By changing two of the fields to use `Option<Ident>` instead of `Ident`.
As a result, `None` now means "no identifier", which is much clearer
than using an empty identifier.
This is part of the implementation of `#[doc(keyword = "match")]`
attributes used by `std` to provide documentation for keywords.
`is_doc_keyword` currently does a crude keyword range test that's
intended to catch all keywords but misses `kw::Yeet`. This commit
changes it to use `Symbol` methods, including the new `is_weak` method
(required for `union`). `Symbol` methods are much less prone to falling
out of date if new keywords are added.
We also have to remove the LLVM argument in cast-target-abi.rs for LLVM
21. I'm not really sure what the best approach here is since that test
already uses revisions. We could also fork the test into a copy for LLVM
19-20 and another for LLVM 21, but what I did for now was drop the
lint-abort-on-error flag to LLVM figuring that some coverage was better
than none, but I'm happy to change this if that was a bad direction.
The above also applies for ffi-out-of-bounds-loads.rs.
r? dianqk
@rustbot label llvm-main
Rollup of 6 pull requests
Successful merges:
- #138176 (Prefer built-in sized impls (and only sized impls) for rigid types always)
- #138749 (Fix closure recovery for missing block when return type is specified)
- #138842 (Emit `unused_attributes` for `#[inline]` on exported functions)
- #139153 (Encode synthetic by-move coroutine body with a different `DefPathData`)
- #139157 (Remove mention of `exhaustive_patterns` from `never` docs)
- #139167 (Remove Amanieu from the libs review rotation)
r? `@ghost`
`@rustbot` modify labels: rollup
Remove Amanieu from the libs review rotation
Unfortunately I've accumulated a large backlog of PRs to review, both in rust-lang and my own repos. Until I've cleared the backlog, I will remove myself from the review rotation for rust-lang/rust.
Remove mention of `exhaustive_patterns` from `never` docs
The example shows an exhaustive match:
```rust
#![feature(exhaustive_patterns)]
use std::str::FromStr;
let Ok(s) = String::from_str("hello");
```
But https://github.com/rust-lang/rust/issues/119612 moved this functionality to `#![feature(min_exhaustive_patterns)` and then stabilized it.
Encode synthetic by-move coroutine body with a different `DefPathData`
See the included test. In the first revision rpass1, we have an async closure `{closure#0}` which has a coroutine as a child `{closure#0}::{closure#0}`. We synthesize a by-move coroutine body, which is `{closure#0}::{closure#1}` which depends on the mir_built query, which depends on the typeck query.
In the second revision rpass2, we've replaced the coroutine-closure by a closure with two children closure. Notably, the def path of the second child closure is the same as the synthetic def id from the last revision: `{closure#0}::{closure#1}`. When type-checking this closure, we end up trying to compute its def_span, which tries to fetch it from the incremental cache; this will try to force the dependencies from the last run, which ends up forcing the mir_built query, which ends up forcing the typeck query, which ends up with a query cycle.
The problem here is that we really should never have used the same `DefPathData` for the synthetic by-move coroutine body, since it's not a closure. Changing the `DefPathData` will mean that we can see that the def ids are distinct, which means we won't try to look up the closure's def span from the incremental cache, which will properly skip replaying the node's dependencies and avoid a query cycle.
Fixes#139142
Emit `unused_attributes` for `#[inline]` on exported functions
I saw someone post a code sample that contained these two attributes, which immediately made me suspicious.
My suspicions were confirmed when I did a small test and checked the compiler source code to confirm that in these cases, `#[inline]` is indeed ignored (because you can't exactly `LocalCopy`an unmangled symbol since that would lead to duplicate symbols, and doing a mix of an unmangled `GloballyShared` and mangled `LocalCopy` instantiation is too complicated for our current instatiation mode logic, which I don't want to change right now).
So instead, emit the usual unused attribute lint with a message saying that the attribute is ignored in this position.
I think this is not 100% true, since I expect LLVM `inlinehint` to still be applied to such a function, but that's not why people use this attribute, they use it for the `LocalCopy` instantiation mode, where it doesn't work.
r? saethlin as the instantiation guy
Procedurally, I think this should be fine to merge without any lang involvement, as this only does a very minor extension to an existing lint.
Fix closure recovery for missing block when return type is specified
Firstly, fix the `is_array_like_block` condition to make sure we're actually recovering a mistyped *block* rather than some other delimited expression. This fixes#138748.
Secondly, split out the recovery of missing braces on a closure body into a separate recovery. Right now, the suggestion `"you might have meant to write this as part of a block"` originates from `suggest_fixes_misparsed_for_loop_head`, which feels kinda brittle and coincidental since AFAICT that recovery wasn't ever really intended to fix this.
We also can make this `MachineApplicable` in this case.
Fixes#138748
r? `@fmease` or reassign if you're busy/don't wanna review this
Prefer built-in sized impls (and only sized impls) for rigid types always
This PR changes the confirmation of `Sized` obligations to unconditionally prefer the built-in impl, even if it has nested obligations. This also changes all other built-in impls (namely, `Copy`/`Clone`/`DiscriminantKind`/`Pointee`) to *not* prefer built-in impls over param-env impls. This aligns the old solver with the behavior of the new solver.
---
In the old solver, we register many builtin candidates with the `BuiltinCandidate { has_nested: bool }` candidate kind. The precedence this candidate takes over other candidates is based on the `has_nested` field. We only prefer builtin impls over param-env candidates if `has_nested` is `false`
2b4694a698/compiler/rustc_trait_selection/src/traits/select/mod.rs (L1804-L1866)
Preferring param-env candidates when the builtin candidate has nested obligations *still* ends up leading to detrimental inference guidance, like:
```rust
fn hello<T>() where (T,): Sized {
let x: (_,) = Default::default();
// ^^ The `Sized` obligation on the variable infers `_ = T`.
let x: (i32,) = x;
// We error here, both a type mismatch and also b/c `T: Default` doesn't hold.
