
+ self.check_lit(cx, lit)
+ }
+ }
+}
+
+impl DecimalLiteralRepresentation {
+ #[must_use]
+ pub fn new(threshold: u64) -> Self {
+ Self { threshold }
+ }
+ fn check_lit(self, cx: &EarlyContext<'_>, lit: &Lit) {
+ // Lint integral literals.
+ if_chain! {
+ if let LitKind::Int(val, _) = lit.kind;
+ if let Some(src) = snippet_opt(cx, lit.span);
+ if let Some(num_lit) = NumericLiteral::from_lit(&src, &lit);
+ if num_lit.radix == Radix::Decimal;
+ if val >= u128::from(self.threshold);
+ then {
+ let hex = format!("{:#X}", val);
+ let num_lit = NumericLiteral::new(&hex, num_lit.suffix, false);
+ let _ = Self::do_lint(num_lit.integer).map_err(|warning_type| {
+ warning_type.display(num_lit.format(), cx, lit.span)
+ });
+ }
+ }
+ }
+
+ fn do_lint(digits: &str) -> Result<(), WarningType> {
+ if digits.len() == 1 {
+ // Lint for 1 digit literals, if someone really sets the threshold that low
+ if digits == "1"
+ || digits == "2"
+ || digits == "4"
+ || digits == "8"
+ || digits == "3"
+ || digits == "7"
+ || digits == "F"
+ {
+ return Err(WarningType::DecimalRepresentation);
+ }
+ } else if digits.len() < 4 {
+ // Lint for Literals with a hex-representation of 2 or 3 digits
+ let f = &digits[0..1]; // first digit
+ let s = &digits[1..]; // suffix
+
+ // Powers of 2
+ if ((f.eq("1") || f.eq("2") || f.eq("4") || f.eq("8")) && s.chars().all(|c| c == '0'))
+ // Powers of 2 minus 1
+ || ((f.eq("1") || f.eq("3") || f.eq("7") || f.eq("F")) && s.chars().all(|c| c == 'F'))
+ {
+ return Err(WarningType::DecimalRepresentation);
+ }
+ } else {
+ // Lint for Literals with a hex-representation of 4 digits or more
+ let f = &digits[0..1]; // first digit
+ let m = &digits[1..digits.len() - 1]; // middle digits, except last
+ let s = &digits[1..]; // suffix
+
+ // Powers of 2 with a margin of +15/-16
+ if ((f.eq("1") || f.eq("2") || f.eq("4") || f.eq("8")) && m.chars().all(|c| c == '0'))
+ || ((f.eq("1") || f.eq("3") || f.eq("7") || f.eq("F")) && m.chars().all(|c| c == 'F'))
+ // Lint for representations with only 0s and Fs, while allowing 7 as the first
+ // digit
+ || ((f.eq("7") || f.eq("F")) && s.chars().all(|c| c == '0' || c == 'F'))
+ {
+ return Err(WarningType::DecimalRepresentation);
+ }
+ }
+
+ Ok(())
+ }
+}
diff --git a/src/tools/clippy/clippy_lints/src/loops.rs b/src/tools/clippy/clippy_lints/src/loops.rs
new file mode 100644
index 00000000000..f7c7fd82d83
--- /dev/null
+++ b/src/tools/clippy/clippy_lints/src/loops.rs
@@ -0,0 +1,2550 @@
+use crate::consts::{constant, Constant};
+use crate::reexport::Name;
+use crate::utils::paths;
+use crate::utils::usage::{is_unused, mutated_variables};
+use crate::utils::{
+ get_enclosing_block, get_parent_expr, get_trait_def_id, has_iter_method, higher, implements_trait,
+ is_integer_const, is_no_std_crate, is_refutable, last_path_segment, match_trait_method, match_type, match_var,
+ multispan_sugg, snippet, snippet_opt, snippet_with_applicability, span_lint, span_lint_and_help,
+ span_lint_and_sugg, span_lint_and_then, SpanlessEq,
+};
+use crate::utils::{is_type_diagnostic_item, qpath_res, same_tys, sext, sugg};
+use if_chain::if_chain;
+use itertools::Itertools;
+use rustc_ast::ast;
+use rustc_data_structures::fx::{FxHashMap, FxHashSet};
+use rustc_errors::Applicability;
+use rustc_hir::def::{DefKind, Res};
+use rustc_hir::intravisit::{walk_block, walk_expr, walk_pat, walk_stmt, NestedVisitorMap, Visitor};
+use rustc_hir::{
+ def_id, BinOpKind, BindingAnnotation, Block, BorrowKind, Expr, ExprKind, GenericArg, HirId, LoopSource,
+ MatchSource, Mutability, Node, Pat, PatKind, QPath, Stmt, StmtKind,
+};
+use rustc_infer::infer::TyCtxtInferExt;
+use rustc_lint::{LateContext, LateLintPass, LintContext};
+use rustc_middle::hir::map::Map;
+use rustc_middle::lint::in_external_macro;
+use rustc_middle::middle::region;
+use rustc_middle::ty::{self, Ty};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::source_map::Span;
+use rustc_span::BytePos;
+use rustc_typeck::expr_use_visitor::{ConsumeMode, Delegate, ExprUseVisitor, Place, PlaceBase};
+use std::iter::{once, Iterator};
+use std::mem;
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for for-loops that manually copy items between
+ /// slices that could be optimized by having a memcpy.
+ ///
+ /// **Why is this bad?** It is not as fast as a memcpy.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```rust
+ /// # let src = vec![1];
+ /// # let mut dst = vec![0; 65];
+ /// for i in 0..src.len() {
+ /// dst[i + 64] = src[i];
+ /// }
+ /// ```
+ /// Could be written as:
+ /// ```rust
+ /// # let src = vec![1];
+ /// # let mut dst = vec![0; 65];
+ /// dst[64..(src.len() + 64)].clone_from_slice(&src[..]);
+ /// ```
+ pub MANUAL_MEMCPY,
+ perf,
+ "manually copying items between slices"
+}
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for looping over the range of `0..len` of some
+ /// collection just to get the values by index.
+ ///
+ /// **Why is this bad?** Just iterating the collection itself makes the intent
+ /// more clear and is probably faster.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```rust
+ /// let vec = vec!['a', 'b', 'c'];
+ /// for i in 0..vec.len() {
+ /// println!("{}", vec[i]);
+ /// }
+ /// ```
+ /// Could be written as:
+ /// ```rust
+ /// let vec = vec!['a', 'b', 'c'];
+ /// for i in vec {
+ /// println!("{}", i);
+ /// }
+ /// ```
+ pub NEEDLESS_RANGE_LOOP,
+ style,
+ "for-looping over a range of indices where an iterator over items would do"
+}
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for loops on `x.iter()` where `&x` will do, and
+ /// suggests the latter.
+ ///
+ /// **Why is this bad?** Readability.
+ ///
+ /// **Known problems:** False negatives. We currently only warn on some known
+ /// types.
+ ///
+ /// **Example:**
+ /// ```rust
+ /// // with `y` a `Vec` or slice:
+ /// # let y = vec![1];
+ /// for x in y.iter() {
+ /// // ..
+ /// }
+ /// ```
+ /// can be rewritten to
+ /// ```rust
+ /// # let y = vec![1];
+ /// for x in &y {
+ /// // ..
+ /// }
+ /// ```
+ pub EXPLICIT_ITER_LOOP,
+ pedantic,
+ "for-looping over `_.iter()` or `_.iter_mut()` when `&_` or `&mut _` would do"
+}
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for loops on `y.into_iter()` where `y` will do, and
+ /// suggests the latter.
