[illumos] use pipe2 to create anonymous pipes
pipe2 allows the newly-created pipe to atomically be CLOEXEC.
pipe2 was added to illumos a long time ago:
5dbfd19ad5. I've verified that this change passes all of std's tests on illumos.
Fix compilation error on Solaris due to flock usage
PR 130999 added the file_lock feature, but libc does not define flock() for the Solaris platform leading to a compilation error.
Additionally, I went through all the Tier 2 platforms and read through their documentation to see whether flock was implemented. This turned up 5 more Unix platforms where flock is not supported, even though it may exist in the libc crate.
Fixes https://github.com/rust-lang/rust/issues/132921
Related to #130999
These types are currently passed by reference, which does not avoid the
backend crashes. Change these back to being passed by value, which makes
the types easier to detect for automatic inlining.
Fix a copy-paste issue in the NuttX raw type definition
This file is copied from the rtems as initial implementation, and forgot to change the OS name in the comment.
Rollup of 7 pull requests
Successful merges:
- #131304 (float types: move copysign, abs, signum to libcore)
- #132907 (Change intrinsic declarations to new style)
- #132971 (Handle infer vars in anon consts on stable)
- #133003 (Make `CloneToUninit` dyn-compatible)
- #133004 (btree: simplify the backdoor between set and map)
- #133008 (update outdated comment about test-float-parse)
- #133012 (Add test cases for #125918)
r? `@ghost`
`@rustbot` modify labels: rollup
This file is copied from the rtems as initial implementation, and
forgot to change the OS name in the comment.
Signed-off-by: Huang Qi <huangqi3@xiaomi.com>
btree: simplify the backdoor between set and map
The internal `btree::Recover` trait acted as a private API between
`BTreeSet` and `BTreeMap`, but we can use `pub(_)` restrictions these
days, and some of the methods don't need special handling anymore.
* `BTreeSet::get` can use `BTreeMap::get_key_value`
* `BTreeSet::take` can use `BTreeMap::remove_entry`
* `BTreeSet::replace` does need help, but this now uses a `pub(super)`
method on `BTreeMap` instead of the trait.
* `btree::Recover` is now removed.
Make `CloneToUninit` dyn-compatible
Make `CloneToUninit` dyn-compatible, by making `clone_to_uninit`'s `dst` parameter `*mut u8` instead of `*mut Self`, so the method does not reference `Self` except in the `self` parameter and is thus dispatchable from a trait object.
This allows, among other things, adding `CloneToUninit` as a supertrait bound for `trait Foo` to allow cloning `dyn Foo` in some containers. Currently, this means that `Rc::make_mut` and `Arc::make_mut` can work with `dyn Foo` where `trait Foo: CloneToUninit`.
<details><summary>Example</summary>
```rs
#![feature(clone_to_uninit)]
use std::clone::CloneToUninit;
use std::rc::Rc;
use std::fmt::Debug;
use std::borrow::BorrowMut;
trait Foo: BorrowMut<u32> + CloneToUninit + Debug {}
impl<T: BorrowMut<u32> + CloneToUninit + Debug> Foo for T {}
fn main() {
let foo: Rc<dyn Foo> = Rc::new(42_u32);
let mut bar = foo.clone();
*Rc::make_mut(&mut bar).borrow_mut() = 37;
dbg!(foo, bar); // 42, 37
}
```
</details>
Eventually, `Box::<T>::clone` is planned to be converted to use `T::clone_to_uninit`, which when combined with this change, will allow cloning `Box<dyn Foo>` where `trait Foo: CloneToUninit` without any additional `unsafe` code for the author of `trait Foo`.[^1]
This PR should have no stable side-effects, as `CloneToUninit` is unstable so cannot be mentioned on stable, and `CloneToUninit` is not used as a supertrait anywhere in the stdlib.
This change removes some length checks that could only fail if library UB was already hit (e.g. calling `<[T]>::clone_to_uninit` with a too-small-length `dst` is library UB and was previously detected[^2]; since `dst` does not have a length anymore, this now cannot be detected[^3]).
r? libs-api
-----
I chose to make the parameter `*mut u8` instead of `*mut ()` because that might make it simpler to pass the result of `alloc` to `clone_to_uninit`, but `*mut ()` would also make sense, and any `*mut ConcreteType` would *work*. The original motivation for [using specifically `*mut ()`](https://github.com/rust-lang/rust/pull/116113#discussion_r1335303908) appears to be `std::ptr::from_raw_parts_mut`, but that now [takes `*mut impl Thin`](https://doc.rust-lang.org/nightly/std/ptr/fn.from_raw_parts.html) instead of `*mut ()`. I have another branch where the parameter is `*mut ()`, if that is preferred.
