std: get rid of `sys_common::process`
Move the public `CommandEnvs` into the `process` module (and make it a wrapper type for an internal iterator type) and everything else into `sys::process` as per #117276.
Something went wrong with a force push, so I can't reopen#139020. This is unchanged from that PR, apart from a rebase.
r? ```@thomcc```
Consistent trait bounds for ExtractIf Debug impls
Closes#137654. Refer to that issue for a table of the **4** different impl signatures we previously had in the standard library for Debug impls of various ExtractIf iterator types.
The one we are standardizing on is the one so far only used by `alloc::collections::linked_list::ExtractIf`, which is _no_ `F: Debug` bound, _no_ `F: FnMut` bound, only `T: Debug` bound.
This PR applies the following signature changes:
```diff
/* alloc::collections::btree_map */
pub struct ExtractIf<'a, K, V, F, A = Global>
where
- F: 'a + FnMut(&K, &mut V) -> bool,
Allocator + Clone,
impl Debug for ExtractIf<'a, K, V, F,
+ A,
>
where
K: Debug,
V: Debug,
- F: FnMut(&K, &mut V) -> bool,
+ A: Allocator + Clone,
```
```diff
/* alloc::collections::btree_set */
pub struct ExtractIf<'a, T, F, A = Global>
where
- T: 'a,
- F: 'a + FnMut(&T) -> bool,
Allocator + Clone,
impl Debug for ExtractIf<'a, T, F, A>
where
T: Debug,
- F: FnMut(&T) -> bool,
A: Allocator + Clone,
```
```diff
/* alloc::collections::linked_list */
impl Debug for ExtractIf<'a, T, F,
+ A,
>
where
T: Debug,
+ A: Allocator,
```
```diff
/* alloc::vec */
impl Debug for ExtractIf<'a, T, F, A>
where
T: Debug,
- F: Debug,
A: Allocator,
- A: Debug,
```
```diff
/* std::collections::hash_map */
pub struct ExtractIf<'a, K, V, F>
where
- F: FnMut(&K, &mut V) -> bool,
impl Debug for ExtractIf<'a, K, V, F>
where
+ K: Debug,
+ V: Debug,
- F: FnMut(&K, &mut V) -> bool,
```
```diff
/* std::collections::hash_set */
pub struct ExtractIf<'a, T, F>
where
- F: FnMut(&T) -> bool,
impl Debug for ExtractIf<'a, T, F>
where
+ T: Debug,
- F: FnMut(&T) -> bool,
```
I have made the following changes to bring these types into better alignment with one another.
- Delete `F: Debug` bounds. These are especially problematic because Rust closures do not come with a Debug impl, rendering the impl useless.
- Delete `A: Debug` bounds. Allocator parameters are unstable for now, but in the future this would become an API commitment that we do not debug-print a representation of the allocator when printing an iterator.
- Delete `F: FnMut` bounds. Requires `hashbrown` PR: https://github.com/rust-lang/hashbrown/pull/616. **API commitment:** we commit to not doing RefCell voodoo inside ExtractIf to have some way for its Debug impl (which takes &self) to call a FnMut closure, if this is even possible.
- Add `T: Debug` bounds (or `K`/`V`), even on Debug impls that do not currently make use of them, but might in the future. **Breaking change.** Must backport into Rust 1.87 (current beta) or do a de-stabilization PR in beta to delay those types by one release.
- Render using `debug_struct` + `finish_non_exhaustive`, instead of `debug_tuple`.
- Do not render the _entire_ underlying collection.
- Show a "peek" field indicating the current position of the iterator.
Correct `extract_if` sample equivalent.
Tracking issue: https://github.com/rust-lang/rust/issues/43244
Original PR: #133265
The sample code marked as equivalent in the doc comment isn't currently equivalent. Given the same predicate and range, if your vector were `[1, 2, 3, 3, 3, 3, 3, 3, 4, 5, 6]`, then all of the 3s would be removed. `i` is only incremented when an element is dropped, but `range.end` is unchanged, so the items shift down. I got very confused when reading the docs and trying to square this sample code with the explanation of how the function works.
