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Merged
merged 17 commits into from
Jun 23, 2025
Merged

minor: sync from downstream #20063

merged 17 commits into from
Jun 23, 2025

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@lnicola lnicola commented Jun 23, 2025

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bors and others added 17 commits June 18, 2025 06:25
Rewrite `inline` attribute parser to use new infrastructure and improve diagnostics for all parsed attributes

r? `@oli-obk`

This PR:
- creates a new parser for inline attributes
- creates consistent error messages and error codes between attribute parsers; inline and others
- as such changes a few error messages for other attributes to be (in my eyes) much more consistent
- tests ast-lowering lints introduced by rust-lang/rust#138164 since this is now useful for the first time
- Coalesce some useless error codes

Builds on top of rust-lang/rust#138164

Closes rust-lang/rust#137950
Change __rust_no_alloc_shim_is_unstable to be a function

This fixes a long sequence of issues:

1. A customer reported that building for Arm64EC was broken: #138541
2. This was caused by a bug in my original implementation of Arm64EC support, namely that only functions on Arm64EC need to be decorated with `#` but Rust was decorating statics as well.
3. Once I corrected Rust to only decorate functions, I started linking failures where the linker couldn't find statics exported by dylib dependencies. This was caused by the compiler not marking exported statics in the generated DEF file with `DATA`, thus they were being exported as functions not data.
4. Once I corrected the way that the DEF files were being emitted, the linker started failing saying that it couldn't find `__rust_no_alloc_shim_is_unstable`. This is because the MSVC linker requires the declarations of statics imported from other dylibs to be marked with `dllimport` (whereas it will happily link to functions imported from other dylibs whether they are marked `dllimport` or not).
5. I then made a change to ensure that `__rust_no_alloc_shim_is_unstable` was marked as `dllimport`, but the MSVC linker started emitting warnings that `__rust_no_alloc_shim_is_unstable` was marked as `dllimport` but was declared in an obj file. This is a harmless warning which is a performance hint: anything that's marked `dllimport` must be indirected via an `__imp` symbol so I added a linker arg in the target to suppress the warning.
6. A customer then reported a similar warning when using `lld-link` (<rust-lang/rust#140176 (comment)>). I don't think it was an implementation difference between the two linkers but rather that, depending on the obj that the declaration versus uses of `__rust_no_alloc_shim_is_unstable` landed in we would get different warnings, so I suppressed that warning as well: #140954.
7. Another customer reported that they weren't using the Rust compiler to invoke the linker, thus these warnings were breaking their build: <rust-lang/rust#140176 (comment)>. At that point, my original change was reverted (#141024) leaving Arm64EC broken yet again.

Taking a step back, a lot of these linker issues arise from the fact that `__rust_no_alloc_shim_is_unstable` is marked as `extern "Rust"` in the standard library and, therefore, assumed to be a foreign item from a different crate BUT the Rust compiler may choose to generate it either in the current crate, some other crate that will be statically linked in OR some other crate that will by dynamically imported.

Worse yet, it is impossible while building a given crate to know if `__rust_no_alloc_shim_is_unstable` will statically linked or dynamically imported: it might be that one of its dependent crates is the one with an allocator kind set and thus that crate (which is compiled later) will decide depending if it has any dylib dependencies or not to import `__rust_no_alloc_shim_is_unstable` or generate it. Thus, there is no way to know if the declaration of `__rust_no_alloc_shim_is_unstable` should be marked with `dllimport` or not.

There is a simple fix for all this: there is no reason `__rust_no_alloc_shim_is_unstable` must be a static. It needs to be some symbol that must be linked in; thus, it could easily be a function instead. As a function, there is no need to mark it as `dllimport` when dynamically imported which avoids the entire mess above.

There may be a perf hit for changing the `volatile load` to be a `tail call`, so I'm happy to change that part back (although I question what the codegen of a `volatile load` would look like, and if the backend is going to try to use load-acquire semantics).

Build with this change applied BEFORE #140176 was reverted to demonstrate that there are no linking issues with either MSVC or MinGW: <https://github.com/rust-lang/rust/actions/runs/15078657205>

Incidentally, I fixed `tests/run-make/no-alloc-shim` to work with MSVC as I needed it to be able to test locally (FYI for #128602)

r? `@bjorn3`
cc `@jieyouxu`
{aarch64,x86_64}-pc-windows-gnullvm: build host tools

This is a temporary single-release workflow to create stage0 for these targets.

I opted for bootstrapping from Linux because that's the easiest host system to work with, but once this hits beta, having dedicated Windows runners would be sensible and probably preferable.

`--enable-full-tools` for whatever reason doesn't seem to work when cross-compiling, because LLVM tools for the new hosts are not copied into the expected directory.

rust-lang/compiler-team#877
ci: split x86_64-gnu-tools job

try-job: x86_64-gnu-tools
try-job: x86_64-gnu-miri
try-job: aarch64-gnu
Handle win32 separator for cygwin paths

This PR handles a issue that cygwin actually supports Win32 path, so we need to handle the Win32 prefix and separaters.

r? `@mati865`

cc `@jeremyd2019`

~~Not sure if I should handle the prefix like the windows target... Cygwin *does* support win32 paths directly going through the APIs, but I think it's not the recommended way.~~

Here I just use `cygwin_conv_path` because it handles both cygwin and win32 paths correctly and convert them into absolute POSIX paths.

UPDATE: Windows path prefix is handled.
…egers, r=tgross35

Use a distinct `ToString` implementation for `u128` and `i128`

Part of rust-lang/rust#135543.

Follow-up of rust-lang/rust#136264.

