In https://github.com/rust-lang/rust/pull/124748, I mistakenly conflated
"not SjLj" to mean "ARM EHABI", which isn't true, watchOS armv7k
(specifically only that architecture) uses a third unwinding method
called "DWARF CFI".
Rollup of 10 pull requests
Successful merges:
- #126452 (Implement raw lifetimes and labels (`'r#ident`))
- #129555 (stabilize const_float_bits_conv)
- #129594 (explain the options bootstrap passes to curl)
- #129677 (Don't build by-move body when async closure is tainted)
- #129847 (Do not call query to compute coroutine layout for synthetic body of async closure)
- #129869 (add a few more crashtests)
- #130009 (rustdoc-search: allow trailing `Foo ->` arg search)
- #130046 (str: make as_mut_ptr and as_bytes_mut unstably const)
- #130047 (Win: Add dbghelp to the list of import libraries)
- #130059 (Remove the unused `llvm-skip-rebuild` option from x.py)
r? `@ghost`
`@rustbot` modify labels: rollup
Win: Add dbghelp to the list of import libraries
This is used by the backtrace crate. But we use a submodule to include backtrace in std (rather than being a real crate) so we need to add the dependency here.
str: make as_mut_ptr and as_bytes_mut unstably const
`@rust-lang/libs-api` the corresponding non-mutable methods are already const fn, so this seems pretty trivial. I hope this is small enough that it does not need an ACP? :)
I would like to get these stabilized ASAP because I want to avoid people doing `s.as_ptr().cast_mut()`, which is UB if they ever write to it, but is already const-stable.
TODO: create a tracking issue.
Inaccurate `{Path,OsStr}::to_string_lossy()` documentation
The documentation of `Path::to_string_lossy()` and `OsStr::to_string_lossy()` says the following:
> Any non-Unicode sequences are replaced with `U+FFFD REPLACEMENT CHARACTER`
which didn't immediately make sense to me. ("non-Unicode sequences"?)
Since both `to_string_lossy` functions eventually become just a call to `String::from_utf8_lossy`, I believe the documentation meant to say:
> Any *non-UTF-8* sequences are replaced with `U+FFFD REPLACEMENT CHARACTER`
This PR corrects this mistake in the documentation.
For the record, a similar quote can be found in the documentation of `String::from_utf8_lossy`:
> ... During this conversion, `from_utf8_lossy()` will replace any invalid UTF-8 sequences with `U+FFFD REPLACEMENT CHARACTER`, ...
The developer experience for panics is to provide the backtrace and
exit the program. When running under debugger, that might be improved
by breaking into the debugger once the code panics thus enabling
the developer to examine the program state at the exact time when
the code panicked.
Let the developer catch the panic in the debugger if it is attached.
If the debugger is not attached, nothing changes. Providing this feature
inside the standard library facilitates better debugging experience.
Validated under Windows, Linux, macOS 14.6, and FreeBSD 13.3..14.1.
Elaborate on deriving vs implementing `Copy`
I was reading this documentation and this wasn't immediately clear to me.
In my mind, it seemed obvious that a type can only claim to be `Copy` if the bits it is storing can be `Copy`, and in the case of a generic struct that can only be the case if `T: Copy`. So the bound added by the derive seemed necessary at all times, and I thought what the documentation was trying to say is that the custom implementation allows you to add _additional bounds_.
Of course what it was actually trying to point out is that just because you have a generic parameter `T`, it doesn't necessarily mean you are storing the bits of `T`. And if you aren't, it may be the case that your own bits can be copied regardless of whether the bits of `T` can be safely copied.
Thought it may be worth elaborating to make that a bit more clear. Haven't tested/didn't try to figure out how to render this locally. Mainly not sure if the `PhantomData` back link is going to just work or need some extra stuff, but I figured someone else probably could just tell.
Stabilize `waker_getters`
Tracking issue: #96992
FCP completed on the tracking issue a while ago. It's not clear whether the libs-api team wanted the `RawWaker` methods moved to `Waker` or went back to the current API after further discussion. `@Amanieu` [wrote "This is just waiting for someone to submit a stabilization PR."](https://github.com/rust-lang/rust/issues/96992#issuecomment-2213685218) so I'm doing just that in hopes of nudging this along.
Edit: Moved the `data` and `vtable` methods from `RawWaker` to `Waker` and added `Waker::new` per https://github.com/rust-lang/rust/issues/96992#issuecomment-1941998046
```rs
impl Waker {
pub const unsafe fn new(data: *const (), vtable: &'static RawWakerVTable) -> Self;
pub fn data(&self) -> *const ();
pub fn vtable(&self) -> &'static RawWakerVTable;
}
```
Closes#96992
Add target support for RTEMS Arm
# `armv7-rtems-eabihf`
This PR adds a new target for the RTEMS RTOS. To get things started it focuses on Xilinx/AMD Zynq-based targets, but in theory it should also support other armv7-based board support packages in the future.
Given that RTEMS has support for many POSIX functions it is mostly enabling corresponding unix features for the new target.
I also previously started a PR in libc (https://github.com/rust-lang/libc/pull/3561) to add the needed OS specific C-bindings and was told that a PR in this repo is needed first. I will update the PR to the newest version after approval here.
I will probably also need to change one line in the backtrace repo.
Current status is that I could compile rustc for the new target locally (with the updated libc and backtrace) and could compile binaries, link, and execute a simple "Hello World" RTEMS application for the target hardware.
> A proposed target or target-specific patch that substantially changes code shared with other targets (not just target-specific code) must be reviewed and approved by the appropriate team for that shared code before acceptance.
There should be no breaking changes for existing targets. Main changes are adding corresponding `cfg` switches for the RTEMS OS and adding the C binding in libc.
# Tier 3 target policy
> - A tier 3 target must have a designated developer or developers (the "target maintainers") on record to be CCed when issues arise regarding the target. (The mechanism to track and CC such developers may evolve over time.)