Fortunately, the real `extract_if()` does not have this problem. I've added an `end` variable to align the behavior. I've also taken the opportunity to simplify the predicate, which now just matches odd numbers, and to pad out the vec of numbers to line up the zero-indexed range with the integers in the vec.
r? the8472
Suggest `retain_mut` over `retain` as `Vec::extract_if` alternative
The docs for `Vec::extract_if` suggest using `Vec::retain` if the user doesn't need the removed item. Given that `extract_if` gives a mutable reference to the evaluated element, `retain_mut` is the most appropriate alternative, not `retain`.
stabilize ptr::swap_nonoverlapping in const
Closes https://github.com/rust-lang/rust/issues/133668
The blocking issue mentioned there is resolved by documentation. We may in the future actually support such code, but that is blocked on https://github.com/rust-lang/const-eval/issues/72 which is non-trivial to implement. Meanwhile, this completes stabilization of all `const fn` in `ptr`. :)
Here's a version of the problematic example to play around with:
https://play.rust-lang.org/?version=nightly&mode=debug&edition=2021&gist=6c390452379fb593e109b8f8ee854d2a
Should be FCP'd with both `@rust-lang/libs-api` and `@rust-lang/lang` since `swap_nonoverlapping` is documented to work as an "untyped" operation but due to the limitation mentioned above, that's not entirely true during const evaluation. I expect this limitation will only be hit in niche corner cases, so the benefits of having this function work most of the time outweigh the downsides of users running into this problem. (Note that unsafe code could already hit this limitation before this PR by doing cursed pointer casts, but having it hidden inside `swap_nonoverlapping` feels a bit different.)
doc(std): fix typo lchown -> lchmod
chown is irrelevant here, as this function does not affect file ownership. chmod is the correct function to reference here.
Use present indicative tense in std::io::pipe() API docs
The inline documentation for all other free functions in the `std::io` module use the phrase "creates a" instead of "create a", except for the currently nightly-only `std::io::pipe()` function. This commit updates the text to align with the predominant wording in the `std::io` module.
I recognize this PR is quite a minuscule nitpick, so feel free to ignore and close if you disagree and/or there are bigger fish to fry. Thanks in advance! 😄
Relates to https://github.com/rust-lang/rust/issues/127154.
Remove `avx512dq` and `avx512vl` implication for `avx512fp16`
According to Intel, `avx512fp16` requires only `avx512bw`, but LLVM also enables `avx512vl` and `avx512dq` when `avx512fp16` is active. This is relic code, and will be fixed in LLVM soon. We should remove this from Rust too asap, especially before the stabilization of AVX512
Related:
- llvm/llvm-project#136209
- #138940
- rust-lang/stdarch#1781
- #111137
``@rustbot`` label O-x86_64 O-x86_32 A-SIMD A-target-feature T-compiler -T-libs
r? ``@Amanieu``
**Update: the LLVM fix has been merged**
cc ``@rust-lang/wg-llvm`` will it be possible to update the rustc llvm version to something after llvm/llvm-project#137450
Avoid redundant WTF-8 checks in `PathBuf`
Eliminate checks for WTF-8 boundaries in `PathBuf::set_extension` and `add_extension`, where joining WTF-8 surrogate halves is impossible. Don't convert the `str` to `OsStr`, because `OsString::push` specializes to skip the joining when given strings.
To assist in this, mark the internal methods `OsString::truncate` and `extend_from_slice` as `unsafe` to communicate their safety invariants better than with module privacy.
Similar to #137777.
cc `@joboet` `@ChrisDenton`
Delegate to inner `vec::IntoIter` from `env::ArgsOs`
Delegate from `std::env::ArgsOs` to the methods of the inner platform-specific iterators, when it would be more efficient than just using the default methods of its own impl. Most platforms use `vec::IntoIter` as the inner type, so prioritize delegating to the methods it provides.
`std::env::Args` is implemented atop `std::env::ArgsOs` and performs UTF-8 validation with a panic for invalid data. This is a visible effect which users certainly rely on, so we can't skip any arguments. Any further iterator methods would skip some elements, so no change is needed for that type.
Add `#[inline]` for any methods which simply wrap the inner iterator.