+ ///
+ /// **Why is this bad?** Readability.
+ ///
+ /// **Known problems:** None
+ ///
+ /// **Example:**
+ /// ```rust
+ /// # let y = vec![1];
+ /// // with `y` a `Vec` or slice:
+ /// for x in y.into_iter() {
+ /// // ..
+ /// }
+ /// ```
+ /// can be rewritten to
+ /// ```rust
+ /// # let y = vec![1];
+ /// for x in y {
+ /// // ..
+ /// }
+ /// ```
+ pub EXPLICIT_INTO_ITER_LOOP,
+ pedantic,
+ "for-looping over `_.into_iter()` when `_` would do"
+}
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for loops on `x.next()`.
+ ///
+ /// **Why is this bad?** `next()` returns either `Some(value)` if there was a
+ /// value, or `None` otherwise. The insidious thing is that `Option<_>`
+ /// implements `IntoIterator`, so that possibly one value will be iterated,
+ /// leading to some hard to find bugs. No one will want to write such code
+ /// [except to win an Underhanded Rust
+ /// Contest](https://www.reddit.com/r/rust/comments/3hb0wm/underhanded_rust_contest/cu5yuhr).
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```ignore
+ /// for x in y.next() {
+ /// ..
+ /// }
+ /// ```
+ pub ITER_NEXT_LOOP,
+ correctness,
+ "for-looping over `_.next()` which is probably not intended"
+}
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for `for` loops over `Option` values.
+ ///
+ /// **Why is this bad?** Readability. This is more clearly expressed as an `if
+ /// let`.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```ignore
+ /// for x in option {
+ /// ..
+ /// }
+ /// ```
+ ///
+ /// This should be
+ /// ```ignore
+ /// if let Some(x) = option {
+ /// ..
+ /// }
+ /// ```
+ pub FOR_LOOP_OVER_OPTION,
+ correctness,
+ "for-looping over an `Option`, which is more clearly expressed as an `if let`"
+}
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for `for` loops over `Result` values.
+ ///
+ /// **Why is this bad?** Readability. This is more clearly expressed as an `if
+ /// let`.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```ignore
+ /// for x in result {
+ /// ..
+ /// }
+ /// ```
+ ///
+ /// This should be
+ /// ```ignore
+ /// if let Ok(x) = result {
+ /// ..
+ /// }
+ /// ```
+ pub FOR_LOOP_OVER_RESULT,
+ correctness,
+ "for-looping over a `Result`, which is more clearly expressed as an `if let`"
+}
+
+declare_clippy_lint! {
+ /// **What it does:** Detects `loop + match` combinations that are easier
+ /// written as a `while let` loop.
+ ///
+ /// **Why is this bad?** The `while let` loop is usually shorter and more
+ /// readable.
+ ///
+ /// **Known problems:** Sometimes the wrong binding is displayed (#383).
+ ///
+ /// **Example:**
+ /// ```rust,no_run
+ /// # let y = Some(1);
+ /// loop {
+ /// let x = match y {
+ /// Some(x) => x,
+ /// None => break,
+ /// };
+ /// // .. do something with x
+ /// }
+ /// // is easier written as
+ /// while let Some(x) = y {
+ /// // .. do something with x
+ /// };
+ /// ```
+ pub WHILE_LET_LOOP,
+ complexity,
+ "`loop { if let { ... } else break }`, which can be written as a `while let` loop"
+}
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for functions collecting an iterator when collect
+ /// is not needed.
+ ///
+ /// **Why is this bad?** `collect` causes the allocation of a new data structure,
+ /// when this allocation may not be needed.
+ ///
+ /// **Known problems:**
+ /// None
+ ///
+ /// **Example:**
+ /// ```rust
+ /// # let iterator = vec![1].into_iter();
+ /// let len = iterator.clone().collect::>().len();
+ /// // should be
+ /// let len = iterator.count();
+ /// ```
+ pub NEEDLESS_COLLECT,
+ perf,
+ "collecting an iterator when collect is not needed"
+}
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for loops over ranges `x..y` where both `x` and `y`
+ /// are constant and `x` is greater or equal to `y`, unless the range is
+ /// reversed or has a negative `.step_by(_)`.
+ ///
+ /// **Why is it bad?** Such loops will either be skipped or loop until
+ /// wrap-around (in debug code, this may `panic!()`). Both options are probably
+ /// not intended.
+ ///
+ /// **Known problems:** The lint cannot catch loops over dynamically defined
+ /// ranges. Doing this would require simulating all possible inputs and code
+ /// paths through the program, which would be complex and error-prone.
+ ///
+ /// **Example:**
+ /// ```ignore
+ /// for x in 5..10 - 5 {
+ /// ..
+ /// } // oops, stray `-`
+ /// ```
+ pub REVERSE_RANGE_LOOP,
+ correctness,
+ "iteration over an empty range, such as `10..0` or `5..5`"
+}
+
+declare_clippy_lint! {
+ /// **What it does:** Checks `for` loops over slices with an explicit counter
+ /// and suggests the use of `.enumerate()`.
+ ///
+ /// **Why is it bad?** Using `.enumerate()` makes the intent more clear,
+ /// declutters the code and may be faster in some instances.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```rust
+ /// # let v = vec![1];
+ /// # fn bar(bar: usize, baz: usize) {}
+ /// let mut i = 0;
+ /// for item in &v {
+ /// bar(i, *item);
+ /// i += 1;
+ /// }
+ /// ```
+ /// Could be written as
+ /// ```rust
+ /// # let v = vec![1];
+ /// # fn bar(bar: usize, baz: usize) {}
+ /// for (i, item) in v.iter().enumerate() { bar(i, *item); }
+ /// ```
+ pub EXPLICIT_COUNTER_LOOP,
+ complexity,
+ "for-looping with an explicit counter when `_.enumerate()` would do"
+}
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for empty `loop` expressions.
+ ///
+ /// **Why is this bad?** Those busy loops burn CPU cycles without doing
+ /// anything. Think of the environment and either block on something or at least
+ /// make the thread sleep for some microseconds.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```no_run
+ /// loop {}
+ /// ```
+ pub EMPTY_LOOP,
+ style,
+ "empty `loop {}`, which should block or sleep"
+}
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for `while let` expressions on iterators.
+ ///
+ /// **Why is this bad?** Readability. A simple `for` loop is shorter and conveys
+ /// the intent better.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```ignore
+ /// while let Some(val) = iter() {
+ /// ..
+ /// }
+ /// ```
+ pub WHILE_LET_ON_ITERATOR,
+ style,
+ "using a while-let loop instead of a for loop on an iterator"
+}
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for iterating a map (`HashMap` or `BTreeMap`) and
+ /// ignoring either the keys or values.
+ ///
+ /// **Why is this bad?** Readability. There are `keys` and `values` methods that
+ /// can be used to express that don't need the values or keys.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```ignore
+ /// for (k, _) in &map {
+ /// ..
+ /// }
+ /// ```
+ ///
+ /// could be replaced by
+ ///
+ /// ```ignore
+ /// for k in map.keys() {
+ /// ..
+ /// }
+ /// ```
+ pub FOR_KV_MAP,
+ style,
+ "looping on a map using `iter` when `keys` or `values` would do"
+}
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for loops that will always `break`, `return` or
+ /// `continue` an outer loop.
+ ///
+ /// **Why is this bad?** This loop never loops, all it does is obfuscating the
+ /// code.
