Move shared offload globals and define per-kernel globals once
This PR moves the shared LLVM global variables logic out of the `offload` intrinsic codegen and generates kernel-specific variables only ont he first call of the intrinsic.
r? `@ZuseZ4`
tracking:
- https://github.com/rust-lang/rust/issues/131513
Extend parsing of `ReprOptions` with `rustc_scalable_vector(N)` which
optionally accepts a single literal integral value - the base multiple of
lanes that are in a scalable vector. Can only be applied to structs.
Co-authored-by: Jamie Cunliffe <Jamie.Cunliffe@arm.com>
148725 moved the default to being homogeneous; this adds heterogeneous ones back under an obvious-bikeshed syntax so people can experiment with that as well.
Essentially resolves 149025 by letting them move to this syntax instead.
Stabilize `asm_cfg`
tracking issue: https://github.com/rust-lang/rust/issues/140364
closes https://github.com/rust-lang/rust/issues/140364
Reference PR:
- https://github.com/rust-lang/reference/pull/2063
# Request for Stabilization
## Summary
The `cfg_asm` feature allows `#[cfg(...)]` and `#[cfg_attr(...)]` on the arguments of the assembly macros, for instance:
```rust
asm!( // or global_asm! or naked_asm!
"nop",
#[cfg(target_feature = "sse2")]
"nop",
// ...
#[cfg(target_feature = "sse2")]
a = const 123, // only used on sse2
);
```
## Semantics
Templates, operands, `options` and `clobber_abi` in the assembly macros (`asm!`, `naked_asm!` and `global_asm!`) can be annotated with `#[cfg(...)]` and `#[cfg_attr(...)]`. When the condition evaluates to true, the annotated argument has no effect, and is completely ignored when expanding the assembly macro.
## Documentation
reference PR: https://github.com/rust-lang/reference/pull/2063
## Tests
- [tests/ui/asm/cfg.rs](https://github.com/rust-lang/rust/blob/master/tests/ui/asm/cfg.rs) checks that `cfg`'d arguments where the condition evaluates to false have no effect
- [tests/ui/asm/cfg-parse-error.rs](https://github.com/rust-lang/rust/blob/master/tests/ui/asm/cfg.rs) checks the parsing rules (parsing effectively assumes that the cfg conditions are all true)
## History
- https://github.com/rust-lang/rust/issues/140279
- https://github.com/rust-lang/rust/pull/140367
# Resolved questions
**how are other attributes handled**
Other attributes are parsed, but explicitly rejected.
# unresolved questions
**operand before template**
The current implementation expects at least one template string before any operands. In the example below, if the `cfg` condition evaluates to true, the assembly block is ill-formed. But even when it evaluates to `false` this block is rejected, because the parser still expects just a template (a template is parsed as an expression and then validated to ensure that it is or expands to a string literal).
Changing how this works is difficult.
```rust
// This is rejected because `a = out(reg) x` does not parse as an expresion.
asm!(
#[cfg(false)]
a = out(reg) x, //~ ERROR expected token: `,`
"",
);
```
**lint on positional arguments?**
Adding a lint to warn on the definition or use of positional arguments being `cfg`'d out was discussed in https://github.com/rust-lang/rust/issues/140279#issuecomment-2832237372 and subsequent comments. Such a lint is not currently implemented, but that may not be a blocker based on the comments there.
r? `@traviscross` (I'm assuming you'll reassign as needed)
Remove `#[const_trait]`
Remove `#[const_trait]` since we now have `const trait`. Update all structured diagnostics that still suggested the attribute.
r? ```@rust-lang/project-const-traits```
Encode cfg trace, not its early counterpart to fix cross-crate `doc(auto_cfg)`
Fixesrust-lang/rust#141301.
<details><summary>Rambling about <code>target_feature</code> which I didn't touch here</summary>
Regarding https://github.com/rust-lang/rust/issues/141301#issuecomment-3390100259 (`#[target_feature(enable = …)]` on inlined cross-crate re-exports), it has the same underlying cause (namely, we neither encode `target_feature` nor `AttributeKind::TargetFeature` in the crate metadata). However, I didn't make that change because I first want to experiment with querying `TyCtxt::codegen_fn_attrs` in rustdoc instead which already works cross-crate (and also use to it for reconstructing `no_mangle`, `export_name`, `link_section` to avoid encoding these attributes unnecessarily (basically reverting rust-lang/rust#144050) as suggested in https://github.com/rust-lang/rust/issues/144004#issuecomment-3077725837).
</details>
r? GuillaumeGomez
Add an attribute to check the number of lanes in a SIMD vector after monomorphization
Allows std::simd to drop the `LaneCount<N>: SupportedLaneCount` trait and maintain good error messages.
Also, extends rust-lang/rust#145967 by including spans in layout errors for all ADTs.
r? ``@RalfJung``
cc ``@workingjubilee`` ``@programmerjake``
reddevilmidzy