I will do the maintenance (for now) further members of the RTEMS community will most likely join once the first steps have been done.
> - Targets must use naming consistent with any existing targets; for instance, a target for the same CPU or OS as an existing Rust target should use the same name for that CPU or OS. Targets should normally use the same names and naming conventions as used elsewhere in the broader ecosystem beyond Rust (such as in other toolchains), unless they have a very good reason to diverge. Changing the name of a target can be highly disruptive, especially once the target reaches a higher tier, so getting the name right is important even for a tier 3 target.
> - Target names should not introduce undue confusion or ambiguity unless absolutely necessary to maintain ecosystem compatibility. For example, if the name of the target makes people extremely likely to form incorrect beliefs about what it targets, the name should be changed or augmented to disambiguate it.
> - If possible, use only letters, numbers, dashes and underscores for the name. Periods (`.`) are known to cause issues in Cargo.
The proposed triple is `armv7-rtems-eabihf`
> - Tier 3 targets may have unusual requirements to build or use, but must not create legal issues or impose onerous legal terms for the Rust project or for Rust developers or users.
> - The target must not introduce license incompatibilities.
> - Anything added to the Rust repository must be under the standard Rust license (`MIT OR Apache-2.0`).
> - The target must not cause the Rust tools or libraries built for any other host (even when supporting cross-compilation to the target) to depend on any new dependency less permissive than the Rust licensing policy. This applies whether the dependency is a Rust crate that would require adding new license exceptions (as specified by the `tidy` tool in the rust-lang/rust repository), or whether the dependency is a native library or binary. In other words, the introduction of the target must not cause a user installing or running a version of Rust or the Rust tools to be subject to any new license requirements.
> - Compiling, linking, and emitting functional binaries, libraries, or other code for the target (whether hosted on the target itself or cross-compiling from another target) must not depend on proprietary (non-FOSS) libraries. Host tools built for the target itself may depend on the ordinary runtime libraries supplied by the platform and commonly used by other applications built for the target, but those libraries must not be required for code generation for the target; cross-compilation to the target must not require such libraries at all. For instance, `rustc` built for the target may depend on a common proprietary C runtime library or console output library, but must not depend on a proprietary code generation library or code optimization library. Rust's license permits such combinations, but the Rust project has no interest in maintaining such combinations within the scope of Rust itself, even at tier 3.
> - "onerous" here is an intentionally subjective term. At a minimum, "onerous" legal/licensing terms include but are _not_ limited to: non-disclosure requirements, non-compete requirements, contributor license agreements (CLAs) or equivalent, "non-commercial"/"research-only"/etc terms, requirements conditional on the employer or employment of any particular Rust developers, revocable terms, any requirements that create liability for the Rust project or its developers or users, or any requirements that adversely affect the livelihood or prospects of the Rust project or its developers or users.
The tools consists of the cross-compiler toolchain (gcc-based). The RTEMS kernel (BSD license) and parts of the driver stack of FreeBSD (BSD license). All tools are FOSS and publicly available here: https://gitlab.rtems.org/rtems
There are also no new features or dependencies introduced to the Rust code.
> - Neither this policy nor any decisions made regarding targets shall create any binding agreement or estoppel by any party. If any member of an approving Rust team serves as one of the maintainers of a target, or has any legal or employment requirement (explicit or implicit) that might affect their decisions regarding a target, they must recuse themselves from any approval decisions regarding the target's tier status, though they may otherwise participate in discussions.
N/A to me. I am not a reviewer nor Rust team member.
> - Tier 3 targets should attempt to implement as much of the standard libraries as possible and appropriate (`core` for most targets, `alloc` for targets that can support dynamic memory allocation, `std` for targets with an operating system or equivalent layer of system-provided functionality), but may leave some code unimplemented (either unavailable or stubbed out as appropriate), whether because the target makes it impossible to implement or challenging to implement. The authors of pull requests are not obligated to avoid calling any portions of the standard library on the basis of a tier 3 target not implementing those portions.
`core` and `std` compile. Some advanced features of the `std` lib might not work yet. However, the goal of this tier 3 target it to make it easier for other people to build and run test applications to better identify the unsupported features and work towards enabling them.
> - The target must provide documentation for the Rust community explaining how to build for the target, using cross-compilation if possible. If the target supports running binaries, or running tests (even if they do not pass), the documentation must explain how to run such binaries or tests for the target, using emulation if possible or dedicated hardware if necessary.
Building is described in platform support doc. Running simple unit tests works. Running the test suite of the stdlib is currently not that easy. Trying to work towards that after the this target has been added to the nightly.
> - Tier 3 targets must not impose burden on the authors of pull requests, or other developers in the community, to maintain the target. In particular, do not post comments (automated or manual) on a PR that derail or suggest a block on the PR based on a tier 3 target. Do not send automated messages or notifications (via any medium, including via ````@`)``` to a PR author or others involved with a PR regarding a tier 3 target, unless they have opted into such messages.
Understood.
> - Backlinks such as those generated by the issue/PR tracker when linking to an issue or PR are not considered a violation of this policy, within reason. However, such messages (even on a separate repository) must not generate notifications to anyone involved with a PR who has not requested such notifications.
Ok
> - Patches adding or updating tier 3 targets must not break any existing tier 2 or tier 1 target, and must not knowingly break another tier 3 target without approval of either the compiler team or the maintainers of the other tier 3 target.
> - In particular, this may come up when working on closely related targets, such as variations of the same architecture with different features. Avoid introducing unconditional uses of features that another variation of the target may not have; use conditional compilation or runtime detection, as appropriate, to let each target run code supported by that target.
I think, I didn't add any breaking changes for any existing targets (see the comment regarding features above).
> - Tier 3 targets must be able to produce assembly using at least one of rustc's supported backends from any host target.
Can produce assembly code via the llvm backend (tested on Linux).