+ ///
+ /// **Known problems:** None
+ ///
+ /// **Example:**
+ /// ```rust
+ /// loop {
+ /// ..;
+ /// break;
+ /// }
+ /// ```
+ pub NEVER_LOOP,
+ correctness,
+ "any loop that will always `break` or `return`"
+}
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for loops which have a range bound that is a mutable variable
+ ///
+ /// **Why is this bad?** One might think that modifying the mutable variable changes the loop bounds
+ ///
+ /// **Known problems:** None
+ ///
+ /// **Example:**
+ /// ```rust
+ /// let mut foo = 42;
+ /// for i in 0..foo {
+ /// foo -= 1;
+ /// println!("{}", i); // prints numbers from 0 to 42, not 0 to 21
+ /// }
+ /// ```
+ pub MUT_RANGE_BOUND,
+ complexity,
+ "for loop over a range where one of the bounds is a mutable variable"
+}
+
+declare_clippy_lint! {
+ /// **What it does:** Checks whether variables used within while loop condition
+ /// can be (and are) mutated in the body.
+ ///
+ /// **Why is this bad?** If the condition is unchanged, entering the body of the loop
+ /// will lead to an infinite loop.
+ ///
+ /// **Known problems:** If the `while`-loop is in a closure, the check for mutation of the
+ /// condition variables in the body can cause false negatives. For example when only `Upvar` `a` is
+ /// in the condition and only `Upvar` `b` gets mutated in the body, the lint will not trigger.
+ ///
+ /// **Example:**
+ /// ```rust
+ /// let i = 0;
+ /// while i > 10 {
+ /// println!("let me loop forever!");
+ /// }
+ /// ```
+ pub WHILE_IMMUTABLE_CONDITION,
+ correctness,
+ "variables used within while expression are not mutated in the body"
+}
+
+declare_lint_pass!(Loops => [
+ MANUAL_MEMCPY,
+ NEEDLESS_RANGE_LOOP,
+ EXPLICIT_ITER_LOOP,
+ EXPLICIT_INTO_ITER_LOOP,
+ ITER_NEXT_LOOP,
+ FOR_LOOP_OVER_RESULT,
+ FOR_LOOP_OVER_OPTION,
+ WHILE_LET_LOOP,
+ NEEDLESS_COLLECT,
+ REVERSE_RANGE_LOOP,
+ EXPLICIT_COUNTER_LOOP,
+ EMPTY_LOOP,
+ WHILE_LET_ON_ITERATOR,
+ FOR_KV_MAP,
+ NEVER_LOOP,
+ MUT_RANGE_BOUND,
+ WHILE_IMMUTABLE_CONDITION,
+]);
+
+impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Loops {
+ #[allow(clippy::too_many_lines)]
+ fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr<'_>) {
+ if let Some((pat, arg, body)) = higher::for_loop(expr) {
+ // we don't want to check expanded macros
+ // this check is not at the top of the function
+ // since higher::for_loop expressions are marked as expansions
+ if body.span.from_expansion() {
+ return;
+ }
+ check_for_loop(cx, pat, arg, body, expr);
+ }
+
+ // we don't want to check expanded macros
+ if expr.span.from_expansion() {
+ return;
+ }
+
+ // check for never_loop
+ if let ExprKind::Loop(ref block, _, _) = expr.kind {
+ match never_loop_block(block, expr.hir_id) {
+ NeverLoopResult::AlwaysBreak => span_lint(cx, NEVER_LOOP, expr.span, "this loop never actually loops"),
+ NeverLoopResult::MayContinueMainLoop | NeverLoopResult::Otherwise => (),
+ }
+ }
+
+ // check for `loop { if let {} else break }` that could be `while let`
+ // (also matches an explicit "match" instead of "if let")
+ // (even if the "match" or "if let" is used for declaration)
+ if let ExprKind::Loop(ref block, _, LoopSource::Loop) = expr.kind {
+ // also check for empty `loop {}` statements
+ if block.stmts.is_empty() && block.expr.is_none() && !is_no_std_crate(cx.tcx.hir().krate()) {
+ span_lint(
+ cx,
+ EMPTY_LOOP,
+ expr.span,
+ "empty `loop {}` detected. You may want to either use `panic!()` or add \
+ `std::thread::sleep(..);` to the loop body.",
+ );
+ }
+
+ // extract the expression from the first statement (if any) in a block
+ let inner_stmt_expr = extract_expr_from_first_stmt(block);
+ // or extract the first expression (if any) from the block
+ if let Some(inner) = inner_stmt_expr.or_else(|| extract_first_expr(block)) {
+ if let ExprKind::Match(ref matchexpr, ref arms, ref source) = inner.kind {
+ // ensure "if let" compatible match structure
+ match *source {
+ MatchSource::Normal | MatchSource::IfLetDesugar { .. } => {
+ if arms.len() == 2
+ && arms[0].guard.is_none()
+ && arms[1].guard.is_none()
+ && is_simple_break_expr(&arms[1].body)
+ {
+ if in_external_macro(cx.sess(), expr.span) {
+ return;
+ }
+
+ // NOTE: we used to build a body here instead of using
+ // ellipsis, this was removed because:
+ // 1) it was ugly with big bodies;
+ // 2) it was not indented properly;
+ // 3) it wasn’t very smart (see #675).
+ let mut applicability = Applicability::HasPlaceholders;
+ span_lint_and_sugg(
+ cx,
+ WHILE_LET_LOOP,
+ expr.span,
+ "this loop could be written as a `while let` loop",
+ "try",
+ format!(
+ "while let {} = {} {{ .. }}",
+ snippet_with_applicability(cx, arms[0].pat.span, "..", &mut applicability),
+ snippet_with_applicability(cx, matchexpr.span, "..", &mut applicability),
+ ),
+ applicability,
+ );
+ }
+ },
+ _ => (),
+ }
+ }
+ }
+ }
+ if let ExprKind::Match(ref match_expr, ref arms, MatchSource::WhileLetDesugar) = expr.kind {
+ let pat = &arms[0].pat.kind;
+ if let (
+ &PatKind::TupleStruct(ref qpath, ref pat_args, _),
+ &ExprKind::MethodCall(ref method_path, _, ref method_args),
+ ) = (pat, &match_expr.kind)
+ {
+ let iter_expr = &method_args[0];
+
+ // Don't lint when the iterator is recreated on every iteration
+ if_chain! {
+ if let ExprKind::MethodCall(..) | ExprKind::Call(..) = iter_expr.kind;
+ if let Some(iter_def_id) = get_trait_def_id(cx, &paths::ITERATOR);
+ if implements_trait(cx, cx.tables.expr_ty(iter_expr), iter_def_id, &[]);
+ then {
+ return;
+ }
+ }
+
+ let lhs_constructor = last_path_segment(qpath);
+ if method_path.ident.name == sym!(next)
+ && match_trait_method(cx, match_expr, &paths::ITERATOR)
+ && lhs_constructor.ident.name == sym!(Some)
+ && (pat_args.is_empty()
+ || !is_refutable(cx, &pat_args[0])
+ && !is_used_inside(cx, iter_expr, &arms[0].body)
+ && !is_iterator_used_after_while_let(cx, iter_expr)
+ && !is_nested(cx, expr, &method_args[0]))
+ {
+ let mut applicability = Applicability::MachineApplicable;
+ let iterator = snippet_with_applicability(cx, method_args[0].span, "_", &mut applicability);
+ let loop_var = if pat_args.is_empty() {
+ "_".to_string()
+ } else {
+ snippet_with_applicability(cx, pat_args[0].span, "_", &mut applicability).into_owned()
+ };
+ span_lint_and_sugg(
+ cx,
+ WHILE_LET_ON_ITERATOR,
+ expr.span.with_hi(match_expr.span.hi()),
+ "this loop could be written as a `for` loop",
+ "try",
+ format!("for {} in {}", loop_var, iterator),
+ applicability,
+ );
+ }
+ }
+ }
+
+ if let Some((cond, body)) = higher::while_loop(&expr) {
+ check_infinite_loop(cx, cond, body);
+ }
+
+ check_needless_collect(expr, cx);
+ }
+}
+
+enum NeverLoopResult {
+ // A break/return always get triggered but not necessarily for the main loop.
