Rollup of 2 pull requests
Successful merges:
- rust-lang/rust#151612 (Update documentation for `cold_path`, `likely`, and `unlikely`)
- rust-lang/rust#151670 (compiletest: Parse aux `proc-macro` directive into struct)
Update documentation for `cold_path`, `likely`, and `unlikely`
* Add a note recommending benchmarks to `cold_path`, as other hints have
* Note that `cold_path` can be used to implement `likely` and `unlikely`
* Update the tracking issue for the `likely_unlikely` feature
Tracking issue: https://github.com/rust-lang/rust/issues/136873
Tracking issue: https://github.com/rust-lang/rust/issues/151619
Fix broken WASIp1 reference link
### Location (URL)
https://doc.rust-lang.org/rustc/platform-support/wasm32-wasip1.html
<img width="800" alt="image" src="https://github.com/user-attachments/assets/b9402b3a-db7b-405f-b4ef-d849c03ad893" />
### Summary
The WASIp1 reference link in the `wasm32-wasip1` platform documentation currently points to a path that no longer exists in the WASI repository.
The WASI project recently migrated the WASI 0.1 (preview1) documentation from the `legacy/preview1` directory to the dedicated `wasi-0.1` branch (WebAssembly/WASI#855).
This updates the link to point to the intended historical WASIp1 reference, which matches the documented intent of the `wasm32-wasip1` target.
Add a `documentation` remapping path scope for rustdoc usage
This PR adds a new remapping path scope for rustdoc usage: `documentation`, instead of rustdoc abusing the other scopes for it's usage.
Like remapping paths in rustdoc, this scope is unstable. (rustdoc doesn't even have yet an equivalent to [rustc `--remap-path-scope`](https://doc.rust-lang.org/nightly/rustc/remap-source-paths.html#--remap-path-scope)).
I also took the opportunity to add a bit of documentation in rustdoc book.
compiletest: add implied `needs-target-std` for `codegen` mode tests unless annotated with `#![no_std]`/`#![no_core]`
A `codegen` mode test (such as `codegen-llvm` test suite) will now by default have an implied `//@ needs-target-std` directive, *unless* the test explicitly has an `#![no_std]`/`#![no_core]` attribute which disables this behavior.
- When a test has both `#![no_std]`/`#![no_core]` and `//@ needs-target-std`, the explicit `//@ needs-target-std` directive will cause the test to be ignored for targets that do not support std still.
This is to make it easier to test out-of-tree targets / custom targets (and targets not tested in r-l/r CI) without requiring target maintainers to do a bunch of manual `//@ needs-target-std` busywork.
Context: [#t-compiler/help > `compiletest` cannot find `core` library for target != host](https://rust-lang.zulipchat.com/#narrow/channel/182449-t-compiler.2Fhelp/topic/.60compiletest.60.20cannot.20find.20.60core.60.20library.20for.20target.20!.3D.20host/with/568652419)
## Implementation remarks
This is an alternative version of https://github.com/rust-lang/rust/pull/150672, with some differences:
- *This* PR applies this implied-`needs-target-std` behavior to all `codegen` test mode tests.
- *This* PR does the synthetic directive injection in the same place as implied-`codegen-run` directives. Both are of course hacks, but at least they're together next to each other.
refactor rustc-hash integration
I found that rustc-hash is used in multiple compiler crates. Also some types use `FxBuildHasher` whereas others use `BuildHasherDefault<FxHasher>` (both do the same thing).
In order to simplify future hashing experiments, I changed every location to use `rustc_data_structures::fx::*` types instead, and also removed the `BuildHasherDefault` variant. This will simplify future experiments with hashing (for example trying out a hasher that doesn't implement `Default` for whatever reason).
A `codegen-llvm` test (and other codegen test mode tests) will now by
default have an implied `//@ needs-target-std` directive, *unless* the
test explicitly has an `#![no_std]`/`#![no_core]` attribute which
disables this implied behavior.
- When a test has both `#![no_std]`/`#![no_core]` and `//@
needs-target-std`, the explicit `//@ needs-target-std` directive will
cause the test to be ignored for targets that do not support std
still.
