This PR makes a number of changes to the UNIX randomness implementation:
* Use `io::Error` for centralized error handling
* Move the file-fallback logic out of the `getrandom`-specific module
* Stop redefining the syscalls on macOS and DragonFly, they have appeared in `libc`
* Add a `OnceLock` to cache the random device file descriptor
chore: refactor backtrace style in panic
# Refactor get_backtrace_style for better readability and potential performance improvements
This PR aims to improve the readability and maintainability of the `set_backtrace_style` and `get_backtrace_style` function.
Revert recent changes to dead code analysis
This is a revert to recent changes to dead code analysis, namely:
* efdf219 Rollup merge of #128104 - mu001999-contrib:fix/128053, r=petrochenkov
* a70dc297a8 Rollup merge of #127017 - mu001999-contrib:dead/enhance, r=pnkfelix
* 31fe9628cf Rollup merge of #127107 - mu001999-contrib:dead/enhance-2, r=pnkfelix
* 2724aeaaeb Rollup merge of #126618 - mu001999-contrib:dead/enhance, r=pnkfelix
* 977c5fd419 Rollup merge of #126315 - mu001999-contrib:fix/126289, r=petrochenkov
* 13314df21b Rollup merge of #125572 - mu001999-contrib:dead/enhance, r=pnkfelix
There is an additional change stacked on top, which suppresses false-negatives that were masked by this work. I believe the functions that are touched in that code are legitimately unused functions and the types are not reachable since this `AnonPipe` type is not publically reachable -- please correct me if I'm wrong cc `@NobodyXu` who added these in ##127153.
Some of these reverts (#126315 and #126618) are only included because it makes the revert apply cleanly, and I think these changes were only done to fix follow-ups from the other PRs?
I apologize for the size of the PR and the churn that it has on the codebase (and for reverting `@mu001999's` work here), but I'm putting this PR up because I am concerned that we're making ad-hoc changes to fix bugs that are fallout of these PRs, and I'd like to see these changes reimplemented in a way that's more separable from the existing dead code pass. I am happy to review any code to reapply these changes in a more separable way.
cc `@mu001999`
r? `@pnkfelix`
Fixes#128272Fixes#126169
Add `#[must_use]` to some `into_raw*` functions.
cc #121287
r? ``@cuviper``
Adds `#[must_use = "losing the pointer will leak memory"]`[^1] to `Box::into_raw(_with_allocator)`, `Vec::into_raw_parts(_with_alloc)`, `String::into_raw_parts`[^2], and `rc::{Rc, Weak}::into_raw_with_allocator` (Rc's normal `into_raw` and all of `Arc`'s `into_raw*`s are already `must_use`).
Adds `#[must_use = "losing the raw <resource name may leak resources"]` to `IntoRawFd::into_raw_fd`, `IntoRawSocket::into_raw_socket`, and `IntoRawHandle::into_raw_handle`.
[^1]: "*will* leak memory" may be too-strong wording (since `Box`/`Vec`/`String`/`rc::Weak` might not have a backing allocation), but I left it as-is for simplicity and consistency.
[^2]: `String::into_raw_parts`'s `must_use` message is changed from the previous (possibly misleading) "`self` will be dropped if the result is not used".
`min`, `max`, and similar functions require external math routines. Add
these under the same gates as `std` math functions (`reliable_f16_math`
and `reliable_f128_math`).
This adds missing functions for math operations on the new float types.
Platform support is pretty spotty at this point, since even platforms
with generally good support can be missing math functions.
`std/build.rs` is updated to reflect this.
android: Remove libstd hacks for unsupported Android APIs
Our minimum supported API version is 21, remove hacks to support older Android APIs.
try-job: arm-android
r? tgross35
Rollup of 7 pull requests
Successful merges:
- #123813 (Add `REDUNDANT_IMPORTS` lint for new redundant import detection)
- #126697 ([RFC] mbe: consider the `_` in 2024 an expression)
- #127159 (match lowering: Hide `Candidate` from outside the lowering algorithm)
- #128244 (Peel off explicit (or implicit) deref before suggesting clone on move error in borrowck, remove some hacks)
- #128431 (Add myself as VxWorks target maintainer for reference)
- #128438 (Add special-case for [T, 0] in dropck_outlives)
- #128457 (Fix docs for OnceLock::get_mut_or_init)
r? `@ghost`
`@rustbot` modify labels: rollup
Cleanup sys module to match house style
This moves a test file out of sys as it's just testing std types. Also cleans up some assorted bits including making the `use` statements match the house style.
std: implement the `once_wait` feature
Tracking issue: #127527
This additionally adds a `wait_force` method to `Once` that doesn't panic on poison.
I also took the opportunity and cleaned up up the code of the queue-based implementation a bit.