When working on rust-lang/rust#142098, I realized that `i128` and `u128` could also benefit from a distinct `ToString` implementation so here it.

The last commit is just me realizing that I forgot to add the format tests for `usize` and `isize`.

Here is the bench comparison:

| bench name | last nightly | with this PR | diff |
|-|-|-|-|
| bench_i128 | 29.25 ns/iter (+/- 0.66) | 17.52 ns/iter (+/- 0.7) | -40.1% |
| bench_u128 | 34.06 ns/iter (+/- 0.21) | 16.1 ns/iter (+/- 0.6) | -52.7% |

I used this code to test:

```rust
#![feature(test)]

extern crate test;

use test::{Bencher, black_box};

#[inline(always)]
fn convert_to_string<T: ToString>(n: T) -> String {
    n.to_string()
}

macro_rules! decl_benches {
    ($($name:ident: $ty:ident,)+) => {
        $(
	    #[bench]
            fn $name(c: &mut Bencher) {
                c.iter(|| convert_to_string(black_box({ let nb: $ty = 20; nb })));
            }
	)+
    }
}

decl_benches! {
    bench_u128: u128,
    bench_i128: i128,
}
```
Use jemalloc for Clippy

The tool macros are annoying, we should IMO just get rid of them, create separate steps for each tool and (re)use some builders in them to share the build code.

r? `@ghost`
…ments, r=saethlin

Rename `LayoutS` to `LayoutData` in comments

`LayoutS` was renamed to `LayoutData`, but some comments in the compiler were not changed. This updates comments in the compiler (and one section of commented-out code in rust-analyzer) to refer to `LayoutData` instead of `LayoutS`.

cc <rust-lang/rust#132252>, `@workingjubilee`
Rollup of 7 pull requests

Successful merges:

 - rust-lang/rust#142502 (rustdoc_json: improve handling of generic args)
 - rust-lang/rust#142597 (error on calls to ABIs that cannot be called)
 - rust-lang/rust#142785 (fix(linkcheck): Build using the lockfile)
 - rust-lang/rust#142787 (Add diagnostic items for Clippy)
 - rust-lang/rust#142788 (add doc(alias("AsciiChar")) to core::ascii::Char)
 - rust-lang/rust#142801 (Use gen blocks in the compiler instead of `from_coroutine`)
 - rust-lang/rust#142804 (Rename `LayoutS` to `LayoutData` in comments)

r? `@ghost`
`@rustbot` modify labels: rollup
Only traverse reachable blocks in JumpThreading.

Fixes rust-lang/rust#131451

We only compute loop headers for reachable blocks. We shouldn't try to perform an opt on unreachable blocks anyway.
…r=nnethercote

Avoid a few more allocations in `write_shared.rs`

Inspired by rust-lang/rust#141421 , avoids a few `Vec`, `PathBuf` and `String` allocations in `write_shared.rs`. I don't think these will show up on benchmarks, but are still worthwhile IMHO.
Also includes a few small cleanups.
r? nnethercote - if you'd like :)
Preserve caches in a call to shrink_to_fit

A small follow up to rust-lang/rust#142542.
completely deduplicate `Visitor` and `MutVisitor`

r? oli-obk

This closes rust-lang/rust#127615.

### Discussion

> * Give every `MutVisitor::visit_*` method a corresponding `flat_map_*` method.

Not every AST node exists in a location where they can be mapped to multiple instances of themselves. Not every AST node exists in a location where they can be removed from existence (e.g. `filter_map_expr`). I don't think this is doable.

> * Give every `MutVisitor::visit_*` method a corresponding `Visitor` method and vice versa

The only three remaining method-level asymmetries after this PR are `visit_stmt` and `visit_nested_use_tree` (only on `Visitor`) and `visit_span` (only on `MutVisitor`).

`visit_stmt` doesn't seem applicable to `MutVisitor` because `walk_flat_map_stmt_kind` will ask `flat_map_item` / `filter_map_expr` to potentially turn a single `Stmt` to multiple based on what a visitor wants. So only using `flat_map_stmt` seems appropriate.

`visit_nested_use_tree` is used for `rustc_resolve` to track stuff. Not useful for `MutVisitor` for now.

`visit_span` is currently not used for `MutVisitor` already, it was just kept in case we want to revive rust-lang/rust#127241. cc `@cjgillot` maybe we could remove for now and re-insert later if we find a use-case? It does involve some extra effort to maintain.

* Remaining FIXMEs

`visit_lifetime` has an extra param for `Visitor` that's not in `MutVisitor`. This is again something only used by `rustc_resolve`. I think we can keep that symmetry for now.
Let String pass #[track_caller] to its Vec calls

I've added `#[track_caller]` to `String` methods that delegate to `Vec` methods that already have `#[track_caller]`.

I've also added `#[track_caller]` to methods that have `assert!` or `panic!` due to invalid inputs.
@rustbot rustbot added the S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. label Jun 23, 2025
@lnicola lnicola enabled auto-merge June 23, 2025 09:20
@lnicola lnicola added this pull request to the merge queue Jun 23, 2025
@github-merge-queue github-merge-queue bot removed this pull request from the merge queue due to failed status checks Jun 23, 2025
@lnicola lnicola added this pull request to the merge queue Jun 23, 2025
@github-merge-queue github-merge-queue bot removed this pull request from the merge queue due to failed status checks Jun 23, 2025
@lnicola lnicola added this pull request to the merge queue Jun 23, 2025
Merged via the queue into rust-lang:master with commit f9e371c Jun 23, 2025
14 checks passed
@lnicola lnicola deleted the sync-from-rust branch June 23, 2025 09:56
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5 participants