Implement `pin!()` using `super let`
Tracking issue for super let: https://github.com/rust-lang/rust/issues/139076
This uses `super let` to implement `pin!()`.
This means we can remove [the hack](https://github.com/rust-lang/rust/pull/138717) we had to put in to fix https://github.com/rust-lang/rust/issues/138596.
It also means we can remove the original hack to make `pin!()` work, which used a questionable public-but-unstable field rather than a proper private field.
While `super let` is still unstable and subject to change, it seems safe to assume that future Rust will always have a way to express `pin!()` in a compatible way, considering `pin!()` is already stable.
It'd help [the experiment](https://github.com/rust-lang/rust/issues/139076) to have `pin!()` use `super let`, so we can get some more experience with it.
sync::mpsc: prevent double free on `Drop`
This PR is fixing a regression introduced by #121646 that can lead to a double free when dropping the channel.
The details of the bug can be found in the corresponding crossbeam PR https://github.com/crossbeam-rs/crossbeam/pull/1187
Fix drop handling in `hint::select_unpredictable`
This intrinsic doesn't drop the value that is not selected so this is manually done in the public function that wraps the intrinsic.
f*::NAN: guarantee that this is a quiet NaN
I think we should guarantee that this is a quiet NaN. This then implies that programs not using `f*::from_bits` (or unsafe type conversions) are guaranteed to only work with quiet NaNs. It would be awkward if people start to write `0.0 / 0.0` instead of using the constant just because they want to get a guaranteed-quiet NaN.
This is a `@rust-lang/libs-api` change. The definition of this constant currently is `0.0 / 0.0`, which is already guaranteed to be a quiet NaN. So all this does is forward that guarantee to our users.
The methods `Take::get_mut` and `Chain::get_mut` include comments
warning about modifying the I/O state of the underlying reader. However,
many readers (e.g. `File`) allow I/O using a shared reference (e.g.
`&File`). So, add the same caveat to the `get_ref` methods.
Fix: Map EOPNOTSUPP to ErrorKind::Unsupported on Unix
This change maps the EOPNOTSUPP errno value (95) to std::io::ErrorKind::Unsupported in the decode_error_kind function for Unix platforms. Previously, it was incorrectly mapped to ErrorKind::Uncategorized.
Fixes#139803
std/thread: Use default stack size from menuconfig for NuttX
* Update comments to clarify the usage of zero as an indication for default stack size configuration
* Adjust conditional compilation to reflect the changes in stack size handling for the NuttX platform
This change improves clarity and consistency in stack size configuration across platforms.
std: sys: process: uefi: Use NULL stdin by default
According to the docs in `Command::output`:
> By default, stdout and stderr are captured (and used to provide the
resulting output). Stdin is not inherited from the parent and any attempt by the child process to read from the stdin stream will result in the stream immediately closing.
This was being violated by UEFI which was inheriting stdin by default.
While the docs don't explicitly state that the default should be NULL, the behaviour seems like reading from NULL.
UEFI however, has a bit of a problem. The `EFI_SIMPLE_TEXT_INPUT_PROTOCOL` only provides support for reading 1 key press. This means that you either get an error, or it is assumed that the keypress was read successfully. So there is no way to have a successful read of length 0. Currently, I am returning UNSUPPORTED error when trying to read from NULL stdin. On linux however, you will get a read of length 0 for Null stdin.
One possible way to get around this is to translate one of the UEFI errors to a read 0 (Maybe unsupported?). It is also possible to have a non-standard error code, but well, not sure if we go that route.
Alternatively, if meaning of Stdio::Null is platform dependent, it should be fine to keep the current behaviour of returning an error.
cc ```@nicholasbishop``` ```@dvdhrm```
Enable contracts for const functions
Use `const_eval_select!()` macro to enable contract checking only at runtime. The existing contract logic relies on closures, which are not supported in constant functions.
This commit also removes one level of indirection for ensures clauses since we no longer build a closure around the ensures predicate.
