Refactor FnDecl and FnSig non-type fields into a new wrapper type
#### Why this Refactor?
This PR is part of an initial cleanup for the [arg splat experiment](https://github.com/rust-lang/rust/issues/153629), but it's a useful refactor by itself.
It refactors the non-type fields of `FnDecl`, `FnSig`, and `FnHeader` into a new packed wrapper types, based on this comment in the `splat` experiment PR:
https://github.com/rust-lang/rust/pull/153697#discussion_r3004637413
It also refactors some common `FnSig` creation settings into their own methods. I did this instead of creating a struct with defaults.
#### Relationship to `splat` Experiment
I don't think we can use functional struct updates (`..default()`) to create `FnDecl` and `FnSig`, because we need the bit-packing for the `splat` experiment.
Bit-packing will avoid breaking "type is small" assertions for commonly used types when `splat` is added.
This PR packs these types:
- ExternAbi: enum + `unwind` variants (38) -> 6 bits
- ImplicitSelfKind: enum variants (5) -> 3 bits
- lifetime_elision_allowed, safety, c_variadic: bool -> 1 bit
#### Minor Changes
Fixes some typos, and applies rustfmt to clippy files that got skipped somehow.
std: Update dependency on `wasi` crate
This commit updates the crate dependency that the standard library has on the `wasi` crate. This is now updated to depending explicitly on the `wasip1` crate and the `wasip2` crate published on crates.io. These crates are managed in the [same location][repo] as the `wasi` crate and represent a different versioning scheme which doesn't require multi-version WASI support to require depending on the same crate at multiple versions. The code in libstd is updated to reference `wasip1` and `wasip2` directly as well.
[repo]: https://github.com/bytecodealliance/wasi-rs
Document why `layout.align() + layout.size()` doesn't overflow
This addition looks suspicious and is safety critical, but is saved by the weird `Layout` invariants.
std: fix HashMap RNG docs wording
Fixes a wording typo in the top-level HashMap docs.
Changed "random number coroutine" to "random number generator" in the seed entropy paragraph.
This section is security-relevant, and "generator" is the correct term in RNG context.
Testing:
- Not run locally (docs-only text change).
fix: add aliasing rules for Box
This is a new revised version for the PR [139857](https://github.com/rust-lang/rust/pull/139857), sorry for the delayed reply. I've rewritten the sentence to closely mirror the wording from `Vec::from_raw_parts`, which clearly states the transfer of ownership and its consequences. This should make the aliasing requirements much clearer.
I opted not to include a note about `mem::forget` by default to keep the documentation focused on the primary contract, similar to `Vec`.
net::tcp/udp: fix docs about how set_nonblocking is implemented
`fcntl` `FIONBIO` doesn't even make sense, it should be `fcntl` `F_SETFL`. However, for some reason we are using `ioctl` by default -- except on Solaris where this doesn't seem to work very well.
Honestly what I would have expected is that we just always use `FileDesc::set_nonblocking` also for network sockets, but for some reason we don't and there are no comments explaining this choice. Cc @nikarh (for "vita") @joboet
Rollup of 5 pull requests
Successful merges:
- rust-lang/rust#155308 (Make `OnDuplicate::Error` the default for attributes)
- rust-lang/rust#154432 (Set up API to make it possible to pass closures instead of `AttributeLint`)
- rust-lang/rust#154843 ( Fix conflicting deref move suggestion for LazyLock patterns)
- rust-lang/rust#155262 (bootstrap.py: fix duplicated "the")
- rust-lang/rust#155478 (Fixed broken documentation link for method lookup in rustc_hir_typeck…)
Fix conflicting deref move suggestion for LazyLock patterns
fixesrust-lang/rust#154826.
Rust was suggesting *V -> V for let (v,) = *V, which then triggered a follow-up error suggesting the opposite. This patch makes that case suggest borrowing (&*V) instead. Also handles destructuring assignment separately so we don’t emit a misleading &*... fix-it there.
Set up API to make it possible to pass closures instead of `AttributeLint`
Part of https://github.com/rust-lang/rust/issues/153099.
This PR sets up the base implementations needed to remove `AttributeLintKind` entirely and migrate two variants as examples.
r? @JonathanBrouwer
Make `OnDuplicate::Error` the default for attributes
This makes two changes, in separate commits for reviewability:
- Changes all unstable attributes that are currently `OnDuplicate::Warn` to error.
- Makes `OnDuplicate::Error` the default and removes the explicit `ON_DUPLICATE` for ones that currently already error
r? @jdonszelmann
Remove fewer Storage calls in CopyProp and GVN
Modify the CopyProp and GVN MIR optimization passes to remove fewer `Storage{Live,Dead}` calls, allowing for better optimizations by LLVM - see rust-lang/rust#141649.
### Details
The idea is to use a new `MaybeUninitializedLocals` analysis and remove only the storage calls of locals that are maybe-uninit when accessed in a new location.