}
```
Therefore this PR adjusts the candidate precedence of `Sized` obligations by making them a distinct candidate kind and unconditionally preferring them over all other candidate kinds.
Special-casing `Sized` this way is necessary as there are a lot of traits with a `Sized` super-trait bound, so a `&'a str: From<T>` where-bound results in an elaborated `&'a str: Sized` bound. People tend to not add explicit where-clauses which overlap with builtin impls, so this tends to not be an issue for other traits.
We don't know of any tests/crates which need preference for other builtin traits. As this causes builtin impls to diverge from user-written impls we would like to minimize the affected traits. Otherwise e.g. moving impls for tuples to std by using variadic generics would be a breaking change. For other builtin impls it's also easier for the preference of builtin impls over where-bounds to result in issues.
---
There are two ways preferring builtin impls over where-bounds can be incorrect and undesirable:
- applying the builtin impl results in undesirable region constraints. E.g. if only `MyType<'static>` implements `Copy` then a goal like `(MyType<'a>,): Copy` would require `'a == 'static` so we must not prefer it over a `(MyType<'a>,): Copy` where-bound
- this is mostly not an issue for `Sized` as all `Sized` impls are builtin and don't add any region constraints not already required for the type to be well-formed
- however, even with `Sized` this is still an issue if a nested goal also gets proven via a where-bound: [playground](https://play.rust-lang.org/?version=stable&mode=debug&edition=2024&gist=30377da5b8a88f654884ab4ebc72f52b)
- if the builtin impl has associated types, we should not prefer it over where-bounds when normalizing that associated type. This can result in normalization adding more region constraints than just proving trait bounds. https://github.com/rust-lang/rust/issues/133044
- not an issue for `Sized` as it doesn't have associated types.
r? lcnr
Revert "Rollup merge of #136127 - WaffleLapkin:dyn_ptr_unwrap_cast, r=compiler-errors"
...not permanently tho. Just until we can land something like #138542, which will fix the underlying perf issues (https://github.com/rust-lang/rust/pull/136127#issuecomment-2743891744). I just don't want this to land on beta and have people rely on this behavior if it'll need some reworking for it to be implemented performantly.
r? `@WaffleLapkin` or reassign -- sorry for reverting ur pr! i'm working on getting it re-landed soon :>
hygiene: Rewrite `apply_mark_internal` to be more understandable
The previous implementation allocated new `SyntaxContext`s in the inverted order, and it was generally very hard to understand why its result matches what the `opaque` and `opaque_and_semitransparent` field docs promise.
```rust
/// This context, but with all transparent and semi-transparent expansions filtered away.
opaque: SyntaxContext,
/// This context, but with all transparent expansions filtered away.
opaque_and_semitransparent: SyntaxContext,
```
It also couldn't be easily reused for the case where the context id is pre-reserved like in #129827.
The new implementation tries to follow the docs in a more straightforward way.
I did the transformation in small steps, so it indeed matches the old implementation, not just the docs.
So I suggest reading only the new version.
Switch some rustc_on_unimplemented uses to diagnostic::on_unimplemented
The use on the SliceIndex impl appears unreachable, there is no mention of "vector indices" in any test output and I could not get it to show up in error messages.
Improve hir_pretty for struct expressions.
While working on https://github.com/rust-lang/rust/pull/139131 I noticed the hir pretty printer outputs an empty line between each field, and is also missing a space before the `{` and the `}`:
```rust
let a =
StructWithSomeFields{
field_1: 1,
field_2: 2,
field_3: 3,
field_4: 4,
field_5: 5,
field_6: 6,};
let a = StructWithSomeFields{ field_1: 1, field_2: 2, ..a};
```
This changes it to:
```rust
let a =
StructWithSomeFields {
field_1: 1,
field_2: 2,
field_3: 3,
field_4: 4,
field_5: 5,
field_6: 6 };
let a = StructWithSomeFields { field_1: 1, field_2: 2, ..a };
```
Remove attribute `#[rustc_error]`
It was an ancient way to write `check-pass` tests, but now it's no longer necessary (except for the `delayed_bug_from_inside_query` flavor, which is retained).
Simplify expansion for format_args!().
Instead of calling `Placeholder::new()`, we can just use a struct expression directly.
Before:
```rust
Placeholder::new(…, …, …, …)
```
After:
```rust
Placeholder {
position: …,
flags: …,
width: …,
precision: …,
}
```
(I originally avoided the struct expression, because `Placeholder` had a lot of fields. But now that https://github.com/rust-lang/rust/pull/136974 is merged, it only has four fields left.)
This will make the `fmt` argument to `fmt::Arguments::new_v1_formatted()` a candidate for const promotion, which is important if we ever hope to tackle https://github.com/rust-lang/rust/issues/92698 (It doesn't change anything yet though, because the `args` argument to `fmt::Arguments::new_v1_formatted()` is not const-promotable.)
Subtree sync for rustc_codegen_cranelift
The main highlights this time are a Cranelift update, support for `#[target_feature]` for inline asm on arm64 and some vendor intrinsic fixes for arm64.
[AIX] Ignore linting on repr(C) structs with repr(packed) or repr(align(n))
This PR updates the lint added in 9b40bd7 to ignore repr(C) structs that also have repr(packed) or repr(align(n)).
As these representations can be modifiers on repr(C), it is assumed that users that add these should know what they are doing, and thus the the lint should not warn on the respective structs. For example, for the time being, using repr(packed) and manually padding a repr(C) struct can be done to correctly align struct members on AIX.
