Derive TypeFoldable using a proc-macro
A new proc macro is added in librustc_macros.
It is used to derive TypeFoldable inside librustc and librustc_traits.
For now, the macro uses the `'tcx` lifetime implicitly, and does not allow for a more robust selection of the adequate lifetime.
The Clone-based TypeFoldable implementations are not migrated.
Closes#65674
Update Cargo, books
## cargo
12 commits in 5da4b4d47963868d9878480197581ccbbdaece74..8280633db680dec5bfe1de25156d1a1d53e6d190
2019-10-28 21:53:41 +0000 to 2019-11-11 23:17:05 +0000
- Don't panic when parsing `/proc/stat` (rust-lang/cargo#7580)
- Fix unused configuration key warning for a few keys under `build`. (rust-lang/cargo#7575)
- Add back support for `BROWSER` envvar in `cargo doc --open`. (rust-lang/cargo#7576)
- Only include "already existing ..." comment in gitignore on conflict (rust-lang/cargo#7570)
- Add VS Code user dir to .gitignore (rust-lang/cargo#7578)
- Added aliases to subcommand typo suggestions. (rust-lang/cargo#7486)
- Use multiple requirement syntax consistently (rust-lang/cargo#7573)
- Update verison to 0.42 (rust-lang/cargo#7568)
- Expand documentation on build scripts. (rust-lang/cargo#7565)
- Update crossbeam-utils requirement from 0.6 to 0.7 (rust-lang/cargo#7566)
- don't download std-docs on CI (rust-lang/cargo#7513)
- Change my-buddy to github-handle (rust-lang/cargo#7553)
## nomicon
2 commits in 5004ad30d69f93553ceef74439fea2159d1f769e..58e36e0e08dec5a379ac568827c058e25990d6cd
2019-10-12 19:52:40 +0200 to 2019-10-30 08:14:24 -0500
- remove references to the nursery
- Add github action to replace Travis.yml (rust-lang-nursery/nomicon#172)
## reference
7 commits in 4b21b646669e0af49fae7cae301898dc4bfaa1f0..45558c464fb458affbcdcb34323946da45c8a117
2019-10-27 22:33:11 +0100 to 2019-11-08 14:47:35 +0100
- Audit code blocks. (rust-lang-nursery/reference#715)
- Update coherence and orphan rules documentation to match RFC 2451 (rust-lang-nursery/reference#703)
- Update organization name (rust-lang-nursery/reference#713)
- State that no_implicit_prelude also applies to nested modules (rust-lang-nursery/reference#707)
- expand Copy docs (rust-lang-nursery/reference#711)
- github action doesn't use the nursery (rust-lang-nursery/reference#706)
- Migrate to GitHub Actions. (rust-lang-nursery/reference#705)
## book
1 commits in 28fa3d15b0bc67ea5e79eeff2198e4277fc61baf..e79dd62aa63396714278d484d91d48826737f47f
2019-10-29 07:16:09 -0500 to 2019-10-30 07:33:12 -0500
- No need for an iterator here to fetch values (rust-lang/book#1957)
## rust-by-example
1 commits in f3197ddf2abab9abdbc029def8164f4a748b0d91..dcee312c66267eb5a2f6f1561354003950e29105
2019-10-29 10:17:40 -0300 to 2019-10-31 11:26:53 -0300
- refactor: simplify extracting Result from Option (rust-lang/rust-by-example#1283)
## edition-guide
2 commits in e58bc4ca104e890ac56af846877c874c432a64b5..f553fb26c60c4623ea88a1cfe731eafe0643ce34
2019-07-31 20:14:12 +0200 to 2019-10-30 08:27:42 -0500
- remove old references to the nursery
- Port from Travis to GitHub Actions (rust-lang-nursery/edition-guide#192)
Clarify transmute_copy documentation example
Currently the documentation for `transmute_copy` implies that the function accepts a slice due to the variable name chosen in the example. This is misleading as `foo_slice` is actually an array and `transmute_copy` cannot take an unsized type anyway.
This PR just clarifies things by renaming the variable used in the example.
Use "field is never read" instead of "field is never used"
this is my first PR here so please let me know if i am doing it wrong
closes#64465
i will be referencing this with a book PR that updates the same language
miri panic_unwind: fix hack for SEH platforms
The old hack didn't work as we ended up duplicating the `eh_personality` lang item...
I have no idea if rustc cares that `eh_catch_typeinfo` has a certain shape, but better safe than sorry. I cannot test this locally.
r? @oli-obk Cc @Aaron1011
Move `DIAGNOSTICS` usage to `rustc_driver`
Remove `rustc_interface`'s dependency on `rustc_error_codes` and centralize all usages of `DIAGNOSTICS` in `rustc_driver`. Once we remove all references to `rustc_error_codes` in all other crates but `rustc_driver`, this should allow for incremental recompilation of the compiler to be smoother when tweaking error codes. This works towards https://github.com/rust-lang/rust/issues/66210#issuecomment-551862528.
(May include traces of minor drive-by cleanup.)
r? @Mark-Simulacrum
Centralize panic macro documentation
This is just the main commit from #61511 (which got closed because the author didn't reply) cherry-picked on the current master. Building `core` and `std` on this branch in stage 1 succeeded, which I thinks means the issues from the previous PR should be gone (but let's see what CI says).
rustc_plugin: Remove `Registry::register_attribute`
Legacy plugins cannot register inert attributes anymore.
The preferred replacement is to use `register_tool` ([tracking issue](https://github.com/rust-lang/rust/issues/66079)).