>
> If a tier 3 target stops meeting these requirements, or the target maintainers no longer have interest or time, or the target shows no signs of activity and has not built for some time, or removing the target would improve the quality of the Rust codebase, we may post a PR to remove it; any such PR will be CCed to the target maintainers (and potentially other people who have previously worked on the target), to check potential interest in improving the situation.GIAt this tier, the Rust project provides no official support for a target, so we place minimal requirements on the introduction of targets.
Understood.
r? compiler-team
enable -Zrandomize-layout in debug CI builds
This builds rustc/libs/tools with `-Zrandomize-layout` on *-debug CI runners.
Only a handful of tests and asserts break with that enabled, which is promising. One test was fixable, the rest is dealt with by disabling them through new cargo features or compiletest directives.
The config.toml flag `rust.randomize-layout` defaults to false, so it has to be explicitly enabled for now.
This regresses binary-size slightly for normal builds, but the important
release_lto_thin_opt_level_s config sees a small improvement in
binary-size and a larger types such as string and 1k see 2-3% run-time
improvements with this change.
While using it results in slightly slammer binaries, it's not deemed
worth it to add yet another sort algorithm to the standard library.
select_nth_unstable has bigger binary-size problems.
Add missing read_buf stub for x86_64-unknown-l4re-uclibc
Before this PR, `x check library/std --target x86_64-unknown-l4re-uclibc` will fail with
```
error[E0599]: no method named `read_buf` found for struct `Socket` in the current scope
--> std/src/os/unix/net/stream.rs:598:16
|
598 | self.0.read_buf(buf)
| ^^^^^^^^
|
::: std/src/sys/pal/unix/l4re.rs:23:5
|
23 | pub struct Socket(FileDesc);
| ----------------- method `read_buf` not found for this struct
|
= help: items from traits can only be used if the trait is implemented and in scope
```
This target doesn't have a maintainer to cc.
Move the Windows remove_dir_all impl into a module and make it more race resistant
This attempts to make the Windows implementation of `remove_dir_all` easier to understand and work with by separating out different concerns into their own functions. The code is mostly the same as before just moved around. There are some changes to make it more robust against races (e.g. two calls to `remove_dir_all` running concurrently). The module level comment explains the issue.
try-job: x86_64-msvc
try-job: i686-msvc
Fix compile error in solid's remove_dir_all
Before this PR, `x check library/std --target=aarch64-kmc-solid_asp3` will fail with:
```
error[E0382]: use of partially moved value: `result`
--> std/src/sys/pal/solid/fs.rs:544:20
|
541 | if let Err(err) = result
| --- value partially moved here
...
544 | return result;
| ^^^^^^ value used here after partial move
|
= note: partial move occurs because value has type `io::error::Error`, which does not implement the `Copy` trait
help: borrow this binding in the pattern to avoid moving the value
|
541 | if let Err(ref err) = result
| +++
```
cc `@kawadakk` I think this will clear up https://solid-rs.github.io/toolstate/ :)
Clarify language around ptrs in slice::raw
More specifically we explicitly mention that the pointer should be non-null as a top level requirement. Nullptrs are always valid for zero sized operations, so just validity (and alignment) does not guarantee non-nullness as implied in the existing docs.
We also explicitly call out ZSTs as an additional example where perhaps unintuitively alignment and non-nullness still have to hold.
Finally we change `data` in the range functions to `start`, which seems like a typo to me.
Touches docs for #89792
r? RalfJung
compiler_fence documentation: emphasize synchronization, not reordering
Our `fence` docs have at some point been update to explain that they are about synchronization, not about "preventing reordering". This updates the `compiler_fence` docs n the same vein, mostly by referring to the `fence` docs.
The old docs make it sound like I can put a compiler_fence in the middle of a bunch of non-atomic operations and that would achieve any kind of guarantee. It does not, atomic operations are still required to do synchronization.
I also slightly tweaked the `fence` docs, to put the synchronization first and the "prevent reordering" second.
Cc `@rust-lang/opsem` `@chorman0773` `@m-ou-se`
Fixes https://github.com/rust-lang/rust/issues/129189
Fixes https://github.com/rust-lang/rust/issues/54962
Rollup of 9 pull requests
Successful merges:
- #127474 (doc: Make block of inline Deref methods foldable)
- #129678 (Deny imports of `rustc_type_ir::inherent` outside of type ir + new trait solver)
- #129738 (`rustc_mir_transform` cleanups)
- #129793 (add extra linebreaks so rustdoc can identify the first sentence)
- #129804 (Fixed some typos in the standard library documentation/comments)
- #129837 (Actually parse stdout json, instead of using hacky contains logic.)
- #129842 (Fix LLVM ABI NAME for riscv64imac-unknown-nuttx-elf)
- #129843 (Mark myself as on vacation for triagebot)
- #129858 (Replace walk with visit so we dont skip outermost expr kind in def collector)
Failed merges:
- #129777 (Add `unreachable_pub`, round 4)
- #129868 (Remove kobzol vacation status)
r? `@ghost`
`@rustbot` modify labels: rollup
add extra linebreaks so rustdoc can identify the first sentence
there should probably be a lint against this in rustdoc, it causes too many lines to be shown in the short documentation overviews
expecially noticable for the slice primative type: https://doc.rust-lang.org/std/index.html
Apply size optimizations to panic machinery and some cold functions
* std dependencies gimli and addr2line are now built with opt-level=s
* various panic-related methods and `#[cold]` methods are now marked `#[optimize(size)]`
Panics should be cold enough that it doesn't make sense to optimize them for speed. The only tradeoff here is if someone does a lot of backtrace captures (without panics) and printing then the opt-level change might impact their perf.
Seems to be the first use of the optimize attribute. Tracking issue #54882
there should probably be a lint against this in rustdoc, it causes
too many lines to be shown in the short documentation overviews
expecially noticable for the slice primative type:
https://doc.rust-lang.org/std/index.html
add `aarch64_unknown_nto_qnx700` target - QNX 7.0 support for aarch64le
This backports the QNX 7.1 aarch64 implementation to 7.0.
