single buffer for exponent fmt of integers
No need for fragmented buffers when formatting.
```
orig.txt: fmt::write_i128_exp 143.39ns/iter +/- 0.32
orig.txt: fmt::write_i64_exp 68.72ns/iter +/- 0.03
new.txt: fmt::write_i128_exp 138.29ns/iter +/- 0.50
new.txt: fmt::write_i64_exp 58.93ns/iter +/- 4.62
```
This patch fully eliminates unsafe pointer use (after rust-lang/rust#135265 and rust-lang/rust#136594).
r? libs
std: Update `wasi` crate dependency
The recent work on the WASIp2 target being integrated into the standard library (rust-lang/rust#146207, rust-lang/rust#145944) ended up causing a bug in nightly on the target. This [has now been fixed](https://github.com/bytecodealliance/wasi-rs/pull/115) in the `wasi` crate so this commit pulls in the updated version to ensure bindings work correctly.
The recent work on the WASIp2 target being integrated into the standard
library ended up causing a bug in nightly on the target. This has now
been fixed in the `wasi` crate so this commit pulls in the updated
version to ensure bindings work correctly.
Simplify `{f16, f32, f64, f128}::midpoint()`
`(float_ty::MAX / 2) - (float_ty::MIN_POSITIVE * 2)` equals `(float_ty::MAX / 2) + (float_ty::MIN_POSITIVE * 2)` equals `(float_ty::MAX / 2)`. So these branches are pointless.
CC `@Urgau` who wrote the original implementation in https://github.com/rust-lang/rust/pull/92048; does this seem right?
`@rustbot` label A-floating-point
Add `__isPlatformVersionAtLeast` and `__isOSVersionAtLeast` symbols
## Motivation
When Objective-C code uses ```@available(...)`,`` Clang inserts a call to [`__isPlatformVersionAtLeast`](https://github.com/llvm/llvm-project/blob/llvmorg-20.1.0/compiler-rt/lib/builtins/os_version_check.c#L276) (`__isOSVersionAtLeast` in older Clang versions). These symbols not being available sometimes ends up causing linker errors. See the new test `tests/run-make/apple-c-available-links` for a minimal reproducer.
The workaround is to link `libclang_rt.osx.a`, see e.g. https://github.com/alexcrichton/curl-rust/issues/279. But that's very difficult for users to figure out (and the backreferences to that issue indicates that people are still running into this in their own projects every so often).
For another recent example, this is preventing `rustc` from using LLVM assertions on macOS, see https://github.com/rust-lang/rust/pull/62592#issuecomment-510670657 and https://github.com/rust-lang/rust/pull/134275#issuecomment-2543067830.
It is also a blocker for [setting the correct minimum OS version in `cc-rs`](https://github.com/rust-lang/rust/issues/136113), since fixing this in `cc-rs` might end up introducing linker errors in places where we weren't before (by default, if using e.g. ```@available(macos`` 10.15, *)`, the symbol usually happens to be left out, since `clang` defaults to compiling for the host macOS version, and thus things _seem_ to work - but the availability check actually compiles down to nothing, which is a huge correctness footgun for running on older OSes).
(My super secret evil agenda is also to expose some variant of ```@available``` in Rust's `std` after https://github.com/rust-lang/rfcs/pull/3750 progresses further, will probably file an ACP for this later. But I believe this PR has value regardless of those future plans, since we'd be making C/Objective-C/Swift interop easier).
## Solution
Implement `__isPlatformVersionAtLeast` and `__isOSVersionAtLeast` as part of the "public ABI" that `std` exposes.
**This is insta-stable**, in the same sense that additions to `compiler-builtins` are insta-stable, though the availability of these symbols can probably be considered a "quality of implementation" detail rather than a stable promise.
I originally proposed to implement this in `compiler-builtins`, see https://github.com/rust-lang/compiler-builtins/pull/794, but we discussed moving it to `std` instead ([Zulip thread](https://rust-lang.zulipchat.com/#narrow/channel/219381-t-libs/topic/Provide.20.60__isPlatformVersionAtLeast.60.20in.20.60std.60.3F/with/507880717)), which makes the implementation substantially simpler, and we avoid gnarly issues with requiring the user to link `libSystem.dylib` (since `std` unconditionally does that).
