Suggest deriving required supertraits
closes https://github.com/rust-lang/rust/issues/91550
I chose to just hardcode handling for PartialOrd and PartialEq because that should be robust enough and I dont know how to go about doing it generically
r? rust-lang/diagnostics
Use `optflag` for `--report-time`
Essentially, what is described here:
https://github.com/rust-lang/rust/issues/64888#issuecomment-1008047228
There is one difference. The comment proposes to add a
`--report-time-color` option. This change instead uses libtest's
existing `--color` option for that purpose.
Add documentation to more `From::from` implementations.
For users looking at documentation through IDE popups, this gives them relevant information rather than the generic trait documentation wording “Performs the conversion”. For users reading the documentation for a specific type for any reason, this informs them when the conversion may allocate or copy significant memory versus when it is always a move or cheap copy.
Notes on specific cases:
* The new documentation for `From<T> for T` explains that it is not a conversion at all.
* Also documented `impl<T, U> Into<U> for T where U: From<T>`, the other central blanket implementation of conversion.
* The new documentation for construction of maps and sets from arrays of keys mentions the handling of duplicates. Future work could be to do this for *all* code paths that convert an iterable to a map or set.
* I did not add documentation to conversions of a specific error type to a more general error type.
* I did not add documentation to unstable code.
This change was prepared by searching for the text "From<... for" and so may have missed some cases that for whatever reason did not match. I also looked for `Into` impls but did not find any worth documenting by the above criteria.
Destabilize cfg(target_has_atomic_load_store = ...)
This was not intended to be stabilized yet.
This keeps the cfg_target_has_atomic feature gate name since compiler-builtins otherwise depends on it and I'd rather not try to manage a bump across a crates.io published repository given the time-sensitivity here (we need to land this quickly to avoid a beta backport).
Closes https://github.com/rust-lang/rust/issues/32976
r? `@Amanieu`
Maintain broken symlink behaviour for the Windows exe resolver
When the resolver was updated to remove the current directory from the search path (see #87704), care was take to avoid unintentional changes that hadn't been discussed. However, I missed the broken symlink behaviour. This PR fixes that.
**Edit** This turned out to be more important than I first realised. There are some types of application stubs that will redirect to the actual process when run using `CreateProcessW`, but due to the way they're implemented they cannot be opened normally using a `File::open` that follows reparse points. So this doesn't work with our current `exists` and `try_exists` methods.
Fixes#91177
Update books
## nomicon
3 commits in 9493715a6280a1f74be759c7e1ef9999b5d13e6f..90993eeac93dbf9388992de92965f99cf6f29a03
2022-01-27 19:00:32 -0800 to 2022-02-13 12:44:12 +0900
- Fix a small typo in exception-safety.md (rust-lang/nomicon#341)
- Make `Vec::new` public in vec-alloc.md (rust-lang/nomicon#336)
- Fix a syntax error in leaking.md (rust-lang/nomicon#335)
## reference
6 commits in 411c2f0d5cebf48453ae2d136ad0c5e611d39aec..70fc73a6b908e08e66aa0306856c5211312f6c05
2022-01-30 12:46:37 -0800 to 2022-02-14 19:33:01 -0800
- Document pre-Rust-2021 special case for IntoIterator method lookup (rust-lang/reference#1154)
- Mention std::is_aarch64_feature_detected (rust-lang/reference#1061)
- Fix link to the Bastion of the Turbofish (rust-lang/reference#1161)
- Improve associated constant item CTFE timing section (rust-lang/reference#1147)
- document `#![feature(const_generics_defaults)]` (rust-lang/reference#1098)
- Update patterns allowed in @ patterns (rust-lang/reference#1158)
## book
6 commits in 98904efaa4fc968db8ff59cf2744d9f7ed158166..67b768c0b660a069a45f0e5d8ae2f679df1022ab
2022-01-29 21:22:31 -0500 to 2022-02-09 21:52:41 -0500
- Snapshot of ch18 for nostarch
- Remove mention of destructuring references as that's not covered currently
- Add note that exhaustiveness checking doesn't extend to match guards
- Change match guard example to actually be unexpressable with patterns alone
- Corrected listing number from 9-10 to 9-13
- Remove duplicate paragraph after No Starch related changes
## rustc-dev-guide
3 commits in 8763adb62c712df69b1d39ea3e692b6d696cc4d9..62f58394ba7b203f55ac35ddcc4c0b79578f5706
2022-01-26 14:01:40 -0800 to 2022-02-11 08:42:50 -0500
- Correction, building stage3 compiler (rust-lang/rustc-dev-guide#1298)
- Triage some date references (rust-lang/rustc-dev-guide#1293)
- mention test folders for cfg(bootstrap) (rust-lang/rustc-dev-guide#1294)
Fix inconsistent symbol mangling with -Zverbose
Always skip arguments that are the defaults of their respective
parameters, to avoid generating inconsistent symbols for builds
with `-Zverbose` flag and without it.
Support pretty printing of invalid constants
Make it possible to pretty print invalid constants by introducing a
fallible variant of `destructure_const` and falling back to debug
formatting when it fails.
Closes#93688.
Make [u8]::cmp implementation branchless
The current implementation generates rather ugly assembly code, branching when the common parts are equal. By performing the comparison of the lengths upfront using a subtraction, the assembly gets much prettier: https://godbolt.org/z/4e5fnEKGd.
This will probably not impact speed too much, as the expensive part is in most cases the `memcmp`, but it sure looks better (I'm porting a sorting algorithm currently, and that branch just bothered me).
Resolve concern of `derive_default_enum`
This resolves the concern in favor of prohibiting multiple instances of
the attribute. This is similar to non-helper attributes as introduced in
#88681.
``@rustbot`` label +S-waiting-on-review +T-libs-api
Treat static refs as `mir::ConstantKind::Val`
With the upcoming introduction of Valtrees we want to treat more values as `mir::ConstantKind::Val` directly.
r? `@lcnr`
cc `@oli-obk`
Always skip arguments that are the defaults of their respective
parameters, to avoid generating inconsistent symbols for builds
with `-Zverbose` flag and without it.
Make it possible to pretty print invalid constants by introducing a
fallible variant of `destructure_const` and falling back to debug
formatting when it fails.
Add support for control-flow protection
This change adds a flag for configuring control-flow protection in the LLVM backend. In Clang, this flag is exposed as `-fcf-protection` with options `none|branch|return|full`. This convention is followed for `rustc`, though as a codegen option: `rustc -Z cf-protection=<none|branch|return|full>`. Tracking issue for future work is #93754.
Rework GAT `where` clause check
rework the GAT where check to use a fixed-point algorithm, and check all GATs in a trait at once
fixes#93278
r? `@jackh726`
cc `@nikomatsakis`
