Override `Waker::clone_from` to avoid cloning `Waker`s unnecessarily
This would be very useful for futures — I think it’s pretty much always what they want to do instead of `*waker = cx.waker().clone()`.
Tracking issue: https://github.com/rust-lang/rust/issues/98287
r? rust-lang/libs-api `@rustbot` label +T-libs-api -T-libs
Avoid unnecessary comparison in partition_equal
The branchy Hoare partition `partition_equal` as part of `slice::sort_unstable` has a bug that makes it perform a comparison of the last element twice.
Measuring inputs with a Zipfian distribution with characterizing exponent s == 1.0, yields a ~0.05% reduction in the total number of comparisons performed.
improve compiler&tool documenting and re-enable cranelift on CI
First commit addresses the linking issue with compiler crates. Second one ensures that compiler crates are linked correctly (with later commits we added this check for tools as well), allowing us to detect these hard-to-catch bugs on CI. Following three commits cherry-picked from #117328 to re-enable the Cranelift backend on CI.
More info: https://github.com/rust-lang/rust/issues/117430
cc `@bjorn3` `@RalfJung`
Rollup of 4 pull requests
Successful merges:
- #116017 (Don't pass `-stdlib=libc++` when building C files on macOS)
- #117524 (bootstrap/setup: create hooks directory if non-existing)
- #117588 (Remove unused LoadResult::DecodeIncrCache variant)
- #117596 (Add diagnostic items for a few of core's builtin macros)
r? `@ghost`
`@rustbot` modify labels: rollup
Add diagnostic items for a few of core's builtin macros
Specifically, `env`, `option_env`, and `include`. There are a number of reasons why people might want to look at these in lints (For example, to ensure that things behave consistently, detect things that might make builds less reproducible, etc).
Concretely, in PL/Rust (well, `plrustc`) we have lints that forbid these (which I'd like to [add to clippy as restriction lints](https://rust-lang.zulipchat.com/#narrow/stream/257328-clippy/topic/Landing.20a.20flotilla.20of.20lints.3F) eventually), and `dylint` also has [lints that look for `env!`/`option_env!`](109a07e9f2/examples/general/env_cargo_path/src/lib.rs) (although perhaps not `include`), which would benefit from this.
My experience is that it's pretty annoying to (robustly) check uses of builtin macros without these IME, although that's perhaps just my own fault (e.g. I could be doing it wrong).
At `@Nilstrieb's` suggestion, I've added a comment that explains why these are here, even though they are not used in the compiler. This is mostly to discourage removal, although it's not a big deal if it happens (I'm certainly not suggesting the presence of these be in any way stable).
---
In theory this is a library PR (in that it's in library/core), but I'm going to roll compiler because the existence of this or not is much more likely something they care about rather than libs. Hopefully nobody objects to this.
r? compiler
bootstrap/setup: create hooks directory if non-existing
When running `./x setup` on a local repository I chose to install a `pre-push` git hook, but this happened:
```shell
Would you like to install the git hook?: [y/N] y
error: could not create hook .git/hooks/pre-push: do you already have the git hook installed?
No such file or directory (os error 2)
thread 'main' panicked at src/core/build_steps/setup.rs:462:9:
install_git_hook_maybe(&config) failed with No such file or directory (os error 2)
```
This was caused because the `.git/hooks` directory did not exist in my local repository. Creating it manually and re-running the command works fine.
This PR tests for the above directory and if it does not exist then it _tries_ to create it before hard linking the pre-push hook - we use `fs::create_dir()` and disregard the result (ie. it could fail if the directory was created in the meantime) and proceed to call `fs::hard_link()` all the same.
Remove obsolete support for linking unwinder on Android
Linking libgcc is no longer supported (see #103673), so remove the related link attributes and the check in unwind's build.rs. The check was the last remaining significant piece of logic in build.rs, so remove build.rs as well.
Add FileCheck annotations to a few MIR opt tests
const_debuginfo did not specify which passes were running.
const_prop_miscompile is renamed and moved to const_prop directory.
while_storage was broken.
Stabilize `const_maybe_uninit_zeroed` and `const_mem_zeroed`
Make `MaybeUninit::zeroed` and `mem::zeroed` const stable. Newly stable API:
```rust
// core::mem
pub const unsafe fn zeroed<T>() ->;
impl<T> MaybeUninit<T> {
pub const fn zeroed() -> MaybeUninit<T>;
}
```
This relies on features based around `const_mut_refs`. Per `@RalfJung,` this should be OK since we do not leak any `&mut` to the user.
For this to be possible, intrinsics `assert_zero_valid` and `assert_mem_uninitialized_valid` were made const stable.
Tracking issue: #91850
Zulip discussion: https://rust-lang.zulipchat.com/#narrow/stream/146212-t-compiler.2Fconst-eval/topic/.60const_mut_refs.60.20dependents
r? libs-api
`@rustbot` label -T-libs +T-libs-api +A-const-eval
cc `@RalfJung` `@oli-obk` `@rust-lang/wg-const-eval`
Make sure that predicates with unmentioned bound vars are still considered global in the old solver
In the old solver, we consider predicates with late-bound vars to not be "global":
9c8a2694fa/compiler/rustc_trait_selection/src/traits/select/mod.rs (L1840-L1844)
The implementation of `has_late_bound_vars` was modified in #115834 so that we'd properly anonymize binders that had late-bound vars but didn't reference them. This fixed an ICE.