Note that this does not solve the linker errors for (pure) `#![no_std]` users, but that's _probably_ fine, if you are using ```@available``` to test the OS version on Apple platforms, you're likely also using `std` (and it is still possible to work around by linking `libclang_rt.*.a`).
A thing to note about the implementation, I've choosen to stray a bit from LLVM's upstream implementation, and not use `_availability_version_check` since [it has problems when compiling with an older SDK](https://github.com/llvm/llvm-project/issues/64227). Instead, we use `sysctl kern.osproductversion` when available to still avoid the costly PList lookup in most cases, but still with a fall back to the PList lookup when that is not available (with the PList fallback being is similar to LLVM's implementation).
## Testing
Apple has a lot of different "modes" that they can run binaries in, which can be a bit difficult to find your bearings in, but I've tried to be as thorough as I could in testing them all.
Tested using roughly the equivalent of `./x test library/std -- platform_version` on the following configurations:
- macOS 14.7.3 on a Macbook Pro M2
- `aarch64-apple-darwin`
- `x86_64-apple-darwin` (under Rosetta)
- `aarch64-apple-ios-macabi`
- `x86_64-apple-ios-macabi` (under Rosetta)
- `aarch64-apple-ios` (using Xcode's "Designed for iPad" setting)
- `aarch64-apple-ios-sim` (in iOS Simulator, as iPhone with iOS 17.5)
- `aarch64-apple-ios-sim` (in iOS Simulator, as iPad with iOS 18.2)
- `aarch64-apple-tvos-sim` (in tvOS Simulator)
- `aarch64-apple-watchos-sim` (in watchOS Simulator)
- `aarch64-apple-ios-sim` (in visionOS simulator, using Xcode's "Designed for iPad" setting)
- `aarch64-apple-visionos-sim` (in visionOS Simulator)
- macOS 15.3.1 VM
- `aarch64-apple-darwin`
- `aarch64-apple-ios-macabi`
- macOS 10.12.6 on an Intel Macbook from 2013
- `x86_64-apple-darwin`
- `i686-apple-darwin`
- `x86_64-apple-ios` (in iOS Simulator)
- iOS 9.3.6 on a 1st generation iPad Mini
- `armv7-apple-ios` with an older compiler
Along with manually inspecting the output of `version_from_sysctl()` and `version_from_plist()`, and verifying that they actually match what's expected.
I believe the only real omissions here would be:
- `aarch64-apple-ios` on a newer iPhone that has `sysctl` available (iOS 11.4 or above).
- `aarch64-apple-ios` on a Vision Pro using Xcode's "Designed for iPad" setting.
But I don't have the hardware available to test those.
``@rustbot`` label O-apple A-linkage -T-compiler -A-meta -A-run-make
try-job: aarch64-apple
std: Implement WASIp2-specific stdio routines
This commit is an extension of rust-lang/rust#145944 but applied to stdio specifically. The stdio routines are updated away from WASIp1 APIs to using WASIp2 APIs natively. The end goal is to eventually drop the dependency on WASIp1 APIs in the standard library entirely in favor of exclusively depending on WASIp2.
Unify and deduplicate algebraic float tests
cc rust-lang/rust#141726
This is a proposal to unify and deduplicate the algebraic tests for f16, f32, f64 and f128
This commit is an extension of previous libstd support but applied to stdio
specifically. The stdio routines are updated away from WASIp1 APIs to using
WASIp2 APIs natively. The end goal is to eventually drop the dependency on
WASIp1 APIs in the standard library entirely in favor of exclusively depending
on WASIp2.
Implement Integer funnel shifts
Tracking issue: rust-lang/rust#145686
ACP: https://github.com/rust-lang/libs-team/issues/642
This implements funnel shifts on primitive integer types. Implements this for cg_llvm, with a fallback impl for everything else
Thanks `@folkertdev` for the fixes and tests
cc `@rust-lang/libs-api`
docs(std): add missing closing code block fences in doc comments
This PR adds a few closing code block fences which I believe are missing in some doc comments. It seems that rustdoc just autocloses code blocks at the end of doc comments and thus these were easily overlooked: I do not think these code blocks are special in any way.
I found these when working on a Clippy lint that checks the last sentence of doc comments for terminal punctuation, and these were failing cases when testing against the std. Therefore I am not entirely sure these are all such cases, but still have high hopes that they are (or at least a well-defined subset of them).
raw_vec.rs: Remove superfluous fn alloc_guard
`alloc_guard` checks that its argument is at most `isize::MAX`, but it is called only with layout sizes, which are already guaranteed to be at most `isize::MAX`.