Rollup of 12 pull requests
Successful merges:
- rust-lang/rust#147811 (naked functions: respect `function-sections`)
- rust-lang/rust#154935 (Add Sized supertrait for CoerceUnsized and DispatchFromDyn)
- rust-lang/rust#139690 (`impl Default for RepeatN`)
- rust-lang/rust#153511 (`std::any::TypeId`: remove misplaced "and" in `Unique<T>` example)
- rust-lang/rust#154943 (Move recursion out of `MatchPairTree::for_pattern` helpers )
- rust-lang/rust#155295 (Fix misleading "borrowed data escapes outside of function" diagnostic)
- rust-lang/rust#155427 (ptr: update text in intro text to one in with_addr doc)
- rust-lang/rust#155428 (Fix ICE in borrowck mutability suggestion with multi-byte ref sigil)
- rust-lang/rust#155435 (rustdoc: Fix `redundant_explicit_links` incorrectly firing (or not firing) under certain scenarios)
- rust-lang/rust#155450 (Remove unnecessary safety conditions related to unchecked uint arithmetic)
- rust-lang/rust#155454 (docs: Fix typo in std/src/thready/scoped.rs)
- rust-lang/rust#155467 (`std::error::Request`: clean up documentation)
docs: Fix typo in std/src/thready/scoped.rs
# Fix typo in std/src/thread/scoped.rs
## Why this pr
This PR fixes the typo mentioned in rust-lang/rust#155275.
I know this was originally fixed in rust-lang/rust#155325 and then in rust-lang/rust#155328.
But since the first issue was closed due to some ai slop and the second one was closed because the first one was already opened, it seems to me that this PR is still needed.
## What this pr does
This PR "just" fixes a typo inside the `std/src/thread/scoped.rs` file
Changing the comment from this:
```
/// borrow non-`'static` data from the outside the scope. See [`scope`] for
/// details.
```
to this:
```
/// borrow non-`'static` data from outside the scope. See [`scope`] for
/// details.
```
rustdoc: Fix `redundant_explicit_links` incorrectly firing (or not firing) under certain scenarios
Hi! I found some issues with the `rustdoc::redundant_explicit_links` lint while working on a personal project.
- After skipping a link that contains inline markups, the lint would incorrectly skip all the remaining links.
For example, with the following snippet, the lint is fired for `[Option][Option]`, but not `[Result][Result]`:
```rs
//! [Option][Option]
//! [**u8**][u8] (skipped)
//! [Result][Result]
```
Happening because of a `?` causing a loop to bail early:
https://github.com/rust-lang/rust/blob/a4a37ed163a6c1d227b58047d91457589c611cf8/src/librustdoc/passes/lint/redundant_explicit_links.rs#L107
- The lint is fired for links that specify titles (like `[link](link "title")`), except that wouldn't be applicable because it's not possible to specify a title without there also being an explicit target. For example:
```
error: redundant explicit link target
--> <anon>:5:12
|
5 | /// [drop](drop "This function is not magic")
| ---- ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ explicit target is redundant
| |
| because label contains path that resolves to same destination
|
= note: when a link's destination is not specified,
the label is used to resolve intra-doc links
help: remove explicit link target
|
5 - /// [drop](drop "This function is not magic")
5 + /// [drop]
|
```
These are found as of:
```
rustdoc 1.97.0-nightly (1b8f2e46e 2026-04-17)
binary: rustdoc
commit-hash: 1b8f2e46e1
commit-date: 2026-04-17
host: aarch64-apple-darwin
release: 1.97.0-nightly
LLVM version: 22.1.2
```
(Note: I ran `./x test tests/rustdoc-ui` locally, but not `./x tidy` due to my slow internet. There was an unrelated failed test at `tests/rustdoc-ui/ice-bug-report-url.rs` which I'm not sure about)
Fix ICE in borrowck mutability suggestion with multi-byte ref sigil
Fixesrust-lang/rust#139089
Similarly to rust-lang/rust#155068, this is another instance where span arithmetic did not account for multi-byte characters. (Note that the ampersand in the test is full-width)
This change also results in correcting some inappropriate suggestions.
Fix misleading "borrowed data escapes outside of function" diagnostic
Fixesrust-lang/rust#154350
Fall back to `report_general_error()` when `fr_name_and_span` is `None` in function items, since the "escaping data" framing is only appropriate for closures capturing outside variables.
Move recursion out of `MatchPairTree::for_pattern` helpers
The helper functions now just iterate over the relevant subpatterns, while leaving recursion up to the main function.
This avoids passing parameters that were only used for recursive plumbing, and consolidates all recursive calls into `for_pattern` itself, which should make it easier to experiment with changes to the recursive structure.
There should be no change to compiler behaviour.
`impl Default for RepeatN`
This creates an empty iterator, like `repeat_n(value, 0)` but without
needing any such value at hand. There's precedent in many other
iterators that the `Default` is empty, like `slice::Iter`.
I found myself wanting this for rayon's `RepeatN` as it lowers to a
sequential iterator [here][1]. Since rayon is also optimizing to avoid
extra clones, it may end up with parallel splits that have count 0 and
no item value. Calling `std::iter::repeat_n(x, 0)` just drops that
value, but there's no way to construct the same result without a value
yet. This would be straightforward with an empty `Default`.
[1]: https://github.com/rayon-rs/rayon/blob/ae07384e3e0b238cea89f0c14891f351c65a5cee/src/iter/repeat.rs#L201-L202
r? libs-api (insta-stable)
Add Sized supertrait for CoerceUnsized and DispatchFromDyn
This is part of rust-lang/rust#149094. I did not include `Receiver` because I think it is correct to allow non-sized receivers.
Folkert de Vries