+ AlwaysBreak,
+ // A continue may occur for the main loop.
+ MayContinueMainLoop,
+ Otherwise,
+}
+
+#[must_use]
+fn absorb_break(arg: &NeverLoopResult) -> NeverLoopResult {
+ match *arg {
+ NeverLoopResult::AlwaysBreak | NeverLoopResult::Otherwise => NeverLoopResult::Otherwise,
+ NeverLoopResult::MayContinueMainLoop => NeverLoopResult::MayContinueMainLoop,
+ }
+}
+
+// Combine two results for parts that are called in order.
+#[must_use]
+fn combine_seq(first: NeverLoopResult, second: NeverLoopResult) -> NeverLoopResult {
+ match first {
+ NeverLoopResult::AlwaysBreak | NeverLoopResult::MayContinueMainLoop => first,
+ NeverLoopResult::Otherwise => second,
+ }
+}
+
+// Combine two results where both parts are called but not necessarily in order.
+#[must_use]
+fn combine_both(left: NeverLoopResult, right: NeverLoopResult) -> NeverLoopResult {
+ match (left, right) {
+ (NeverLoopResult::MayContinueMainLoop, _) | (_, NeverLoopResult::MayContinueMainLoop) => {
+ NeverLoopResult::MayContinueMainLoop
+ },
+ (NeverLoopResult::AlwaysBreak, _) | (_, NeverLoopResult::AlwaysBreak) => NeverLoopResult::AlwaysBreak,
+ (NeverLoopResult::Otherwise, NeverLoopResult::Otherwise) => NeverLoopResult::Otherwise,
+ }
+}
+
+// Combine two results where only one of the part may have been executed.
+#[must_use]
+fn combine_branches(b1: NeverLoopResult, b2: NeverLoopResult) -> NeverLoopResult {
+ match (b1, b2) {
+ (NeverLoopResult::AlwaysBreak, NeverLoopResult::AlwaysBreak) => NeverLoopResult::AlwaysBreak,
+ (NeverLoopResult::MayContinueMainLoop, _) | (_, NeverLoopResult::MayContinueMainLoop) => {
+ NeverLoopResult::MayContinueMainLoop
+ },
+ (NeverLoopResult::Otherwise, _) | (_, NeverLoopResult::Otherwise) => NeverLoopResult::Otherwise,
+ }
+}
+
+fn never_loop_block(block: &Block<'_>, main_loop_id: HirId) -> NeverLoopResult {
+ let stmts = block.stmts.iter().map(stmt_to_expr);
+ let expr = once(block.expr.as_deref());
+ let mut iter = stmts.chain(expr).filter_map(|e| e);
+ never_loop_expr_seq(&mut iter, main_loop_id)
+}
+
+fn stmt_to_expr<'tcx>(stmt: &Stmt<'tcx>) -> Option<&'tcx Expr<'tcx>> {
+ match stmt.kind {
+ StmtKind::Semi(ref e, ..) | StmtKind::Expr(ref e, ..) => Some(e),
+ StmtKind::Local(ref local) => local.init.as_deref(),
+ _ => None,
+ }
+}
+
+fn never_loop_expr(expr: &Expr<'_>, main_loop_id: HirId) -> NeverLoopResult {
+ match expr.kind {
+ ExprKind::Box(ref e)
+ | ExprKind::Unary(_, ref e)
+ | ExprKind::Cast(ref e, _)
+ | ExprKind::Type(ref e, _)
+ | ExprKind::Field(ref e, _)
+ | ExprKind::AddrOf(_, _, ref e)
+ | ExprKind::Struct(_, _, Some(ref e))
+ | ExprKind::Repeat(ref e, _)
+ | ExprKind::DropTemps(ref e) => never_loop_expr(e, main_loop_id),
+ ExprKind::Array(ref es) | ExprKind::MethodCall(_, _, ref es) | ExprKind::Tup(ref es) => {
+ never_loop_expr_all(&mut es.iter(), main_loop_id)
+ },
+ ExprKind::Call(ref e, ref es) => never_loop_expr_all(&mut once(&**e).chain(es.iter()), main_loop_id),
+ ExprKind::Binary(_, ref e1, ref e2)
+ | ExprKind::Assign(ref e1, ref e2, _)
+ | ExprKind::AssignOp(_, ref e1, ref e2)
+ | ExprKind::Index(ref e1, ref e2) => never_loop_expr_all(&mut [&**e1, &**e2].iter().cloned(), main_loop_id),
+ ExprKind::Loop(ref b, _, _) => {
+ // Break can come from the inner loop so remove them.
+ absorb_break(&never_loop_block(b, main_loop_id))
+ },
+ ExprKind::Match(ref e, ref arms, _) => {
+ let e = never_loop_expr(e, main_loop_id);
+ if arms.is_empty() {
+ e
+ } else {
+ let arms = never_loop_expr_branch(&mut arms.iter().map(|a| &*a.body), main_loop_id);
+ combine_seq(e, arms)
+ }
+ },
+ ExprKind::Block(ref b, _) => never_loop_block(b, main_loop_id),
+ ExprKind::Continue(d) => {
+ let id = d
+ .target_id
+ .expect("target ID can only be missing in the presence of compilation errors");
+ if id == main_loop_id {
+ NeverLoopResult::MayContinueMainLoop
+ } else {
+ NeverLoopResult::AlwaysBreak
+ }
+ },
+ ExprKind::Break(_, ref e) | ExprKind::Ret(ref e) => {
+ if let Some(ref e) = *e {
+ combine_seq(never_loop_expr(e, main_loop_id), NeverLoopResult::AlwaysBreak)
+ } else {
+ NeverLoopResult::AlwaysBreak
+ }
+ },
+ ExprKind::Struct(_, _, None)
+ | ExprKind::Yield(_, _)
+ | ExprKind::Closure(_, _, _, _, _)
+ | ExprKind::LlvmInlineAsm(_)
+ | ExprKind::Path(_)
+ | ExprKind::Lit(_)
+ | ExprKind::Err => NeverLoopResult::Otherwise,
+ }
+}
+
+fn never_loop_expr_seq<'a, T: Iterator
- >>(es: &mut T, main_loop_id: HirId) -> NeverLoopResult {
+ es.map(|e| never_loop_expr(e, main_loop_id))
+ .fold(NeverLoopResult::Otherwise, combine_seq)
+}
+
+fn never_loop_expr_all<'a, T: Iterator
- >>(es: &mut T, main_loop_id: HirId) -> NeverLoopResult {
+ es.map(|e| never_loop_expr(e, main_loop_id))
+ .fold(NeverLoopResult::Otherwise, combine_both)
+}
+
+fn never_loop_expr_branch<'a, T: Iterator
- >>(e: &mut T, main_loop_id: HirId) -> NeverLoopResult {
+ e.map(|e| never_loop_expr(e, main_loop_id))
+ .fold(NeverLoopResult::AlwaysBreak, combine_branches)
+}
+
+fn check_for_loop<'a, 'tcx>(
+ cx: &LateContext<'a, 'tcx>,
+ pat: &'tcx Pat<'_>,
+ arg: &'tcx Expr<'_>,
+ body: &'tcx Expr<'_>,
+ expr: &'tcx Expr<'_>,
+) {
+ check_for_loop_range(cx, pat, arg, body, expr);
+ check_for_loop_reverse_range(cx, arg, expr);
+ check_for_loop_arg(cx, pat, arg, expr);
+ check_for_loop_explicit_counter(cx, pat, arg, body, expr);
+ check_for_loop_over_map_kv(cx, pat, arg, body, expr);
+ check_for_mut_range_bound(cx, arg, body);
+ detect_manual_memcpy(cx, pat, arg, body, expr);
+}
+
+fn same_var<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, expr: &Expr<'_>, var: HirId) -> bool {
+ if_chain! {
+ if let ExprKind::Path(ref qpath) = expr.kind;
+ if let QPath::Resolved(None, ref path) = *qpath;
+ if path.segments.len() == 1;
+ if let Res::Local(local_id) = qpath_res(cx, qpath, expr.hir_id);
+ // our variable!