It *could* also take something like `&mut [MaybeUninit<u8>]` to be dyn-compatible but still allow size-checking and in some cases safe writing, but this is already an `unsafe` API where misuse is UB, so I'm not sure how many guardrails it's worth adding here, and `&mut [MaybeUninit<u8>]` might be overly cumbersome to construct for callers compared to `*mut u8`
[^1]: Note that `impl<T: CloneToUninit + ?Sized> Clone for Box` must be added before or at the same time as when `CloneToUninit` becomes stable, due to `Box` being `#[fundamental]`, as if there is any stable gap between the stabilization of `CloneToUninit` and `impl<T: CloneToUninit + ?Sized> Clone for Box`, then users could implement both `CloneToUninit for dyn LocalTrait` and separately `Clone for Box<dyn LocalTrait>` during that gap, and be broken by the introduction of `impl<T: CloneToUninit + ?Sized> Clone for Box`.
[^2]: Using a `debug_assert_eq` in [`core::clone::uninit::CopySpec::clone_slice`](https://doc.rust-lang.org/nightly/src/core/clone/uninit.rs.html#28).
[^3]: This PR just uses [the metadata (length) from `self`](e0c1c8bc50/library/core/src/clone.rs (L286)) to construct the `*mut [T]` to pass to `CopySpec::clone_slice` in `<[T]>::clone_to_uninit`.
Change intrinsic declarations to new style
Pr is for issue #132735
This changes the first `extern "rust-intrinsic"` block to the new style.
r? `@RalfJung`
float types: move copysign, abs, signum to libcore
These operations are explicitly specified to act "bitwise", i.e. they just act on the sign bit and do not even quiet signaling NaNs. We also list them as ["non-arithmetic operations"](https://doc.rust-lang.org/nightly/std/primitive.f32.html#nan-bit-patterns), and all the other non-arithmetic operations are in libcore. There's no reason to expect them to require any sort of runtime support, and from [these experiments](https://github.com/rust-lang/rust/issues/50145#issuecomment-997301250) it seems like LLVM indeed compiles them in a way that does not require any sort of runtime support.
Nominating for `@rust-lang/libs-api` since this change takes immediate effect on stable.
Part of https://github.com/rust-lang/rust/issues/50145.
improve codegen of fmt_num to delete unreachable panic
it seems LLVM doesn't realize that `curr` is always decremented at least once in either loop formatting characters of the input string by their appropriate radix, and so the later `&buf[curr..]` generates a check for out-of-bounds access and panic. this is unreachable in reality as even for `x == T::zero()` we'll produce at least the character `Self::digit(T::zero())`, yielding at least one character output, and `curr` will always be at least one below `buf.len()`.
adjust `fmt_int` to make this fact more obvious to the compiler, which fortunately (or unfortunately) results in a measurable performance improvement for workloads heavy on formatting integers.
in the program i'd noticed this in, you can see the `cmp $0x80,%rdi; ja 7c` here, which branches to a slice index fail helper:
<img width="660" alt="before" src="https://github.com/rust-lang/rust/assets/4615790/ac482d54-21f8-494b-9c83-4beadc3ca0ef">
where after this change the function is broadly similar, but smaller, with one fewer registers updated in each pass through the loop in addition the never-taken `cmp/ja` being gone:
<img width="646" alt="after" src="https://github.com/rust-lang/rust/assets/4615790/1bee1d76-b674-43ec-9b21-4587364563aa">
this represents a ~2-3% difference in runtime in my [admittedly comically i32-formatting-bound](https://github.com/athre0z/disas-bench/blob/master/bench/yaxpeax/src/main.rs#L58-L67) use case (printing x86 instructions, including i32 displacements and immediates) as measured on a ryzen 9 3950x.
the impact on `<impl LowerHex for i8>::fmt` is both more dramatic and less impactful: it continues to have a loop that is evaluated at most twice, though the compiler doesn't know that to unroll it. the generated code there is identical to the impl for `i32`. there, the smaller loop body has less effect on runtime, and removing the never-taken slice bounds check is offset by whatever address recalculation is happening with the `lea/add/neg` at the end of the loop. it behaves about the same before and after.
---
i initially measured slightly better outcomes using `unreachable_unchecked()` here instead, but that was hacking on std and rebuilding with `-Z build-std` on an older rustc (nightly 5b377cece, 2023-06-30). it does not yield better outcomes now, so i see no reason to proceed with that approach at all.
