Fix redundant boolean comparison in `Mutex::try_lock`
Simplify boolean return in `Mutex::try_lock`.
Replace `expr == false` with `!expr` for cleaner code.
Replace the hacky macro with a generic function and a new
`FlatMapInPlaceVec` trait. More verbose but more readable and typical.
LLM disclosure: I asked Claude Code to critique this file and it
suggested the generic function + trait idea. I implemented the idea
entirely by hand.
Fix performance regression introduced in #142531 by excluding `Storage{Live,Dead}` from CGU size estimation
Fix performance regression introduced in rust-lang/rust#142531 ([rust-timer comment](https://github.com/rust-lang/rust/pull/142531#issuecomment-4273712294)) by excluding `Storage{Live,Dead}` from CGU size estimation.
Also, avoid unneeded work for storage removal in non-opt builds in CopyProp and GVN
by allocating local sets for the storage accounting only when `tcx.sess.emit_lifetime_markers()`.
r? saethlin
Update books
## rust-embedded/book
2 commits in 2463edeb8003c5743918b3739a9f6870b86396f5..0789b0f29e73ecb91213cac10ad0eec1b9333770
2026-04-11 08:46:22 UTC to 2026-04-10 14:01:38 UTC
- remove IO chapter, is covered in next chapter (rust-embedded/book#411)
- add embassy chapter (rust-embedded/book#412)
## rust-lang/reference
10 commits in d2715c07e9dd9839c0c7675ecfa18bec539a6ee9..8c88f9d0bdd75ffdc0691676d83212ae22a18cee
2026-04-20 15:20:24 UTC to 2026-04-07 16:25:09 UTC
- typo in example code (rust-lang/reference#2232)
- oxford comma (rust-lang/reference#2233)
- improve readability (rust-lang/reference#2234)
- typo (rust-lang/reference#2230)
- Clarify items.fn.generics.param-bounds (rust-lang/reference#2229)
- follow formatting style guideline (rust-lang/reference#2228)
- Update `derive` export locations (rust-lang/reference#2223)
- Clarify that `{self}` imports require a module parent (rust-lang/reference#2221)
- stabilize s390x vector registers (rust-lang/reference#2215)
- Fix misuse of *usage* throughout the Reference (rust-lang/reference#2222)
## rust-lang/rust-by-example
2 commits in b31e3b8da01eeba0460f86a52a55af82709fadf5..898f0ac1479223d332309e0fce88d44b39927d28
2026-04-19 11:40:28 UTC to 2026-04-19 11:38:45 UTC
- remove debug printing for the u32 and bool in variable_bindings.md (rust-lang/rust-by-example#1999)
- Update for.md (rust-lang/rust-by-example#2008)
Fix LLVM offload install docs to use semicolon-separated CMake lists
Update so the LLVM CMake example uses and , which is the correct list separator syntax for LLVM CMake options.[Docs] Remove shortcode from models page heading
Suggest removing `&` when awaiting a reference to a future
Fixesrust-lang/rust#87211
When `.await`ing `&impl Future`, suggest removing the `&` instead of removing `.await`.
Make E0284 generic argument suggestions more explicit
Closesrust-lang/rust#147313
Previously, when type annotations were missing for a function call, rust suggested: "consider specifying the generic argument". This PR improves the diagnostics:
- If only one generic type is missing:
"consider specifying a concrete type for the generic type `<T>`" with the turbofish being "::\<SomeConcreteType>"
- If only one const generic is missing:
"consider specifying a const for the const generic `<CONST>`" with the turbofish being "::<SOME_CONST>"
Multiple missing generics still produce the original more general suggestion
Merge BuildReducedGraphVisitor into DefPathVisitor
These two visitors run right after each other on the same immutable AST. There's also a hash map for transferring the TyCtxtFeed created in the def collector to the BRG when it visits the same items. There are possibly more avenues for sharing logic, but I want to keep this PR simple.
only opening for perf runs for now. I'm still investigating how to ensure that future changes don't introduce subtle bugs by forgetting that def collection and reduced graph building are one pass now
Best reviewed commit-by-commit. I took a lot of care for making the individual changes reviewable, but all the `Merge *` commits aren't able to compile libcore until the last one.
Another interal change that shouldn't impact rustc users.
This time, regroup into `visit_indirections` the code dealing with the
FFI safety of Boxes, Refs and RawPtrs.
Another interal change that shouldn't impact rustc users.
the list of simpler type-based decisions made by `visit_type` are
reordered and are given better documentation.
Another interal change that shouldn't impact rustc users.
The goal (of this commit and a few afterwards) is to break apart the gigantic
visit_type function into more managable and easily-editable bits that focus
on specific parts of FFI safety.
For now, we break the code specific to enums one side, and
structs/unions on the other, into separate visit_? methods
Simplify macros for target-modifier and mitigation flags
- Rebased and revised version of https://github.com/rust-lang/rust/pull/154501.
---
The macros used for handling command-line flags that are “target modifiers” or “mitigations” are quite complicated, and can be significantly simplified by tweaking their syntax and by making use of `${ignore(..)}` metavars.
It's possible that more code could be moved out of macros (e.g. declaring some of the enums by hand), but that can be investigated in a potential follow-up.
There should be no change to compiler behaviour.
Suggest returning a reference for unsized place from a closure
Fixesrust-lang/rust#152064
There are 3 similar note:
`the size for values of type str cannot be known at compilation time`
for different spans, maybe need more work to remove some of them.
This PR only adds a suggestion for using a reference.
Rollup of 11 pull requests
Successful merges:
- rust-lang/rust#154654 (Move `std::io::ErrorKind` to `core::io`)
- rust-lang/rust#145270 (Fix an ICE observed with an explicit tail-call in a default trait method)
- rust-lang/rust#154895 (borrowck: Apply `user_arg_index` nomenclature more broadly)
- rust-lang/rust#155213 (resolve: Make sure visibilities of import declarations make sense)
- rust-lang/rust#155346 (`single_use_lifetimes`: respect `anonymous_lifetime_in_impl_trait`)
- rust-lang/rust#155517 (Add a test for Mach-O `#[link_section]` API inherited from LLVM)
- rust-lang/rust#155549 (Remove some unnecessary lifetimes.)
- rust-lang/rust#154248 (resolve : mark repr_simd as internal)
- rust-lang/rust#154772 (slightly optimize the `non-camel-case-types` lint)
- rust-lang/rust#155541 (Add `#[rust_analyzer::prefer_underscore_import]` to the traits in `rustc_type_ir::inherent`)
- rust-lang/rust#155544 (bootstrap: Make "detected modifications" for download-rustc less verbose)
Remove `HashStable` impl for `[hir::Attribute]`.
This impl skips:
- All doc comments
- A handful of other attributes, mostly `rustc_*` ones related to incremental compilation testing.
This skipping originated in rust-lang/rust#36025 and was extended a couple of times, e.g. in rust-lang/rust#36370. Those PRs don't have any explanation of why the skipping exists. Perhaps the reasoning was that doc comments should only affect rustdoc and rustdoc doesn't use incremental compilation? But doc comments end up in metadata, and there is a query `attrs_for_def` that returns a `&'tcx [hir::Attribute]`. So skipping some attributes just seems plainly wrong.
This commit removes the impl, which means `[hir::Attribute]` hashing falls back to the default impl for `[T]`. This has no noticeable effect on the test suite. It does slightly hurt performance, because of the doc comments. This perf regression seems worth it for the correctness benefits.
Tshepang Mbambo