Rollup of 10 pull requests
Successful merges:
- #87960 (Suggest replacing an inexisting field for an unmentioned field)
- #88855 (Allow simd_shuffle to accept vectors of any length)
- #88966 (Check for shadowing issues involving block labels)
- #88996 (Fix linting when trailing macro expands to a trailing semi)
- #89017 (fix potential race in AtomicU64 time monotonizer)
- #89021 (Add a separate error for `dyn Trait` in `const fn`)
- #89051 (Add intra-doc links and small changes to `std::os` to be more consistent)
- #89053 (refactor: VecDeques IntoIter fields to private)
- #89055 (Suggest better place to add call parentheses for method expressions wrapped in parentheses)
- #89081 (Fix a typo)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
refactor: VecDeques IntoIter fields to private
Made the fields of VecDeque's IntoIter private by creating a IntoIter::from(...) function to create a new instance of IntoIter and migrating usage to use IntoIter::from(...).
Add intra-doc links and small changes to `std::os` to be more consistent
I believe that a few items in `std::os` should be linked. I've also added a basic example in `std::os::windows`.
fix potential race in AtomicU64 time monotonizer
The AtomicU64-based monotonizer introduced in #83093 is incorrect because several threads could try to update the value concurrently and a thread which doesn't have the newest value among all the updates could win.
That bug probably has little real world impact since it doesn't make observed time worse than hardware clocks. The worst case would probably be a thread which has a clock that is behind by several cycles observing several inconsistent fixups, which should be similar to observing the unfiltered backslide in the first place.
New benchmarks, they don't look as good as the original PR but still an improvement compared to the mutex.
I don't know why the contended mutex case is faster now than in the previous benchmarks.
```
actually_monotonic() == true:
test time::tests::instant_contention_01_threads ... bench: 44 ns/iter (+/- 0)
test time::tests::instant_contention_02_threads ... bench: 45 ns/iter (+/- 0)
test time::tests::instant_contention_04_threads ... bench: 45 ns/iter (+/- 0)
test time::tests::instant_contention_08_threads ... bench: 45 ns/iter (+/- 0)
test time::tests::instant_contention_16_threads ... bench: 46 ns/iter (+/- 0)
atomic u64:
test time::tests::instant_contention_01_threads ... bench: 66 ns/iter (+/- 0)
test time::tests::instant_contention_02_threads ... bench: 287 ns/iter (+/- 14)
test time::tests::instant_contention_04_threads ... bench: 296 ns/iter (+/- 43)
test time::tests::instant_contention_08_threads ... bench: 604 ns/iter (+/- 163)
test time::tests::instant_contention_16_threads ... bench: 1,147 ns/iter (+/- 29)
mutex:
test time::tests::instant_contention_01_threads ... bench: 78 ns/iter (+/- 0)
test time::tests::instant_contention_02_threads ... bench: 652 ns/iter (+/- 275)
test time::tests::instant_contention_04_threads ... bench: 900 ns/iter (+/- 32)
test time::tests::instant_contention_08_threads ... bench: 1,927 ns/iter (+/- 62)
test time::tests::instant_contention_16_threads ... bench: 3,748 ns/iter (+/- 146)
```
Avoid codegen for Result::into_ok in lang_start
This extra codegen seems to be the cause for the regressions in max-rss on #86034. While LLVM will certainly optimize the dead code away, avoiding it's generation in the first place seems good, particularly when it is so simple.
#86034 produced this [diff](https://gist.github.com/Mark-Simulacrum/95c7599883093af3b960c35ffadf4dab#file-86034-diff) for a simple `fn main() {}`. With this PR, that diff [becomes limited to just a few extra IR instructions](https://gist.github.com/Mark-Simulacrum/95c7599883093af3b960c35ffadf4dab#file-88988-from-pre-diff) -- no extra functions.
Note that these are pre-optimization; LLVM surely will eliminate this during optimization. However, that optimization can end up generating more work and bump memory usage, and this eliminates that.
Allow `panic!("{}", computed_str)` in const fn.
Special-case `panic!("{}", arg)` and translate it to `panic_display(&arg)`. `panic_display` will behave like `panic_any` in cosnt eval and behave like `panic!(format_args!("{}", arg))` in runtime.
This should bring Rust 2015 and 2021 to feature parity in terms of `const_panic`; and hopefully would unblock the stabilisation of #51999.
`@rustbot` modify labels: +T-compiler +T-libs +A-const-eval +A-const-fn
r? `@oli-obk`
Add chown functions to std::os::unix::fs to change the owner and group of files
This is a straightforward wrapper that uses the existing helpers for C
string handling and errno handling.
Having this available is convenient for UNIX utility programs written in
Rust, and avoids having to call unsafe functions like `libc::chown`
directly and handle errors manually, in a program that may otherwise be
entirely safe code.
In addition, these functions provide a more Rustic interface by
accepting appropriate traits and using `None` rather than `-1`.
Add TcpListener::into_incoming and IntoIncoming
The `incoming` method is really useful, however for some use cases the borrow
this introduces is needlessly restricting. Thus, an owned variant is added.
r? ``@joshtriplett``
The RefCell is now borrowed exactly once. In addition a code sequence
that contains an unwrap that is guaranteed to never panic at runtime is
replaced with get_or_insert_with, which makes the intended behavior
clearer and will not emit code to panic even without optimizations.
Previously the thread name would first be heap allocated and then
re-allocated to add a nul terminator. Now it will be heap allocated only
once with nul terminator added form the start.
