stabilize const_swap
libs-api FCP passed in https://github.com/rust-lang/rust/issues/83163.
However, I only just realized that this actually involves an intrinsic. The intrinsic could be implemented entirely with existing stable const functionality, but we choose to make it a primitive to be able to detect more UB. So nominating for `@rust-lang/lang` to make sure they are aware; I leave it up to them whether they want to FCP this.
While at it I also renamed the intrinsic to make the "nonoverlapping" constraint more clear.
Fixes#83163
Unify fs::copy and io::copy on Linux
Currently, `fs::copy` first tries a regular file copy (via copy_file_range) and then falls back to userspace read/write copying. We should use `io::copy` instead as it tries copy_file_range, sendfile, and splice before falling back to userspace copying. This was discovered here: https://github.com/SUPERCILEX/fuc/issues/40
Perf impact: `fs::copy` will now have two additional statx calls to decide which syscall to use. I wonder if we should get rid of the statx calls and only continue down the next fallback when the relevant syscalls say the FD isn't supported.
Add a compiler intrinsic to back `bigint_helper_methods`
cc https://github.com/rust-lang/rust/issues/85532
This adds a new `carrying_mul_add` intrinsic, to implement `wide_mul` and `carrying_mul`.
It has fallback MIR for all types -- including `u128`, which isn't currently supported on nightly -- so that it'll continue to work on all backends, including CTFE.
Then it's overridden in `cg_llvm` to use wider intermediate types, including `i256` for `u128::carrying_mul`.
Rollup of 8 pull requests
Successful merges:
- #134606 (ptr::copy: fix docs for the overlapping case)
- #134622 (Windows: Use WriteFile to write to a UTF-8 console)
- #134759 (compiletest: Remove the `-test` suffix from normalize directives)
- #134787 (Spruce up the docs of several queries related to the type/trait system and const eval)
- #134806 (rustdoc: use shorter paths as preferred canonical paths)
- #134815 (Sort triples by name in platform_support.md)
- #134816 (tools: fix build failure caused by PR #134420)
- #134819 (Fix mistake in windows file open)
r? `@ghost`
`@rustbot` modify labels: rollup
Windows: Use WriteFile to write to a UTF-8 console
If the console code page is UTF-8 then we can simply write to it without needing to convert to UTF-16 and calling `WriteConsole`.
ptr::copy: fix docs for the overlapping case
Fixes https://github.com/rust-lang/unsafe-code-guidelines/issues/549
As discussed in that issue, it doesn't make any sense for `copy` to read a byte via `src` after it was already written via `dst`. The entire point of this method is that is copies correctly even if they overlap, and that requires always reading any given location before writing it.
Cc `@rust-lang/opsem`
Fix renaming symlinks on Windows
Previously we only detected mount points and not other types of links when determining reparse point behaviour.
Also added some tests to avoid this regressing again in the future.
docs: inline `std::ffi::c_str` types to `std::ffi`
Rustdoc has no way to show that an item is stable, but only at a different path. `std::ffi::c_str::NulError` is not stable, but `std::ffi::NulError` is.
To avoid marking these types as unstable when someone just wants to follow a link from `CString`, inline them into their stable paths.
Fixes#134702
r? `@tgross35`
unwinding: bump version to fix naked_asm on Xous
With #80608 the `unwinding` crate no longer builds. The upstream crate has been updated to build by manually adding directives to the naked_asm stream.
Bump the dependency in Rust to get this newer version. This fixes the build for Xous, and closes#134403.
Update Code Example for `Iterator::rposition`
Added an additional assertion to the example to show the behavior of `iter.next_back` after using `iter.rposition`.
Fix forgetting to save statx availability on success
Looks like we forgot to save the statx state on success which means the first failure (common when checking if a file exists) will always require spending an invalid statx to confirm the failure is real.
r? `@thomcc`
Document collection `From` and `FromIterator` impls that drop duplicate keys.
This behavior is worth documenting because there are other plausible alternatives, such as panicking when a duplicate is encountered, and it reminds the programmer to consider whether they should, for example, coalesce duplicate keys first.
Followup to #89869.
Add `into_array` conversion destructors for `Box`, `Rc`, and `Arc`.
Tracking issue: #133508
This PR adds the `into_array` destructor for `alloc::boxed::Box<[T]>`, `alloc::rc::Rc<[T]>`, and `alloc::sync::Arc<[T]>`.
Note that this PR assumes the initial proposal of these functions returning `Option`. It is still an open question whether this should instead be `Result`. We can, however, easily change this in a follow-up PR with the necessary consensus.
Rustdoc has no way to show that an item is stable,
but only at a different path. `std::ffi::c_str::NulError` is
not stable, but `std::ffi::NulError` is.
To avoid marking these types as unstable when someone just
wants to follow a link from `CString`, inline them into their
stable paths.
With #80608 the `unwinding` crate no longer builds. The upstream crate
has been updated to build by manually adding directives to the naked_asm
stream.
Bump the dependency in Rust to get this newer version. This fixes the
build for Xous, and closes#134403.
Signed-off-by: Sean Cross <sean@xobs.io>
Windows: Use FILE_ALLOCATION_INFO for truncation
We use `FILE_END_OF_FILE_INFO` here only because WINE does not support `FILE_ALLOCATION_INFO`. Instead of going with the one with broadest support, let's just use that as fallback only.
core: fix const ptr::swap_nonoverlapping when there are pointers at odd offsets
Ensure that the pointer gets swapped correctly even if it is not stored at an aligned offset. This rules out implementations that copy things in a `usize` loop -- so our implementation needs to be adjusted to avoid such a loop when running in const context.
Part of https://github.com/rust-lang/rust/issues/133668
Fix safety docs for `dyn Any + Send {+ Sync}`
Fixes the `# Safety` docs for `dyn Any + Send`'s `downcast_{mut/ref}_unchecked` to show the direct instructions , where previously the would tell the user to find the docs on `dyn Any` themselves.
This also adds them for `downcast_{mut/ref}_unchecked` on `dyn Any + Send + Sync`
