disable naked-dead-code-elimination test if no RET mnemonic is available
this test emit x86_64 specific ret asm instruction and should not be compiled on any other arch.
Document that CFI diverges from Rust wrt. ABI-compatibility rules
The CFI sanitizer is a sanitizer that checks that no ABI-incompatible function calls are made at runtime, but there is currently an unfortunate divergence between the Rust ABI-compatibility rules and what the CFI sanitizer checks. Thus, document that this divergence exists.
There are proposals for how we can align the ABI rules to eliminate this discrepancy, and I would like to follow through with those, but for now I think we can at least document that the discrepancy exists.
For further discussion please see [Re-evaluate ABI compatibility rules in light of CFI](https://github.com/rust-lang/unsafe-code-guidelines/issues/489) and [Can CFI be made compatible with type erasure schemes?](https://github.com/rust-lang/rust/issues/128728) and [`fn_cast!` macro](https://github.com/rust-lang/rust/issues/140803).
cc @rcvalle @samitolvanen @maurer @bjorn3 @RalfJung
Rendered:
<img width="956" height="391" alt="image" src="https://github.com/user-attachments/assets/410d3eaa-9476-4800-9ef8-bbb100a100c5" />
Tweak irrefutable let else warning output
Fixes https://github.com/rust-lang/rust/issues/153454
Greeting!
This PR tweak diagnostic output for `irrefutable-let-else` patterns and adds a check for `let a = Some(b) else {...}`
Thanks for the review!
```
help: consider using `let Some(name) = case` to match on a specific variant
|
LL - let name = Some(case) else {
LL + let Some(name) = case else {
|
```
switch to v0 mangling by default on stable
Following rust-lang/rust#89117, rustc has defaulted to the v0 mangling scheme by default (since Nov 20th 2025). This surfaced two bugs:
- rust-lang/rust#138261 was a small ICE (found via fuzzing) where an implementation-internal namespace was missing for global assembly - this occurs with names instantiated within global assembly (that can happen inside constants)
- rust-lang/rust#134479 only occurs with unstable `generic_const_exprs`
Since there have been three-to-four months for users to find bugs with this mangling scheme on nightly, that the scheme has been waiting many years to be stabilised, and has been used successfully internally at Microsoft, Meta and Google for many years, this patch proposes stabilising the v0 mangling scheme on stable.
This patch does not propose removing the legacy mangling, it will remain usable on nightly as an escape-hatch if there are remaining bugs (though admittedly it would require switching to nightly for those on stable) - it is anticipated that this would be unlikely given current testing undergone by v0. Legacy mangling can be removed in another follow-up.
r? @wesleywiser
Only exclude the #155473 change for 1-byte bool-likes
That's the thing we handle differently in codegen (see `to_immediate_scalar`) so if the other ones are fine, that helps narrow it down further.
cc https://github.com/rust-lang/rust/pull/155473
Subtree sync for rustc_codegen_cranelift
The main highlights this time are a Cranelift update and fixing backtraces for arm64 macOS (x86_64 macOS is still broken).
r? @ghost
@rustbot label +A-codegen +A-cranelift +T-compiler +subtree-sync
Add regression test for #101363
Adds test for rust-lang/rust#101363
Since it's my first time adding tests, I'm not sure if the test itself, its location, or its name are appropriate.
Rename the diagnostic item for `std::sync::mpsc::Receiver`
`MpscReceiver` aligns with `MpscSender`. The original name appears to not actually have been in use, for better or worse.
r? mejrs
[codex] tests: mark migrated UI tests as check-pass
## Summary
Migrate a small set of UI tests left behind by the `compile-pass` migration from `build-pass` to `check-pass`.
These tests exercise attributes, cfg_attr, range trait type checking, and reachable-code diagnostics. None of the changed tests need codegen or linking, so `check-pass` matches the intended coverage and removes the stale `FIXME(#62277)` notes.
## Validation
- `python x.py test tests/ui/attributes/attr-before-view-item.rs tests/ui/attributes/attr-before-view-item2.rs tests/ui/attributes/attr-mix-new.rs tests/ui/attributes/class-attributes-1.rs tests/ui/attributes/class-attributes-2.rs tests/ui/attributes/method-attributes.rs tests/ui/attributes/unrestricted-attribute-tokens.rs tests/ui/attributes/variant-attributes.rs tests/ui/conditional-compilation/cfg-attr-multi-false.rs tests/ui/conditional-compilation/cfg-attr-multi-true.rs tests/ui/range/range_traits-4.rs tests/ui/range/range_traits-5.rs tests/ui/range/range_traits-7.rs tests/ui/reachable/expr_andand.rs tests/ui/reachable/expr_oror.rs`
- `python x.py test tidy`
[AIX] update linker default to bcdtors
The bcdtor mode affects how the AIX linker choose to pull in static constructors and destructors (https://www.ibm.com/docs/en/aix/7.2.0?topic=l-ld-command) to the link.
