Fix span edition for 2024 RPIT coming from an external macro
This fixes a problem where code generated by an external macro with an RPIT would end up using the call-site edition instead of the macro's edition for the RPIT. When used from a 2024 crate, this caused the code to change behavior to the 2024 capturing rules, which we don't want.
This was caused by the impl-trait lowering code would replace the span with one marked with `DesugaringKind::OpaqueTy` desugaring. However, it was also overriding the edition of the span with the edition of the local crate. Instead it should be using the edition of the span itself.
Fixes https://github.com/rust-lang/rust/issues/132917
make UI test OS-agnostic
the internal representation of `std::sync::Mutex` depends on the compilation target. due to this, the compiler produces different number of errors for UI test `issue-17431-6.rs` depending on the compilation target.
for example, when compiling the UI test to an `*-apple-*` or `*-qnx7*` target, the "cycle detected" error is not reported
``` console
$ cat src/lib.rs
use std::sync::Mutex;
enum Foo {
X(Mutex<Option<Foo>>),
}
impl Foo {
fn bar(self) {}
}
fn main() {}
$ cargo check --target x86_64-apple-ios 2>&1 | rg '^error\['
error[E0072]: recursive type `Foo` has infinite size
```
whereas rustc produces two errors for other OSes, like Linux, which is what the UI test expects
``` console
$ cargo check --target x86_64-unknown-linux-gnu 2>&1 | rg '^error\['
error[E0072]: recursive type `Foo` has infinite size
error[E0391]: cycle detected when computing when `Foo` needs drop
```
this commit replaces the problematic `Mutex` with `UnsafeCell`, which has the same internal representation regardless of the compilation target. with that change, rustc reports two errors for all compilation targets.
``` console
$ cat src/lib.rs
use std::cell::UnsafeCell;
enum Foo {
X(UnsafeCell<Option<Foo>>),
}
impl Foo {
fn bar(self) {}
}
fn main() {}
$ cargo check --target x86_64-apple-ios 2>&1 | rg '^error\['
error[E0072]: recursive type `Foo` has infinite size
error[E0391]: cycle detected when computing when `Foo` needs drop
```
with this change, we can remove the `ignore-apple` directive as the UI test now also passes on apple targets.
Mention both release *and* edition breakage for never type lints
This PR makes ~~two changes~~ a change to the never type lints (`dependency_on_unit_never_type_fallback` and `never_type_fallback_flowing_into_unsafe`):
1. Change the wording of the note to mention that the breaking change will be made in an edition _and_ in a future release
2. ~~Make these warnings be reported in deps (hopefully the lints are matured enough)~~
r? ``@compiler-errors``
cc ``@ehuss``
closes#132930
Rollup of 4 pull requests
Successful merges:
- #132817 (Recurse into APITs in `impl_trait_overcaptures`)
- #133021 (Refactor `configure_annotatable`)
- #133045 (tests: Test pac-ret flag merging on clang with LTO)
- #133049 (Change Visitor::visit_precise_capturing_arg so it returns a Visitor::Result)
r? `@ghost`
`@rustbot` modify labels: rollup
This fixes a problem where code generated by an external macro with an
RPIT would end up using the call-site edition instead of the macro's
edition for the RPIT. When used from a 2024 crate, this caused the code
to change behavior to the 2024 capturing rules, which we don't want.
This was caused by the impl-trait lowering code would replace the span
with one marked with `DesugaringKind::OpaqueTy` desugaring. However, it
was also overriding the edition of the span with the edition of the
local crate. Instead it should be using the edition of the span itself.
Fixes https://github.com/rust-lang/rust/issues/132917
Recurse into APITs in `impl_trait_overcaptures`
We were previously not detecting cases where an RPIT was located in the return type of an async function, leading to underfiring of the `impl_trait_overcaptures`. This PR does this recursion properly now.
cc https://github.com/rust-lang/rust/issues/132809
Separate `RemoveLet` span into primary span for `let` and removal
suggestion span for `let `, so that primary span does not include
whitespace.
Fixes: #133031
Signed-off-by: Tyrone Wu <wudevelops@gmail.com>
check_consts: fix error requesting feature gate when that gate is not actually needed
When working on https://github.com/rust-lang/hashbrown/pull/586 I noticed that the compiler asks for the `rustc_private` feature to be enabled if one forgets to set `rustc_const_stable_indirect` on a function -- but enabling `rustc_private` would not actually help. This fixes the diagnostics.
r? `@compiler-errors`
the internal representation of `std::sync::Mutex` depends on the compilation target. due to this,
the compiler produces different number of errors for UI test
`issue-17431-6.rs` depending on the compilation target.
for example, when compiling the UI test to an `*-apple-*` or `*-qnx7*` target, the "cycle detected"
error is not reported
``` console
$ cat src/lib.rs
use std::sync::Mutex;
enum Foo {
X(Mutex<Option<Foo>>),
}
impl Foo {
fn bar(self) {}
}
fn main() {}
$ cargo check --target x86_64-apple-ios 2>&1 | rg '^error\['
error[E0072]: recursive type `Foo` has infinite size
```
whereas rustc produces two errors for other OSes, like Linux, which is what the UI test expects
``` console
$ cargo check --target x86_64-unknown-linux-gnu 2>&1 | rg '^error\['
error[E0072]: recursive type `Foo` has infinite size
error[E0391]: cycle detected when computing when `Foo` needs drop
```
this commit replaces the problematic `Mutex` with `UnsafeCell`, which has the same internal
representation regardless of the compilation target. with that change, rustc reports two errors for
all compilation targets.