<details>
<summary>initial notes about that, seemingly irrelevant on modern rustc</summary>
i went through a few tries at getting llvm to understand the bounds check isn't necessary, but i should mention the _best_ i'd seen here was actually from the existing `fmt_int` with a diff like
```diff
if x == zero {
// No more digits left to accumulate.
break;
};
}
}
+
+ if curr >= buf.len() {
+ unsafe { core::hint::unreachable_unchecked(); }
+ }
let buf = &buf[curr..];
```
posting a random PR to `rust-lang/rust` to do that without a really really compelling reason seemed a bit absurd, so i tried to work that into something that seems more palatable at a glance. but if you're interested, that certainly produced better (x86_64) code through LLVM. in that case with `buf.iter_mut().rev()` as the iterator, `<impl LowerHex for i8>::fmt` actually unrolls into something like
```
put_char(x & 0xf);
let mut len = 1;
if x > 0xf {
put_char((x >> 4) & 0xf);
len = 2;
}
pad_integral(buf[buf.len() - len..]);
```
it's pretty cool! `<impl LowerHex for i32>::fmt` also was slightly better. that all resulted in closer to an 6% difference in my use case.
</details>
---
i have not looked at formatters other than LowerHex/UpperHex with this change, though i'd be a bit shocked if any were _worse_.
(i have absolutely _no_ idea how you'd regression test this, but that might be just my not knowing what the right tool for that would be in rust-lang/rust. i'm of half a mind that this is small and fiddly enough to not be worth landing lest it quietly regress in the future anyway. but i didn't want to discard the idea without at least offering it upstream here)
The internal `btree::Recover` trait acted as a private API between
`BTreeSet` and `BTreeMap`, but we can use `pub(_)` restrictions these
days, and some of the methods don't need special handling anymore.
* `BTreeSet::get` can use `BTreeMap::get_key_value`
* `BTreeSet::take` can use `BTreeMap::remove_entry`
* `BTreeSet::replace` does need help, but this now uses a `pub(super)`
method on `BTreeMap` instead of the trait.
* `btree::Recover` is now removed.
PR 130999 added the file_lock feature, but libc does not define
flock() for the Solaris platform leading to a compilation error.
Additionally, I went through all the Tier 2 platforms and read through
their documentation to see whether flock was implemented. This turned up
5 more Unix platforms where flock is not supported, even though it may
exist in the libc crate.
pipe2 allows the newly-created pipe to atomically be CLOEXEC.
pipe2 was added to illumos a long time ago:
5dbfd19ad5.
I've verified that this change passes all tests.
Update grammar in std::cell docs.
Using "having" in both the leading sentence and the bullets is unnecessary.
It makes it read as "it is only possible to have having several immutable...".
split up the first paragraph of doc comments for better summaries
used `./x clippy -Aclippy::all '-Wclippy::too_long_first_doc_paragraph' library/core library/alloc` to find these issues.
Arbitrary self types v2: (unused) Receiver trait
This commit contains a new `Receiver` trait, which is the basis for the Arbitrary Self Types v2 RFC. This allows smart pointers to be method receivers even if they're not Deref.
This is currently unused by the compiler - a subsequent PR will start to use this for method resolution if the `arbitrary_self_types` feature gate is enabled. This is being landed first simply to make review simpler: if people feel this should all be in an atomic PR let me know.
This is a part of the arbitrary self types v2 project, https://github.com/rust-lang/rfcs/pull/3519https://github.com/rust-lang/rust/issues/44874
r? `@wesleywiser`
Using "having" in both the leading sentence and the bullets is unnecessary.
It makes it read as "it is only possible to have having several immutable...".
Implement file_lock feature
This adds lock(), lock_shared(), try_lock(), try_lock_shared(), and unlock() to File gated behind the file_lock feature flag
This is the initial implementation of https://github.com/rust-lang/rust/issues/130994 for Unix and Windows platforms. I will follow it up with an implementation for WASI preview 2
ABI compatibility: remove section on target features
Once https://github.com/rust-lang/rust/pull/127731 lands, we will properly diagnose ABI issues caused by target feature mismatch (at least on tier 1 targets). So I'd say we can remove the corresponding part of the docs here -- this is now something the compiler can take care of, so programmers don't need to be concerned. For now this is just a lint, but that's just a transition period, like in prior cases where we fix I-unsound bugs by adding a new check that goes through the "future incompatibility" stages. We have decided that it's actually a bug that we have ABI risks around target features, and we shouldn't document that bug as-if it was intended behavior.
Cc `@rust-lang/opsem` `@chorman0773` `@veluca93`
remove support for rustc_safe_intrinsic attribute; use rustc_intrinsic functions instead
This brings us one step closer towards removing support for `extern "rust-intrinsic"` blocks, in favor of `#[rustc_intrinsic]` functions.
Also move `#[rustc_intrinsic]` under the `intrinsics` feature gate, to match the `extern "rust-intrinsic"` style.
Initialize channel `Block`s directly on the heap
The channel's `Block::new` was causing a stack overflow because it held
32 item slots, instantiated on the stack before moving to `Box::new`.
The 32x multiplier made modestly-large item sizes untenable.
That block is now initialized directly on the heap.