Resolves#136925
**Call-out:** This is still a draft PR since CI is broken due to a new warning message for unreachable code when the bottom of the function is indeed unreachable. It's not clear to me why the warning wasn't triggered before.
r? ```@compiler-errors```
Avoid unused clones in `Cloned<I>` and `Copied<I>`
Avoid cloning in `Cloned<I>` or copying in `Copied<I>` when elements are only needed by reference or not at all. There is already some precedent for this, given that `__iterator_get_unchecked` is implemented, which can skip elements. The reduced clones are technically observable by a user impl of `Clone`.
r? libs-api
This change maps the EOPNOTSUPP errno value (95) to std::io::ErrorKind::Unsupported in the decode_error_kind function for Unix platforms. Previously, it was incorrectly mapped to ErrorKind::Uncategorized.
Fixes#139803
Rollup of 8 pull requests
Successful merges:
- #139127 (Fix up partial res of segment in primitive resolution hack)
- #139392 (Detect and provide suggestion for `&raw EXPR`)
- #139767 (Visit place in `BackwardIncompatibleDropHint` statement)
- #139777 (Remove `define_debug_via_print` for `ExistentialProjection`, use regular structural debug impl)
- #139796 (ptr docs: add missing backtics around 'usize')
- #139801 (Add myself to mailmap)
- #139804 (use `realpath` in `bootstrap.py` when creating build-dir)
- #139807 (Improve wording of post-merge report)
r? `@ghost`
`@rustbot` modify labels: rollup
Avoid cloning in `Cloned<I>` or copying in `Copied<I>` when elements are
only needed by reference or not at all. There is already some precedent
for this, given that `__iterator_get_unchecked` is implemented, which
can skip elements. The reduced clones are technically observable by a
user impl of `Clone`.
Initial `UnsafePinned` implementation [Part 1: Libs]
Initial libs changes necessary to unblock further work on [RFC 3467](https://rust-lang.github.io/rfcs/3467-unsafe-pinned.html).
Tracking issue: #125735
This PR is split off from #136964, and includes just the libs changes:
- `UnsafePinned` struct
- private `UnsafeUnpin` structural auto trait
- Lang items for both
- Compiler changes necessary to block niches on `UnsafePinned`
This PR does not change codegen, miri, the existing `!Unpin` hack, or anything else. That work is to be split into later PRs.
---
cc ``@RalfJung`` ``@Noratrieb``
``@rustbot`` label F-unsafe_pinned T-libs-api
Stdio::MakePipe is not supported.
For Stdio::Null, return UNSUPPORTED. This is treated as read(0).
Additionally, have infinte loop on the notify function to prevent
wait_for_key from returning.
Signed-off-by: Ayush Singh <ayush@beagleboard.org>
According to the docs in `Command::output`:
> By default, stdout and stderr are captured (and used to provide the
resulting output). Stdin is not inherited from the parent and any attempt
by the child process to read from the stdin stream will result in the
stream immediately closing.
This was being violated by UEFI which was inheriting stdin by default.
While the docs don't explicitly state that the default should be NULL,
the behaviour seems like reading from NULL.
UEFI however, has a bit of a problem. The `EFI_SIMPLE_TEXT_INPUT_PROTOCOL`
only provides support for reading 1 key press. This means that you
either get an error, or it is assumed that the keypress was read
successfully. So there is no way to have a successful read of length 0.
Currently, I am returning UNSUPPORTED error when trying to read from
NULL stdin. On linux however, you will get a read of length 0 for Null
stdin.
One possible way to get around this is to translate one of the UEFI
errors to a read 0 (Maybe unsupported?). It is also possible to have a
non-standard error code, but well, not sure if we go that route.
Alternatively, if meaning of Stdio::Null is platform dependent, it
should be fine to keep the current behaviour of returning an error.
Signed-off-by: Ayush Singh <ayush@beagleboard.org>
* Update comments to clarify the usage of zero as an indication for default stack size configuration
* Adjust conditional compilation to reflect the changes in stack size handling for the NuttX platform
This change improves clarity and consistency in stack size configuration across platforms.
Signed-off-by: Huang Qi <huangqi3@xiaomi.com>
Move `select_unpredictable` to the `hint` module
There has been considerable discussion in both the ACP (rust-lang/libs-team#468) and tracking issue (#133962) about whether the `bool::select_unpredictable` method should be in `core::hint` instead.
