Delete architecture-specific memchr code in std::sys
Currently all architecture-specific memchr code is only used in `std::io`. Most of the actual `memchr` capacity exposed to the user through the slice API is instead implemented in `core::slice::memchr`.
Hence this commit deletes `memchr` from `std::sys[_common]` and replace calls to it by calls to `core::slice::memchr` functions. This deletes `(r)memchr` from the list of symbols linked to libc.
The interest of putting architecture specific code back in core is linked to the discussion to be had in #113654
Use volatile access instead of `#[used]` for `on_tls_callback`
The first commit adds a volatile load of `p_thread_callback` when registering a dtor so that the compiler knows if the callback is used or not. I don't believe the added volatile instruction is otherwise significant in the context. In my testing using the volatile load allowed the compiler to correctly reason about whether `on_tls_callback` is used or not, allowing it to be omitted entirely in some cases. Admittedly it usually is used due to `Thread` but that can be avoided (e.g. in DLLs or with custom entry points that avoid the offending APIs). Ideally this would be something the compiler could help a bit more with so we didn't have to use tricks like `#[used]` or volatile. But alas.
I also used this as an opportunity to clean up the `unused` lints which I don't think serve a purpose any more.
The second commit removes the volatile load of `_tls_used` with `#cfg[target_thread_local]` because `#[thread_local]` already implies it. And if it ever didn't then `#[thread_local]` would be broken when there aren't any dtors.
add platform-specific function to get the error number for HermitOS
Extending `std` to get the last error number for HermitOS.
HermitOS is a tier 3 platform and this PR changes only files, wich are related to the tier 3 platform.
Implement unwind safety for Condvar on all platforms
Closes#118009
This commit adds unwind safety consistency to Condvar. Previously, only select platforms implemented unwind safety through auto traits. Known by this committer: On Linux, `Condvar` implemented `UnwindSafe` but on Mac and Windows, it did not. This change changes the implementation from auto to explicit.
In #118009, it was suggested that the platform differences were a bug and that a simple PR could address this. In trying to determine the best information to put in the `#[stable]` attribute, it [was suggested](https://github.com/rust-lang/rust/issues/121690#issuecomment-1968298470) I copy the stability information from the previous unwind safety implementations.
Increase visibility of `join_path` and `split_paths`
Add some crosslinking among `std::env` pages to make it easier to discover `join_paths` and `split_paths`. Also add aliases to help anyone searching for `PATH`.
Closes#118009
This commit adds unwind safety to Condvar. Previously, only select
platforms implemented unwind safety through auto traits. Known by this
committer: Linux was unwind safe, but Mac and Windows are not before
this change.
Extending `std` to get the last error number for HermitOS.
HermitOS is a tier 3 platform and this PR changes only files,
wich are related to the tier 3 platform.
Add a new `wasm32-wasi-preview2` target
This is the initial implementation of the MCP https://github.com/rust-lang/compiler-team/issues/694 creating a new tier 3 target `wasm32-wasi-preview2`. That MCP has been seconded and will most likely be approved in a little over a week from now. For more information on the need for this target, please read the [MCP](https://github.com/rust-lang/compiler-team/issues/694).
There is one aspect of this PR that will become insta-stable once these changes reach a stable compiler:
* A new `target_family` named `wasi` is introduced. This target family incorporates all wasi targets including `wasm32-wasi` and its derivative `wasm32-wasi-preview1-threads`. The difference between `target_family = wasi` and `target_os = wasi` will become much clearer when `wasm32-wasi` is renamed to `wasm32-wasi-preview1` and the `target_os` becomes `wasm32-wasi-preview1`. You can read about this target rename in [this MCP](https://github.com/rust-lang/compiler-team/issues/695) which has also been seconded and will hopefully be officially approved soon.
Additional technical details include:
* Both `std::sys::wasi_preview2` and `std::os::wasi_preview2` have been created and mostly use `#[path]` annotations on their submodules to reach into the existing `wasi` (soon to be `wasi_preview1`) modules. Over time the differences between `wasi_preview1` and `wasi_preview2` will grow and most like all `#[path]` based module aliases will fall away.
