When a trait isn't implemented, but another similar impl is found, point at it
```
error[E0277]: the trait bound `u32: Trait` is not satisfied
--> $DIR/trait_objects_fail.rs:26:9
|
LL | foo(&10_u32);
| ^^^^^^^ the trait `Trait` is not implemented for `u32`
|
help: the trait `Trait<12>` is not implemented for `u32`
but trait `Trait<2>` is implemented for it
--> $DIR/trait_objects_fail.rs:7:1
|
LL | impl Trait<2> for u32 {}
| ^^^^^^^^^^^^^^^^^^^^^
= note: required for the cast from `&u32` to `&dyn Trait`
```
Pointing at the `impl` definition that *could* apply given a different self type is *particularly* useful when it has a blanket self type, as it might not be obvious and is not trivially greppable:
```
error[E0277]: the trait bound `RawImpl<_>: Raw<_>` is not satisfied
--> $DIR/issue-62742.rs:4:5
|
LL | WrongImpl::foo(0i32);
| ^^^^^^^^^ unsatisfied trait bound
|
help: the trait `Raw<_>` is not implemented for `RawImpl<_>`
but trait `Raw<[_]>` is implemented for it
--> $DIR/issue-62742.rs:29:1
|
LL | impl<T> Raw<[T]> for RawImpl<T> {
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
note: required by a bound in `SafeImpl`
--> $DIR/issue-62742.rs:33:35
|
LL | pub struct SafeImpl<T: ?Sized, A: Raw<T>>(PhantomData<(A, T)>);
| ^^^^^^ required by this bound in `SafeImpl`
```
Rollup of 10 pull requests
Successful merges:
- rust-lang/rust#135602 (Tweak output of missing lifetime on associated type)
- rust-lang/rust#139751 (Implement pin-project in pattern matching for `&pin mut|const T`)
- rust-lang/rust#142682 (Update bundled musl to 1.2.5)
- rust-lang/rust#148171 (Simplify code to generate line numbers in highlight)
- rust-lang/rust#148263 (Unpin `libc` and `rustix` in `compiler` and `rustbook`)
- rust-lang/rust#148301 ([rustdoc search] Include extern crates when filtering on `import`)
- rust-lang/rust#148330 (Don't require dlltool with the dummy backend on MinGW)
- rust-lang/rust#148338 (cleanup: upstream dropped amx-transpose functionality)
- rust-lang/rust#148340 (Clippy subtree update)
- rust-lang/rust#148343 (`nonpoison::Condvar` should take `MutexGuard` by reference)
r? `@ghost`
`@rustbot` modify labels: rollup
`nonpoison::Condvar` should take `MutexGuard` by reference
Feature: `#![feature(nonpoison_condvar)]`
Tracking Issue: https://github.com/rust-lang/rust/issues/134645
Specific comment: https://github.com/rust-lang/rust/issues/134645#issuecomment-3458525913
Changes the `nonpoison::Condvar` API to take `MutexGuard` by reference instead of ownership.
I'm actually not entirely sure why the current poison variant of `Condvar` takes by ownership, is it just legacy reasons?
Additionally, the `nonpoison_and_poison_unwrap_test` macro doesn't really make sense anymore now that the APIs are completely different, so this reverts that change from a few months ago.
r? ````@Amanieu````
cleanup: upstream dropped amx-transpose functionality
See also LLVM change 5322fb626820. Looks like this was just removed entirely.
It seems a little bad to just drop it, but I don't see an easy way to conditionalize
this and if it's really just Gone and we marked it as unstable (which it looks like
we did?) I guess we should just dump it.
````@rustbot```` label llvm-main
Don't require dlltool with the dummy backend on MinGW
The dummy backend should be able to cross-compile to any target without requiring any external tool or library other than the rust standard library.
For https://github.com/rust-lang/miri/pull/4648.
[rustdoc search] Include extern crates when filtering on `import`
As discussed https://github.com/rust-lang/rust/pull/147909, some filters should have been "grouped". This PR allows extern crates to match the `import` filter.
This PR also allowed me to uncover a bug for the URL generated for renamed extern crates. Opened rust-lang/rust#148300 for it.
r? `````@notriddle`````
Implement pin-project in pattern matching for `&pin mut|const T`
This PR implements part of rust-lang/rust#130494. It supports pin-project in pattern matching for `&pin mut|const T`.