Clean and enable `rustdoc::unescaped_backticks` for `core/alloc/std/test/proc_macro`
I am not sure if the lint is supposed to be "ready enough" (since it is `allow` by default), but it does catch a couple issues in `core` (`alloc`, `std`, `test` and `proc_macro` are already clean), so I propose making it `warn` in all the crates rendered in the website.
Cc: `@GuillaumeGomez`
std: unsafe-wrap personality::dwarf::eh
Moves the forbiddance up a little. This is another largely whitespace diff, except for hoisting some variable declarations to allow enclosing the `unsafe {}` scope fully and make it clearer where the bounds of some temporaries are.
Replace `io::Cursor::{remaining_slice, is_empty}`
This is a late follow up to the concerns raised in https://github.com/rust-lang/rust/issues/86369.
https://github.com/rust-lang/rust/issues/86369#issuecomment-953096691
> This API seems focussed on the `Read` side of things. When `Seek`ing around and `Write`ing data, `is_empty` becomes confusing and `remaining_slice` is not very useful. When writing, the part of the slice before the cursor is much more interesting. Maybe we should have functions for both? Or a single function that returns both slices? (If we also have a `mut` version, a single function would be useful to allow mutable access to both sides at once.)
New feature name: `cursor_remaining` > `cursor_split`.
Added functions:
```rust
fn split(&self) -> (&[u8], &[u8]);
// fn before(&self) -> &[u8];
// fn after(&self) -> &[u8];
fn split_mut(&mut self) -> (&mut [u8], &mut [u8]);
// fn before_mut(&mut self) -> &mut [u8];
// fn after_mut(&mut self) -> &mut [u8];
```
A question was raised in https://github.com/rust-lang/rust/issues/86369#issuecomment-927124211 about whether to return a lifetime that would reflect the lifetime of the underlying bytes (`impl Cursor<&'a [u8]> { fn after(&self) -> &'a [u8] }`). The downside of doing this would be that it would not be possible to implement these functions generically over `T: AsRef<[u8]>`.
## Update
Based on the review, before* and after* methods where removed.
Stabilize `const_waker`
Closes: https://github.com/rust-lang/rust/issues/102012.
For `local_waker` and `context_ext` related things, I just ~~moved them to dedicated feature gates and reused their own tracking issue (maybe it's better to open a new one later, but at least they should not be tracked under https://github.com/rust-lang/rust/issues/102012 from the beginning IMO.)~~ reused their own feature gates as suggested by ``@tgross35.``
``@rustbot`` label: +T-libs-api
r? libs-api
Fix doc nits
Many tiny changes to stdlib doc comments to make them consistent (for example "Returns foo", rather than "Return foo"), adding missing periods, paragraph breaks, backticks for monospace style, and other minor nits.
Both these platforms have MSG_NOSIGNAL available, and we should set it for
socket writes in the event that the SIGPIPE handler has been reset to SIG_DFL
(i.e. terminate the process).
I've verified via a quick program at
https://github.com/sunshowers/msg-nosignal-test/ that even when the SIGPIPE
handler is reset to SIG_DFL, writes to closed sockets now error out with EPIPE.
(Under ordinary circumstances UDP writes won't cause MSG_NOSIGNAL.)
Use `#[rustfmt::skip]` on some `use` groups to prevent reordering.
`use` declarations will be reformatted in #125443. Very rarely, there is a desire to force a group of `use` declarations together in a way that auto-formatting will break up. E.g. when you want a single comment to apply to a group. #126776 dealt with all of these in the codebase, ensuring that no comments intended for multiple `use` declarations would end up in the wrong place. But some people were unhappy with it.
This commit uses `#[rustfmt::skip]` to create these custom `use` groups in an idiomatic way for a few of the cases changed in #126776. This works because rustfmt treats any `use` item annotated with `#[rustfmt::skip]` as a barrier and won't reorder other `use` items around it.
r? `@cuviper`
Rollup of 6 pull requests
Successful merges:
- #126908 (Use Cow<'static, str> for InlineAsmTemplatePiece::String)
- #127999 (Inject arm32 shims into Windows metadata generation)
- #128137 (CStr: derive PartialEq, Eq; add test for Ord)
- #128185 (Fix a span error when parsing a wrong param of function.)
- #128187 (Fix 1.80.0 version in RELEASES.md)
- #128189 (Turn an unreachable code path into an ICE)
r? `@ghost`
`@rustbot` modify labels: rollup
Inject arm32 shims into Windows metadata generation
I had been keen to eventually move to using windows-sys as a normal Cargo dependency. But for linking, compile times and other reasons that's unlikely to ever happen.
