Limit read size in `File::read_to_end` loop
Fixes#110650.
Windows file reads have perf overhead that's proportional to the buffer size. When we have a reasonable expectation that we know the file size, we can set a reasonable upper bound for the size of the buffer in one read call.
Add `tidy-alphabetical` to features in `alloc` & `std`
So that people have to keep them sorted in future, rather than just sticking them on the end where they conflict more often.
Follow-up to #110269
cc `@jyn514`
Stabilize `nonnull_slice_from_raw_parts`
FCP is done: https://github.com/rust-lang/rust/issues/71941#issuecomment-1100910416
Note that this doesn't const-stabilize `NonNull::slice_from_raw_parts` as `slice_from_raw_parts_mut` isn't const-stabilized yet. Given #67456 and #57349, it's not likely available soon, meanwhile, stabilizing only the feature makes some sense, I think.
Closes#71941
Stabilize `atomic_as_ptr`
Fixes#66893
This stabilizes the `as_ptr` methods for atomics. The stabilization feature gate used here is `atomic_as_ptr` which supersedes `atomic_mut_ptr` to match the change in https://github.com/rust-lang/rust/pull/107736.
This needs FCP.
New stable API:
```rust
impl AtomicBool {
pub const fn as_ptr(&self) -> *mut bool;
}
impl AtomicI32 {
pub const fn as_ptr(&self) -> *mut i32;
}
// Includes all other atomic types
impl<T> AtomicPtr<T> {
pub const fn as_ptr(&self) -> *mut *mut T;
}
```
r? libs-api
``@rustbot`` label +needs-fcp
Add `round_ties_even` to `f32` and `f64`
Tracking issue: #96710
Redux of #82273. See also #55107
Adds a new method, `round_ties_even`, to `f32` and `f64`, that rounds the float to the nearest integer , rounding halfway cases to the number with an even least significant bit. Uses the `roundeven` LLVM intrinsic to do this.
Of the five IEEE 754 rounding modes, this is the only one that doesn't already have a round-to-integer function exposed by Rust (others are `round`, `floor`, `ceil`, and `trunc`). Ties-to-even is also the rounding mode used for int-to-float and float-to-float `as` casts, as well as float arithmentic operations. So not having an explicit rounding method for it seems like an oversight.
Bikeshed: this PR currently uses `round_ties_even` for the name of the method. But maybe `round_ties_to_even` is better, or `round_even`, or `round_to_even`?
[stdio][windows] Use MBTWC and WCTMB
`MultiByteToWideChar` and `WideCharToMultiByte` are extremely well optimized, and therefore should probably be used when we know we can (specifically in the Windows stdio stuff).
Fixes#107092
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`
The UNIX and WASI implementations use `isatty`. The Windows
implementation uses the same logic the `atty` crate uses, including the
hack needed to detect msys terminals.
Implement this trait for `File` and for `Stdin`/`Stdout`/`Stderr` and
their locked counterparts on all platforms. On UNIX and WASI, implement
it for `BorrowedFd`/`OwnedFd`. On Windows, implement it for
`BorrowedHandle`/`OwnedHandle`.
Based on https://github.com/rust-lang/rust/pull/91121
Co-authored-by: Matt Wilkinson <mattwilki17@gmail.com>
PR #98165 with commits 7c360dc117 and c1a2db3372
has moved all of the components of these modules into different places,
namely {std,core}::sync and {std,core}::cell. The empty
modules remained. As they are unstable, we can simply remove them.
Stabilize bench_black_box
This PR stabilize `feature(bench_black_box)`.
```rust
pub fn black_box<T>(dummy: T) -> T;
```
The FCP was completed in https://github.com/rust-lang/rust/issues/64102.
`@rustbot` label +T-libs-api -T-libs
Stabilize `#![feature(mixed_integer_ops)]`
Tracked and FCP completed in #87840.
````@rustbot```` label +T-libs-api +S-waiting-on-review +relnotes
r? rust-lang/t-libs-api
Make `from_waker`, `waker` and `from_raw` unstably `const`
Make
- `Context::from_waker`
- `Context::waker`
- `Waker::from_raw`
`const`.
Also added a small test.
On later stages, the feature is already stable.
Result of running:
rg -l "feature.let_else" compiler/ src/librustdoc/ library/ | xargs sed -s -i "s#\\[feature.let_else#\\[cfg_attr\\(bootstrap, feature\\(let_else\\)#"
