Rollup of 3 pull requests
Successful merges:
- rust-lang/rust#154827 (distinguish "expected a single argument" and "expected an argument" on attribute parsing)
- rust-lang/rust#155104 (bootstrap: auto-patch libgccjit.so for NixOS)
- rust-lang/rust#155120 (Use a linting node closer the parsing of `#[cfg_attr]`)
bootstrap: auto-patch libgccjit.so for NixOS
Currently all downloaded rustc and LLVM components are auto patched on NixOS, but this is not done for libgccjit.so, so when GCC backend is enabled on NixOS, the build ICEs with errors like this:
thread 'rustc' (2286205) panicked at compiler/rustc_codegen_gcc/src/lib.rs:191:9:
Cannot load libgccjit.so: libzstd.so.1: cannot open shared object file: No such file or directory
Fix this by auto-patch libgccjit.so, too. `zstd` is added to the dependency environment.
Rollup of 6 pull requests
Successful merges:
- rust-lang/rust#152901 (Introduce a `#[diagnostic::on_unknown]` attribute)
- rust-lang/rust#155078 (Reject dangling attributes in where clauses)
- rust-lang/rust#154449 (Invert dependency between `rustc_errors` and `rustc_abi`.)
- rust-lang/rust#154646 (Add suggestion to `.to_owned()` used on `Cow` when borrowing)
- rust-lang/rust#154993 (compiletest: pass -Zunstable-options for unpretty and no-codegen paths)
- rust-lang/rust#155097 (Make `rustc_attr_parsing::SharedContext::emit_lint` take a `MultiSpan` instead of a `Span`)
compiletest: pass -Zunstable-options for unpretty and no-codegen paths
When using custom targets via `RUST_TARGET_PATH`, compiletest does not
consistently pass `-Zunstable-options` in all code paths.
In particular, `unpretty` and `-Zno-codegen` (typecheck) paths invoke
rustc without `-Zunstable-options`, which causes failures when the
target is not built-in.
Pass `-Zunstable-options` in these code paths to ensure consistent
behavior when using custom targets.
This primarily affects setups using custom targets without `.json`
suffix (resolved via `RUST_TARGET_PATH`).
Add suggestion to `.to_owned()` used on `Cow` when borrowing
fixesrust-lang/rust#144792
supersedes rust-lang/rust#144925 with the review comments addressed
the tests suggested from @Kivooeo from https://github.com/rust-lang/rust/pull/144925#discussion_r2252703007 didn't work entirely, because these tests failed due to error `[E0308]` mismatched types, which actually already provides a suggestion, that actually makes the code compile:
```
$ cargo check
error[E0308]: mismatched types
--> src/main.rs:3:5
|
1 | fn test_cow_suggestion() -> String {
| ------ expected `std::string::String` because of return type
2 | let os_string = std::ffi::OsString::from("test");
3 | os_string.to_string_lossy().to_owned()
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected `String`, found `Cow<'_, str>`
|
= note: expected struct `std::string::String`
found enum `std::borrow::Cow<'_, str>`
help: try using a conversion method
|
3 | os_string.to_string_lossy().to_owned().to_string()
| ++++++++++++
```
now this suggestion is of course not good or efficient code, but via clippy with `-Wclippy::nursery` lint group you can actually get to the correct code, so i don't think this is too much of an issue:
<details>
<summary>the clippy suggestions</summary>
```
$ cargo clippy -- -Wclippy::nursery
warning: this `to_owned` call clones the `Cow<'_, str>` itself and does not cause its contents to become owned
--> src/main.rs:3:5
|
3 | os_string.to_string_lossy().to_owned().to_string()
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= help: for further information visit https://rust-lang.github.io/rust-clippy/beta/index.html#suspicious_to_owned
= note: `#[warn(clippy::suspicious_to_owned)]` on by default
help: depending on intent, either make the `Cow` an `Owned` variant
|
3 | os_string.to_string_lossy().into_owned().to_string()
| ++
help: or clone the `Cow` itself
|
3 - os_string.to_string_lossy().to_owned().to_string()
3 + os_string.to_string_lossy().clone().to_string()
|
$ # apply first suggestion
$ cargo c -- -Wclippy::nursery
warning: redundant clone
--> src/main.rs:3:45
|
3 | os_string.to_string_lossy().into_owned().to_string()
| ^^^^^^^^^^^^ help: remove this
|
note: this value is dropped without further use
--> src/main.rs:3:5
|
3 | os_string.to_string_lossy().into_owned().to_string()
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
= help: for further information visit https://rust-lang.github.io/rust-clippy/beta/index.html#redundant_clone
= note: `-W clippy::redundant-clone` implied by `-W clippy::nursery`
= help: to override `-W clippy::nursery` add `#[allow(clippy::redundant_clone)]`
```
</details>
the actual error that we are looking for is error `[E0515]`, cannot return value referencing local variable, which was only present in the original issue due to automatic type inference assuming you want to return a cloned `Cow<'_, str>`, which is of course not possible. this is why i took the original test functions and turned them into closures, where it's less obvious that it's trying to return the wrong type.
r? davidtwco
(because you reviewed the last attempt)
(also, let me know if i should squash this down to one commit and add myself as the co-contributor)
Currently all downloaded rustc and LLVM components are auto patched on
NixOS, but this is not done for libgccjit.so, so when GCC backend is
enabled on NixOS, the build ICEs with errors like this:
thread 'rustc' (2286205) panicked at compiler/rustc_codegen_gcc/src/lib.rs:191:9:
Cannot load libgccjit.so: libzstd.so.1: cannot open shared object file: No such file or directory
Fix this by auto-patch libgccjit.so, too. `zstd` is added to the dependency
environment.
