`#[lang_item]` for `core::ptr::Unique`
Tree Borrows is about to introduce experimental special handling of `core::ptr::Unique` in Miri to give it a semantics.
As of now there does not seem to be a clean way (i.e. other than `&format!("{adt:?}") == "std::ptr::Unique"`) to check if an `AdtDef` represents a `Unique`.
r? `@RalfJung`
Draft: making a lang item
Fix building libstd documentation on FreeBSD.
It fixes the following error:
```
error[E0412]: cannot find type `sockcred2` in module `libc`
--> library/std/src/os/unix/net/ancillary.rs:211:29
|
211 | pub struct SocketCred(libc::sockcred2);
| ^^^^^^^^^ not found in `libc`
```
Extend `unused_must_use` to cover block exprs
Given code like
```rust
#[must_use]
fn foo() -> i32 {
42
}
fn warns() {
{
foo();
}
}
fn does_not_warn() {
{
foo()
};
}
fn main() {
warns();
does_not_warn();
}
```
### Before This PR
```
warning: unused return value of `foo` that must be used
--> test.rs:8:9
|
8 | foo();
| ^^^^^
|
= note: `#[warn(unused_must_use)]` on by default
help: use `let _ = ...` to ignore the resulting value
|
8 | let _ = foo();
| +++++++
warning: 1 warning emitted
```
### After This PR
```
warning: unused return value of `foo` that must be used
--> test.rs:8:9
|
8 | foo();
| ^^^^^
|
= note: `#[warn(unused_must_use)]` on by default
help: use `let _ = ...` to ignore the resulting value
|
8 | let _ = foo();
| +++++++
warning: unused return value of `foo` that must be used
--> test.rs:14:9
|
14 | foo()
| ^^^^^
|
help: use `let _ = ...` to ignore the resulting value
|
14 | let _ = foo();
| +++++++ +
warning: 2 warnings emitted
```
Fixes#104253.
Mention `env!` in `option_env!`'s docs
`env!` mentions that there is an alternative that returns an `Option<...>` instead of emitting a compile error.
Now `option_env!` also mentions that there is an alternative that emits a compile error instead of returning an `Option<...>`.
Update runtime guarantee for `select_nth_unstable`
#106933 changed the runtime guarantee for `select_nth_unstable` from O(n) to O(n log n), since the old guarantee wasn't actually met by the implementation at the time. Now with #107522, `select_nth_unstable` should be truly linear in runtime, so we can revert its runtime guarantee to O(n). Since #106933 was considered a bug fix, this will probably need an FCP because it counts as a new API guarantee.
r? `@Amanieu`
Stabilize String::leak
Stabilizes the following API:
```Rust
impl String {
pub fn leak(self) -> &'static mut str;
}
```
closes#102929
blocked by having an FCP for stabilization.
Implement `TryFrom<&OsStr>` for `&str`
Recently when trying to work with `&OsStr` I was surprised to find this `impl` missing.
Since the `to_str` method already existed the actual implementation is fairly non-controversial, except for maybe the choice of the error type. I chose an opaque error here instead of something like `std::str::Utf8Error`, since that would already make a number of assumption about the underlying implementation of `OsStr`.
As this is a trait implementation, it is insta-stable, if I'm not mistaken?
Either way this will need an FCP.
I chose "1.64.0" as the version, since this is unlikely to land before the beta cut-off.
`@rustbot` modify labels: +T-libs-api
API Change Proposal: rust-lang/rust#99031 (accepted)
Add support for targets without unwinding in `mir-opt`, and improve `--bless` for it
The main goal of this PR is to add support for targets without unwinding support in the `mir-opt` test suite, by adding the `EMIT_MIR_FOR_EACH_PANIC_STRATEGY` comment. Similarly to 32bit vs 64bit, when that comment is present, blessed output files will have the `.panic-unwind` or `.panic-abort` suffix, and the right one will be chosen depending on the target's panic strategy.
The `EMIT_MIR_FOR_EACH_PANIC_STRATEGY` comment replaced all the `ignore-wasm32` comments in the `mir-opt` test suite, as those comments were added due to `wasm32` being a target without unwinding support. The comment was also added on other tests that were only executed on x86 but were still panic strategy dependent.
The `mir-opt` suite was then blessed, which caused a ton of churn as most of the existing output files had to be renamed and (mostly) duplicated with the abort strategy.
---
After [asking on Zulip](https://rust-lang.zulipchat.com/#narrow/stream/131828-t-compiler/topic/mir-opt.20tests.20and.20panic.3Dabort), the main concern about this change is it'd make blessing the `mir-opt` suite even harder, as you'd need to both bless it with an unwinding target and an aborting target. This exacerbated the current situation, where you'd need to bless it with a 32bit and a 64bit target already.