The current setting of all makes static init in archive members live regardless of if the archive member would be otherwise referenced, causing that whole archive member to become part of the link.
This default was initially retained for compatibility purposes with historical compilers on the platform which defaulted to this setting. Unfortunately this greedy pulling in of static init can have unintended consequences for applications, for example for programs linked against parts of compiler-rt which contain optional instrumentation (containing static initializers) which may be unused as these now become live in all programs regardless of use.
For that reason and similar reasons, this PR switches the default to mbr, which only extracts static init from archive members which would otherwise be referenced. This gives a behaviour very consistent with linkers on other platforms (e.g. Linux).
Users requiring the old default behaviour can manually pass `-bcdtors:all` on the link step which will override any default we pass here.
(Note: this mirrors LLVM change: https://github.com/llvm/llvm-project/pull/191265)
`slice::join`: borrow only once during length calc
This ensures the length calculation will always be self-consistent even if the real length changes when we actually come to use them.
This is a follow up to rust-lang/rust#155708
Don't reload length in String::push
Same as in `Vec::push_mut`, we get `.len()` once at the start since it won't change in the `reserve()` call.
Saves reloading the length after the allocation: https://godbolt.org/z/W3G165Gd7
Fix a bug in `ChunkedBitSet::subtract`
An operator precedence bug means an incorrect mask is used in `ChunkedBitSet::subtract`. Details in individual commits.
r? @dingxiangfei2009
Add infrastructure to query LLVM backend for specific assembly mnemonics
and use it in compiletest to conditionally run tests based on instruction
availability.
This fixes test failures with naked-dead-code-elimination which requires
the `RET` mnemonic.
Co-authored-by: Folkert de Vries <flokkievids@gmail.com>
Remove `WithCachedTypeInfo::stable_hash`.
We store a stable hash value in the most common interned values (e.g. types, predicates, regions). This is 16 bytes of data.
- In non-incremental builds it's a straightforward performance loss: the stable hash isn't computed or used, and the 16 bytes of space goes to waste (but it still gets hashed when interning).
- In incremental builds it avoids some hashing but doesn't seem to actually be a genuine performance win, and the complexity doesn't seem worth it.
r? @oli-obk
Rollup of 3 pull requests
Successful merges:
- rust-lang/rust#155894 (triagebot: add myself to libs rotation)
- rust-lang/rust#155897 (Add regression test for LLVM bug with huge stack frames)
- rust-lang/rust#155900 (Refer to `FnDef` as "function item", not "function pointer")
`MpscReceiver` aligns with `MpscSender`. The original name appears to
not actually have been in use, for better or worse.
Along the way, sprinkle the attribute onto `mpmc::Receiver` and
`mpmc::Sender` too.
CI: rfl: move job forward to Linux v7.1-rc1
Linux v7.1 will have our new MSRVs: Rust 1.85.0 and `bindgen` 0.71.1.
r? @lqd @Kobzol
try-job: x86_64-rust-for-linux
@rustbot label A-rust-for-linux
@bors try
Fix ICE: Scalar layout for non-primitive non-enum type unsafe binder
`UnsafeBinder` uses the inner layout, but the debug layout check still looked at the outer type. Check the inner type first so this does not ICE.
Tracking issue: rust-lang/rust#130516Closes: rust-lang/rust#154426
Change `ItemKind::Trait` to a field variant.
This changes `ItemKind::Trait` from an octuple(!!) to an enum variant with fields. Their names were chosen to match up with existing usage and minimize renaming.
I'm leaning towards renaming `ident` to `name` as well; let me know if that's desired.
Remove `AttributeLintKind`
Part of https://github.com/rust-lang/rust/issues/153099.
The `AttributeLintKind` type is finally gone! \o/
Diff is this big because I moved a file and a lot of `Diagnostic` types. :')
r? @JonathanBrouwer
Create a new `SharedContext::emit_dyn_lint_with_sess` method to simplify code when `Session` is not needed
Remove crate name from `UnexpectedCfgCargoMacroHelp`
Jonathan Brouwer