```rust
#![register_tool(servo)]
#[servo::must_root]
struct S;
```
The more direct replacement is `register_attribute` ([tracking issue](https://github.com/rust-lang/rust/issues/66080))
```rust
#![register_attr(must_root)]
#[must_root]
struct S;
```
, but it requires registering each attribute individually rather than registering the tool once, and is more likely to be removed rather than stabilized.
Improve documentation of `Vec::split_off(...)`
The previous ordering of the sentences kept switching between the return
value and the value of `self` after execution, making it hard to follow.
Additionally, as rendered in the browser, the period in "`Self`. `self`"
was difficult to make out as being a sentence separator and not one code
block.
The previous ordering of the sentences kept switching between the return
value and the value of `self` after execution, making it hard to follow.
Additionally, as rendered in the browser, the period in "`Self`. `self`"
was difficult to make out as being a sentence separator and not one code
block.
Fully integrate derive helpers into name resolution
```rust
#[derive(Foo)]
#[foo_helper] // already goes through name resolution
struct S {
#[foo_helper] // goes through name resolution after this PR
field: u8
}
```
How name resolution normally works:
- We have an identifier we need to resolve, take its location (in some sense) and look what names are in scope in that location.
How derive helper attributes are "resolved" (before this PR):
- After resolving the derive `Foo` we visit the derive's input (`struct S { ... } `) as a piece of AST and mark attributes textually matching one of the derive's helper attributes (`foo_helper`) as "known", so they never go through name resolution.
This PR changes the rules for derive helpers, so they are not proactively marked as known (which is a big hack ignoring any ambiguities or hygiene), but go through regular name resolution instead.
This change was previously blocked by attributes not being resolved in some positions at all (fixed in https://github.com/rust-lang/rust/pull/63468).
"Where exactly are derive helpers in scope?" is an interesting question, and I need some feedback from proc macro authors to answer it, see the post below (https://github.com/rust-lang/rust/pull/64694#issuecomment-533925160).
These helpers are resolved before their respective derives through a kind of look ahead into future expansions.
Some of these will migrate to proper resolution, others will be deprecated.
```
#[trait_helper] // Deprecate
#[derive(Trait)]
#[trait_helper] // Migrate to proper resolution
```
Update cc, git2, num_cpus.
This updates the `cc` crate, bringing in better parallel building support. Also updates `git2` which enables the parallel feature. (Note: I don't expect it will have a significant impact on build time, but seems good to update anyways.)
The main thorn is that `cc` gained knowledge about RISC-V architectures (https://github.com/alexcrichton/cc-rs/pull/428, https://github.com/alexcrichton/cc-rs/pull/429, https://github.com/alexcrichton/cc-rs/pull/430), but the builders on CI do not have the riscv C compiler installed. This means that bootstraps' cc detection was finding a C compiler that isn't installed, and fails.
The solution here is to override the cc detection to `false`. The C compiler isn't actually used on riscv platforms. AFAIK, the only location would be compiler_builtins, and it currently forces C support off (a533ae9c5a/build.rs (L49-L55)).
Other possible solutions:
- Add the override in cc_detect for riscv (or any "no-C" platform like wasm32 and nvptx)
- Install and use the appropriate c compiler. I tried this the `g++-riscv64-linux-gnu` package, but it failed missing some header file.
Closes#66232
Rollup of 5 pull requests
Successful merges:
- #66350 (protect creation of destructors by a mutex)
- #66407 (Add more tests for fixed ICEs)
- #66415 (Add --force-run-in-process unstable option to libtest)
- #66427 (Move the JSON error emitter to librustc_errors)
- #66441 (libpanic_unwind for Miri: make sure we have the SEH lang items when needed)
Failed merges:
r? @ghost
Refactor integer range handling in the usefulness algorithm
Integer range handling had accumulated a lot of debt. This cleans up a lot of it.
In particular this:
- removes unnecessary conversions between `Const` and `u128`, and between `Constructor` and `IntRange`
- clearly distinguishes between on the one hand ranges of integers that may or may not be matched exhaustively, and on the other hand ranges of non-integers that are never matched exhaustively and are compared using Const-based shenanigans
- cleans up some overly complicated code paths
- generally tries to be more idiomatic.
As a nice side-effect, I measured a 10% perf increase on `unicode_normalization`.
There's one thing that I feel remains to clean up: the [overlapping range check](https://github.com/rust-lang/rust/pull/64007), which is currently quite ad-hoc. But that is intricate enough that I'm leaving it out of this PR.
There's also one little thing I'm not sure I understand: can `try_eval_bits` fail for an integer constant value in that code ? What would that mean, and how do I construct a test case for this possibility ?
libpanic_unwind for Miri: make sure we have the SEH lang items when needed
r? @oli-obk @alexcrichton This is required to fix the Miri toolstate. Turns out rustc complains when doing codegen for MSVC and these lang items do not exist. For now `cfg(miri)` needs to still be able to codegen (we [plan to change that](https://github.com/rust-lang/miri/pull/1048#issuecomment-554108470) but that's a larger project requiring improvements to xargo and maybe also cargo; that should not block fixing the toolstate). Yes, this is a hack, but it is inside `cfg(miri)` so I hope this is okay.
Cc @Aaron1011
Move the JSON error emitter to librustc_errors
This is done both as a cleanup (it makes little sense for this emitter to be in libsyntax), but also as part of broader work to decouple Session from librustc itself.
Along the way, this also moves SourceMap to syntax_pos, which is also nice for the above reasons, as well as allowing dropping the SourceMapper trait from code. This had the unfortunate side-effect of moving `FatalError` to rustc_data_structures (it's needed in syntax_pos, due to SourceMap, but putting it there feels somehow worse).
