mgca: Add ConstArg representation for const items
tracking issue: rust-lang/rust#132980fixesrust-lang/rust#131046fixesrust-lang/rust#134641
As part of implementing `min_generic_const_args`, we need to distinguish const items that can be used in the type system, such as in associated const equality projections, from const items containing arbitrary const code, which must be kept out of the type system. Specifically, all "type consts" must be either concrete (no generics) or generic with a trivial expression like `N` or a path to another type const item.
To syntactically distinguish these cases, we require, for now at least, that users annotate all type consts with the `#[type_const]` attribute. Then, we validate that the const's right-hand side is indeed eligible to be a type const and represent it differently in the HIR.
We accomplish this representation using a new `ConstItemRhs` enum in the HIR, and a similar but simpler enum in the AST. When `#[type_const]` is **not** applied to a const (e.g. on stable), we represent const item right-hand sides (rhs's) as HIR bodies, like before. However, when the attribute is applied, we instead lower to a `hir::ConstArg`. This syntactically distinguishes between trivial const args (paths) and arbitrary expressions, which are represented using `AnonConst`s. Then in `generics_of`, we can take advantage of the existing machinery to bar the `AnonConst` rhs's from using parent generics.
When mgca is enabled, const rhs's that are paths may have false
negatives with the lints in non_copy_const.rs. But these should probably
be using the trait solver anyway, and it only happens under mgca.
re-use `self.get_all_attrs` result for pass indirectly attribute
Could be a fix for a potential performance regression reported here https://github.com/rust-lang/rust/pull/144529#issuecomment-3491236458. Apparently the regression later disappeared. Nevertheless, this seems like a decent refactor.
r? ````@JonathanBrouwer```` (vaguely attribute-related, maybe there are other optimizations to that PR that we're missing)
[rustdoc] Replace `print` methods with functions to improve code readability
We have a lot of `print` methods, making it quite tricky to know what the types we're manipulating are.
We did something similar with `Clean` trait a few years ago (the first PR was https://github.com/rust-lang/rust/pull/99638, followed by a lot of them).
Each commit replaces one type for easier review.
r? `````@yotamofek`````
Fix rust-by-example spanish translation
A spanish translation was added in https://github.com/rust-lang/rust-by-example/pull/1910, but the upstream integration was never added.
```@marioidival,``` I assume you intended for this to go live?
update isolate_highest_one for NonZero<T>
## Rationale
Let `x = self` and
`m = (((1 as $Int) << (<$Int>::BITS - 1)).wrapping_shr(self.leading_zeros()))`
Then the previous code computed `NonZero::new_unchecked(x & m)`.
Since `m` has exactly one bit set (the most significant 1-bit of `x`), `(x & m) == m`.
Therefore, the masking step was redundant.
The shift is safe and does not need wrapping because:
* `self.leading_zeros() < $Int::BITS` because `self` is non-zero.
* The result of `unchecked_shr` is non-zero, satisfying the `NonZero` invariant. if wrapping happens we would be violating `NonZero` invariants.
why this micro optimization?
the old code was suboptimal it duplicated `$Int`’s isolate_highest_one logic instead of delegating to it. Since the type already wraps `$Int`, either delegation should be used for clarity or, if keeping a custom implementation, it should be optimized as above.
Add LLVM realtime sanitizer
This is a new attempt at adding the [LLVM real-time sanitizer](https://clang.llvm.org/docs/RealtimeSanitizer.html) to rust.
Previously this was attempted in https://github.com/rust-lang/rfcs/pull/3766.
Since then the `sanitize` attribute was introduced in https://github.com/rust-lang/rust/pull/142681 and it is a lot more flexible than the old `no_santize` attribute. This allows adding real-time sanitizer without the need for a new attribute, like it was proposed in the RFC. Because i only add a new value to a existing command line flag and to a attribute i don't think an MCP is necessary.
Currently real-time santizer is usable in rust code with the [rtsan-standalone](https://crates.io/crates/rtsan-standalone) crate. This downloads or builds the sanitizer runtime and then links it into the rust binary.
