Add note about absolute paths to Path::join
The note already exists on `PathBuf::push`, but I think it is good to have it on `Path::join` as well since it can cause issues if you are not careful with your input.
Fix the stability attributes for `std::os::fd`.
As `@bjorn3` pointed out [here], I used the wrong stability attribute in #98368 when making `std::os::fd` public. I set it to Rust 1.63, which was when io-safety was stabilized, but it should be Rust 1.66, which was when `std::os::fd` was stabilized.
[here]: https://github.com/rust-lang/rust/pull/98368#discussion_r1063721420
As @bjorn3 pointed out [here], I used the wrong stability attribute in #98368
when making `std::os::fd` public. I set it to Rust 1.63, which was when
io-safety was stabilized, but it should be Rust 1.66, which was when
`std::os::fd` was stabilized.
[here]: https://github.com/rust-lang/rust/pull/98368#discussion_r1063721420
Remove various double spaces in the libraries.
I was just pretty bothered by this when reading the source for a function, and was suggested to check if this happened elsewhere.
Stop probing for statx unless necessary
As is the current toy program:
fn main() -> std::io::Result<()> {
use std::fs;
let metadata = fs::metadata("foo.txt")?;
assert!(!metadata.is_dir());
Ok(())
}
... observed under strace will issue:
[snip]
statx(0, NULL, AT_STATX_SYNC_AS_STAT, STATX_ALL, NULL) = -1 EFAULT (Bad address) statx(AT_FDCWD, "foo.txt", AT_STATX_SYNC_AS_STAT, STATX_ALL, {stx_mask=STATX_ALL|STATX_MNT_ID, stx_attributes=0, stx_mode=S_IFREG|0644, stx_size=0, ...}) = 0
While statx is not necessarily always present, checking for it can be delayed to the first error condition. Said condition may very well never happen, in which case the check got avoided altogether.
Note this is still suboptimal as there still will be programs issuing it, but bulk of the problem is removed.
Tested by forbidding the syscall for the binary and observing it correctly falls back to newfstatat.
While here tidy up the commentary, in particular by denoting some problems with the current approach.
[LSDA] Take ttype_index into account when taking unwind action
If `cs_action != 0`, we should check the `ttype_index` field in action record. If `ttype_index == 0`, a clean up action is taken; otherwise catch action is taken.
This can fix unwind failure on AIX which uses LLVM's libunwind by default. IIUC, rust's LSDA is borrowed from c++ and I'm assuming itanium-cxx-abi https://itanium-cxx-abi.github.io/cxx-abi/exceptions.pdf should be followed, so the fix follows what libcxxabi does. See ec48682ce9/libcxxabi/src/cxa_personality.cpp (L152) for use of `ttype_index`.
std tests: use __OsLocalKeyInner from realstd
This is basically the same as https://github.com/rust-lang/rust/pull/100201, but for __OsLocalKeyInner:
Some std tests are failing in Miri on Windows because [this static](a377893da2/library/std/src/sys/windows/thread_local_key.rs (L234-L239)) is getting duplicated, and Miri does not handle that properly -- Miri does not support this magic `.CRT$XLB` linker section, but instead just looks up this particular hard-coded static in the standard library. This PR lets the test suite use the std static instead of having its own copy.
Fixes https://github.com/rust-lang/miri/issues/2754
r? `@thomcc`
As is the current toy program:
fn main() -> std::io::Result<()> {
use std::fs;
let metadata = fs::metadata("foo.txt")?;
assert!(!metadata.is_dir());
Ok(())
}
... observed under strace will issue:
[snip]
statx(0, NULL, AT_STATX_SYNC_AS_STAT, STATX_ALL, NULL) = -1 EFAULT (Bad address)
statx(AT_FDCWD, "foo.txt", AT_STATX_SYNC_AS_STAT, STATX_ALL, {stx_mask=STATX_ALL|STATX_MNT_ID, stx_attributes=0, stx_mode=S_IFREG|0644, stx_size=0, ...}) = 0
While statx is not necessarily always present, checking for it can be
delayed to the first error condition. Said condition may very well never
happen, in which case the check got avoided altogether.