~Pin-projection by field access (i.e. `&pin mut|const place.field`) is not fully supported yet since pinned-borrow is not ready (rust-lang/rust#135731).~
CC ``````@traviscross``````
Tweak output of missing lifetime on associated type
Each commit can be reviewed independently. Address parts of #135589.
---
When an associated type is missing a lifetime, point at its enclosing `impl`, whether it has or doesn't have lifetimes defined. If it does have a lifetime, suggest using it.
```
error: in the trait associated type is declared without lifetime parameters, so using a borrowed type for them requires that lifetime to come from the implemented type
--> $DIR/missing-lifetime-in-assoc-type-1.rs:8:17
|
LL | impl<'a> IntoIterator for &S {
| ---- there is a named lifetime specified on the impl block you could use
...
LL | type Item = &T;
| ^ this lifetime must come from the implemented type
|
help: consider using the lifetime from the impl block
|
LL | type Item = &'a T;
| ++
```
```
error: in the trait associated type is declared without lifetime parameters, so using a borrowed type for them requires that lifetime to come from the implemented type
--> $DIR/missing-lifetime-in-assoc-type-2.rs:5:17
|
LL | impl IntoIterator for &S {
| - you could add a lifetime on the impl block, if the trait or the self type can have one
LL | type Item = &T;
| ^ this lifetime must come from the implemented type
```
---
On unconstrained lifetime on impl block, suggest using it if there's an implicit borrow in the self type
```
error[E0207]: the lifetime parameter `'a` is not constrained by the impl trait, self type, or predicates
--> $DIR/missing-lifetime-in-assoc-type-1.rs:4:6
|
LL | impl<'a> IntoIterator for &S {
| ^^ unconstrained lifetime parameter
|
help: consider using the named lifetime here instead of an implict lifetime
|
LL | impl<'a> IntoIterator for &'a S {
| ++
```
---
Do not suggest introducing lifetime in impl assoc type
---
Previously we only showed the trait's assoc item if the trait was local, because we were looking for a small span only for the generics, which we don't have for foreign traits. We now use `def_span` for the item, so we at least provide some context, even if its span is too wide.
```
error[E0195]: lifetime parameters or bounds on type `IntoIter` do not match the trait declaration
--> tests/ui/lifetimes/missing-lifetime-in-assoc-type-4.rs:7:18
|
7 | type IntoIter<'a> = std::collections::btree_map::Values<'a, i32, T>;
| ^^^^ lifetimes do not match type in trait
|
::: /home/gh-estebank/rust/library/core/src/iter/traits/collect.rs:292:5
|
292 | type IntoIter: Iterator<Item = Self::Item>;
| ------------------------------------------ lifetimes in impl do not match this type in trait
```
Update cargo submodule
6 commits in 6c1b6100343691341b9e76c5acc594e78220f963..6368002885a04cbeae39a82cf5118f941559a40a
2025-10-28 16:27:52 +0000 to 2025-10-31 14:31:52 +0000
- feat(build-analysis): emit timing-info log (rust-lang/cargo#16179)
- Remove libc pin message (rust-lang/cargo#16182)
- feat(config-include): add optional field support (rust-lang/cargo#16180)
- feat(config-include): support inline and array of tables (rust-lang/cargo#16174)
- test(script): Update from rustc's test suite (rust-lang/cargo#16169)
- Fix links for options in man pages (rust-lang/cargo#16172)
r? ghost
```
error[E0207]: the lifetime parameter `'a` is not constrained by the impl trait, self type, or predicates
--> $DIR/missing-lifetime-in-assoc-type-1.rs:4:6
|
LL | impl<'a> IntoIterator for &S {
| ^^ unconstrained lifetime parameter
|
help: consider using the named lifetime here instead of an implict lifetime
|
LL | impl<'a> IntoIterator for &'a S {
| ++
```
When an associated type is missing a lifetime, point at its enclosing `impl`, whether it has or doesn't have lifetimes defined. If it does have a lifetime, suggest using it.
```
error: in the trait associated type is declared without lifetime parameters, so using a borrowed type for them requires that lifetime to come from the implemented type
--> $DIR/missing-lifetime-in-assoc-type-1.rs:8:17
|
LL | impl<'a> IntoIterator for &S {
| ---- there is a named lifetime specified on the impl block you could use
...