+ if local_id == var;
+ then {
+ return true;
+ }
+ }
+
+ false
+}
+
+struct Offset {
+ value: String,
+ negate: bool,
+}
+
+impl Offset {
+ fn negative(s: String) -> Self {
+ Self { value: s, negate: true }
+ }
+
+ fn positive(s: String) -> Self {
+ Self {
+ value: s,
+ negate: false,
+ }
+ }
+}
+
+struct FixedOffsetVar {
+ var_name: String,
+ offset: Offset,
+}
+
+fn is_slice_like<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, ty: Ty<'_>) -> bool {
+ let is_slice = match ty.kind {
+ ty::Ref(_, subty, _) => is_slice_like(cx, subty),
+ ty::Slice(..) | ty::Array(..) => true,
+ _ => false,
+ };
+
+ is_slice || is_type_diagnostic_item(cx, ty, sym!(vec_type)) || is_type_diagnostic_item(cx, ty, sym!(vecdeque_type))
+}
+
+fn get_fixed_offset_var<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, expr: &Expr<'_>, var: HirId) -> Option {
+ fn extract_offset<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, e: &Expr<'_>, var: HirId) -> Option {
+ match e.kind {
+ ExprKind::Lit(ref l) => match l.node {
+ ast::LitKind::Int(x, _ty) => Some(x.to_string()),
+ _ => None,
+ },
+ ExprKind::Path(..) if !same_var(cx, e, var) => Some(snippet_opt(cx, e.span).unwrap_or_else(|| "??".into())),
+ _ => None,
+ }
+ }
+
+ if let ExprKind::Index(ref seqexpr, ref idx) = expr.kind {
+ let ty = cx.tables.expr_ty(seqexpr);
+ if !is_slice_like(cx, ty) {
+ return None;
+ }
+
+ let offset = match idx.kind {
+ ExprKind::Binary(op, ref lhs, ref rhs) => match op.node {
+ BinOpKind::Add => {
+ let offset_opt = if same_var(cx, lhs, var) {
+ extract_offset(cx, rhs, var)
+ } else if same_var(cx, rhs, var) {
+ extract_offset(cx, lhs, var)
+ } else {
+ None
+ };
+
+ offset_opt.map(Offset::positive)
+ },
+ BinOpKind::Sub if same_var(cx, lhs, var) => extract_offset(cx, rhs, var).map(Offset::negative),
+ _ => None,
+ },
+ ExprKind::Path(..) => {
+ if same_var(cx, idx, var) {
+ Some(Offset::positive("0".into()))
+ } else {
+ None
+ }
+ },
+ _ => None,
+ };
+
+ offset.map(|o| FixedOffsetVar {
+ var_name: snippet_opt(cx, seqexpr.span).unwrap_or_else(|| "???".into()),
+ offset: o,
+ })
+ } else {
+ None
+ }
+}
+
+fn fetch_cloned_fixed_offset_var<'a, 'tcx>(
+ cx: &LateContext<'a, 'tcx>,
+ expr: &Expr<'_>,
+ var: HirId,
+) -> Option {
+ if_chain! {
+ if let ExprKind::MethodCall(ref method, _, ref args) = expr.kind;
+ if method.ident.name == sym!(clone);
+ if args.len() == 1;
+ if let Some(arg) = args.get(0);
+ then {
+ return get_fixed_offset_var(cx, arg, var);
+ }
+ }
+
+ get_fixed_offset_var(cx, expr, var)
+}
+
+fn get_indexed_assignments<'a, 'tcx>(
+ cx: &LateContext<'a, 'tcx>,
+ body: &Expr<'_>,
+ var: HirId,
+) -> Vec<(FixedOffsetVar, FixedOffsetVar)> {
+ fn get_assignment<'a, 'tcx>(
+ cx: &LateContext<'a, 'tcx>,
+ e: &Expr<'_>,
+ var: HirId,
+ ) -> Option<(FixedOffsetVar, FixedOffsetVar)> {
+ if let ExprKind::Assign(ref lhs, ref rhs, _) = e.kind {
+ match (
+ get_fixed_offset_var(cx, lhs, var),
+ fetch_cloned_fixed_offset_var(cx, rhs, var),
+ ) {
+ (Some(offset_left), Some(offset_right)) => {
+ // Source and destination must be different
+ if offset_left.var_name == offset_right.var_name {
+ None
+ } else {
+ Some((offset_left, offset_right))
+ }
+ },
+ _ => None,
+ }
+ } else {
+ None
+ }
+ }
+
+ if let ExprKind::Block(ref b, _) = body.kind {
+ let Block {
+ ref stmts, ref expr, ..
+ } = **b;
+
+ stmts
+ .iter()
+ .map(|stmt| match stmt.kind {
+ StmtKind::Local(..) | StmtKind::Item(..) => None,
+ StmtKind::Expr(ref e) | StmtKind::Semi(ref e) => Some(get_assignment(cx, e, var)),
+ })
+ .chain(expr.as_ref().into_iter().map(|e| Some(get_assignment(cx, &*e, var))))
+ .filter_map(|op| op)
+ .collect::>>()
+ .unwrap_or_default()
+ } else {
+ get_assignment(cx, body, var).into_iter().collect()
+ }
+}
+
+/// Checks for for loops that sequentially copy items from one slice-like
+/// object to another.
