tests: Fix the SIMD FFI tests with certain x86 configuration
This pull request fixes the SIMD FFI tests with certain x86 configurations by gating the SSE2 intrinsic behind the `sse2` feature gate. A generic LLVM intrinsic that is easy to un-fuse on those platforms is added to compensate for those platforms.
Always inline functions signatures containing `f16` or `f128`
There are a handful of tier 2 and tier 3 targets that cause a LLVM crash or linker error when generating code that contains `f16` or `f128`. The cranelift backend also does not support these types. To work around this, every function in `std` or `core` that contains these types must be marked `#[inline]` in order to avoid sending any code to the backend unless specifically requested.
However, this is inconvenient and easy to forget. Introduce a check for these types in the frontend that automatically inlines any function signatures that take or return `f16` or `f128`.
Note that this is not a perfect fix because it does not account for the types being passed by reference or as members of aggregate types, but this is sufficient for what is currently needed in the standard library.
Fixes: https://github.com/rust-lang/rust/issues/133035
Closes: https://github.com/rust-lang/rust/pull/133037
[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.
There are a handful of tier 2 and tier 3 targets that cause a LLVM crash
or linker error when generating code that contains `f16` or `f128`. The
cranelift backend also does not support these types. To work around
this, every function in `std` or `core` that contains these types must
be marked `#[inline]` in order to avoid sending any code to the backend
unless specifically requested.
However, this is inconvenient and easy to forget. Introduce a check for
these types in the frontend that automatically inlines any function
signatures that take or return `f16` or `f128`.
Note that this is not a perfect fix because it does not account for the
types being passed by reference or as members of aggregate types, but
this is sufficient for what is currently needed in the standard library.
Fixes: https://github.com/rust-lang/rust/issues/133035
Closes: https://github.com/rust-lang/rust/pull/133037
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.
compiletest: add `max-llvm-major-version` directive
To complement existing `min-llvm-version` so contributors don't have to use `ignore-llvm-version: 20 - 99` to emulate `max-llvm-major-version: 19`.
Closes#132305.
cc `@workingjubilee` who suggested this.
### Implementation steps
- [x] 1. Implement the directive (this PR)
- [x] 2. Open an accompanying dev-guide PR to describe the directive (https://github.com/rust-lang/rustc-dev-guide/pull/2129)
r? bootstrap
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>
[rustdoc] Fix duplicated footnote IDs
Fixes https://github.com/rust-lang/rust/issues/131901.
Footnote IDs were increased locally (ie, on the docblock) and not globally (ie, on the whole item page).
cc `@aDotInTheVoid`
r? `@notriddle`
compiletest: Add ``exact-llvm-major-version`` directive
Now contributors don't need to use `min-llvm-version: X` + `ignore-llvm-version: X+1 - 99`, so they can simply use `exact-llvm-major-version: X`
To be honest, I didn't find any usages of that hack other than the one mentioned in the issue. ( `tests/codegen/try_question_mark_nop.rs`)
Closes#132348.
rustc-dev-guide PR for `//@ exact-llvm-major-version`: https://github.com/rust-lang/rustc-dev-guide/pull/2135
r? jieyouxu
rustdoc: Treat declarative macros more like other item kinds
Apparently at some time in the past we were unable to generate an href for the module path inside the visibility of decl macros 2.0 (`pub(in ...)`). As a result of this, a whole separate function was introduced specifically for printing the visibility of decl macros that didn't attempt to generate any links. The description of PR https://github.com/rust-lang/rust/pull/84074 states:
> This fixes the overly-complex invariant mentioned in https://github.com/rust-lang/rust/pull/83237#issuecomment-815346570, where the macro source can't have any links in it only because the cache hasn't been populated yet.
I can no longer reproduce the original issue. Reusing the existing visibility rendering logic *seems* to work just fine (I couldn't come up with any counterexamples, though I invite you to prove me wrong).
* Fixes#83000
* Fixes the visibility showing up "twice" in rustdoc-JSON output: Once as the `visibility` field, once baked into the source[^1]
* Fixes `#[doc(hidden)]` not getting rendered on doc(hidden) decl macros 2.0 under `--document-hiden-items` (for decl macros 1.2 the issue remains; I will address this separately when fixing #132304).
---
<details><summary>Outdated Section</summary>
NOTE: The current version of this PR is committing a UI crime, I'd like to receive feedback on that. Maybe you have a satisfactory solution for how to remedy it. Namely, as you know we have two different ways of / modes for highlighting code with color:
1. Only highlighting links / item paths and avoiding to highlight tokens by kind like keywords (to reduce visual noise and maybe also artifact size). Used for item declarations(\*).
2. Highlighting tokens by kind. Used for code blocks written by the user.
(\*): With the notable exception being macro declarations! Well, since this PR reuses the same function for rendering the item visibility (which only makes sense), we have a clash of modes: We now use both ways of highlighting code for decl macros: №1 for the visibility, №2 for the rest. This awkward. See for yourself:
* On master: 
* On this branch: 
</details>
Furthermore, we now no longer syntax-highlight declarative macros (be it `macro_rules!` or `macro`) since that was inconsistent with the way we render all other item kinds. See (collapsed) *Outdated Section* above. See also https://github.com/rust-lang/rust/pull/132302#discussion_r1821310783.
| On master | On this branch |
|---|---|
|  |  |
[^1]: E.g., `"visibility":{"restricted":{"parent":1,"path":"::a"}},/*OMITTED*/,"inner":{"macro":"pub(in a) macro by_example_vis_named($foo:expr) {\n ...\n}"}`
CFI: Append debug location to CFI blocks
Currently we're not appending debug locations to the inserted CFI blocks. This shows up in #132615 and #100783. This change fixes that by passing down the debug location to the CFI type-test generation and appending it to the blocks.
Credits also belong to `@jakos-sec` who worked with me on this.
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.
