wasi: Fix sleeping for `Duration::MAX`
This commit fixes an assert in the WASI-specific implementation of thread sleep to ensure that sleeping for a very large period of time blocks instead of panicking. This can come up when testing programs that sleep "forever", for example.
I'll note that I haven't included a test for this since it's sort of difficult to test. I've tested this locally though that long sleeps do indeed block and short sleeps still only sleep for a short amount of time.
This commit fixes an assert in the WASI-specific implementation of
thread sleep to ensure that sleeping for a very large period of time
blocks instead of panicking. This can come up when testing programs that
sleep "forever", for example.
copysign with sign being a NaN can have non-portable results
Follow-up to https://github.com/rust-lang/rust/pull/129559.
Cc ```@tgross35``` ```@beetrees```
There's no portable variant we can recommend instead here, is there? Something with a semantics like "if `sign` is a NaN, then return `self` unaltered, otherwise return `self` with the sign changed to that of `sign`"?
Clean up cfg-gating of ProcessPrng extern
This removes a bit of duplication and is consistent with how `api-ms-win-core-synch-l1-2-0` externs are imported.
rustc_target: Add various aarch64 features
Add various aarch64 features already supported by LLVM and Linux.
Additionally include some comment fixes to ensure consistency of feature names with the Arm ARM.
Compiler support for features added to stdarch by https://github.com/rust-lang/stdarch/pull/1614.
Tracking issue for unstable aarch64 features is https://github.com/rust-lang/rust/issues/127764.
List of added features:
- FEAT_CSSC
- FEAT_ECV
- FEAT_FAMINMAX
- FEAT_FLAGM2
- FEAT_FP8
- FEAT_FP8DOT2
- FEAT_FP8DOT4
- FEAT_FP8FMA
- FEAT_HBC
- FEAT_LSE128
- FEAT_LSE2
- FEAT_LUT
- FEAT_MOPS
- FEAT_LRCPC3
- FEAT_SVE_B16B16
- FEAT_SVE2p1
- FEAT_WFxT
- FEAT_SME
- FEAT_SME_F16F16
- FEAT_SME_F64F64
- FEAT_SME_F8F16
- FEAT_SME_F8F32
- FEAT_SME_FA64
- FEAT_SME_I16I64
- FEAT_SME_LUTv2
- FEAT_SME2
- FEAT_SME2p1
- FEAT_SSVE_FP8DOT2
- FEAT_SSVE_FP8DOT4
- FEAT_SSVE_FP8FMA
FEAT_FPMR is added in the first commit and then removed in a separate one to highlight it being removed from upstream LLVM 19. The intention is for it to be detectable at runtime through stdarch but not have a corresponding Rust compile-time feature.
A partial stabilization that only affects:
- AllocType<T>::new_uninit
- AllocType<T>::assume_init
- AllocType<[T]>::new_uninit_slice
- AllocType<[T]>::assume_init
where "AllocType" is Box, Rc, or Arc
exit: explain our expectations for the exit handlers registered in a Rust program
This documents the position of ``@Amanieu`` and others in https://github.com/rust-lang/rust/issues/126600: a library with an atexit handler that destroys state that other threads could still be working on is buggy. We do not consider it acceptable for a library to say "you must call the following cleanup function before exiting from `main` or calling `exit`". I don't know if this is established ``@rust-lang/libs-api`` consensus so I presume this will have to go through FCP.
Given that Rust supports concurrency, I don't think there is any way to write a sound Rust wrapper around a library that has such a required cleanup function: even if we made `exit` unsafe, and the Rust wrapper used the scope-with-callback approach to ensure it can run cleanup code before returning from the wrapper (like `thread::scope`), one could still call this wrapper in a second thread and then return from `main` while the wrapper runs. Making this sound would require `std` to provide a way to "block" returning from `main`, so that while the wrapper runs returning from `main` waits until the wrapper is done... that just doesn't seem feasible.
The `exit` docs do not seem like the best place to document this, but I also couldn't think of a better one.
Add SME aarch64 features already supported by LLVM and Linux.
This commit adds compiler support for the following features:
- FEAT_SME
- FEAT_SME_F16F16
- FEAT_SME_F64F64
- FEAT_SME_F8F16
- FEAT_SME_F8F32
- FEAT_SME_FA64
- FEAT_SME_I16I64
- FEAT_SME_LUTv2
- FEAT_SME2
- FEAT_SME2p1
- FEAT_SSVE_FP8DOT2
- FEAT_SSVE_FP8DOT4
- FEAT_SSVE_FP8FMA
Add various aarch64 features already supported by LLVM and Linux.
The features are marked as unstable using a newly added symbol, i.e.
aarch64_unstable_target_feature.
Additionally include some comment fixes to ensure consistency of
feature names with the Arm ARM and support for architecture version
target features up to v9.5a.