+fn detect_manual_memcpy<'a, 'tcx>(
+ cx: &LateContext<'a, 'tcx>,
+ pat: &'tcx Pat<'_>,
+ arg: &'tcx Expr<'_>,
+ body: &'tcx Expr<'_>,
+ expr: &'tcx Expr<'_>,
+) {
+ if let Some(higher::Range {
+ start: Some(start),
+ ref end,
+ limits,
+ }) = higher::range(cx, arg)
+ {
+ // the var must be a single name
+ if let PatKind::Binding(_, canonical_id, _, _) = pat.kind {
+ let print_sum = |arg1: &Offset, arg2: &Offset| -> String {
+ match (&arg1.value[..], arg1.negate, &arg2.value[..], arg2.negate) {
+ ("0", _, "0", _) => "".into(),
+ ("0", _, x, false) | (x, false, "0", false) => x.into(),
+ ("0", _, x, true) | (x, false, "0", true) => format!("-{}", x),
+ (x, false, y, false) => format!("({} + {})", x, y),
+ (x, false, y, true) => {
+ if x == y {
+ "0".into()
+ } else {
+ format!("({} - {})", x, y)
+ }
+ },
+ (x, true, y, false) => {
+ if x == y {
+ "0".into()
+ } else {
+ format!("({} - {})", y, x)
+ }
+ },
+ (x, true, y, true) => format!("-({} + {})", x, y),
+ }
+ };
+
+ let print_limit = |end: &Option<&Expr<'_>>, offset: Offset, var_name: &str| {
+ if let Some(end) = *end {
+ if_chain! {
+ if let ExprKind::MethodCall(ref method, _, ref len_args) = end.kind;
+ if method.ident.name == sym!(len);
+ if len_args.len() == 1;
+ if let Some(arg) = len_args.get(0);
+ if snippet(cx, arg.span, "??") == var_name;
+ then {
+ return if offset.negate {
+ format!("({} - {})", snippet(cx, end.span, ".len()"), offset.value)
+ } else {
+ String::new()
+ };
+ }
+ }
+
+ let end_str = match limits {
+ ast::RangeLimits::Closed => {
+ let end = sugg::Sugg::hir(cx, end, "");
+ format!("{}", end + sugg::ONE)
+ },
+ ast::RangeLimits::HalfOpen => format!("{}", snippet(cx, end.span, "..")),
+ };
+
+ print_sum(&Offset::positive(end_str), &offset)
+ } else {
+ "..".into()
+ }
+ };
+
+ // The only statements in the for loops can be indexed assignments from
+ // indexed retrievals.
+ let manual_copies = get_indexed_assignments(cx, body, canonical_id);
+
+ let big_sugg = manual_copies
+ .into_iter()
+ .map(|(dst_var, src_var)| {
+ let start_str = Offset::positive(snippet(cx, start.span, "").to_string());
+ let dst_offset = print_sum(&start_str, &dst_var.offset);
+ let dst_limit = print_limit(end, dst_var.offset, &dst_var.var_name);
+ let src_offset = print_sum(&start_str, &src_var.offset);
+ let src_limit = print_limit(end, src_var.offset, &src_var.var_name);
+ let dst = if dst_offset == "" && dst_limit == "" {
+ dst_var.var_name
+ } else {
+ format!("{}[{}..{}]", dst_var.var_name, dst_offset, dst_limit)
+ };
+
+ format!(
+ "{}.clone_from_slice(&{}[{}..{}])",
+ dst, src_var.var_name, src_offset, src_limit
+ )
+ })
+ .join("\n ");
+
+ if !big_sugg.is_empty() {
+ span_lint_and_sugg(
+ cx,
+ MANUAL_MEMCPY,
+ expr.span,
+ "it looks like you're manually copying between slices",
+ "try replacing the loop by",
+ big_sugg,
+ Applicability::Unspecified,
+ );
+ }
+ }
+ }
+}
+
+/// Checks for looping over a range and then indexing a sequence with it.
+/// The iteratee must be a range literal.
+#[allow(clippy::too_many_lines)]
+fn check_for_loop_range<'a, 'tcx>(
+ cx: &LateContext<'a, 'tcx>,
+ pat: &'tcx Pat<'_>,
+ arg: &'tcx Expr<'_>,
+ body: &'tcx Expr<'_>,
+ expr: &'tcx Expr<'_>,
+) {
+ if let Some(higher::Range {
+ start: Some(start),
+ ref end,
+ limits,
+ }) = higher::range(cx, arg)
+ {
+ // the var must be a single name
+ if let PatKind::Binding(_, canonical_id, ident, _) = pat.kind {
+ let mut visitor = VarVisitor {
+ cx,
+ var: canonical_id,
+ indexed_mut: FxHashSet::default(),
+ indexed_indirectly: FxHashMap::default(),
+ indexed_directly: FxHashMap::default(),
+ referenced: FxHashSet::default(),
+ nonindex: false,
+ prefer_mutable: false,
+ };
+ walk_expr(&mut visitor, body);
+
+ // linting condition: we only indexed one variable, and indexed it directly
+ if visitor.indexed_indirectly.is_empty() && visitor.indexed_directly.len() == 1 {
+ let (indexed, (indexed_extent, indexed_ty)) = visitor
+ .indexed_directly
+ .into_iter()
+ .next()
+ .expect("already checked that we have exactly 1 element");
+
+ // ensure that the indexed variable was declared before the loop, see #601
+ if let Some(indexed_extent) = indexed_extent {
+ let parent_id = cx.tcx.hir().get_parent_item(expr.hir_id);
+ let parent_def_id = cx.tcx.hir().local_def_id(parent_id);
+ let region_scope_tree = cx.tcx.region_scope_tree(parent_def_id);
+ let pat_extent = region_scope_tree.var_scope(pat.hir_id.local_id);
+ if region_scope_tree.is_subscope_of(indexed_extent, pat_extent) {
+ return;
+ }
+ }
+
+ // don't lint if the container that is indexed does not have .iter() method
+ let has_iter = has_iter_method(cx, indexed_ty);
+ if has_iter.is_none() {
+ return;
+ }
+
+ // don't lint if the container that is indexed into is also used without
+ // indexing
+ if visitor.referenced.contains(&indexed) {
+ return;
+ }
+
+ let starts_at_zero = is_integer_const(cx, start, 0);
+
+ let skip = if starts_at_zero {
+ String::new()
+ } else {
+ format!(".skip({})", snippet(cx, start.span, ".."))