* [x] required `-lregex` disabled, see https://github.com/rust-lang/libc/pull/3775 (released in libc 0.2.156)
* [x] uses `libgcc.a` instead of `libgcc_s.so` (7.0 used ancient GCC 5.4 which didn't have gcc_s)
* [x] a fix in `backtrace` crate to support stack traces https://github.com/rust-lang/backtrace-rs/pull/648
This PR bumps libc dependency to 0.2.158
CC: to the folks who did the [initial implementation](https://doc.rust-lang.org/rustc/platform-support/nto-qnx.html): `@flba-eb,` `@gh-tr,` `@jonathanpallant,` `@japaric`
# Compile target
```bash
# Configure qcc build environment
source _path_/_to_/qnx7.0/qnxsdp-env.sh
# Tell rust to use qcc when building QNX 7.0 targets
export build_env='
CC_aarch64-unknown-nto-qnx700=qcc
CFLAGS_aarch64-unknown-nto-qnx700=-Vgcc_ntoaarch64le_cxx
CXX_aarch64-unknown-nto-qnx700=qcc
AR_aarch64_unknown_nto_qnx700=ntoaarch64-ar'
# Build rust compiler, libs, and the remote test server
env $build_env ./x.py build \
--target x86_64-unknown-linux-gnu,aarch64-unknown-nto-qnx700 \
rustc library/core library/alloc library/std src/tools/remote-test-server
rustup toolchain link stage1 build/host/stage1
```
# Compile "hello world"
```bash
source _path_/_to_/qnx7.0/qnxsdp-env.sh
cargo new hello_world
cd hello_world
cargo +stage1 build --release --target aarch64-unknown-nto-qnx700
```
# Configure a remote for testing
Do this from a new shell - we will need to run more commands in the previous one. I ran into these two issues, and found some workarounds.
* Temporary dir might not work properly
* Default `remote-test-server` has issues binding to an address
```
# ./remote-test-server
starting test server
thread 'main' panicked at src/tools/remote-test-server/src/main.rs:175:29:
called `Result::unwrap()` on an `Err` value: Os { code: 249, kind: AddrNotAvailable, message: "Can't assign requested address" }
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
```
Specifying `--bind` param actually fixes that, and so does setting `TMPDIR` properly.
```bash
# Copy remote-test-server to remote device. You may need to use sftp instead.
# ATTENTION: Note that the path is different from the one in the remote testing documentation for some reason
scp ./build/x86_64-unknown-linux-gnu/stage1-tools-bin/remote-test-server qnxdevice:/path/
# Run ssh with port forwarding - so that rust tester can connect to the local port instead
ssh -L 12345:127.0.0.1:12345 qnxdevice
# on the device, run
rm -rf tmp && mkdir -p tmp && TMPDIR=$PWD/tmp ./remote-test-server --bind 0.0.0.0:12345
```
# Run test suit
Assume all previous environment variables are still set, or re-init them
```bash
export TEST_DEVICE_ADDR="localhost:12345"
# tidy needs to be skipped due to using un-published libc dependency
export exclude_tests='
--exclude src/bootstrap
--exclude src/tools/error_index_generator
--exclude src/tools/linkchecker
--exclude src/tools/tidy
--exclude tests/ui-fulldeps
--exclude rustc
--exclude rustdoc
--exclude tests/run-make-fulldeps'
env $build_env ./x.py test $exclude_tests --stage 1 --target aarch64-unknown-nto-qnx700
```
try-job: dist-x86_64-msvc
refactor: standardize duplicate processes in parser
## Summary
This PR refactors the `read_number` function to standardize duplicate code, improve readability, and enhance efficiency.
## Changes
- Merged the logic for both `max_digits` cases into a single `read_atomically` closure
- Simplified control flow and reduced code duplication
core: use `compare_bytes` for more slice element types
`bool`, `NonZero<u8>`, `Option<NonZero<u8>>` and `ascii::Char` can be compared the same way as `u8`.
Rollup of 11 pull requests
Successful merges:
- #128523 (Add release notes for 1.81.0)
- #129605 (Add missing `needs-llvm-components` directives for run-make tests that need target-specific codegen)
- #129650 (Clean up `library/profiler_builtins/build.rs`)
- #129651 (skip stage 0 target check if `BOOTSTRAP_SKIP_TARGET_SANITY` is set)
- #129684 (Enable Miri to pass pointers through FFI)
- #129762 (Update the `wasm-component-ld` binary dependency)
- #129782 (couple more crash tests)
- #129816 (tidy: say which feature gate has a stability issue mismatch)
- #129818 (make the const-unstable-in-stable error more clear)
- #129824 (Fix code examples buttons not appearing on click on mobile)
- #129826 (library: Fix typo in `core::mem`)
r? `@ghost`
`@rustbot` modify labels: rollup
Clean up `library/profiler_builtins/build.rs`
This PR makes a series of improvements to the long-neglected build script for `profiler_builtins`.
Most notably:
- The logic that silently skips missing source files has been removed, since it is currently unnecessary and makes build errors more confusing.
- The script now emits `cargo::rerun-if-changed` directives for the `compiler-rt` source and include directories.
Compiler behaviour and user programs should be unaffected by these changes.
Two improvements to the documentation:
- Document `-` as a valid character for signed integer destinations
- Make the documentation even more clear that extra whitespace and non-digit characters is invalid. Many other
languages, e.g. c++, are very permissive in string to integer routines and simply try to consume as much as they can,
ignoring the rest. This is trying to make the transition for developers who are used to the conversion semantics in
these languages a bit easier.
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.
Bump backtrace to 0.3.74~ish
Commit: https://github.com/rust-lang/backtrace-rs/commit/230570f
This should help with backtraces on Android, QNX NTO 7.0, and Windows.
It addresses a case of backtrace incurring undefined behavior on Android.