``` console
$ cat src/lib.rs
use std::cell::UnsafeCell;
enum Foo {
X(UnsafeCell<Option<Foo>>),
}
impl Foo {
fn bar(self) {}
}
fn main() {}
$ cargo check --target x86_64-apple-ios 2>&1 | rg '^error\['
error[E0072]: recursive type `Foo` has infinite size
error[E0391]: cycle detected when computing when `Foo` needs drop
```
with this change, we can remove the `ignore-apple` directive as the UI test now also passes on apple
targets.
[AIX] Add crate "unwind" to link with libunwind
The Rust on IBM AIX uses LLVM's `libunwind`. Since crate `unwind` is a dependency of crate `std` and `#![no_std]` is specified in the test case, `libunwind` is not included in the link command by default. As a result, the test case fails to link with the error "Undefined symbol: ._Unwind_Resume" on AIX. This PR explicitly adds crate `unwind` for AIX, along with feature `panic_unwind`, which is required to include the `unwind` crate.
borrowck diagnostics: suggest borrowing function inputs in generic positions
# Summary
This generalizes borrowck's existing suggestions to borrow instead of moving when passing by-value to a function that's generic in that input. Previously, this was special-cased to `AsRef`/`Borrow`-like traits and `Fn`-like traits. This PR changes it to test if, for a moved place with type `T`, that the callee's signature and clauses don't break if you substitute in `&T` or `&mut T`. For instance, it now works with `Read`/`Write`-like traits.
Fixes https://github.com/rust-lang/rust/issues/131413
# Incidental changes
- No longer spuriously suggests mutable borrows of closures in some situations (see e.g. the tests in [tests/ui/closures/2229_closure_analysis/](https://github.com/rust-lang/rust/compare/master...dianne:rust:suggest-borrow-generic?expand=1#diff-8dfb200c559f0995d0f2ffa2f23bc6f8041b263e264e5c329a1f4171769787c0)).
- No longer suggests cloning closures that implement `Fn`, since they can be borrowed (see e.g. [tests/ui/moves/borrow-closures-instead-of-move.stderr](https://github.com/rust-lang/rust/compare/master...dianne:rust:suggest-borrow-generic?expand=1#diff-5db268aac405eec56d099a72d8b58ac46dab523cf013e29008104840168577fb)).
This keeps the behavior to suppress suggestions of `fn_once.clone()()`. I think it might make sense to suggest it with a "but this might not be your desired behavior" caveat, as is done when something is used after being consumed as the receiver for a method call. That's probably out of the scope of this PR though.
# Limitations and possible improvements
- This doesn't work for receivers of method calls. This is a small change, and I have it implemented locally, but I'm not sure it's useful on its own. In most cases I've found borrowing the receiver would change the call's output type (see below). In other cases (e.g. `Iterator::sum`), borrowing the receiver isn't useful since it's consumed.
- This doesn't work when it would change the call's output type. In general, I figure inserting references into the output type is an unwanted change. However, this also means it doesn't work in cases where the new output type would be effectively the same as the old one. For example, from the rand crate, the iterator returned by [`Rng::sample_iter`](https://docs.rs/rand/latest/rand/trait.Rng.html#method.sample_iter) is effectively the same (modulo regions) whether you borrow or consume the receiver `Rng`, so common usage involves borrowing it. I'm not sure whether the best approach is to add a more complex check of approximate equivalence, to forego checking the call's output type and give spurious suggestions, or to leave it as-is.
- This doesn't work when it would change the call's other input types. Instead, it could suggest borrowing any others that have the same parameter type (but only when suggesting shared borrows). I think this would be a pretty easy change, but I don't think it's very useful so long as the normalized output type can't change.
I'm happy to implement any of these (or other potential improvements to this), but I'm not sure which are common enough patterns to justify the added complexity. Please let me know if any sound worthwhile.
PassWrapper: disable UseOdrIndicator for Asan Win32
As described in https://reviews.llvm.org/D137227 UseOdrIndicator should be disabled on Windows since link.exe does not support duplicate weak definitions.
Fixes https://github.com/rust-lang/rust/issues/124390.
Credits also belong to `@1c3t3a` who worked with me on this.
We are currently testing this on a Windows machine.