+ };
+
+ let mut end_is_start_plus_val = false;
+
+ let take = if let Some(end) = *end {
+ let mut take_expr = end;
+
+ if let ExprKind::Binary(ref op, ref left, ref right) = end.kind {
+ if let BinOpKind::Add = op.node {
+ let start_equal_left = SpanlessEq::new(cx).eq_expr(start, left);
+ let start_equal_right = SpanlessEq::new(cx).eq_expr(start, right);
+
+ if start_equal_left {
+ take_expr = right;
+ } else if start_equal_right {
+ take_expr = left;
+ }
+
+ end_is_start_plus_val = start_equal_left | start_equal_right;
+ }
+ }
+
+ if is_len_call(end, indexed) || is_end_eq_array_len(cx, end, limits, indexed_ty) {
+ String::new()
+ } else {
+ match limits {
+ ast::RangeLimits::Closed => {
+ let take_expr = sugg::Sugg::hir(cx, take_expr, "");
+ format!(".take({})", take_expr + sugg::ONE)
+ },
+ ast::RangeLimits::HalfOpen => format!(".take({})", snippet(cx, take_expr.span, "..")),
+ }
+ }
+ } else {
+ String::new()
+ };
+
+ let (ref_mut, method) = if visitor.indexed_mut.contains(&indexed) {
+ ("mut ", "iter_mut")
+ } else {
+ ("", "iter")
+ };
+
+ let take_is_empty = take.is_empty();
+ let mut method_1 = take;
+ let mut method_2 = skip;
+
+ if end_is_start_plus_val {
+ mem::swap(&mut method_1, &mut method_2);
+ }
+
+ if visitor.nonindex {
+ span_lint_and_then(
+ cx,
+ NEEDLESS_RANGE_LOOP,
+ expr.span,
+ &format!("the loop variable `{}` is used to index `{}`", ident.name, indexed),
+ |diag| {
+ multispan_sugg(
+ diag,
+ "consider using an iterator".to_string(),
+ vec![
+ (pat.span, format!("({},
- )", ident.name)),
+ (
+ arg.span,
+ format!("{}.{}().enumerate(){}{}", indexed, method, method_1, method_2),
+ ),
+ ],
+ );
+ },
+ );
+ } else {
+ let repl = if starts_at_zero && take_is_empty {
+ format!("&{}{}", ref_mut, indexed)
+ } else {
+ format!("{}.{}(){}{}", indexed, method, method_1, method_2)
+ };
+
+ span_lint_and_then(
+ cx,
+ NEEDLESS_RANGE_LOOP,
+ expr.span,
+ &format!(
+ "the loop variable `{}` is only used to index `{}`.",
+ ident.name, indexed
+ ),
+ |diag| {
+ multispan_sugg(
+ diag,
+ "consider using an iterator".to_string(),
+ vec![(pat.span, "
- ".to_string()), (arg.span, repl)],
+ );
+ },
+ );
+ }
+ }
+ }
+ }
+}
+
+fn is_len_call(expr: &Expr<'_>, var: Name) -> bool {
+ if_chain! {
+ if let ExprKind::MethodCall(ref method, _, ref len_args) = expr.kind;
+ if len_args.len() == 1;
+ if method.ident.name == sym!(len);
+ if let ExprKind::Path(QPath::Resolved(_, ref path)) = len_args[0].kind;
+ if path.segments.len() == 1;
+ if path.segments[0].ident.name == var;
+ then {
+ return true;
+ }
+ }
+
+ false
+}
+
+fn is_end_eq_array_len<'tcx>(
+ cx: &LateContext<'_, 'tcx>,
+ end: &Expr<'_>,
+ limits: ast::RangeLimits,
+ indexed_ty: Ty<'tcx>,
+) -> bool {
+ if_chain! {
+ if let ExprKind::Lit(ref lit) = end.kind;
+ if let ast::LitKind::Int(end_int, _) = lit.node;
+ if let ty::Array(_, arr_len_const) = indexed_ty.kind;
+ if let Some(arr_len) = arr_len_const.try_eval_usize(cx.tcx, cx.param_env);
+ then {
+ return match limits {
+ ast::RangeLimits::Closed => end_int + 1 >= arr_len.into(),
+ ast::RangeLimits::HalfOpen => end_int >= arr_len.into(),
+ };
+ }
+ }
+
+ false
+}
+
+fn check_for_loop_reverse_range<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, arg: &'tcx Expr<'_>, expr: &'tcx Expr<'_>) {
+ // if this for loop is iterating over a two-sided range...
+ if let Some(higher::Range {
+ start: Some(start),
+ end: Some(end),
+ limits,
+ }) = higher::range(cx, arg)
+ {
+ // ...and both sides are compile-time constant integers...
+ if let Some((start_idx, _)) = constant(cx, cx.tables, start) {
+ if let Some((end_idx, _)) = constant(cx, cx.tables, end) {
+ // ...and the start index is greater than the end index,
+ // this loop will never run. This is often confusing for developers
+ // who think that this will iterate from the larger value to the
+ // smaller value.
+ let ty = cx.tables.expr_ty(start);
+ let (sup, eq) = match (start_idx, end_idx) {
+ (Constant::Int(start_idx), Constant::Int(end_idx)) => (
+ match ty.kind {
+ ty::Int(ity) => sext(cx.tcx, start_idx, ity) > sext(cx.tcx, end_idx, ity),
+ ty::Uint(_) => start_idx > end_idx,
+ _ => false,
+ },
+ start_idx == end_idx,
+ ),
+ _ => (false, false),
+ };
+
+ if sup {
+ let start_snippet = snippet(cx, start.span, "_");
+ let end_snippet = snippet(cx, end.span, "_");
+ let dots = if limits == ast::RangeLimits::Closed {
+ "..="
+ } else {
+ ".."
+ };
+
+ span_lint_and_then(
+ cx,
+ REVERSE_RANGE_LOOP,
+ expr.span,
+ "this range is empty so this for loop will never run",
+ |diag| {
+ diag.span_suggestion(
+ arg.span,
+ "consider using the following if you are attempting to iterate over this \
+ range in reverse",
+ format!(
+ "({end}{dots}{start}).rev()",
+ end = end_snippet,
+ dots = dots,
+ start = start_snippet
+ ),
+ Applicability::MaybeIncorrect,
+ );
+ },
+ );
+ } else if eq && limits != ast::RangeLimits::Closed {
+ // if they are equal, it's also problematic - this loop
+ // will never run.
+ span_lint(
+ cx,
+ REVERSE_RANGE_LOOP,
+ expr.span,
+ "this range is empty so this for loop will never run",
+ );
+ }
+ }
+ }
+ }
+}
+
+fn lint_iter_method(cx: &LateContext<'_, '_>, args: &[Expr<'_>], arg: &Expr<'_>, method_name: &str) {
+ let mut applicability = Applicability::MachineApplicable;
+ let object = snippet_with_applicability(cx, args[0].span, "_", &mut applicability);
+ let muta = if method_name == "iter_mut" { "mut " } else { "" };
+ span_lint_and_sugg(
+ cx,
+ EXPLICIT_ITER_LOOP,
+ arg.span,
+ "it is more concise to loop over references to containers instead of using explicit \
+ iteration methods",
+ "to write this more concisely, try",
+ format!("&{}{}", muta, object),
+ applicability,
+ )
+}
+
+fn check_for_loop_arg(cx: &LateContext<'_, '_>, pat: &Pat<'_>, arg: &Expr<'_>, expr: &Expr<'_>) {
+ let mut next_loop_linted = false; // whether or not ITER_NEXT_LOOP lint was used
+ if let ExprKind::MethodCall(ref method, _, ref args) = arg.kind {
+ // just the receiver, no arguments
+ if args.len() == 1 {
+ let method_name = &*method.ident.as_str();
+ // check for looping over x.iter() or x.iter_mut(), could use &x or &mut x
+ if method_name == "iter" || method_name == "iter_mut" {
+ if is_ref_iterable_type(cx, &args[0]) {
+ lint_iter_method(cx, args, arg, method_name);
+ }
+ } else if method_name == "into_iter" && match_trait_method(cx, arg, &paths::INTO_ITERATOR) {
+ let receiver_ty = cx.tables.expr_ty(&args[0]);
+ let receiver_ty_adjusted = cx.tables.expr_ty_adjusted(&args[0]);
+ if same_tys(cx, receiver_ty, receiver_ty_adjusted) {
+ let mut applicability = Applicability::MachineApplicable;
+ let object = snippet_with_applicability(cx, args[0].span, "_", &mut applicability);
+ span_lint_and_sugg(
+ cx,
+ EXPLICIT_INTO_ITER_LOOP,
+ arg.span,
+ "it is more concise to loop over containers instead of using explicit \
+ iteration methods",
+ "to write this more concisely, try",
+ object.to_string(),
+ applicability,
+ );
+ } else {
+ let ref_receiver_ty = cx.tcx.mk_ref(
+ cx.tcx.lifetimes.re_erased,
+ ty::TypeAndMut {
+ ty: receiver_ty,
+ mutbl: Mutability::Not,
+ },
+ );
+ if same_tys(cx, receiver_ty_adjusted, ref_receiver_ty) {
+ lint_iter_method(cx, args, arg, method_name)
+ }
+ }
+ } else if method_name == "next" && match_trait_method(cx, arg, &paths::ITERATOR) {
+ span_lint(
+ cx,
+ ITER_NEXT_LOOP,
+ expr.span,
+ "you are iterating over `Iterator::next()` which is an Option; this will compile but is \
+ probably not what you want",
+ );
+ next_loop_linted = true;
+ }
+ }
+ }
+ if !next_loop_linted {
+ check_arg_type(cx, pat, arg);
+ }
+}
+
+/// Checks for `for` loops over `Option`s and `Result`s.