The first commit adds support for more detailed sanitizer information.
The second commit then actually adds real-time sanitizer.
The third adds a warning against using real-time sanitizer with async functions, cloures and blocks because it doesn't behave as expected when used with async functions. I am not sure if this is actually wanted, so i kept it in a seperate commit.
The fourth commit adds the documentation for real-time sanitizer.
Add -Zannotate-moves for profiler visibility of move/copy operations (codegen)
**Note:** this is an alternative implementation of https://github.com/rust-lang/rust/pull/147206; rather than being a MIR transform, it adds the annotations closer to codegen. It's functionally the same but the implementation is lower impact and it could be more correct.
---
This implements a new unstable compiler flag `-Zannotate-moves` that makes move and copy operations visible in profilers by creating synthetic debug information. This is achieved with zero runtime cost by manipulating debug info scopes to make moves/copies appear as calls to `compiler_move<T, SIZE>` and `compiler_copy<T, SIZE>` marker functions in profiling tools.
This allows developers to identify expensive move/copy operations in their code using standard profiling tools, without requiring specialized tooling or runtime instrumentation.
The implementation works at codegen time. When processing MIR operands (`Operand::Move` and `Operand::Copy`), the codegen creates an `OperandRef` with an optional `move_annotation` field containing an `Instance` of the appropriate profiling marker function. When storing the operand, `store_with_annotation()` wraps the store operation in a synthetic debug scope that makes it appear inlined from the marker.
Two marker functions (`compiler_move` and `compiler_copy`) are defined in `library/core/src/profiling.rs`. These are never actually called - they exist solely as debug info anchors.
Operations are only annotated if:
- We're generating debug info and the feature is enabled.
- Meets the size threshold (default: 65 bytes, configurable via `-Zannotate-moves=SIZE`), and is non-zero
- Has a memory representation
This has a very small size impact on object file size. With the default limit it's well under 0.1%, and even with a very small limit of 8 bytes it's still ~1.5%. This could be enabled by default.
Update memchr to 2.7.6
memchr 2.7.6 contains a bugfix for aarch64_be.
Note: I'm not sure about how dependency updates are managed in rust.git. If something should go through another branch or will happen automatically, please let me know.
Liveness: Cache the set of string constants for suggestions.
Even on a slow diagnostic path, listing all the constants in MIR can be expensive, so cache it.
Rollup of 12 pull requests
Successful merges:
- rust-lang/rust#145768 (Offload device)
- rust-lang/rust#145992 (Stabilize `vec_deque_pop_if`)
- rust-lang/rust#147416 (Early return if span is from expansion so we dont get empty span and ice later on)
- rust-lang/rust#147808 (btree: cleanup difference, intersection, is_subset)
- rust-lang/rust#148520 (style: Use binary literals instead of hex literals in doctests for `highest_one` and `lowest_one`)
- rust-lang/rust#148559 (Add typo suggestion for a misspelt Cargo environment variable)
- rust-lang/rust#148567 (Fix incorrect precedence caused by range expression)
- rust-lang/rust#148570 (Fix mismatched brackets in generated .dir-locals.el)
- rust-lang/rust#148575 (fix dev guide link in rustc_query_system/dep_graph/README.md)
- rust-lang/rust#148578 (core docs: add notes about availability of `Atomic*::from_mut_slice`)
- rust-lang/rust#148603 (Backport 1.91.1 relnotes to main)
- rust-lang/rust#148609 (Sync str::rsplit_once example with str::split_once)
r? `@ghost`
`@rustbot` modify labels: rollup
Sync str::rsplit_once example with str::split_once
This adds `"cfg=".rsplit_once('=')` case to `rsplit_once` example, bringing it in sync with example for `split_once`. For consistency and to make life easier for ones who want to ensure bahaviour of this specific edge case.
Backport 1.91.1 relnotes to main
Backport of the release notes from https://github.com/rust-lang/rust/pull/148593 to the main branch. This should land before Monday so that the automation creates the GitHub release.
joboet