Re-enable android tests/benches in alloc/core
This is basically a revert of https://github.com/rust-lang/rust/pull/73729. These tests better work on android now; it's been 4 years and we don't use dlmalloc on that target anymore.
And I've validated that they should pass now with a try-build :)
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.
debug-fmt-detail option
I'd like to propose a new option that makes `#[derive(Debug)]` generate no-op implementations that don't print anything, and makes `{:?}` in format strings a no-op.
There are a couple of motivations for this:
1. A more thorough stripping of debug symbols. Binaries stripped of debug symbols still retain some of them through `Debug` implementations. It's hard to avoid that without compiler's help, because debug formatting can be used in many places, including dependencies, and their loggers, asserts, panics, etc.
* In my testing it gives about 2% binary size reduction on top of all other binary-minimizing best practices (including `panic_immediate_abort`). There are targets like Web WASM or embedded where users pay attention to binary sizes.
* Users distributing closed-source binaries may not want to "leak" any symbol names as a matter of principle.
2. Adds ability to test whether code depends on specifics of the `Debug` format implementation in unwise ways (e.g. trying to get data unavailable via public interface, or using it as a serialization format). Because current Rust's debug implementation doesn't change, there's a risk of it becoming a fragile de-facto API that [won't be possible to change in the future](https://www.hyrumslaw.com/). An option that "breaks" it can act as a [grease](https://www.rfc-editor.org/rfc/rfc8701.html).
This implementation is a `-Z fmt-debug=opt` flag that takes:
* `full` — the default, current state.
* `none` — makes derived `Debug` and `{:?}` no-ops. Explicit `impl Debug for T` implementations are left unharmed, but `{:?}` format won't use them, so they may get dead-code eliminated if they aren't invoked directly.
* `shallow` — makes derived `Debug` print only the type's name, without recursing into fields. Fieldless enums print their variant names. `{:?}` works.
The `shallow` option is a compromise between minimizing the `Debug` code, and compatibility. There are popular proc-macro crates that use `Debug::fmt` as a way to convert enum values into their Rust source code.
There's a corresponding `cfg` flag: `#[cfg(fmt_debug = "none")]` that can be used in user code to react to this setting to minimize custom `Debug` implementations or remove unnecessary formatting helper functions.
* Use a lookup table for 8-bit integers and the Karatsuba square root
algorithm for larger integers.
* Include optimization hints that give the compiler the exact numeric
range of results.
* Choose test inputs more thoroughly and systematically.
* Check that `isqrt` and `checked_isqrt` have equivalent results for
signed types, either equivalent numerically or equivalent as a panic
and a `None`.
* Check that `isqrt` has numerically-equivalent results for unsigned
types and their `NonZero` counterparts.
* Reuse `ilog10` benchmarks, plus benchmarks that use a uniform
distribution.
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`"?
Add fmt::Debug to sync::Weak<T, A>
Currently, `sync::Weak<T>` implements `Debug`, but `sync::Weak<T, A>` does not. This appears to be an oversight, as `rc::Weak<T, A>` implements `Debug`. (Note: `sync::Weak` is the weak for `Arc`, and `rc::Weak` is the weak for `Rc`.)
This PR adds the Debug trait for `sync::Weak<T, A>`. The issue was initially brought up here: https://github.com/rust-lang/wg-allocators/issues/131
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.
Rollup of 11 pull requests
Successful merges:
- #129421 (add repr to the allowlist for naked functions)
- #129480 (docs: correct panic conditions for rem_euclid and similar functions)
- #129551 (ub_checks intrinsics: fall back to cfg(ub_checks))
- #129608 (const-eval: do not make UbChecks behavior depend on current crate's flags)
- #129613 (interpret: do not make const-eval query result depend on tcx.sess)
- #129641 (rustdoc: fix missing resource suffix on `crates.js`)
- #129657 (Rename `BikeshedIntrinsicFrom` to `TransmuteFrom`)
- #129666 (interpret: add missing alignment check in raw_eq)
- #129667 (Rustc driver cleanup)
- #129668 (Fix Pin::set bounds regression)
- #129686 (coverage: Rename `CodeRegion` to `SourceRegion`)
r? `@ghost`
`@rustbot` modify labels: rollup
Rename `BikeshedIntrinsicFrom` to `TransmuteFrom`
As our implementation of MCP411 nears completion and we begin to solicit testing, it's no longer reasonable to expect testers to type or remember `BikeshedIntrinsicFrom`. The name degrades the ease-of-reading of documentation, and the overall experience of using compiler safe transmute.
Tentatively, we'll instead adopt `TransmuteFrom`.
This name seems to be the one most likely to be stabilized, after discussion on Zulip [1]. We may want to revisit the ordering of `Src` and `Dst` before stabilization, at which point we'd likely consider `TransmuteInto` or `Transmute`.
[1] https://rust-lang.zulipchat.com/#narrow/stream/216762-project-safe-transmute/topic/What.20should.20.60BikeshedIntrinsicFrom.60.20be.20named.3F
Tracking Issue: https://github.com/rust-lang/rust/issues/99571
r? `@compiler-errors`
ub_checks intrinsics: fall back to cfg(ub_checks)
Not sure why the fallback body uses `debug_assertions`, probably a leftover from when `cfg!(ub_checks)` did not exist yet?
r? `@saethlin`
Tweak some attributes to improve panic_immediate_abort
This is similar to https://github.com/rust-lang/rust/pull/117332; I did the same approach as before where I build a really big project with `-Zbuild-std -Zbuild-std-features=panic_immediate_abort` and grep its symbols for things that look panic-related.
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
Fix typos in floating-point primitive type docs
Fixes a few typos. Also reflows the text of a couple of paragraphs in the source code to the standard line width to make the source easier to read (will have no effect on the rendered documentation).
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.