This commit adds compiler support for the following features:
- FEAT_CSSC
- FEAT_ECV
- FEAT_FAMINMAX
- FEAT_FLAGM2
- FEAT_FP8
- FEAT_FP8DOT2
- FEAT_FP8DOT4
- FEAT_FP8FMA
- FEAT_FPMR
- FEAT_HBC
- FEAT_LSE128
- FEAT_LSE2
- FEAT_LUT
- FEAT_MOPS
- FEAT_LRCPC3
- FEAT_SVE_B16B16
- FEAT_SVE2p1
- FEAT_WFxT
library: Move unstable API of new_uninit to new features
- `new_zeroed` variants move to `new_zeroed_alloc`
- the `write` fn moves to `box_uninit_write`
The remainder will be stabilized in upcoming patches, as it was decided to only stabilize `uninit*` and `assume_init`.
- `new_zeroed` variants move to `new_zeroed_alloc`
- the `write` fn moves to `box_uninit_write`
The remainder will be stabilized in upcoming patches, as
it was decided to only stabilize `uninit*` and `assume_init`.
Update `compiler_builtins` to `0.1.120`
Includes https://github.com/rust-lang/compiler-builtins/pull/672 which fixes regression issue with Apple and Windows compilers.
try-job: aarch64-apple
try-job: x86_64-apple-1
try-job: x86_64-msvc
Fix `thread::sleep` Duration-handling for ESP-IDF
Addresses the ESP-IDF specific aspect of https://github.com/rust-lang/rust/issues/129212
#### A short summary of the problems addressed by this PR:
================================================
1. **Problem 1** - the current implementation of `std:🧵:sleep` does not properly round up the passed `Duration`
As per the documentation of `std:🧵:sleep`, the implementation should sleep _at least_ for the provided duration, but not less. Since the minimum supported resolution of the `usleep` syscall which is used with ESP-IDF is one microsecond, this means that we need to round-up any sub-microsecond nanos to one microsecond. Moreover, in the edge case where the user had passed a duration of < 1000 nanos (i.e. less than one microsecond), the current implementation will _not_ sleep _at all_.
This is addressed by this PR.
2. **Problem 2** - the implementation of `usleep` on the ESP-IDF can overflow if the passed number of microseconds is >= `u32::MAX - 1_000_000`
This is also addressed by this PR.
Extra details for Problem 2:
`u32::MAX - 1_000_000` is chosen to accommodate for the longest possible systick on the ESP IDF which is 1000ms.
The systick duration is selected when compiling the ESP IDF FreeRTOS task scheduler itself, so we can't know it from within `STD`. The default systick duration is 10ms, and might be lowered down to 1ms. (Making it longer I have never seen, but in theory it can go up to a 1000ms max, even if obviously a one second systick is unrealistic - but we are paranoid in the PR.)
While the overflow is reported upstream in the ESP IDF repo[^1], I still believe we should workaround it in the Rust wrappers as well, because it might take time until it is fixed, and they might not fix it for all released ESP IDF versions.
For big durations, rather than calling `usleep` repeatedly on the ESP-IDF in chunks of `u32::MAX - 1_000_000`us, it might make sense to call instead with 1_000_000us (one second) as this is the max period that seems to be agreed upon as a safe max period in the `usleep` POSIX spec. On the other hand, that might introduce less precision (as we need to call more times `usleep` in a loop) and, we would be fighting a theoretical problem only, as I have big doubts the ESP IDF will stop supporting durations higher than 1_000_000us - ever - because of backwards compatibility with code which already calls `usleep` on the ESP IDF with bigger durations.
[^1]: https://github.com/espressif/esp-idf/issues/14390
doc: std::env::var: Returns None for names with '=' or NUL byte
The documentation incorrectly stated that std::env::var could return an error for variable names containing '=' or the NUL byte. Copy the correct documentation from var_os.
var_os was fixed in Commit 8a7a665, Pull Request #109894, which closed Issue #109893.
This documentation was incorrectly added in commit f2c0f292, which replaced a panic in var_os by returning None, but documented the change as "May error if ...".
Reference the specific error values and link to them.
CloneToUninit impls
As per #126799.
Also implements it for `Wtf8` and both versions of `os_str::Slice`.
Maybe it is worth to slap `#[inline]` on some of those impls.
r? `@dtolnay`
Rollup of 7 pull requests
Successful merges:
- #122884 (Optimize integer `pow` by removing the exit branch)
- #127857 (Allow to customize `// TODO:` comment for deprecated safe autofix)
- #129034 (Add `#[must_use]` attribute to `Coroutine` trait)
- #129049 (compiletest: Don't panic on unknown JSON-like output lines)
- #129050 (Emit a warning instead of an error if `--generate-link-to-definition` is used with other output formats than HTML)
- #129056 (Fix one usage of target triple in bootstrap)
- #129058 (Add mw back to review rotation)
r? `@ghost`
`@rustbot` modify labels: rollup
Add windows-targets crate to std's sysroot
With this PR, when backtrace is used as a crate from crates.io it will (once updated) use the real [windows-targets](https://crates.io/crates/windows-targets) crate. But when used from std it'll use std's replacement version.
This allows sharing our customized `windows_tagets::link!` macro between std proper and the backtrace crate when used as part of std, ensuring a consistent linking story. This will be especially important once we move to using [`raw-dylib`](https://doc.rust-lang.org/reference/items/external-blocks.html#dylib-versus-raw-dylib) by default.
Allow to customize `// TODO:` comment for deprecated safe autofix
Relevant for the deprecation of `CommandExt::before_exit` in #125970.
Tracking:
- #124866