This is to make it easier to test out-of-tree targets / custom targets
(and targets not tested in r-l/r CI) without requiring target
maintainers to do a bunch of manual `//@ needs-target-std` busywork.
Co-authored-by: Edoardo Marangoni <ecmm@anche.no>
LoongArch: Fix direct-access-external-data test
On LoongArch targets, `-Cdirect-access-external-data` defaults to `no`. Since copy relocations are not supported, `dso_local` is not emitted under `-Crelocation-model=static`, unlike on other targets.
Fix suppression of `unused_assignment` in binding of `unused_variable`
Unused assignments to an unused variable should trigger only the `unused_variables` lint and not also the `unused_assignments` lint. This was previously implemented by checking whether the span of the assignee was within the span of the binding pattern, however that failed to capture situations was imported from elsewhere (eg from the input tokenstream of a proc-macro that generates the binding pattern).
By comparing the span of the assignee to those of the variable introductions instead, a reported stable-to-stable regression is resolved.
This fix also impacted some other preexisting tests, which had (undesirably) been triggering both the `unused_variables` and `unused_assignments` lints on the same initializing assignment; those tests have therefore now been updated to expect only the former lint.
Fixesrust-lang/rust#151514
r? cjgillot (as author of reworked liveness testing in rust-lang/rust#142390)
The SSE2 helper function is not inlined across crate boundaries,
so we cannot verify the codegen in an assembly test. The fix is
still verified by the absence of performance regression.
Fix 'the the' typo in library/core/src/array/iter.rs
This PR fixes a small grammatical error in a safety comment within `library/core/src/array/iter.rs` where the word "the" was duplicated.
No functional changes.
Rename `DepKindStruct` to `DepKindVTable`
This type is used by dependency-tracking code in the query system, for looking up function pointers and other metadata associated with a particular `DepKind`.
Calling it “struct” is not particularly helpful, whereas calling it a “vtable” at least gives some basic intuition for what it is and how it is used.
Some associated identifiers have also drifted a bit over time, and this PR adjusts those as well.
There should be no change to compiler behaviour.
r? nnethercote (or compiler)
x86 soft-float feature: mark it as forbidden rather than unstable
I am not sure why I made it "unstable" in f755f4cd1a; I think at the time "forbidden" did not work for some reason.
Making it "forbidden" instead has no significant effect on `-Ctarget-feature` use, it just changes the warning. It *does* have the effect that one cannot query this using `cfg(target_feature)` on nightly any more, but that seems fine to me. It only ever worked as an accidental side-effect of f755f4cd1a anyway.
r? @workingjubilee
Various refactors to the proc_macro bridge
This reduces the amount of types, traits and other abstractions that are involved with the bridge, which should make it easier to understand and modify. This should also help a bit with getting rid of the type marking hack, which is complicating the code a fair bit.
Fixes: rust-lang/rust#139810
Fix(lib/win/thread): Ensure `Sleep`'s usage passes over the requested duration under Win7
Fixesrust-lang/rust#149935. See the added comment for more details.
This makes the concerned test now reproducibly pass, for us at least. Also, testing this separately revealed successful: see the issue.
@rustbot label C-bug I-flaky-test O-windows-7 T-libs A-time A-thread
add CSE optimization tests for iterating over slice
This PR is regression test for issue rust-lang/rust#119573.
This PR introduces a new regression test to verify a critical optimization known as Common Subexpression Elimination (CSE) is correctly applied during various slice iteration patterns.
std: avoid tearing `dbg!` prints
Fixes https://github.com/rust-lang/rust/issues/136703.
This is an alternative to rust-lang/rust#149859. Instead of formatting everything into a string, this PR makes multi-expression `dbg!` expand into multiple nested matches, with the final match containing a single `eprint!`. By using macro recursion and relying on hygiene, this allows naming every bound value in that `eprint!`.
CC @orlp
r? libs
abi: add a rust-preserve-none calling convention
This is the conceptual opposite of the rust-cold calling convention and is particularly useful in combination with the new `explicit_tail_calls` feature.
For relatively tight loops implemented with tail calling (`become`) each of the function with the regular calling convention is still responsible for restoring the initial value of the preserved registers. So it is not unusual to end up with a situation where each step in the tail call loop is spilling and reloading registers, along the lines of:
foo:
push r12
; do things
pop r12
jmp next_step
This adds up quickly, especially when most of the clobberable registers are already used to pass arguments or other uses.