LL | type Item = &T;
| ^ this lifetime must come from the implemented type
|
help: consider using the lifetime from the impl block
|
LL | type Item = &'a T;
| ++
```
```
error: in the trait associated type is declared without lifetime parameters, so using a borrowed type for them requires that lifetime to come from the implemented type
--> $DIR/missing-lifetime-in-assoc-type-2.rs:5:17
|
LL | impl IntoIterator for &S {
| - you could add a lifetime on the impl block, if the trait or the self type can have one
LL | type Item = &T;
| ^ this lifetime must come from the implemented type
```
```
error[E0277]: the trait bound `[[u16; 3]; 2]: Bar` is not satisfied
--> $DIR/issue-67185-2.rs:21:6
|
LL | impl Foo for FooImpl {}
| ^^^ the trait `Bar` is not implemented for `[[u16; 3]; 2]`
|
help: the following other types implement trait `Bar`
--> $DIR/issue-67185-2.rs:9:1
|
LL | impl Bar for [u16; 4] {}
| ^^^^^^^^^^^^^^^^^^^^^ `[u16; 4]`
LL | impl Bar for [[u16; 3]; 3] {}
| ^^^^^^^^^^^^^^^^^^^^^^^^^^ `[[u16; 3]; 3]`
note: required by a bound in `Foo`
--> $DIR/issue-67185-2.rs:14:30
|
LL | trait Foo
| --- required by a bound in this trait
LL | where
LL | [<u8 as Baz>::Quaks; 2]: Bar,
| ^^^ required by this bound in `Foo`
```
```
error[E0277]: the trait bound `u32: Trait` is not satisfied
--> $DIR/trait_objects_fail.rs:26:9
|
LL | foo(&10_u32);
| ^^^^^^^ the trait `Trait` is not implemented for `u32`
|
help: the trait `Trait<12>` is not implemented for `u32`
but trait `Trait<2>` is implemented for it
--> $DIR/trait_objects_fail.rs:7:1
|
LL | impl Trait<2> for u32 {}
| ^^^^^^^^^^^^^^^^^^^^^
= note: required for the cast from `&u32` to `&dyn Trait`
```
Pointing at the `impl` definition that *could* apply given a different self type is particularly useful when it has a blanket self type, as it might not be obvious and is not trivially greppable:
```
error[E0277]: the trait bound `RawImpl<_>: Raw<_>` is not satisfied
--> $DIR/issue-62742.rs:4:5
|
LL | WrongImpl::foo(0i32);
| ^^^^^^^^^ unsatisfied trait bound
|
help: the trait `Raw<_>` is not implemented for `RawImpl<_>`
but trait `Raw<[_]>` is implemented for it
--> $DIR/issue-62742.rs:29:1
|
LL | impl<T> Raw<[T]> for RawImpl<T> {
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
note: required by a bound in `SafeImpl`
--> $DIR/issue-62742.rs:33:35
|
LL | pub struct SafeImpl<T: ?Sized, A: Raw<T>>(PhantomData<(A, T)>);
| ^^^^^^ required by this bound in `SafeImpl`
```
Since non-poisoning `Condvar` take non-poisoing `Mutex`es when
`wait`ing, we do not need to take by ownership since a poison error
cannot occur while we wait.
Signed-off-by: Connor Tsui <connor.tsui20@gmail.com>
Setup for writing different tests for the `nonpoison::Condvar` since it
will have a different API.
Signed-off-by: Connor Tsui <connor.tsui20@gmail.com>
Enable file locking support in illumos
https://github.com/rust-lang/rust/pull/132977 introduced an allow-list of targets supporting file locking, but forgot to add illumos to it (which introduced support for it in ~2015). `File::lock` and friends are now stable, and the ecosystem is slowly replacing custom libc calls with the standard library. Crucially, in 1.91 both Cargo and bootstrap switched to `File::lock`, both breaking build directory locking.
This PR enables file locking on illumos. Fixes https://github.com/rust-lang/rust/issues/146312.
cg_llvm: Pass `debuginfo_compression` through FFI as an enum
There are only three possible values, making an enum more appropriate.
This avoids string allocation on the Rust side, and avoids ad-hoc `!strcmp` to convert back to an enum on the C++ side.
Use fstatat() in DirEntry::metadata on Apple platforms
Apple supports `fstatat` on macOS >=10.10 ([source](https://gitlab.gnome.org/GNOME/glib/-/issues/2203)), and according to [Platform Support](https://doc.rust-lang.org/beta/rustc/platform-support.html) the oldest supported version is 10.12.