Adds the following items under the `read_buf_at` feature:
- `std::os::unix::fs::FileExt::read_buf_at`
- `std::os::unix::fs::FileExt::read_buf_exact_at`
- `std::os::windows::fs::FileExt::seek_read_buf`
std: Start supporting WASIp2 natively
This commit is the start of an effort to support WASIp2 natively in the
standard library. Before this commit the `wasm32-wasip2` target behaved
exactly like `wasm32-wasip1` target by importing APIs from the core wasm
module `wasi_snapshot_preview1`. These APIs are satisfied by the
`wasm-component-ld` target by using an [adapter] which implements WASIp1
in terms of WASIp2. This adapter comes at a cost, however, in terms of
runtime indirection and instantiation cost, so ideally the adapter would
be removed entirely. The purpose of this adapter was to provide a
smoother on-ramp from WASIp1 to WASIp2 when it was originally created.
The `wasm32-wasip2` target has been around for long enough now that it's
much more established. Additionally the only thing historically blocking
using WASIp2 directly was implementation effort. Work is now underway to
migrate wasi-libc itself to using WASIp2 directly and now seems as good
a time as any to migrate the Rust standard library too.
Implementation-wise the milestones here are:
* The `wasm32-wasip2` target now also depends on the `wasi` crate at
version 0.14.* in addition to the preexisting dependency of 0.11.*.
The 0.14.* release series binds WASIp2 APIs instead of WASIp1 APIs.
* Some preexisting naming around `mod wasi` or `wasi.rs` was renamed to
`wasip1` where appropriate. For example `std::sys::pal::wasi` is now
called `std::sys::pal::wasip1`.
* More platform-specific WASI modules are now split between WASIp1 and
WASIp2. For example getting the current time, randomness, and
process arguments now use WASIp2 APIs directly instead of using WASIp1
APIs that require an adapter.
It's worth pointing out that this PR does not migrate the entire
standard library away from using WASIp1 APIs on the `wasm32-wasip2`
target. Everything related to file descriptors and filesystem APIs is
still using WASIp1. Migrating that is left for a future PR. In the
meantime the goal of this change is to lay the groundwork necessary for
migrating in the future. Eventually the goal is to drop the `wasi`
0.11.* dependency on the `wasm32-wasip2` target (the `wasm32-wasip1`
target will continue to retain this dependency).
[adapter]: https://github.com/bytecodealliance/wasmtime/blob/main/crates/wasi-preview1-component-adapter/README.md
Constify conversion traits (part 1)
This is the first part of rust-lang/rust#144289 being split into smaller pieces. It adds/moves constness of several traits under the `const_convert` feature:
* `From`
* `Into`
* `TryFrom`
* `TryInto`
* `FromStr`
* `AsRef`
* `AsMut`
* `Borrow`
* `BorrowMut`
* `Deref`
* `DerefMut`
There are a few methods that are intrinsically tied to these traits which I've included in the feature. Particularly, those which are wrappers over `AsRef`:
* `ByteStr::new` (unstable under `bstr` feature)
* `OsStr::new`
* `Path::new`
Those which directly use `Into`:
* `Result::into_ok`
* `Result::into_err`
And those which use `Deref` and `DerefMut`:
* `Pin::as_ref`
* `Pin::as_mut`
* `Pin::as_deref_mut`
* `Option::as_deref`
* `Option::as_deref_mut`
* `Result::as_deref`
* `Result::as_deref_mut`
(note: the `Option` and `Result` methods were suggested by ``@npmccallum`` initially as rust-lang/rust#146101)
The parts which are missing from this PR are:
* Anything that involves heap-allocated types
* Making any method const than the ones listed above
* Anything that could rely on the above, *or* could rely on system-specific code for `OsStr` or `Path` (note: this mostly makes these methods useless since `str` doesn't implement `AsRef<OsStr>` yet, but it's better to track the method for now and add impls later, IMHO)
r? ``@tgross35`` (who mostly already reviewed this)
improve process::abort rendering in Miri backtraces
Also, avoid using the `sys` function directly in the panic machinery -- that seems like an unnecessary layering violation.
stabilize c-style varargs for sysv64, win64, efiapi, aapcs
This has been split up so the PR now only contains the extended_varargs_abi_support stabilization; "system" has been moved to https://github.com/rust-lang/rust/pull/145954.