* Building `wasi-preview2` relies on a [`wasi-sdk`](https://github.com/WebAssembly/wasi-sdk) in the same way that `wasi-preview1` does (one must include a `wasi-root` path in the `Config.toml` pointing to sysroot included in the wasi-sdk). The target should build against [wasi-sdk v21](https://github.com/WebAssembly/wasi-sdk/releases/tag/wasi-sdk-21) without modifications. However, the wasi-sdk itself is growing [preview2 support](https://github.com/WebAssembly/wasi-sdk/pull/370) so this might shift rapidly. We will be following along quickly to make sure that building the target remains possible as the wasi-sdk changes.
* This requires a [patch to libc](https://github.com/rylev/rust-libc/tree/wasm32-wasi-preview2) that we'll need to land in conjunction with this change. Until that patch lands the target won't actually build.
os::net: expanding TcpStreamExt for Linux with `tcp_deferaccept`.
allows for socket to process only when there is data to process, the option sets a number of seconds until the data is ready.
rename 'try' intrinsic to 'catch_unwind'
The intrinsic has nothing to do with `try` blocks, and corresponds to the stable `catch_unwind` function, so this makes a lot more sense IMO.
Also rename Miri's special function while we are at it, to reflect the level of abstraction it works on: it's an unwinding mechanism, on which Rust implements panics.
Always use WaitOnAddress on Win10+
`WaitOnAddress` and `WakeByAddressSingle` are always available since Windows 8 so they can now be used without needing to delay load. I've also moved the Windows 7 thread parking fallbacks into a separate sub-module.
Fix sgx unit test compilation
Fixes a compilation error:
```
error[E0583]: file not found for module `tests`
--> library/std/src/sys/locks/rwlock/sgx.rs:2:1
|
2 | mod tests;
| ^^^^^^^^^^
|
= help: to create the module `tests`, create file "library/std/src/sys/locks/rwlock/sgx/tests.rs" or "library/std/src/sys/locks/rwlock/sgx/tests/mod.rs"
= note: if there is a `mod tests` elsewhere in the crate already, import it with `use crate::...` instead
For more information about this error, try `rustc --explain E0583`.
error: could not compile `std` (lib test) due to 1 previous error`
```
When running command:
```
`TF_BUILD=True RUST_TEST_THREADS=1 ./x.py test --stage 1 "library/std" tests/assembly tests/run-make --target=x86_64-fortanix-unknown-sgx --no-doc --exclude src/tools/linkchecker --exclude src/tools/rust-demangler --no-fail-fast 2>&1
```
The fix is done by moving a file to the location suggested by the compiler.
The issue was introduced by PR: https://github.com/rust-lang/rust/pull/121177
Implement `MappedMutexGuard`, `MappedRwLockReadGuard`, and `MappedRwLockWriteGuard`.
ACP: https://github.com/rust-lang/libs-team/issues/260
Tracking issue: https://github.com/rust-lang/rust/issues/117108
<details> <summary> (Outdated) </summary>
`MutexState`/`RwLockState` structs
~~Having `sys::(Mutex|RwLock)` and `poison::Flag` as separate fields in the `Mutex`/`RwLock` would require `MappedMutexGuard`/`MappedRwLockWriteGuard` to hold an additional pointer, so I combined the two fields into a `MutexState`/`RwLockState` struct. This should not noticeably affect perf or layout, but requires an additional field projection when accessing the former `.inner` or `.poison` fields (now `.state.inner` and `.state.poison`).~~ If this is not desired, then `MappedMutexGuard`/`MappedRwLockWriteGuard` can instead hold separate pointers to the two fields.
</details>
The doc-comments are mostly copied from the existing `*Guard` doc-comments, with some parts from `lock_api::Mapped*Guard`'s doc-comments.
Unresolved question: Are more tests needed?
Fix incorrect doc of ScopedJoinHandle::is_finished
Fixes the explanation how to use `is_finished` to achieve a non-blocking join. The updated version matches the documentation of the non-scoped JoinHandle::is_finished.
Fixes the explanation how to use is_finished to achieve a non-blocking
join. The updated version matches the documentation of the non-scoped
JoinHandle::is_finished.
Help with common API confusion, like asking for `push` when the data structure really has `append`.
```
error[E0599]: no method named `size` found for struct `Vec<{integer}>` in the current scope
--> $DIR/rustc_confusables_std_cases.rs:17:7
|
LL | x.size();
| ^^^^
|
help: you might have meant to use `len`
|
LL | x.len();
| ~~~
help: there is a method with a similar name
|
LL | x.resize();
| ~~~~~~
```
#59450