Google says iOS >=10 supports `fstatat` but doesn't provide a source. [*-apple-ios](https://doc.rust-lang.org/beta/rustc/platform-support/apple-ios.html#os-version) says the minimum supported iOS version is 10.0.
Unsure about tvOS, watchOS and visionOS, hoping CI can confirm this.
I am testing with [fastdu](https://github.com/jesseschalken/fastdu) which is effectively a stress test for `DirEntry::metadata`. In one test this provides a **1.13x** speedup.
```
$ hyperfine --warmup 1 'target/release/fastdu testdir' 'fastdu testdir'
Benchmark 1: target/release/fastdu testdir
Time (mean ± σ): 154.6 ms ± 17.4 ms [User: 31.7 ms, System: 187.6 ms]
Range (min … max): 148.4 ms … 225.5 ms 19 runs
Benchmark 2: fastdu testdir
Time (mean ± σ): 175.3 ms ± 15.8 ms [User: 50.0 ms, System: 196.2 ms]
Range (min … max): 165.4 ms … 211.7 ms 17 runs
Summary
target/release/fastdu testdir ran
1.13 ± 0.16 times faster than fastdu testdir
```
You can also reproduce a speedup with a program like this (providing a directory with many entries):
```rust
fn main() {
let args: Vec<_> = std::env::args_os().collect();
let dir: PathBuf = args[1].clone().into();
for entry in dir.read_dir().as_mut().unwrap() {
let entry = entry.as_ref().unwrap();
let metadata = entry.metadata();
let metadata = metadata.as_ref().unwrap();
println!("{} {}", metadata.len(), entry.file_name().display());
}
}
```
```
$ hyperfine './target/release/main testdir' './main testdir'
Benchmark 1: ./target/release/main testdir
Time (mean ± σ): 148.3 ms ± 5.2 ms [User: 23.1 ms, System: 122.9 ms]
Range (min … max): 145.2 ms … 167.2 ms 19 runs
Benchmark 2: ./main testdir
Time (mean ± σ): 164.4 ms ± 9.5 ms [User: 32.6 ms, System: 128.8 ms]
Range (min … max): 158.5 ms … 199.5 ms 17 runs
Summary
./target/release/main testdir ran
1.11 ± 0.07 times faster than ./main testdir
```
`unicode_data` refactors
Minor refactors to `unicode_data` that occured to me while trying to reduce the size of the tables. Splitting into a separate PR. NFC
add first HelenOS compilation targets
I'm working on adding a HelenOS compilation target for Rust as my bachelor thesis. I understood that the policy for tier 3 targets is quite liberal, so here's my attempt at upstreaming the initial support. I'm quite new to Rust internals, so thanks in advance for all assistance with my stupid questions :)
libstd support is coming, but I understood compiler support must come first before libc bindings can get merged (https://github.com/rust-lang/libc/pull/4355#issuecomment-2768489857)
Locally, I also needed to update `cc-rs`, to do two things:
- add [here](59578addda/src/lib.rs (L3397)) the binutils prefixes (`x86_64-unknown-helenos` -> `amd64-helenos`
- add the targets to `generated.rs`
From the "Adding tier 3 target" guide it sound like the latter will happen automatically, the first I need to do manually? I'm not sure if the test suite will pass or fail without it.
I'm also quite unsure about all the target spec configuration flags. I copied the specs from other small OSs with some tweaks and things seems to work now, but I have no idea how to better judge if it's correct.
Finally, I'm also working on support for arm (32-bit and 64), but there I'm currently running into some issues with linking, so I'll send that later, if I figure it out.
---
<details>
<summary>Tier 3 policy "form"</summary>
> A tier 3 target must have a designated developer or developers (the "target maintainers") on record to be CCed when issues arise regarding the target. (The mechanism to track and CC such developers may evolve over time.)
That would be me, I suppose. I agree.
> Targets must use naming consistent with any existing targets; for instance, a target for the same CPU or OS as an existing Rust target should use the same name for that CPU or OS. Targets should normally use the same names and naming conventions as used elsewhere in the broader ecosystem beyond Rust (such as in other toolchains), unless they have a very good reason to diverge. Changing the name of a target can be highly disruptive, especially once the target reaches a higher tier, so getting the name right is important even for a tier 3 target.