I believe this is the right move for the following reasons:
- The documentation explicitly says that it is a hint, not a codegen guarantee.
- `bool` doesn't have a corresponding `select` method, and I don't think we should be adding one.
- This shouldn't be something that people reach for with auto-completion unless they specifically understand the interactions with branch prediction. Using conditional moves can easily make code *slower* by preventing the CPU from speculating past the condition due to the data dependency.
- Although currently `core::hint` only contains no-ops, this isn't a hard rule (for example `unreachable_unchecked` is a bit of a gray area). The documentation only status that the module contains "hints to compiler that affects how code should be emitted or optimized". This is consistent with what `select_unpredictable` does.
Use `with_native_path` for Windows
Ideally, each platform should use their own native path type internally. This will, for example, allow passing a UTF-16 string directly to `std::fs::File::open` and therefore avoid the need for allocating a new null-terminated wide string. However, doing that for every function and platform all at once makes for a large PR that is way too prone to breaking. So this just does some of the Windows parts.
As with the previous Unix PR (#138832) this is intended to be merely a refactoring so I've avoided anything that may require more substantial changes.
Fix profiler_builtins build script to handle full path to profiler lib
LLVM_PROFILER_RT_LIB may be set to an absolute path (e.g., in Fedora builds), but `-l` expects a library name, not a path. After #138273, this caused builds to fail with a "could not find native static library" error.
This patch updates the build script to split the path into directory and filename, using `cargo::rustc-link-search` for the directory and `cargo::rustc-link-lib=+verbatim` for the file. This allows profiler_builtins to correctly link the static library even when an absolute path is provided.
update ```miniz_oxide``` to 0.8.8
I would normally let the auto actions handle this but it turns out 0.8.7 can trigger a panic when debug assertions are enabled in a few cases so I feel it's important it gets sorted more quickly. (and I would ideally like to yank that version but was worried that could cause some issues had been pulled in as a dependency by this repo already before I discovered the problem)
As it can only happen when debug assertions are enabled (the overflow results in the intended result so it doesn't cause any issue in release mode) and using the wrapping buffer mode when decompressing it is very unlikely to cause any issues here but I would like to get it sorted just to be safe. ```miniz_oxide``` is used in the standard library (and some tools) via ```backtrace-rs ``` which doesn't use a wrapping buffer, and thus won't trigger this condition. There does however seem like there are some tools that do dependency on ```flate2``` which does use ```miniz_oxide``` decompression using a a wrapping buffer and could in theory trigger it if they are run when compiled with debug assertions enabled.
It's kinda unclear what version what tool uses though as several of them specify older versions of flate2 which depended on ```miniz_oxide``` 0.7.x in cargo.toml, and ```miniz_oxide```, and not all have a cargo.lock and due to an older version of ```backtrace``` being in the root Cargo.lock which still depended on ```miniz_oxide``` 0.7.4, so that version is also pulled in alongside the newer version.
libtest: Pass the test's panic payload as Option instead of Result
Passing a `Result<(), &dyn Any>` to `calc_result` requires awkward code at both call sites to build a fake result, for no real benefit. It's much easier to just pass the payload as `Option<&dyn Any>`.
No functional change.
std: Fix build for NuttX targets
Fix std build for all NuttX targets. It is the single largest set of failures on <https://does-it-build.noratrieb.dev/>. Although, ESP-IDF also requires these same gates, there are other issues for those targets.
This can verified be running `x check library/std --target=` for all NuttX targets.
cc ``@no1wudi``
Use the chaining methods on PartialOrd for slices too
#138135 added these doc-hidden trait methods to improve the tuple codegen. This PR adds more implementations and callers so that the codegen for slice (and array) comparisons also improves.
Rollup of 6 pull requests
Successful merges:
- #139107 (std: make `cmath` functions safe)
- #139607 (Add regression test for #127424)
- #139691 (Document that `opt-dist` requires metrics to be enabled)
- #139707 (Fix comment in bootstrap)
- #139708 (Fix name of field in doc comment)
- #139709 (bootstrap: fix typo in doc string)
r? `@ghost`
`@rustbot` modify labels: rollup