I was thinking of making the name of this ABI a little less LLVM-derived and more like a conceptual inverse of `rust-cold`, but could not come with a great name (`rust-cold` is itself not a great name: cold in what context? from which perspective? is it supposed to mean that the function is rarely called?)
Other hints have a note recommending benchmarks to ensure they actually
do what is intended. This is also applicable for `cold_path`, so add a
note here.
Fix cstring-merging test for Hexagon target
Hexagon assembler uses `.string` directive instead of `.asciz` for null-terminated strings. Both are equivalent but the test was only checking for `.asciz`.
Update the CHECK patterns to accept both directives using `.{{asciz|string}}` regex pattern.
Extend build-manifest local test guide
Fill in more blanks about how to test build-manifest changes with Rustup.
Figured this out while working on https://github.com/rust-lang/rust/pull/151156, with the help of bjorn3.
Add Korean translation to Rust By Example
Hello,
I’ve added a Korean translation file to Rust By Example.
This contribution will help Korean readers learn Rust more easily by providing localized explanations and examples.
Please review the proposed additions when you have time.
Thanks in advance for your time and review! 🙏
Add Korean translation. Thanks in advance.
std: `sleep_until` on Motor and VEX
This PR:
* Forwards the public `sleep_until` to the private `sleep_until` on Motor OS
* Adds a `sleep_until` implementation on VEX that yields until the deadline has passed
CC @lasiotus
CC @lewisfm @tropicaaal @Gavin-Niederman @max-niederman
compiletest: Make `aux-crate` directive explicitly handle `--extern` modifiers
With `-Zunstable-options` it is possible to pass options to `--extern`. See here for an exhaustive list of possible options:
b5dd72d292/compiler/rustc_session/src/config.rs (L2356-L2367)
Using these options works with the `aux-crate` directive, but only because the options pretend to be part of the name. Make it clearer what `aux-crate` supports by explicitly handling `--extern` options.
This PR is step one of splitting up https://github.com/rust-lang/rust/pull/151258 into smaller pieces.
r? @Zalathar
add `simd_splat` intrinsic
Add `simd_splat` which lowers to the LLVM canonical splat sequence.
```llvm
insertelement <N x elem> poison, elem %x, i32 0
shufflevector <N x elem> v0, <N x elem> poison, <N x i32> zeroinitializer
```
Right now we try to fake it using one of
```rust
fn splat(x: u32) -> u32x8 {
u32x8::from_array([x; 8])
}
```
or (in `stdarch`)
```rust
fn splat(value: $elem_type) -> $name {
#[derive(Copy, Clone)]
#[repr(simd)]
struct JustOne([$elem_type; 1]);
let one = JustOne([value]);
// SAFETY: 0 is always in-bounds because we're shuffling
// a simd type with exactly one element.
unsafe { simd_shuffle!(one, one, [0; $len]) }
}
```
Both of these can confuse the LLVM optimizer, producing sub-par code. Some examples:
- https://github.com/rust-lang/rust/issues/60637
- https://github.com/rust-lang/rust/issues/137407
- https://github.com/rust-lang/rust/issues/122623
- https://github.com/rust-lang/rust/issues/97804
---
As far as I can tell there is no way to provide a fallback implementation for this intrinsic, because there is no `const` way of evaluating the number of elements (there might be issues beyond that, too). So, I added implementations for all 4 backends.
Both GCC and const-eval appear to have some issues with simd vectors containing pointers. I have a workaround for GCC, but haven't yet been able to make const-eval work. See the comments below.
Currently this just adds the intrinsic, it does not actually use it anywhere yet.
Fix(lib/win/net): Remove hostname support under Win7
Fixesrust-lang/rust#150896. `GetHostNameW` is not available under Windows 7, leading to dynamic linking failures upon program executions. For now, as it is still unstable, this therefore appropriately cfg-gates the feature in order to mark the Win7 as unsupported with regards to this particular feature. Porting the functionality for Windows 7 would require changing the underlying system call and so more work for the immediate need.
@rustbot label C-bug O-windows-7 T-libs A-io