I'm using the standard Rust conventions.
> Tier 3 targets may have unusual requirements to build or use, but must not create legal issues or impose onerous legal terms for the Rust project or for Rust developers or users.
> - The target must not introduce license incompatibilities.
> - Anything added to the Rust repository must be under the standard Rust license (MIT OR Apache-2.0).
I am not aware of any legal issues. HelenOS itself is open-source under BSD license. All code contributed in this PR (and later for libstd) is either fully my own or an adaptation of existing code from this repo (some PAL pieces).
> - The target must not cause the Rust tools or libraries built for any other host (even when supporting cross-compilation to the target) to depend on any new dependency less permissive than the Rust licensing policy. This applies whether the dependency is a Rust crate that would require adding new license exceptions (as specified by the tidy tool in the rust-lang/rust repository), or whether the dependency is a native library or binary. In other words, the introduction of the target must not cause a user installing or running a version of Rust or the Rust tools to be subject to any new license requirements.
I am not adding any new dependencies.
> - Compiling, linking, and emitting functional binaries, libraries, or other code for the target (whether hosted on the target itself or cross-compiling from another target) must not depend on proprietary (non-FOSS) libraries. Host tools built for the target itself may depend on the ordinary runtime libraries supplied by the platform and commonly used by other applications built for the target, but those libraries must not be required for code generation for the target; cross-compilation to the target must not require such libraries at all. For instance, rustc built for the target may depend on a common proprietary C runtime library or console output library, but must not depend on a proprietary code generation library or code optimization library. Rust's license permits such combinations, but the Rust project has no interest in maintaining such combinations within the scope of Rust itself, even at tier 3.
The HelenOS build tools consist of open-source patches to GCC and binutils, so I suppose we're fine.
> Neither this policy nor any decisions made regarding targets shall create any binding agreement or estoppel by any party. If any member of an approving Rust team serves as one of the maintainers of a target, or has any legal or employment requirement (explicit or implicit) that might affect their decisions regarding a target, they must recuse themselves from any approval decisions regarding the target's tier status, though they may otherwise participate in discussions.
Understood.
> Tier 3 targets should attempt to implement as much of the standard libraries as possible and appropriate (core for most targets, alloc for targets that can support dynamic memory allocation, std for targets with an operating system or equivalent layer of system-provided functionality), but may leave some code unimplemented (either unavailable or stubbed out as appropriate), whether because the target makes it impossible to implement or challenging to implement. The authors of pull requests are not obligated to avoid calling any portions of the standard library on the basis of a tier 3 target not implementing those portions.
The libstd PR will fully support core+alloc, and enough of std to run interesting programs (stdio, argv and fs) - so we can run tools like [imagecli](https://github.com/theotherphil/imagecli). But yes, major parts of std are missing - pipe, process and net are currently forwarded to `unsupported()`. Some barebones `net` should be possible, but e.g. cloning of the descriptor is unheard of in HelenOS, so it won't be as straightforward as the rest. Also, some places of the `fs` and `thread` module are also quite stubby (but part of it is just because HelenOS has no file permissions, for example). HelenOS is a small, experimental OS, so its own libc is stubbed out as well in some places. I hope this state is acceptable?
> The target must provide documentation for the Rust community explaining how to build for the target, using cross-compilation if possible. If the target supports running binaries, or running tests (even if they do not pass), the documentation must explain how to run such binaries or tests for the target, using emulation if possible or dedicated hardware if necessary.
I hope the guide in doc is sufficient.
> Tier 3 targets must not impose burden on the authors of pull requests, or other developers in the community, to maintain the target. In particular, do not post comments (automated or manual) on a PR that derail or suggest a block on the PR based on a tier 3 target. Do not send automated messages or notifications (via any medium, including via ```@)``` to a PR author or others involved with a PR regarding a tier 3 target, unless they have opted into such messages.
Understood.
> Patches adding or updating tier 3 targets must not break any existing tier 2 or tier 1 target, and must not knowingly break another tier 3 target without approval of either the compiler team or the maintainers of the other tier 3 target.
Understood.
> Tier 3 targets must be able to produce assembly using at least one of rustc's supported backends from any host target. (Having support in a fork of the backend is not sufficient, it must be upstream.)
Umm, I think this is satisfied? Code generation works with the default LLVM backend, even though it has no idea about HelenOS. And our GCC patch is then used only for linking.
</details>