Signed-off-by: Gary Guo <gary@garyguo.net>
Always exhaustively match on typing mode
r? @lcnr
Unimplements Eq/PartialEq for TypingMode, adds TypingModeEqWrapper for the few cases where we need it (mainly in the query system), and adds a new rustc internal lint to detect cases where we non-exhaustively match on typing mode.
Moreover, dereference `ty_layout.align` for `#[rustc_dump_layout(align)]`
to render `align: Align($N bytes)` instead of `align: AbiAlign { abi: Align($N bytes) }`
which contains the same amount of information but it more concise and legible.
Rollup of 10 pull requests
Successful merges:
- rust-lang/rust#154973 (Break a single query cycle in the deadlock handler)
- rust-lang/rust#155034 (Implement `GenericTypeVisitable` for some types)
- rust-lang/rust#151377 (Fix linker error by resolving regions for main return type obligations)
- rust-lang/rust#154677 (hwaddress: automatically add `-Ctarget-feature=+tagged-globals`)
- rust-lang/rust#154774 (Add myself as co-maintainer for hexagon-unknown-linux-musl)
- rust-lang/rust#155015 (Add tests for three fixed issues (an LLVM crash, an ICE and poor codegen))
- rust-lang/rust#155039 (minor follow up to removing soft mode `#[unstable]`)
- rust-lang/rust#155043 (Fix if branch in op.rs)
- rust-lang/rust#155071 (Deny `#[global_allocator]` + `#[thread_local]`)
- rust-lang/rust#155072 (Set the Fuchsia ABI to the documented minimum)
Add myself as co-maintainer for hexagon-unknown-linux-musl
Two dedicated target maintainers are needed for tier 2 promotion. Coordinated with the existing maintainer r? @androm3da.
hwaddress: automatically add `-Ctarget-feature=+tagged-globals`
Note that since HWAddressSanitizer is/should be a target modifier, we do not have to worry about whether this LLVM target feature changes the ABI.
Fixes: rust-lang/rust#148185
delegation: fix cycles during delayed lowering
This PR forces lowering of delayed owners after `hir_crate_items`, as some diagnostics use `hir_crate_items` which results in query cycle which is then hangs calling `def_path_str` again and again. Fixesrust-lang/rust#154169. Part of rust-lang/rust#118212.
r? @petrochenkov
Fix pattern types rendering in rustdoc
Closesrust-lang/rust#150889 .
`core` was rendering local pattern-type impls through `clean_ty`, which formatted `rustc_hir::TyPat` with derived Debug, while inlined docs go through `clean_middle_ty` and get the pretty-printed `rustc_middle::ty::Pattern`.
Lower local HIR pattern types before formatting so both paths share the same canonical pattern printer and stop exposing `TyPat { ... }` in implementors.
#### Current result:
<img width="1133" height="738" alt="截屏2026-04-07 22 47 26" src="https://github.com/user-attachments/assets/bb5f8942-30b1-400a-a0a0-f581da5bb59f" />
Use fine grained component-wise span tracking in use trees
This often produces nicer spans and even doesn't need a Span field anymore (not that I expect the unused field to affect any perf, but still neat).
Cargo submodule update
11 commits in a357df4c26fc14514e66aae2a269456b5545c7db..101549dddbd2b08e806f50154e3aa4cb3374cc21
2026-04-03 16:47:15 +0000 to 2026-04-08 12:51:20 +0000
- Never include use extra-filename in build scripts (rust-lang/cargo#16855)
- fix(toml): Force script edition warnings on quiet (rust-lang/cargo#16848)
- GitHub fast path uses `http_async` (rust-lang/cargo#16847)
- feat(manifest): allow git dependency alongside alternate registry (rust-lang/cargo#16810)
- fix(auth): add auth scheme hint to token rejected error for alt registries (rust-lang/cargo#16794)
- Warn on invalid jobserver file descriptors (rust-lang/cargo#16843)
- docs(unstable): List the minimum required MSRV for 'public' field (rust-lang/cargo#16841)
- feat(lints): Emit unused_dependencies lint (rust-lang/cargo#16600)
- fix(tree): clarify error message when `-i` is used without a package name (rust-lang/cargo#16818)
- fix: Typo in target.<cfg>.linker (rust-lang/cargo#16839)
- Send Content-Type header with cargo publish requests (rust-lang/cargo#16832)
r? ghost
bors