Note this is still suboptimal as there still will be programs issuing
it, but bulk of the problem is removed.
Tested by forbidding the syscall for the binary and observing it
correctly falls back to newfstatat.
While here tidy up the commentary, in particular by denoting some
problems with the current approach.
Update `rand` in the stdlib tests, and remove the `getrandom` feature from it.
The main goal is actually removing `getrandom`, so that eventually we can allow running the stdlib test suite on tier3 targets which don't have `getrandom` support. Currently those targets can only run the subset of stdlib tests that exist in uitests, and (generally speaking), we prefer not to test libstd functionality in uitests, which came up recently in https://github.com/rust-lang/rust/pull/104095 and https://github.com/rust-lang/rust/pull/104185. Additionally, the fact that we can't update `rand`/`getrandom` means we're stuck with the old set of tier3 targets, so can't test new ones.
~~Anyway, I haven't checked that this actually does allow use on tier3 targets (I think it does not, as some work is needed in stdlib submodules) but it moves us slightly closer to this, and seems to allow at least finally updating our `rand` dep, which definitely improves the status quo.~~ Checked and works now.
For the most part, our tests and benchmarks are fine using hard-coded seeds. A couple tests seem to fail with this (stuff manipulating the environment expecting no collisions, for example), or become pointless (all inputs to a function become equivalent). In these cases I've done a (gross) dance (ab)using `RandomState` and `Location::caller()` for some extra "entropy".
Trying to share that code seems *way* more painful than it's worth given that the duplication is a 7-line function, even if the lines are quite gross. (Keeping in mind that sharing it would require adding `rand` as a non-dev dep to std, and exposing a type from it publicly, all of which sounds truly awful, even if done behind a perma-unstable feature).
See also some previous attempts:
- https://github.com/rust-lang/rust/pull/86963 (in particular https://github.com/rust-lang/rust/pull/86963#issuecomment-885438936 which explains why this is non-trivial)
- https://github.com/rust-lang/rust/pull/89131
- https://github.com/rust-lang/rust/pull/96626#issuecomment-1114562857 (I tried in that PR at the same time, but settled for just removing the usage of `thread_rng()` from the benchmarks, since that was the main goal).
- https://github.com/rust-lang/rust/pull/104185
- Probably more. It's very tempting of a thing to "just update".
r? `@Mark-Simulacrum`
default OOM handler: use non-unwinding panic, to match std handler
The OOM handler in std will by default abort. This adjusts the default in liballoc to do the same, using the `can_unwind` flag on the panic info to indicate a non-unwinding panic.
In practice this probably makes little difference since the liballoc default will only come into play in no-std situations where people write a custom panic handler, which most likely will not implement unwinding. But still, this seems more consistent.
Cc `@rust-lang/wg-allocators,` https://github.com/rust-lang/rust/issues/66741
Add notes and examples about non-intuitive `PathBuf::set_extension` behavior
Basically, passing the empty string will actually remove the extension instead of setting it to the empty string. This might change what is considered to be an extension. Additionally, passing an extension that contains dots will make the path only consider the last part of it to be the new extension.
Unify id-based thread parking implementations
Multiple platforms currently use thread-id-based parking implementations (NetBSD and SGX[^1]). Even though the strategy does not differ, these are duplicated for each platform, as the id is encoded into an atomic thread variable in different ways for each platform.
Since `park` is only called by one thread, it is possible to move the thread id into a separate field. By ensuring that the field is only written to once, before any other threads access it, these accesses can be unsynchronized, removing any restrictions on the size and niches of the thread id.
This PR also renames the internal `thread_parker` modules to `thread_parking`, as that name now better reflects their contents. I hope this does not add too much reviewing noise.
r? `@m-ou-se`
`@rustbot` label +T-libs
[^1]: SOLID supports this as well, I will switch it over in a follow-up PR.