**Previous (combined) PR description:**
This stabilizes extern block declarations of variadic functions with the system, sysv64, win64, efiapi, aapcs ABIs. This corresponds to the extended_varargs_abi_support and extern_system_varargs feature gates.
The feature gates were split up since it seemed like there might be further discussion needed for what exactly "system" ABI variadic functions should do, but a [consensus](https://github.com/rust-lang/rust/issues/136946#issuecomment-2967847553) has meanwhile been reached: they shall behave like "C" functions. IOW, the ABI of a "system" function is (bold part is new in this PR):
- "stdcall" for win32 targets **for non-variadic functions**
- "C" for everything else
This had been previously stabilized *without FCP* in https://github.com/rust-lang/rust/pull/116161, which got reverted in https://github.com/rust-lang/rust/pull/136897. There was also a "fun" race condition involved with the system ABI being [added](https://github.com/rust-lang/rust/pull/119587) to the list of variadic-supporting ABIs between the creation and merge of rust-lang/rust#116161.
There was a question raised [here](https://github.com/rust-lang/rust/pull/116161#issuecomment-1983829513) whether t-lang even needs to be involved for a change like this. Not sure if that has meanwhile been clarified? The behavior of the "system" ABI (a Rust-specific ABI) definitely feels like t-lang territory to me.
Fixesrust-lang/rust#100189
Cc `@rust-lang/lang`
# Stabilization report
> ## General design
> ### What is the RFC for this feature and what changes have occurred to the user-facing design since the RFC was finalized?
AFAIK there is no RFC. The tracking issues are
- https://github.com/rust-lang/rust/issues/100189
- https://github.com/rust-lang/rust/issues/136946
> ### What behavior are we committing to that has been controversial? Summarize the major arguments pro/con.
The only controversial point is whether "system" ABI functions should support variadics.
- Pro: This allows crates like windows-rs to consistently use "system", see e.g. https://github.com/microsoft/windows-rs/issues/3626.
- Cons: `@workingjubilee` had some implementation concerns, but I think those have been [resolved](https://github.com/rust-lang/rust/issues/136946#issuecomment-2967847553). EDIT: turns out Jubilee still has concerns (she mentioned that in a DM); I'll let her express those.
Note that "system" is already a magic ABI we introduced to "do the right thing". This just makes it do the right thing in more cases. In particular, it means that on Windows one can almost always just do
```rust
extern "system" {
// put all the things here
}
```
and it'll do the right thing, rather than having to split imports into non-varargs and varargs, with the varargs in a separate `extern "C"` block (and risking accidentally putting a non-vararg there).
(I am saying "almost" always because some Windows API functions actually use cdecl, not stdcall, on x86. Those of course need to go in `extern "C"` blocks.)
> ### Are there extensions to this feature that remain unstable? How do we know that we are not accidentally committing to those?
Actually defining variadic functions in Rust remains unstable, under the [c_variadic feature gate](https://github.com/rust-lang/rust/issues/44930).
> ## Has a Call for Testing period been conducted? If so, what feedback was received?
>
> Does any OSS nightly users use this feature? For instance, a useful indication might be "search <grep.app> for `#![feature(FEATURE_NAME)]` and had `N` results".
There was no call for testing.
A search brings up https://github.com/rust-osdev/uefi-rs/blob/main/uefi-raw/src/table/boot.rs using this for "efiapi". This doesn't seem widely used, but it is an "obvious" gap in our support for c-variadics.
> ## Implementation quality
All rustc does here is forward the ABI to LLVM so there's lot a lot to say here...
> ### Summarize the major parts of the implementation and provide links into the code (or to PRs)
>
> An example for async closures: <https://rustc-dev-guide.rust-lang.org/coroutine-closures.html>.
The check for allowed variadic ABIs is [here](https://github.com/rust-lang/rust/blob/9c870d30e2d6434c9e9a004b450c5ccffdf3d844/compiler/rustc_hir_analysis/src/lib.rs#L109-L126).
The special handling of "system" is [here](https://github.com/rust-lang/rust/blob/c24914ec8329b22ec7bcaa6ab534a784b2bd8ab9/compiler/rustc_target/src/spec/abi_map.rs#L82-L85).
> ### Summarize existing test coverage of this feature
>
> Consider what the "edges" of this feature are. We're particularly interested in seeing tests that assure us about exactly what nearby things we're not stabilizing.