Clarify `async` block behaviour
Adds some documentation for control flow behaviour pertaining to `return` and `?` within `async` blocks. Fixes (or at least improves) #101444.
r? rust-lang/docs
std: use the address of `errno` to identify threads in `unique_thread_exit`
Getting the address of `errno` should be just as cheap as `pthread_self()` and avoids having to use the expensive `Mutex` logic because it always results in a pointer.
Delegate from `std::env::ArgsOs` to the methods of the inner
platform-specific iterators, when it would be more efficient than just
using the default methods of its own impl. Most platforms use
`vec::IntoIter` as the inner type, so prioritize delegating to the
methods it provides.
`std::env::Args` is implemented atop `std::env::ArgsOs` and performs
UTF-8 validation with a panic for invalid data. This is a visible effect
which users certainly rely on, so we can't skip any arguments. Any
further iterator methods would skip some elements, so no change is
needed for that type.
Add `#[inline]` for any methods which simply wrap the inner iterator.
Clean up "const" situation in format_args!().
This cleans up the "const" situation in the format_args!() expansion/lowering.
Rather than marking the Argument::new_display etc. functions as non-const, this marks the Arguments::new_v1 functions as non-const.
Example expansion/lowering of format_args!() in const:
```rust
// Error: cannot call non-const formatting macro in constant functions
const {
fmt::Arguments::new_v1( // Now the error is produced here.
&["Hello, ", "!\n"],
&[
fmt::Argument::new_display(&world) // The error used to be produced here.
],
)
}
```
std: mention `remove_dir_all` can emit `DirectoryNotEmpty` when concurrently written into
Closes#139958
The current documentation for `std::fs::remove_dir_all` function does not explicitly mention the error types that may be returned in concurrent scenarios. Specifically, when one thread attempts to remove a directory tree while another thread simultaneously writes files to that directory, the function may return an `io::ErrorKind::DirectoryNotEmpty` error, but this behavior is not clearly mentioned in the current documentation.
r? libs
simd_select_bitmask: the 'padding' bits in the mask are just ignored
Fixes https://github.com/rust-lang/rust/issues/137942: we documented simd_select_bitmask to require the 'padding' bits in the mask (the mask can sometimes be longer than the vector; I am referring to these extra bits as 'padding' here) to be zero, mostly because nobody felt like doing the research for what should be done when they are non-zero. However, codegen is already perfectly happy just ignoring them, so in practice they can have any value. Some of the intrinsic wrappers in stdarch have trouble ensuring that they are zero. So let's just adjust the docs and Miri to permit non-zero 'padding' bits.
Cc ````@Amanieu```` ````@workingjubilee````
Fix some grammar errors and hyperlinks in doc for `trait Allocator`
I was reading the allocator docs and noticed some weird sentences and missing hyperlink, so I fixed them and made this small PR.
* "while until either" could also be changed to "for a while until either", but I just deleted "while".
* fixed sentence with incorrect "at" and "has/have".
* linked [*currently allocated*] similar to other methods. All other hyperlinks are fine.
docs: Add example to `Iterator::take` with `by_ref`
If you want to logically split an iterator after `n` items, you might first discover `take`. Before this change, you'd find that `take` consumes the iterator, and you'd probably be stuck. The answer involves `by_ref`, but that's hard to discover, especially since `by_ref` is a bit abstract and `Iterator` has many methods.
After this change, you'd see the example showing `take` along with `by_ref`, which allows you to continue using the rest of the iterator. `by_ref` had a good example involving `take` already, so this change just duplicates that existing example under `take`.
Refactor `diy_float`
The refactor replaces bespoke algorithms with functions already inside the standard library, improving both codegen and readability.
The inline documentation for all other free functions in the `std::io`
module use the phrase "creates a" instead of "create a", except for the
currently nightly-only `std::io::pipe()` function. This commit updates
the text to align with the predominant wording in the `std::io` module.
I recognize this PR is quite a minuscule nitpick, so feel free to ignore
and close if you disagree and/or there are bigger fish to fry. 😄
Eliminate checks for WTF-8 boundaries in `PathBuf::set_extension` and
`add_extension`, where joining WTF-8 surrogate halves is impossible.
Don't convert the `str` to `OsStr`, because `OsString::push` specializes
to skip the joining when given strings.
