Always check the result of `pthread_mutex_lock`
Fixes#120147.
Instead of manually adding a list of "good" platforms, I've simply made the check unconditional. pthread's mutex is already quite slow on most platforms, so one single well-predictable branch shouldn't hurt performance too much.
Currently, when building with `build-std`, some library build scripts
check properties of the target by inspecting the target triple at
`env::TARGET`, which is simply set to the filename of the JSON file
when using JSON target files.
This patch alters these build scripts to use `env::CARGO_CFG_*` to
fetch target information instead, allowing JSON target files
describing platforms without `restricted_std` to build correctly when
using `-Z build-std`.
Fixes wg-cargo-std-aware/#60.
fix#120603 by adding a check in default_read_buf
Fixes#120603 by checking the returned read n is in-bounds of the cursor.
Interestingly, I noticed that `BorrowedBuf` side-steps this issue by using checked accesses. Maybe this can be switched to unchecked to mirror what BufReader does bf3c6c5bed/library/core/src/io/borrowed_buf.rs (L95)
Store SHOULD_CAPTURE as AtomicU8
`BacktraceStyle` easily fits into a u8, so `SHOULD_CAPTURE`, which is just `Atomic<Option<BacktraceStyle>>`, should be stored as `AtomicU8`
std: thread_local::register_dtor fix proposal for FreeBSD.
following-up 5d3d347 commit, rust started to spin
__cxa_thread_call_dtors warnings even without any TLS usage. using instead home made TLS destructor handler `register_dtor_fallback`.
close#120413
Revert outdated version of "Add the wasm32-wasi-preview2 target"
An outdated version of #119616 was merged in rollup #120309.
This reverts those changes to enable #119616 to “retain the intended diff” after a rebase.
```@rylev``` has agreed that this would be the cleanest approach with respect to the history.
Unblocks #119616.
r? ```@petrochenkov``` or compiler or libs
std: Update documentation of seek_write on Windows
Currently the documentation of `FileExt::seek_write` on Windows indicates that writes beyond the end of the file leave intermediate bytes uninitialized. This commentary dates back to the original inclusion of these functions in #35704 (wow blast from the past!). At the time the functionality here was implemented using `WriteFile`, but nowadays the `NtWriteFile` method is used instead. The documentation for `NtWriteFile` explicitly states:
> If Length and ByteOffset specify a write operation past the current
> end-of-file mark, NtWriteFile automatically extends the file and updates
> the end-of-file mark; any bytes that are not explicitly written between
> such old and new end-of-file marks are defined to be zero.
This commentary has had a downstream impact in the `system-interface` crate where it tries to handle this by explicitly writing zeros, but I don't believe that's necessary any more. I'm sending a PR upstream here to avoid future confusion and codify that zeros are written in the intermediate bytes matching what Windows currently provides.
Handle out of memory errors in io:Read::read_to_end()
#116570 got stuck due to a [procedural confusion](https://github.com/rust-lang/rust/pull/116570#issuecomment-1768271068). Retrying so that it can get FCP with the proper team now. cc `@joshtriplett` `@BurntSushi`
----
I'd like to propose handling of out-of-memory errors in the default implementation of `io::Read::read_to_end()` and `fs::read()`. These methods create/grow a `Vec` with a size that is external to the program, and could be arbitrarily large.
Due to being I/O methods, they can already fail in a variety of ways, in theory even including `ENOMEM` from the OS too, so another failure case should not surprise anyone.
While this may not help much Linux with overcommit, it's useful for other platforms like WASM. [Internals thread](https://internals.rust-lang.org/t/io-read-read-to-end-should-handle-oom/19662).
I've added documentation that makes it explicit that the OOM handling is a nice-to-have, and not a guarantee of the trait.
I haven't changed the implementation of `impl Read for &[u8]` and `VecDeque` out of caution, because in these cases users could assume `read` can't fail.
This code uses `try_reserve()` + `extend_from_slice()` which is optimized since #117503.