As our implementation of MCP411 nears completion and we begin to
solicit testing, it's no longer reasonable to expect testers to
type or remember `BikeshedIntrinsicFrom`. The name degrades the
ease-of-reading of documentation, and the overall experience of
using compiler safe transmute.
Tentatively, we'll instead adopt `TransmuteFrom`.
This name seems to be the one most likely to be stabilized, after
discussion on Zulip [1]. We may want to revisit the ordering of
`Src` and `Dst` before stabilization, at which point we'd likely
consider `TransmuteInto` or `Transmute`.
[1] https://rust-lang.zulipchat.com/#narrow/stream/216762-project-safe-transmute/topic/What.20should.20.60BikeshedIntrinsicFrom.60.20be.20named.3F
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
This behaviour was introduced during the upgrade to LLVM 11. Now that the list
of source files has been cleaned up, we can reasonably expect _all_ of the
listed source files to be present.
simd_shuffle intrinsic: allow argument to be passed as vector
See https://github.com/rust-lang/rust/issues/128738 for context.
I'd like to get rid of [this hack](6c0b89dfac/compiler/rustc_codegen_ssa/src/mir/block.rs (L922-L935)). https://github.com/rust-lang/rust/pull/128537 almost lets us do that since constant SIMD vectors will then be passed as immediate arguments. However, simd_shuffle for some reason actually takes an *array* as argument, not a vector, so the hack is still required to ensure that the array becomes an immediate (which then later stages of codegen convert into a vector, as that's what LLVM needs).
This PR prepares simd_shuffle to also support a vector as the `idx` argument. Once this lands, stdarch can hopefully be updated to pass `idx` as a vector, and then support for arrays can be removed, which finally lets us get rid of that hack.
Document & implement the transmutation modeled by `BikeshedIntrinsicFrom`
Documents that `BikeshedIntrinsicFrom` models transmute-via-union, which is slightly more expressive than the transmute-via-cast implemented by `transmute_copy`. Additionally, we provide an implementation of transmute-via-union as a method on the `BikeshedIntrinsicFrom` trait with additional documentation on the boundary between trait invariants and caller obligations.
Whether or not transmute-via-union is the right kind of transmute to model remains up for discussion [1]. Regardless, it seems wise to document the present behavior.
[1] https://rust-lang.zulipchat.com/#narrow/stream/216762-project-safe-transmute/topic/What.20'kind'.20of.20transmute.20to.20model.3F/near/426331967
Tracking Issue: https://github.com/rust-lang/rust/issues/99571
r? `@compiler-errors`
cc `@scottmcm,` `@Lokathor`
Remove cfg(test) from library/core
The diff here is very small with the ignore whitespace option.
`core` doesn't/can't have unit tests. All of its tests are just modules under `tests/`, so it has no use for `cfg(test)`, because the entire contents of `library/core/src` are only ever compiled with that cfg off, and the entire contents of `library/core/tests` are only ever compiled with that cfg on.
You can tell this is what's happening because we had `#[cfg(test)]` on a module declaration that has no source file.
I also deleted the extra `mod tests {` layer of nesting; there's no need to mention again in the module path that this is a module of tests. This exposes a name collision between the `u128` module of tests and `core::u128`. Fixed that by using `<u128>::MAX` like is done in the `check!` macro, which is what avoids this name ambiguity for the other types.
link to Future::poll from the Poll docs
The most important thing about Poll is that Future::poll returns it, but previously the docs didn't emphasize this.
Add implementations for `unbounded_shl`/`unbounded_shr`
Tracking Issue: https://github.com/rust-lang/rust/issues/129375
This implements `unbounded_shl` and `unbounded_shr` under the feature gate `unbounded_shifts`
Rollup of 9 pull requests
Successful merges:
- #129288 (Use subtyping for `UnsafeFnPointer` coercion, too)
- #129405 (Fixing span manipulation and indentation of the suggestion introduced by #126187)
- #129518 (gitignore: ignore ICE reports regardless of directory)
- #129519 (Remove redundant flags from `lower_ty_common` that can be inferred from the HIR)
- #129525 (rustdoc: clean up tuple <-> primitive conversion docs)
- #129526 (Use `FxHasher` on new solver unconditionally)
- #129544 (Removes dead code from the compiler)
- #129553 (add back test for stable-const-can-only-call-stable-const)
- #129590 (Avoid taking reference of &TyKind)
r? `@ghost`
`@rustbot` modify labels: rollup
rustdoc: clean up tuple <-> primitive conversion docs
This adds a minor missing feature to `fake_variadic`, so that it can render `impl From<(T,)> for [T; 1]` correctly.
- Stable sort uses a simple merge-sort that re-uses the existing - rather gnarly - merge function.
- Unstable sort jumps directly to the branchless heapsort fallback.
- select_nth_unstable jumps directly to the median_of_medians fallback, which is augmented with a
custom tiny smallsort and partition impl.
Some code is duplicated but de-duplication would bring it's own problems. For example `swap_if_less`
is critical for performance, if the sorting networks don't inline it perf drops drastically,
however `#[inline(always)]` is also a poor fit, if the provided comparison function is huge,
it gives the compiler an out to only instantiate `swap_if_less` once and call it. Another aspect
that would suffer when making `swap_if_less` pub, is having to cfg out dozens of functions in
in smallsort module.
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`.
Build `library/profiler_builtins` from `ci-llvm` if appropriate
Running all of `tests/coverage` requires the LLVM profiler runtime, which requires setting `build.profiler = true`.
Historically, doing that has required checking out the entire `src/llvm-project` submodule. For compiler contributors who otherwise don't need that submodule (thanks to `download-ci-vm`), that's quite inconvenient.
However, thanks to #129116, the downloaded CI LLVM tarball now contains a copy of LLVM's `compiler-rt` directory, which includes all the files needed to build the profiler runtime. So with a little bit of extra logic in bootstrap, we can have `library/profiler_builtins` look for the `compiler-rt` files in `ci-llvm` instead of the `src/llvm-project` submodule.
