Stabilize slice::strip_prefix and slice::strip_suffix
These two methods are useful. The corresponding methods on `str` are already stable.
I believe that stablising these now would not get in the way of, in the future, extending these to take a richer pattern API a la `str`'s patterns.
Tracking PR: #73413. I also have an outstanding PR to improve the docs for these two functions and the corresponding ones on `str`: #75078
I have tried to follow the [instructions in the dev guide](https://rustc-dev-guide.rust-lang.org/stabilization_guide.html#stabilization-pr). The part to do with `compiler/rustc_feature` did not seem applicable. I assume that's because these are just library features, so there is no corresponding machinery in rustc.
Make `ExpnData` fields `krate` and `orig_id` private
These fields are only used by hygiene serialized, and should not be
accessed by anything outside of `rustc_span`.
Optimize DST field access
For
struct X<T: ?Sized>(T)
struct Y<T: ?Sized>(u8, T)
the offset of the unsized field is
0
mem::align_of_val(&self.1)
respectively. This patch changes the expression used to compute these
offsets so that the optimizer can perform this optimization.
Consider
```rust
fn f(x: &X<dyn Any>) -> &dyn Any {
&x.0
}
```
Before:
```asm
test:
movq %rsi, %rdx
movq 16(%rsi), %rax
leaq -1(%rax), %rcx
negq %rax
andq %rcx, %rax
addq %rdi, %rax
retq
```
After:
```asm
test:
movq %rsi, %rdx
movq %rdi, %rax
retq
```
Optimize away a `fs::metadata` call.
This also eliminates a use of a `Path` convenience function, in support
of #80741, refactoring `std::path` to focus on pure data structures and
algorithms.
* Rename `ModuleData.normal_ancestor_id` to `nearest_parent_mod`
`normal_ancestor_id` is a very confusing name if you don't already
understand what it means. Adding docs helps, but using a clearer and
more obvious name is also important.
* Rename `Resolver::nearest_mod_parent` to `nearest_parent_mod`
* Add more docs
This also eliminates a use of a `Path` convenience function, in support
of #80741, refactoring `std::path` to focus on pure data structures and
algorithms.
Remove useless doc_alias feature gate
As `@jyn514` rightfully noted in https://github.com/rust-lang/rust/pull/80686 , this feature is no more. Therefore, cleanup time!
r? `@jyn514`
Add more code spans to docs in intrinsics.rs
I have added some more code spans in core/src/intrinsics.rs, changing some `=` to `==`, etc. I also changed the wording in some sections.
Rollup of 12 pull requests
Successful merges:
- #80442 (Mention Arc::make_mut and Rc::make_mut in the documentation of Cow)
- #80533 (bootstrap: clippy fixes)
- #80538 (Add check for `[T;N]`/`usize` mismatch in astconv)
- #80612 (Remove reverted change from relnotes)
- #80627 (Builder: Warn if test file does not exist)
- #80637 (Use Option::filter instead of open-coding it)
- #80643 (Move variable into the only branch where it is relevant)
- #80656 (Fixed documentation error for `std::hint::spin_loop`)
- #80666 (Fix missing link for "fully qualified syntax")
- #80672 (./x.py clippy: allow the most noisy lints)
- #80677 (doc -- list edit for consistency)
- #80696 (make sure that promoteds which fail to evaluate in dead const code behave correctly)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
make sure that promoteds which fail to evaluate in dead const code behave correctly
https://github.com/rust-lang/rust/pull/80243 showed that we'll have to live with these kinds of failing promoteds for a while, so let's make sure we have a test that covers them.
./x.py clippy: allow the most noisy lints
This silences the following clippy lints in ./x.py clippy:
many_single_char_names (there are a lot of warnings caused by stdarch)
collapsible_if (can reduce readability)
type_complexity
missing_safety_doc (there are almost 3K warnings issued)
too_many_arguments
needless_lifetimes (people want 'tcx lifetimes etc)
wrong_self_convention (warns about from_..(), to_..(), into_..().. fns that do or do not take self by reference.
Just for clarification; this only changes the output of `x.py clippy` inside the rustc repo and does not change anything about clippy or how `cargo clippy` is run on peoples crates.
Move variable into the only branch where it is relevant
At the `if` branch `filter` (the `let` binding) is `None` iff `filter` (the parameter) was `None`.
We can branch on the parameter, move the binding into the `if`, and the complexity of handling
`Option<Option<_>` largely dissolves.
`@rustbot` modify labels +C-cleanup +T-compiler
Note: I have no idea how hot this code is. If this method frequently gets called with a `None` filter, there might be a small perf improvement.
Builder: Warn if test file does not exist
Running `./x.py test` with a file that does not exists (but where the path belongs to a test suite) silently ignores the missing file and runs the whole test suite. This PR prints a warning to reduce the potential surprise factor.
Closes#80621
Add check for `[T;N]`/`usize` mismatch in astconv
Helps clarify the issue in #80506
by adding a specific check for mismatches between [T;N] and usize.
r? `@lcnr`
Don't use `self.date` unconditionally for `program_out_of_date()`
This avoids unnecessary cache invalidations for programs not affected by
the stage0 version (which is everything except the stage0 compiler
itself).
The redundant invalidations weren't noticed until now because they only
showed up on stage0 bumps, at which point people are used to rebuilding
everything anyway. I noticed it in https://github.com/rust-lang/rust/pull/79540
because I wasn't adding `self.date` to the stamp file (because I didn't realize it was necessary). Rather than
adding self.date I thought it was better to remove it from the cache key.
use PlaceRef more consistently instead of loosely coupled local+projection
Instead of working directly with the `projections` array, use `iter_projections` and `last_projection`. This avoids having to construct new `PlaceRef` from the pieces everywhere.
I only did this for a few files, to see how people think about this. If y'all are happy with this, I'll open an E-mentor issue to complete this. I grepped for `Place::ty_from` to find the places that need adjusting -- this could miss some, but I am not sure what else to grep for.