So if we're sticking with generated bindings then injecting any necessary missing type definitions (i.e. for the MS unsupported arm32) is simpler than defining whole functions ourselves just because we need to manually implement those types on a tier 3 platform. This also reduces the places we need to change when making changes to how we use `#[link]`.
r? libs
std: unsafe-wrap personality::gcc
Nothing seems obviously wrong with these implementations except for some unanswered questions. Admittedly, I don't want to burn excessive time on exceptional exception handlers. Thus this is mostly a brute-force syntactic wrapping and some comments where they seemed correct, creating another largely whitespace diff.
try-job: armhf-gnu
Fix connect timeout for non-linux targets, read readiness of socket connection, Read readiness to detect errors. `Fixes #127018`
Fixes#127018
Connect_timeout would call `poll` and check `pollfd.revents` for POLLHUP error, rather that checking readiness. This behavior was meant for Linux as it returns POLLHUP | POLLOUT | POLLERR in case of errors. But on targets that do not return POLLHUP in `pollfd.revents`, this would indicate a false success and result in this issue. To resolve this we will check readiness of socket using `getsockopt():` and return success from connect_timeout when there are no errors.
Changes were tested on Linux and an rtos.

Thank you.
Import `c_void` rather than using the full path
Follow up to #128092. As requested, this imports `c_void` in more places. I also fixed up some imports to use `core` for core types instead of `crate`. While that is not strictly necessary, I think ideally things in `sys/pal` should only depend on itself or core so that the code is less spaghetti. We're far away from that ideal at the moment but I can at least try to slowly move in that direction.
Also this forbids `unsafe_op_in_unsafe_fn` for library/std/src/sys/pal/windows by fixing up the remaining unsafe bits that are just punting their unsafe requirements onto the caller of the `unsafe` function (or definition macro).
<!--
r? workingjubilee
-->
Replace some `mem::forget`'s with `ManuallyDrop`
> but I would like to see a larger effort to replace all uses of `mem::forget`.
_Originally posted by `@saethlin` in https://github.com/rust-lang/rust/issues/127584#issuecomment-2226087767_
So,
r? `@saethlin`
Sorry, I have finished writing all of this before I got your response.
Fix build failure on vxworks #127084
PR to address issue #127084 .
1. Skip `reset_segpipe` for vxworks
2. Return unimplemented error for vxworks from settimes and lchown
3. Temporarily skip dirfd for vxworks
4. Add allow unused unsafe on read_at and write_at functions in unix/fs.rs
5. Using cfg disable ON_BROKEN_PIPE_FLAG_USED and on_broken_pipe_flag_used() for vxworks
6. Remove old crate::syscommon:🧵:min_stack() reference from process_vxworks.rs and update to set stack size of rtpthread
Thank you.
Fix return type of FileAttr methods on AIX target
At some point it seems `SystemTime::new` changed from returning `SystemTime` to `io::Result<SystemTime>`. This seems to have been addressed on other platforms, but was never changed for AIX.
This was caught by running
```
python3 x.py build --host x86_64-unknown-linux-gnu --target powerpc64-ibm-aix
```
Remove wrapper functions from c.rs
I'd like for the windows `c.rs` just to contain the basic platform definitions and not anything higher level unless absolutely necessary. So this removes some wrapper functions that weren't really necessary in any case. The functions are only used in a few places which themselves are relatively thin wrappers. The "interesting" bit is that we had an `AlertableIoFn` that abstracted over `ReadFileEx` and `WriteFileEx`. I've replaced this with a closure.
Also I removed an `#[allow(unsafe_op_in_unsafe_fn)]` while I was moving things around.
At some point it seems `SystemTime::new` changed from returning `SystemTime` to `io::Result<SystemTime>`. This seems to have been addressed on other platforms, but was never changed for AIX.
This was caught by running
```
python3 x.py build --host x86_64-unknown-linux-gnu --target powerpc64-ibm-aix
```
Clean up warnings + `unsafe_op_in_unsafe_fn` when building std for armv6k-nintendo-3ds
See #127747
ping `@AzureMarker` `@Meziu`
I could only find one instance needing an extra `unsafe` that was not also shared with many other `unix` targets (presumably these will get covered in larger sweeping changes, I didn't want to introduce churn that would potentially conflict with those). The one codepath I found is shared with `vita` however, so also pinging `@nikarh` `@pheki` `@zetanumbers` just to make sure they're aware of this change.
Also removed one unused import from `process_unsupported` which should simply fix the warning for any target that uses it.
Deal with invalid UTF-8 from `gai_strerror`
When the system is using a non-UTF-8 locale, the value will indeed not be UTF-8. That sucks for everyone involved, but is no reason for panic. We can "handle" this gracefully by just using from lossy, replacing the invalid UTF-8 with � and keeping the accidentally valid UTF-8. Good luck when debugging, but at least it's not a crash.
We already do this for `strerror_r`.
fixes#127563
When the system is using a non-UTF-8 locale, the value will indeed not
be UTF-8. That sucks for everyone involved, but is no reason for panic.
We can "handle" this gracefully by just using from lossy, replacing the
invalid UTF-8 with the ? and keeping the accidentally valid UTF-8.
Good luck when debugging, but at least it's not a crash.
We already do this for `strerror_r`.