Put Pin::as_deref_mut in impl Pin<Ptr> / rearrange Pin methods
Tracking issue: #86918
Based on the suggestion in https://github.com/rust-lang/rust/issues/86918#issuecomment-2189367582
> Some advantages:
>
> * Synergy with the existing `as_ref` and `as_mut` signatures (stable since Rust 1.33)
>
> * Lifetime elision reduces noise in the signature
>
> * Turbofish less verbose: `Pin::<&mut T>::as_deref_mut` vs `Pin::<&mut Pin<&mut T>>::as_deref_mut`
The comment seemed to imply that `Pin::as_ref` and `Pin::as_mut` already share an impl block, which they don't. So, I rearranged it so that they do, and we can see which looks better in the docs.
<details><summary><b>Docs screenshots</b></summary>
Current nightly:
`Pin::as_deref_mut` moved into the same block as `as_mut`:
`Pin::as_ref`, `as_mut`, and `as_deref_mut` all in the same block:
</details>
I think I like the last one the most; obviously I'm biased since I'm the one who rearranged it, but it doesn't make sense to me to have `as_ref` methods split up by an `into_inner` method.
r? dtolnay
Add a special case for `CStr`/`CString` in the `improper_ctypes` lint
Revives #120176. Just needed to bless a test and fix an argument, but seemed reasonable to me otherwise.
Instead of saying to "consider adding a `#[repr(C)]` or `#[repr(transparent)]` attribute to this struct", we now tell users to "Use `*const ffi::c_char` instead, and pass the value from `CStr::as_ptr()`" when the type involved is a `CStr` or a `CString`.
The suggestion is not made for `&mut CString` or `*mut CString`.
r? ``````@cjgillot`````` (since you were the reviewer of the original PR #120176, but feel free to reroll)
remove invalid `TyCompat` relation for effects
if the current impl uses `Maybe` (`impl const`), the parent impl must use `Maybe` (`impl const`) as well.
I'd like to rename `TyCompat` to `Sub` which is probably clearer. But it would conflict with my other PR.
r? ``@rust-lang/project-const-traits``
- `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`.
Documents that `BikeshedIntrinsicFrom` models transmute-via-union,
which is slightly more expressive than the transmute-via-cast
implemented by `transmute_copy`. Additionally, we provide an
implementation of transmute-via-union as a method on the
`BikeshedIntrinsicFrom` trait with additional documentation on
the boundary between trait invariants and caller obligations.
Whether or not transmute-via-union is the right kind of transmute
to model remains up for discussion [1]. Regardless, it seems wise
to document the present behavior.
[1] https://rust-lang.zulipchat.com/#narrow/stream/216762-project-safe-transmute/topic/What.20'kind'.20of.20transmute.20to.20model.3F/near/426331967
Rollup of 9 pull requests
Successful merges:
- #128511 (Document WebAssembly target feature expectations)
- #129243 (do not build `cargo-miri` by default on stable channel)
- #129263 (Add a missing compatibility note in the 1.80.0 release notes)
- #129276 (Stabilize feature `char_indices_offset`)
- #129350 (adapt integer comparison tests for LLVM 20 IR changes)
- #129408 (Fix handling of macro arguments within the `dropping_copy_types` lint)
- #129426 (rustdoc-search: use tighter json for names and parents)
- #129437 (Fix typo in a help diagnostic)
- #129457 (kobzol vacation)
r? `@ghost`
`@rustbot` modify labels: rollup
Stabilize feature `char_indices_offset`
Stabilized API:
```rust
impl CharIndices<'_> {
pub fn offset(&self) -> usize;
}
```
Tracking issue: https://github.com/rust-lang/rust/issues/83871
Closes https://github.com/rust-lang/rust/issues/83871
I also attempted to improved the documentation to make it more clear that it returns the offset of the character that will be returned by the next call to `next()`.
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
The current `build.rs` will automatically skip source files that don't exist.
An unfortunate side-effect is that if _no_ files could be found (e.g. because
the directory was wrong), the build fails with a mysterious linker error.
We can reduce the awkwardness of this by explicitly checking that at least one
source file was found.
Rollup of 8 pull requests
Successful merges:
- #128432 (WASI: forbid `unsafe_op_in_unsafe_fn` for `std::{os, sys}`)
- #129373 (Add missing module flags for CFI and KCFI sanitizers)
- #129374 (Use `assert_unsafe_precondition!` in `AsciiChar::digit_unchecked`)
- #129376 (Change `assert_unsafe_precondition` docs to refer to `check_language_ub`)
- #129382 (Add `const_cell_into_inner` to `OnceCell`)
- #129387 (Advise against removing the remaining Python scripts from `tests/run-make`)
- #129388 (Do not rely on names to find lifetimes.)
- #129395 (Pretty-print own args of existential projections (dyn-Trait w/ GAT constraints))
r? `@ghost`
`@rustbot` modify labels: rollup
Add `const_cell_into_inner` to `OnceCell`
`Cell` and `RefCell` have their `into_inner` methods const unstable. `OnceCell` has the same logic, so add it under the same gate.
Tracking issue: https://github.com/rust-lang/rust/issues/78729
`Cell` and `RefCell` have their `into_inner` methods const unstable.
`OnceCell` has the same logic, so add it under the same gate.
Tracking issue: https://github.com/rust-lang/rust/issues/78729
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
Implement `debug_more_non_exhaustive`
This implements the ACP at https://github.com/rust-lang/libs-team/issues/248, adding `.finish_non_exhaustive()` for `DebugTuple`, `DebugSet`, `DebugList`, and `DebugMap`.
Also used this as an opportunity to make some documentation and tests more readable by using raw strings instead of escaped quotes.
Tracking issue: https://github.com/rust-lang/rust/issues/127942
Avoid extra `cast()`s after `CStr::as_ptr()`
These used to be `&str` literals that did need a pointer cast, but that
became a no-op after switching to `c""` literals in #118566.