Fixes#102246
try-job: test-various
Compile `test_num_f128` conditionally on `reliable_f128_math` config
With #132434 merged, our internal SGX CI started failing with:
```
05:27:34 = note: rust-lld: error: undefined symbol: fmodl
05:27:34 >>> referenced by arith.rs:617 (core/src/ops/arith.rs:617)
05:27:34 >>> /home/jenkins/workspace/rust-sgx-ci/rust/build/x86_64-unknown-linux-gnu/stage1-std/x86_64-fortanix-unknown-sgx/release/deps/std-5d5f11eb008c9091.std.d8141acc61ab7ac8-cgu.10.rcgu.o:(std::num::test_num::h7dd9449f6c01fde8)
05:27:34 >>> did you mean: fmodf
05:27:34 >>> defined in: /home/jenkins/workspace/rust-sgx-ci/rust/build/x86_64-unknown-linux-gnu/stage1-std/x86_64-fortanix-unknown-sgx/release/deps/libcompiler_builtins-0376f439a2ebf305.rlib(compiler_builtins-0376f439a2ebf305.compiler_builtins.c22db39d25d6f802-cgu.148.rcgu.o)
```
This originated from the `test_num_f128` test not having the required conditional compilation. This PR fixes that issue.
cc: ````@jethrogb,```` ````@workingjubilee````
core: move intrinsics.rs into intrinsics folder
This makes the rustbot notification we have set up for this folder in `triagebot.toml` actually work. Also IMO it makes more sense to have it all in one folder.
The channel's `Block::new` was causing a stack overflow because it held
32 item slots, instantiated on the stack before moving to `Box::new`.
The 32x multiplier made modestly-large item sizes untenable.
That block is now initialized directly on the heap.
Fixes#102246
unpin and update memchr
I'm unable to build x86_64-pc-windows-gnu Rust due to some weird binutils bug, but thinlto issue seems to be no longer present. Let's give it a go on the CI.
Possibly fixed by https://github.com/rust-lang/rust/pull/129079Fixes#127890
Inline str::repeat
`str` is non-generic and `str.repeat()` doesn't get inlined, which makes it use a slower algorithm in case of 1-char repetitions. Equivalent byte slice does get inlined: https://rust.godbolt.org/z/4arvh97r4
Revert using `HEAP` static in Windows alloc
Fixes#131468
This does the minimum to remove the `HEAP` static that was causing chromium issues. It would be worth having a more substantial look at this module but for now I think this addresses the immediate issue.
cc `@danakj`
Fix an extra newline in rendered std doc
Fixes#132564
(taken from the issue above)
The problem with the formatting is due to that newline between `<code>` and `<svg>`. Any newlines outside of the code (i.e., within elements inside of it) are fine.
Add new unstable feature `const_eq_ignore_ascii_case`
Tracking issue - #131719
Mark `[u8]`, `str` `eq_ignore_ascii_case` functions const
---
The codegen for this implementation matches the existing `iter::zip` implementation better than incrementing with a counter
while loop with counter - https://rust.godbolt.org/z/h9cs5zajc
while let - https://rust.godbolt.org/z/ecMeMjjEb
make char::is_whitespace unstably const
I am adding this to the existing https://github.com/rust-lang/rust/issues/132241 feature gate, since `is_digit` and `is_whitespace` seem similar enough that one can group them together.
Rollup of 8 pull requests
Successful merges:
- #132259 (rustc_codegen_llvm: Add a new 'pc' option to branch-protection)
- #132409 (CI: switch 7 linux jobs to free runners)
- #132498 (Suggest fixing typos and let bindings at the same time)
- #132524 (chore(style): sync submodule exclusion list between tidy and rustfmt)
- #132567 (Properly suggest `E::assoc` when we encounter `E::Variant::assoc`)
- #132571 (add const_eval_select macro to reduce redundancy)
- #132637 (Do not filter empty lint passes & re-do CTFE pass)
- #132642 (Add documentation on `ast::Attribute`)
r? `@ghost`
`@rustbot` modify labels: rollup
add const_eval_select macro to reduce redundancy
I played around a bit with a macro to make const_eval_select invocations look a bit nicer and avoid repeating the argument lists. Here's what I got. What do you think?
I didn't apply this everywhere yet because I wanted to gather feedback first.
The second commit moves the macros from https://github.com/rust-lang/rust/pull/132542 into a more sensible place. It didn't seem worth its own PR and would conflict with this PR if done separately.
Cc ``@oli-obk`` ``@saethlin`` ``@tgross35``
try-job: dist-aarch64-msvc
[core/fmt] Replace checked slice indexing by unchecked to support panic-free code
Fixes#126425
Replace the potentially panicking `[]` indexing with `get_unchecked()` to prevent linking with panic-related code.