Because of that, this PR also makes significant enhancements to `--bless` for the `mir-opt` suite, where it will automatically bless the suite four times with different targets, while requiring minimal cross-compilation.
To handle the 32bit vs 64bit blessing, there is now an hardcoded list of target mapping between 32bit and 64bit. The goal of the list is to find a related target that will *probably* work without requiring additional cross-compilation toolchains on the system. If a mapping is found, bootstrap will bless the suite with both targets, otherwise just with the current target.
To handle the panic strategy blessing (abort vs unwind), I had to resort to what I call "synthetic targets". For each of the target we're blessing (so either the current one, or a 32bit and a 64bit depending on the previous paragraph), bootstrap will extract the JSON spec of the target and change it to include `"panic-strategy": "abort"`. It will then build the standard library with this synthetic target, and bless the `mir-opt` suite with it.
As a result of these changes, blessing the `mir-opt` suite will actually bless it two or four times with different targets, ensuring all possible variants are actually blessed.
---
This PR is best reviewed commit-by-commit.
r? `@jyn514`
cc `@saethlin` `@oli-obk`
Ignore `core`, `alloc` and `test` tests that require unwinding on `-C panic=abort`
Some of the tests for `core` and `alloc` require unwinding through their use of `catch_unwind`. These tests fail when testing using `-C panic=abort` (in my case through a target without unwinding support, and `-Z panic-abort-tests`), while they should be ignored as they don't indicate a failure.
This PR marks all of these tests with this attribute:
```rust
#[cfg_attr(not(panic = "unwind"), ignore = "test requires unwinding support")]
```
I'm not aware of a way to test this on rust-lang/rust's CI, as we don't test any target with `-C panic=abort`, but I tested this locally on a Ferrocene target and it does indeed make the test suite pass.
It fixes the following error:
error[E0412]: cannot find type `sockcred2` in module `libc`
--> library/std/src/os/unix/net/ancillary.rs:211:29
|
211 | pub struct SocketCred(libc::sockcred2);
| ^^^^^^^^^ not found in `libc`
Make BinaryHeap parametric over Allocator
Tracking issue: #32838
Related: https://github.com/rust-lang/wg-allocators/issues/7
This parametrizes `BinaryHeap` with `A`, similarly to how other collections are parametrized.
A couple things I left out:
```
BinaryHeap::append
Currently requires both structures to have the same allocator type. Could
change, but depends on Vec::append, which has the same constraints.
impl<T: Ord> Default for BinaryHeap<T>
Not parametrized, because there's nowhere to conjure the allocator from.
impl<T: Ord> FromIterator<T> for BinaryHeap<T>
Not parametrized, because there's nowhere to conjure the allocator from.
impl<T: Ord, const N: usize> From<[T; N]> for BinaryHeap<T>
Not parametrized, because there's nowhere to conjure the allocator from.
unsafe impl<I> AsVecIntoIter for IntoIter<I>
AsVecIntoIter is not allocator aware, and I didn't dare change it without guidance. Is this something important?
```
I've seen very few tests for allocator_api in general, but I'd like to at least test this on some usage code in my projects before moving forward.
EDIT: Updated the list of impls and functions that are not affected by this. `BinaryHeap` no longer has a `SpecExtend` impl, and prior work made implementing `Extend` possible.
It might happen that a synthetic target name does not match one of the
hardcoded ones in std's build script, causing std to fail to build. This
commit changes the std build script avoid including the restricted-std
feature unconditionally when a synthetic target is being built.
Fix ntdll linkage issues on Windows UWP platforms
See discussion: https://github.com/rust-lang/rust/issues/112265#issuecomment-1575479683
Static loading `ntdll` functions does not work for UWP programs, which will end up link errors complaining about missing symbols, or failure to pass the WACK tests. The breakage was introduced in #108262.
This PR basically reverts part of the changes in #108262 for UWP only, and fixes some lint suggestions.
Uplift `clippy::cmp_nan` lint
This PR aims at uplifting the `clippy::cmp_nan` lint into rustc.
## `invalid_nan_comparisons`
~~(deny-by-default)~~ (warn-by-default)
The `invalid_nan_comparisons` lint checks comparison with `f32::NAN` or `f64::NAN` as one of the operand.
### Example
```rust,compile_fail
let a = 2.3f32;
if a == f32::NAN {}
```
### Explanation
NaN does not compare meaningfully to anything – not even itself – so those comparisons are always false.
-----
Mostly followed the instructions for uplifting a clippy lint described here: https://github.com/rust-lang/rust/pull/99696#pullrequestreview-1134072751
`@rustbot` label: +I-lang-nominated
r? compiler