Handle infer vars in anon consts on stable
Fixes#132955
Diagnostics will sometimes try to replace generic parameters with inference variables in failing goals. This means that if we have some failing goal with an array repeat expr count anon const in it, we will wind up with some `ty::ConstKind::Unevaluated(anon_const_def, [?x])` during diagnostics which will then ICE if we do not handle inference variables correctly on stable when normalizing type system consts.
r? ```@compiler-errors```
This subsumes the suggestions to borrow arguments with `AsRef`/`Borrow` bounds and those to borrow
arguments with `Fn` and `FnMut` bounds. It works for other traits implemented on references as well,
such as `std::io::Read`, `std::io::Write`, and `core::fmt::Write`.
Incidentally, by making the logic for suggesting borrowing closures general, this removes some
spurious suggestions to mutably borrow `FnMut` closures in assignments, as well as an unhelpful
suggestion to add a `Clone` constraint to an `impl Fn` argument.
This is setup for unifing the logic for suggestions to borrow arguments in generic positions.
As of this commit, it's still special cases for `AsRef`/`Borrow`-like traits and `Fn`-like traits.
This also downgrades its applicability to MaybeIncorrect. Its suggestion can result in ill-typed
code when the type parameter it suggests providing a different generic argument for appears
elsewhere in the callee's signature or predicates.
As described here UseOdrIndicator should be disabled on Windows
since link.exe does not support duplicate weak definitions
(https://reviews.llvm.org/D137227).
Co-Authored-By: Bastian Kersting <bkersting@google.com>
Make precise capturing suggestion machine-applicable only if it has no APITs
cc https://github.com/rust-lang/rust/issues/132932
The only case where this suggestion is not machine-applicable is when we suggest turning arg-position impl trait into type parameters, which may expose type parameters that were not turbofishable before.
Proper support for cross-crate recursive const stability checks
~~Stacked on top of https://github.com/rust-lang/rust/pull/132492; only the last three commits are new.~~
In a crate without `staged_api` but with `-Zforce-unstable-if-unmarked`, we now subject all functions marked with `#[rustc_const_stable_indirect]` to recursive const stability checks. We require an opt-in so that by default, a crate can be built with `-Zforce-unstable-if-unmarked` and use nightly features as usual. This property is recorded in the crate metadata so when a `staged_api` crate calls such a function, it sees the `#[rustc_const_stable_indirect]` and allows it to be exposed on stable. This, finally, will let us expose `const fn` from hashbrown on stable.
The second commit makes const stability more like regular stability: via `check_missing_const_stability`, we ensure that all publicly reachable functions have a const stability attribute -- both in `staged_api` crates and `-Zforce-unstable-if-unmarked` crates. To achieve this, we move around the stability computation so that const stability is computed after regular stability is done. This lets us access the final result of the regular stability computation, which we use so that `const fn` can inherit the regular stability (but only if that is "unstable"). Fortunately, this lets us get rid of an `Option` in `ConstStability`.
This is the last PR that I have planned in this series.
r? `@compiler-errors`
Make sure to ignore elided lifetimes when pointing at args for fulfillment errors
See the comment I left in the code.
---
If we have something like:
```
fn foo<'a, T: 'a + BoundThatIsNotSatisfied>() {}
```
And the user turbofishes just the type args:
```
foo::<()>();
```
Then if we try pointing at `()` (i.e. the type argument for `T`), we don't actually consider the possibility that the lifetimes may have been left out of the turbofish. We try indexing incorrectly into the HIR args, and bail on the suggestion.
Consolidate type system const evaluation under `traits::evaluate_const`
Part of #130704Fixes#128232Fixes#118545
Removes `ty::Const::{normalize_internal, eval_valtree}` and `InferCtxt::(try_)const_eval_resolve`, consolidating the associated logic into `evaluate_const` in `rustc_trait_selection`. This results in an API for `ty::Const` that is free of any normalization/evaluation functions that would be incorrect to use under `min_generic_const_args`/`associated_const_equality`/`generic_const_exprs` or, more generally, that would be incorrect to use in the presence of generic type system constants.
Moving this logic to `rustc_trait_selection` and out of `rustc_middle` is also a pre-requisite for ensuring that we do not evaluate constants whose where clauses do not hold.
From this point it should be relatively simple (hah) to implement more complex normalization of type system constants such as: checking wf'ness before invoking CTFE machinery, or being able to normalize const aliases that still refer to generic parameters.
r? `@compiler-errors`
Feature gate yield expressions not in 2024
This changes it so that yield expressions are no longer allowed in the 2024 edition without a feature gate. We are currently only reserving the `gen` keyword in the 2024 edition, and not allowing anything else to be implicitly enabled by the edition.
In practice this doesn't have a significant difference since yield expressions can't really be used outside of coroutines or gen blocks, which have their own feature gates. However, it does affect what is accepted pre-expansion, and I would feel more comfortable not allowing yield expressions.
I believe the stabilization process for gen blocks or coroutines will not need to check the edition here, so this shouldn't ever be needed.
Remove attributes from generics in built-in derive macros
Related issue #132561
Removes all attributes from generics in the expanded implementations of built-in derive macros.
