rust/compiler/rustc_feature/src, branch 1.89.0

Mitigate `#[align]` name resolution ambiguity regression with a rename

2025-07-24T18:02:01+00:00

From `#[align]` -> `#[rustc_align]`. Attributes starting with `rustc` are always perma-unstable and feature-gated by `feature(rustc_attrs)`. See regression RUST-143834. For the underlying problem where even introducing new feature-gated unstable built-in attributes can break user code such as ```rs macro_rules! align { () => { /* .. */ }; } pub(crate) use align; // `use` here becomes ambiguous ``` refer to RUST-134963. Since the `#[align]` attribute is still feature-gated by `feature(fn_align)`, we can rename it as a mitigation. Note that `#[rustc_align]` will obviously mean that current unstable user code using `feature(fn_aling)` will need additionally `feature(rustc_attrs)`, but this is a short-term mitigation to buy time, and is expected to be changed to a better name with less collision potential. See where mitigation options were considered. (cherry picked from commit 69b71e44107b4905ec7ad84ccb3edf4f14b3df69)

Update version placeholders

2025-06-23T21:13:20+00:00

Port `#[rustc_pub_transparent]` to the new attribute system

2025-06-21T18:52:25+00:00

correct template for `#[align]`

2025-06-19T11:58:23+00:00

it should not suggest just `#[align]`

Rollup merge of #142507 - folkertdev:fn-align-align-attribute, r=jdonszelmann

2025-06-19T00:22:49+00:00

use `#[align]` attribute for `fn_align` Tracking issue: https://github.com/rust-lang/rust/issues/82232 https://github.com/rust-lang/rfcs/pull/3806 decides to add the `#[align]` attribute for alignment of various items. Right now it's used for functions with `fn_align`, in the future it will get more uses (statics, struct fields, etc.) (the RFC finishes FCP today) r? `@ghost`

Rollup merge of #141610 - BoxyUwU:stabilize_generic_arg_infer, r=lcnr,traviscross

2025-06-18T16:06:49+00:00

Stabilize `feature(generic_arg_infer)` Fixes rust-lang/rust#85077 r? lcnr cc ````@rust-lang/project-const-generics````

add `#[align]` attribute

2025-06-18T10:37:08+00:00

Right now it's used for functions with `fn_align`, in the future it will get more uses (statics, struct fields, etc.)

fix bugs in inline/force_inline and diagnostics of all attr parsers

2025-06-17T21:19:31+00:00

Auto merge of #137944 - davidtwco:sized-hierarchy, r=oli-obk

2025-06-17T15:08:50+00:00

Sized Hierarchy: Part I This patch implements the non-const parts of rust-lang/rfcs#3729. It introduces two new traits to the standard library, `MetaSized` and `PointeeSized`. See the RFC for the rationale behind these traits and to discuss whether this change makes sense in the abstract. These traits are unstable (as is their constness), so users cannot refer to them without opting-in to `feature(sized_hierarchy)`. These traits are not behind `cfg`s as this would make implementation unfeasible, there would simply be too many `cfg`s required to add the necessary bounds everywhere. So, like `Sized`, these traits are automatically implemented by the compiler. RFC 3729 describes changes which are necessary to preserve backwards compatibility given the introduction of these traits, which are implemented and as follows: - `?Sized` is rewritten as `MetaSized` - `MetaSized` is added as a default supertrait for all traits w/out an explicit sizedness supertrait already. There are no edition migrations implemented in this, as these are primarily required for the constness parts of the RFC and prior to stabilisation of this (and so will come in follow-up PRs alongside the const parts). All diagnostic output should remain the same (showing `?Sized` even if the compiler sees `MetaSized`) unless the `sized_hierarchy` feature is enabled. Due to the use of unstable extern types in the standard library and rustc, some bounds in both projects have had to be relaxed already - this is unfortunate but unavoidable so that these extern types can continue to be used where they were before. Performing these relaxations in the standard library and rustc are desirable longer-term anyway, but some bounds are not as relaxed as they ideally would be due to the inability to relax `Deref::Target` (this will be investigated separately). It is hoped that this is implemented such that it could be merged and these traits could exist "under the hood" without that being observable to the user (other than in any performance impact this has on the compiler, etc). Some details might leak through due to the standard library relaxations, but this has not been observed in test output. **Notes:** - Any commits starting with "upstream:" can be ignored, as these correspond to other upstream PRs that this is based on which have yet to be merged. - This best reviewed commit-by-commit. I've attempted to make the implementation easy to follow and keep similar changes and test output updates together. - Each commit has a short description describing its purpose. - This patch is large but it's primarily in the test suite. - I've worked on the performance of this patch and a few optimisations are implemented so that the performance impact is neutral-to-minor. - `PointeeSized` is a different name from the RFC just to make it more obvious that it is different from `std::ptr::Pointee` but all the names are yet to be bikeshed anyway. - `@nikomatsakis` has confirmed [that this can proceed as an experiment from the t-lang side](https://rust-lang.zulipchat.com/#narrow/channel/435869-project-goals/topic/SVE.20and.20SME.20on.20AArch64.20.28goals.23270.29/near/506196491) - FCP in https://github.com/rust-lang/rust/pull/137944#issuecomment-2912207485 Fixes rust-lang/rust#79409. r? `@ghost` (I'll discuss this with relevant teams to find a reviewer)

trait_sel: `{Meta,Pointee}Sized` on `Sized` types

2025-06-16T15:00:22+00:00

Introduce the `MetaSized` and `PointeeSized` traits as supertraits of `Sized` and initially implement it on everything that currently implements `Sized` to isolate any changes that simply adding the traits introduces.