However, this also led to a behavioral change in https://github.com/rust-lang/rust/issues/117056#issuecomment-1775014545 for a couple of crates, which now consider `for<'a> GL33: Shader` (note the binder var that is *not* used in the predicate) to not be "global". This forces associated types to not be normalizable due to the old trait solver being dumb.
This PR distinguishes types which *reference* late-bound vars and binders which *have* late-bound vars. The latter is represented with the new type flag `TypeFlags::HAS_BINDER_VARS`, which is used when we only care about knowing whether binders have vars in their bound var list (even if they're not used, like for binder anonymization).
This should fix (after beta backport) the `luminance-gl` and `luminance-webgl` crates in #117056.
r? types
**(priority is kinda high on a review here given beta becomes stable on November 16.)**
Hint optimizer about try-reserved capacity
This is #116568, but limited only to the less-common `try_reserve` functions to reduce bloat in debug binaries from debug info, while still addressing the main use-case #116570
Rollup of 6 pull requests
Successful merges:
- #110340 (Deref docs: expand and remove "smart pointer" qualifier)
- #116894 (Guarantee that `char` has the same size and alignment as `u32`)
- #117534 (clarify that the str invariant is a safety, not validity, invariant)
- #117562 (triagebot no-merges: exclude different case)
- #117570 (fallback for `construct_generic_bound_failure`)
- #117583 (Remove `'tcx` lifetime on `PlaceholderConst`)
r? `@ghost`
`@rustbot` modify labels: rollup
fallback for `construct_generic_bound_failure`
Fixes#117547
This case regressed at #115882.
In this context, `generic_param_scope` is produced by `RPITVisitor` and not included by `hir_owner`. Therefore, I've added a fallback to address this.
Deref docs: expand and remove "smart pointer" qualifier
**Ready for review**
~~This is an unpolished draft to be sanity-checked~~
Fixes#91004
~~Comments on substance and content of this are welcome. This is deliberately unpolished until ready to review so please try to stay focused on the big-picture.~~
~~Once this has been sanity checked, I will similarly update `DerefMut` and polish for review.~~
Make `core::mem::zeroed` const stable. Newly stable API:
// core::mem
pub const unsafe fn zeroed<T>() -> T;
This is stabilized with `const_maybe_uninit_zeroed` since it is a simple
wrapper.
In order to make this possible, intrinsics `assert_zero_valid` was made
const stable under `const_assert_type2`.
`assert_mem_uninitialized_valid` was also made const stable since it is
under the same gate.
Make `MaybeUninit::zeroed` const stable. Newly stable API:
// core::mem
impl<T> MaybeUninit<T> {
pub const fn zeroed() -> MaybeUninit<T>;
}
Use of `const_mut_refs` should be acceptable since we do not leak the
mutability.
Tracking issue: #91850
Update the alignment checks to match rust-lang/reference#1387
Previously, we had a special case to not check `Rvalue::AddressOf` in this pass because we weren't quite sure if pointers needed to be aligned in the Place passed to it: https://github.com/rust-lang/rust/pull/112026
Since https://github.com/rust-lang/reference/pull/1387 merged, this PR updates this pass to match. The behavior of the check is nearly unchanged, except we also avoid inserting a check for creating references. Most of the changes in this PR are cleanup and new tests.
Re-draft Deref docs
Make general advice more explicit and note the difference between
generic and specific implementations.
Re-draft DerefMut docs in-line with Deref
Fix Deref docs typos
Fix broken links
Clarify advice for specific-over-generic impls
Add comment addressing Issue #73682
x fmt
Copy faillibility warning to DerefMut
Warn users who set `non_exhaustive_omitted_patterns` lint level on a match arm
Before https://github.com/rust-lang/rust/pull/116734, the recommended usage of the [`non_exhaustive_omitted_patterns` lint](https://github.com/rust-lang/rust/issues/89554) was:
```rust
match Bar::A {
Bar::A => {},
#[warn(non_exhaustive_omitted_patterns)]
_ => {},
}
```
After https://github.com/rust-lang/rust/pull/116734 this no longer makes sense, and recommended usage is now:
```rust
#[warn(non_exhaustive_omitted_patterns)]
match Bar::A {
Bar::A => {},
_ => {},
}
```
As you can guess, this silently breaks all uses of the lint that used the previous form. This is a problem in particular because `syn` recommends usage of this lint to its users in the old way. This PR emits a warning when the previous form is used so users can update.
r? `@cjgillot`
This was a leftover from when inline asm wasn't universally supported by
the cranelift backend yet. It would cause the optimized inline asm
intrinsics to be avoided for the standard library distributed with
rustup now that we build the cranelift backend by default on nightly for
several tier 1 targets.