+fn check_arg_type(cx: &LateContext<'_, '_>, pat: &Pat<'_>, arg: &Expr<'_>) {
+ let ty = cx.tables.expr_ty(arg);
+ if is_type_diagnostic_item(cx, ty, sym!(option_type)) {
+ span_lint_and_help(
+ cx,
+ FOR_LOOP_OVER_OPTION,
+ arg.span,
+ &format!(
+ "for loop over `{0}`, which is an `Option`. This is more readably written as an \
+ `if let` statement.",
+ snippet(cx, arg.span, "_")
+ ),
+ None,
+ &format!(
+ "consider replacing `for {0} in {1}` with `if let Some({0}) = {1}`",
+ snippet(cx, pat.span, "_"),
+ snippet(cx, arg.span, "_")
+ ),
+ );
+ } else if is_type_diagnostic_item(cx, ty, sym!(result_type)) {
+ span_lint_and_help(
+ cx,
+ FOR_LOOP_OVER_RESULT,
+ arg.span,
+ &format!(
+ "for loop over `{0}`, which is a `Result`. This is more readably written as an \
+ `if let` statement.",
+ snippet(cx, arg.span, "_")
+ ),
+ None,
+ &format!(
+ "consider replacing `for {0} in {1}` with `if let Ok({0}) = {1}`",
+ snippet(cx, pat.span, "_"),
+ snippet(cx, arg.span, "_")
+ ),
+ );
+ }
+}
+
+fn check_for_loop_explicit_counter<'a, 'tcx>(
+ cx: &LateContext<'a, 'tcx>,
+ pat: &'tcx Pat<'_>,
+ arg: &'tcx Expr<'_>,
+ body: &'tcx Expr<'_>,
+ expr: &'tcx Expr<'_>,
+) {
+ // Look for variables that are incremented once per loop iteration.
+ let mut visitor = IncrementVisitor {
+ cx,
+ states: FxHashMap::default(),
+ depth: 0,
+ done: false,
+ };
+ walk_expr(&mut visitor, body);
+
+ // For each candidate, check the parent block to see if
+ // it's initialized to zero at the start of the loop.
+ if let Some(block) = get_enclosing_block(&cx, expr.hir_id) {
+ for (id, _) in visitor.states.iter().filter(|&(_, v)| *v == VarState::IncrOnce) {
+ let mut visitor2 = InitializeVisitor {
+ cx,
+ end_expr: expr,
+ var_id: *id,
+ state: VarState::IncrOnce,
+ name: None,
+ depth: 0,
+ past_loop: false,
+ };
+ walk_block(&mut visitor2, block);
+
+ if visitor2.state == VarState::Warn {
+ if let Some(name) = visitor2.name {
+ let mut applicability = Applicability::MachineApplicable;
+
+ // for some reason this is the only way to get the `Span`
+ // of the entire `for` loop
+ let for_span = if let ExprKind::Match(_, arms, _) = &expr.kind {
+ arms[0].body.span
+ } else {
+ unreachable!()
+ };
+
+ span_lint_and_sugg(
+ cx,
+ EXPLICIT_COUNTER_LOOP,
+ for_span.with_hi(arg.span.hi()),
+ &format!("the variable `{}` is used as a loop counter.", name),
+ "consider using",
+ format!(
+ "for ({}, {}) in {}.enumerate()",
+ name,
+ snippet_with_applicability(cx, pat.span, "item", &mut applicability),
+ make_iterator_snippet(cx, arg, &mut applicability),
+ ),
+ applicability,
+ );
+ }
+ }
+ }
+ }
+}
+
+/// If `arg` was the argument to a `for` loop, return the "cleanest" way of writing the
+/// actual `Iterator` that the loop uses.
+fn make_iterator_snippet(cx: &LateContext<'_, '_>, arg: &Expr<'_>, applic_ref: &mut Applicability) -> String {
+ let impls_iterator = get_trait_def_id(cx, &paths::ITERATOR)
+ .map_or(false, |id| implements_trait(cx, cx.tables.expr_ty(arg), id, &[]));
+ if impls_iterator {
+ format!(
+ "{}",
+ sugg::Sugg::hir_with_applicability(cx, arg, "_", applic_ref).maybe_par()
+ )
+ } else {
+ // (&x).into_iter() ==> x.iter()
+ // (&mut x).into_iter() ==> x.iter_mut()
+ match &arg.kind {
+ ExprKind::AddrOf(BorrowKind::Ref, mutability, arg_inner)
+ if has_iter_method(cx, cx.tables.expr_ty(&arg_inner)).is_some() =>
+ {
+ let meth_name = match mutability {
+ Mutability::Mut => "iter_mut",
+ Mutability::Not => "iter",
+ };
+ format!(
+ "{}.{}()",
+ sugg::Sugg::hir_with_applicability(cx, &arg_inner, "_", applic_ref).maybe_par(),
+ meth_name,
+ )
+ }
+ _ => format!(
+ "{}.into_iter()",
+ sugg::Sugg::hir_with_applicability(cx, arg, "_", applic_ref).maybe_par()
+ ),
+ }
+ }
+}
+
+/// Checks for the `FOR_KV_MAP` lint.
+fn check_for_loop_over_map_kv<'a, 'tcx>(
+ cx: &LateContext<'a, 'tcx>,
+ pat: &'tcx Pat<'_>,
+ arg: &'tcx Expr<'_>,
+ body: &'tcx Expr<'_>,
+ expr: &'tcx Expr<'_>,
+) {
+ let pat_span = pat.span;
+
+ if let PatKind::Tuple(ref pat, _) = pat.kind {
+ if pat.len() == 2 {
+ let arg_span = arg.span;
+ let (new_pat_span, kind, ty, mutbl) = match cx.tables.expr_ty(arg).kind {
+ ty::Ref(_, ty, mutbl) => match (&pat[0].kind, &pat[1].kind) {
+ (key, _) if pat_is_wild(key, body) => (pat[1].span, "value", ty, mutbl),
+ (_, value) if pat_is_wild(value, body) => (pat[0].span, "key", ty, Mutability::Not),
+ _ => return,
+ },
+ _ => return,
+ };
+ let mutbl = match mutbl {
+ Mutability::Not => "",
+ Mutability::Mut => "_mut",
+ };
+ let arg = match arg.kind {
+ ExprKind::AddrOf(BorrowKind::Ref, _, ref expr) => &**expr,
+ _ => arg,
+ };
+
+ if is_type_diagnostic_item(cx, ty, sym!(hashmap_type)) || match_type(cx, ty, &paths::BTREEMAP) {
+ span_lint_and_then(
+ cx,
+ FOR_KV_MAP,
+ expr.span,
+ &format!("you seem to want to iterate on a map's {}s", kind),
+ |diag| {
+ let map = sugg::Sugg::hir(cx, arg, "map");
+ multispan_sugg(
+ diag,
+ "use the corresponding method".into(),
+ vec![
+ (pat_span, snippet(cx, new_pat_span, kind).into_owned()),
+ (arg_span, format!("{}.{}s{}()", map.maybe_par(), kind, mutbl)),
+ ],
+ );
+ },
+ );
+ }
+ }
+ }
+}
+
+struct MutatePairDelegate {
+ hir_id_low: Option