>
> Within each test, include a comment at the top describing the purpose of the test and what set of invariants it intends to demonstrate. This is a great help to those reviewing the tests at stabilization time.
>
> - What does the test coverage landscape for this feature look like?
> - Tests for compiler errors when you use the feature wrongly or make mistakes?
> - Tests for the feature itself:
> - Limits of the feature (so failing compilation)
> - Exercises of edge cases of the feature
> - Tests that checks the feature works as expected (where applicable, `//@ run-pass`).
> - Are there any intentional gaps in test coverage?
>
> Link to test folders or individual tests (ui/codegen/assembly/run-make tests, etc.).
Prior PRs add a codegen test for all ABIs and tests actually calling extern variadic functions for sysv64 and win64:
- https://github.com/rust-lang/rust/pull/144359
- https://github.com/rust-lang/rust/pull/144379
We don't have a way of executing uefi target code in the test suite, so it's unclear how to fully test efiapi. aapcs could probably be done? (But note that we have hardly an such actually-calling-functions tests for ABI things, we almost entirely rely on codegen tests.)
The test ensuring that we do *not* stabilize *defining* c-variadic functions is `tests/ui/feature-gates/feature-gate-c_variadic.rs`.
> ### What outstanding bugs in the issue tracker involve this feature? Are they stabilization-blocking?
None that I am aware of.
> ### What FIXMEs are still in the code for that feature and why is it ok to leave them there?
None that I am aware of.
> ### Summarize contributors to the feature by name for recognition and assuredness that people involved in the feature agree with stabilization
`@Soveu` added sysv64, win64, efiapi, aapcs to the list of ABIs that allow variadics, `@beepster4096` added system. `@workingjubilee` recently refactored the ABI handling in the compiler, also affecting this feature.
> ### Which tools need to be adjusted to support this feature. Has this work been done?
>
> Consider rustdoc, clippy, rust-analyzer, rustfmt, rustup, docs.rs.
Maybe RA needs to be taught about the new allowed ABIs? No idea how precisely they mirror what exactly rustc accepts and rejects here.
> ## Type system and execution rules
> ### What compilation-time checks are done that are needed to prevent undefined behavior?
>
> (Be sure to link to tests demonstrating that these tests are being done.)
Nothing new here, this just expands the existing support for calling variadic functions to more ABIs.
> ### Does the feature's implementation need checks to prevent UB or is it sound by default and needs opt in in places to perform the dangerous/unsafe operations? If it is not sound by default, what is the rationale?
Nothing new here, this just expands the existing support for calling variadic functions to more ABIs.
> ### Can users use this feature to introduce undefined behavior, or use this feature to break the abstraction of Rust and expose the underlying assembly-level implementation? (Describe.)
Nothing new here, this just expands the existing support for calling variadic functions to more ABIs.
> ### What updates are needed to the reference/specification? (link to PRs when they exist)
- https://github.com/rust-lang/reference/pull/1936
> ## Common interactions
> ### Does this feature introduce new expressions and can they produce temporaries? What are the lifetimes of those temporaries?
No.
> ### What other unstable features may be exposed by this feature?
None.
Rollup of 5 pull requests
Successful merges:
- rust-lang/rust#145468 (dedup recip, powi, to_degrees, and to_radians float tests)
- rust-lang/rust#145643 (coverage: Build an "expansion tree" and use it to unexpand raw spans)
- rust-lang/rust#145754 (fix(lexer): Don't require frontmatters to be escaped with indented fences)
- rust-lang/rust#146060 (fixup nix dev shell again)
- rust-lang/rust#146068 (compiletest: Capture panic messages via a custom panic hook)
r? `@ghost`
`@rustbot` modify labels: rollup
dedup recip, powi, to_degrees, and to_radians float tests
Deduplicates recip, powi, to_degrees, and to_radians float tests.
I had to fiddle and slightly increase the tolerances for a few comparisons, so maybe not all of the tests are worth deduplicating.
Part of rust-lang/rust#141726.
Best reviewed commit-by-commit.
r? `@tgross35`
Add `Bound::copied`
Tracking Issue: https://github.com/rust-lang/rust/issues/145966
Some questions:
- [x] Should I update the documentation for `cloned` to actual used a `Clone` type instead of an integer?
- [x] I removed the `must_use` since this is a cheap copy, does that make sense?
Romain Perier