Add a precondition check for Layout::from_size_align_unchecked
Ran into this while looking into https://github.com/rust-lang/miri/issues/3679. This is of course not the cause of the ICE, but the reproducer doesn't encounter a precondition check and it ought to.
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`
float to/from bits and classify: update for float semantics RFC
With https://github.com/rust-lang/rfcs/pull/3514 having been accepted, it is clear that hardware which e.g. flushes subnormal to zero is just non-conformant from a Rust perspective -- this is a hardware bug, or maybe an LLVM backend bug (where LLVM doesn't lower floating-point ops in a way that they have the standardized behavior). So update the comments here to make it clear that we don't have to do any of this, we're just being nice.
Also remove the subnormal/NaN checks from the (unstable) const-version of to/from-bits; they are not needed since we decided with the aforementioned RFC that it is okay to get a different result at const-time and at run-time.
r? `@workingjubilee` since I think you wrote many of the comments I am editing here.
Implement DoubleEnded and ExactSize for Take<Repeat> and Take<RepeatWith>
Repeat iterator always returns the same element and behaves the same way
backwards and forwards. Take iterator can trivially implement backwards
iteration over Repeat inner iterator by simply doing forwards iteration.
DoubleEndedIterator is not currently implemented for Take<Repeat<T>>
because Repeat doesn’t implement ExactSizeIterator which is a required
bound on DEI implementation for Take.
Similarly, since Repeat is an infinite iterator which never stops, Take
can trivially know how many elements it’s going to return. This allows
implementing ExactSizeIterator on Take<Repeat<T>>.
While at it, observe that ExactSizeIterator can also be implemented for
Take<RepeatWhile<F>> so add that implementation too. Since in contrast
to Repeat, RepeatWhile doesn’t guarante to always return the same value,
DoubleEndedIterator isn’t implemented.
Those changes render core::iter::repeat_n somewhat redundant.
Issue: https://github.com/rust-lang/rust/issues/104434
Issue: https://github.com/rust-lang/rust/issues/104729
- [ ] ACP: https://github.com/rust-lang/libs-team/issues/120 (this is actually ACP for repeat_n but this is nearly the same functionality so hijacking it so both approaches can be discussed in one place)
Improve docs for Waker::noop and LocalWaker::noop
* Add a warning about a likely misuse. (See my commit message for longer rationale.)
* Apply some probably-accidentally-omitted changes to `LocalWaker`'s docs
* Add a comment about the clone-and-hack of the docs
I have used [semantic linefeeds](https://rhodesmill.org/brandon/2012/one-sentence-per-line/) for the docs formatting.
Hash Ipv*Addr as an integer
The `Ipv4Addr` and `Ipv6Addr` structs always have a fixed size, but directly derive `Hash`. This causes them to call the bytestring hasher implementation, which adds extra work for most hashers. This PR converts the internal representation to a fixed-width integer before passing to the hasher to prevent this.
derive(SmartPointer): register helper attributes
Fix#128888
This PR enables built-in macros to register helper attributes, if any, to support correct name resolution in the correct lexical scope under the macros.
Also, `#[pointee]` is moved into the scope under `derive(SmartPointer)`.
cc `@Darksonn` `@davidtwco`
CommandExt::before_exec: deprecate safety in edition 2024
Similar to `set_var`, we had to find out after 1.0 was released that `before_exec` should have been unsafe. We partially rectified this by deprecating that function a long time ago, but since https://github.com/rust-lang/rust/pull/124636 we have the ability to also deprecate the safety of the old function and make it a *hard error* to call the old function outside `unsafe` in the next edition. So just in case anyone still uses the old function, let's ensure this can't be ignored when moving code to the new edition.
Cc `@rust-lang/libs-api`
Tracking:
- https://github.com/rust-lang/rust/issues/124866
Explicitly specify type parameter on FromResidual for Option and ControlFlow.
~~Remove type parameter default `R = <Self as Try>::Residual` from `FromResidual`~~ _Specify default type parameter on `FromResidual` impls in the stdlib_ to work around https://github.com/rust-lang/rust/issues/99940 / https://github.com/rust-lang/rust/issues/87350 ~~as mentioned in https://github.com/rust-lang/rust/issues/84277#issuecomment-1773259264~~.
This does not completely fix the issue, but works around it for `Option` and `ControlFlow` specifically (`Result` does not have the issue since it already did not use the default parameter of `FromResidual`).
~~(Does this need an ACP or similar?)~~ ~~This probably needs at least an FCP since it changes the API described in [the RFC](https://github.com/rust-lang/rfcs/pull/3058). Not sure if T-lang, T-libs-api, T-libs, or some combination (The tracking issue is tagged T-lang, T-libs-api).~~ This probably doesn't need T-lang input, since it is not changing the API of `FromResidual` from the RFC? Maybe needs T-libs-api FCP?
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.
Add `#[must_use]` attribute to `Coroutine` trait
[Coroutines tracking issue](https://github.com/rust-lang/rust/issues/43122)
Like closures (`FnOnce`, `AsyncFn`, etc.), coroutines are lazy and do nothing unless called (resumed). Closure traits like `FnOnce` have `#[must_use = "closures are lazy and do nothing unless called"]` to catch likely bugs for users of APIs that produce them. This PR adds such a `#[must_use]` attribute to `trait Coroutine`.
Allow to customize `// TODO:` comment for deprecated safe autofix
Relevant for the deprecation of `CommandExt::before_exit` in #125970.
Tracking:
- #124866
Optimize integer `pow` by removing the exit branch
The branch at the end of the `pow` implementations is redundant with multiplication code already present in the loop. By rotating the exit check, this branch can be largely removed, improving code size and reducing instruction cache misses.
Testing on my machine (`x86_64`, 11th Gen Intel Core i5-1135G7 @ 2.40GHz), the `num::int_pow` benchmarks improve by some 40% for the unchecked operations and show some slight improvement for the checked operations as well.
