do not allow ABI mismatches inside repr(C) types
In https://github.com/rust-lang/rust/pull/115476 we allowed ABI mismatches inside `repr(C)` types. This wasn't really discussed much; I added it because from how I understand calling conventions, this should actually be safe in practice. However I entirely forgot to actually allow this in Miri, and in the mean time I have learned that too much ABI compatibility can be a problem for CFI (it can reject fewer calls so that gives an attacker more room to play with).
So I propose we take back that part about ABI compatibility in `repr(C)`. It is anyway something that C and C++ do not allow, as far as I understand.
In the future we might want to introduce a class of ABI compatibilities where we say "this is a bug and it may lead to aborting the process, but it won't lead to arbitrary misbehavior -- worst case it'll just transmute the arguments from the caller type to the callee type". That would give CFI leeway to reject such calls without introducing the risk of arbitrary UB. (The UB can still happen if the transmute leads to bad results, of course, but it wouldn't be due to ABI weirdness.)
#115476 hasn't reached beta yet so if we land this before Dec 22nd we can just pretend this all never happened. ;) Otherwise we should do a beta backport (of the docs change at least).
Cc `@rust-lang/opsem` `@rust-lang/types`
fix: Update metavariable expression implementation
Fixes https://github.com/rust-lang/rust-analyzer/issues/16154
This duplicates behavior of that before and after PR https://github.com/rust-lang/rust/pull/117050 based on the toolchain version. There are some 1.76 nightlies that are still broken (any before that PR basically) but fetching and storing the commit makes little sense to me (opposed to the toolchain version).
add more niches to rawvec
Previously RawVec only had a single niche in its `NonNull` pointer. With this change it now has `isize::MAX` niches since half the value-space of the capacity field is never needed, we can't have a capacity larger than isize::MAX.
match lowering: Remove the `make_target_blocks` hack
This hack was introduced 4 years ago in [`a1d0266` (#60730)](a1d0266878) to improve LLVM optimization time, specifically noticed in the `encoding` benchmark. Measurements today indicate it is no longer needed.
r? `@matthewjasper`
Make exhaustiveness usable outside of rustc
With this PR, `rustc_pattern_analysis` compiles on stable (with the `stable` feature)! `rust-analyzer` will be able to use it to provide match-related diagnostics and refactors.
Two questions:
- Should I name the feature `nightly` instead of `rustc` for consistency with other crates? `rustc` makes more sense imo.
- `typed-arena` is an optional dependency but tidy made me add it to the allow-list anyway. Can I avoid that somehow?
r? `@compiler-errors`
minor: Optimizing Performance with `Promise.all` 🏎
Hello,
This pull request introduces a modest performance improvement by executing asynchronous tasks using `Promise.all`, thereby enhancing the efficient utilization of hardware resources.
Thank you for considering this enhancement.
Ref-: https://github.com/rust-lang/rust/pull/119108
minor: Use reserve when removing markdown from text
After markdown syntax removal the length of the text is roughly the same so we can reserve memory beforehand
fix(mbe): desugar doc correctly for mbe
Fixes#16110.
The way rust desugars doc comments when expanding macros is rendering it as raw strings delimited with hashes. Rust-analyzer wasn't aware of this, so the desugared doc comments wouldn't match correctly when on the LHS of macro declarations.
This PR fixes this by porting the code used by rustc:
59096cdad0/compiler/rustc_ast/src/tokenstream.rs (L662-L671)
Add new tier 3 aarch64-apple-watchos target
Apple Xcode 14/15 releases add a new apple watchos target architecture arm64 out of arm64_32 and armv7k, now add a new tier 3 target support for this target.
### Tier 3 Target Requirements
Adds support for Apple WatchOS aarch64-apple-watchos target.
Below are details on how this target meets the requirements for tier 3:
> tier 3 target must have a designated developer or developers (the "target maintainers") on record to be CCed when issues arise regarding the target. (The mechanism to track and CC such developers may evolve over time.)
`@leohowell` has volunteered to be the target maintainer. I am also happy to help if a second maintainer is required.
> Targets must use naming consistent with any existing targets; for instance, a target for the same CPU or OS as an existing Rust target should use the same name for that CPU or OS. Targets should normally use the same names and naming conventions as used elsewhere in the broader ecosystem beyond Rust (such as in other toolchains), unless they have a very good reason to diverge. Changing the name of a target can be highly disruptive, especially once the target reaches a higher tier, so getting the name right is important even for a tier 3 target.
Uses the same naming as the LLVM target, and the same convention as other Apple targets.
> Target names should not introduce undue confusion or ambiguity unless absolutely necessary to maintain ecosystem compatibility. For example, if the name of the target makes people extremely likely to form incorrect beliefs about what it targets, the name should be changed or augmented to disambiguate it.
I don't believe there is any ambiguity here.
> Tier 3 targets may have unusual requirements to build or use, but must not create legal issues or impose onerous legal terms for the Rust project or for Rust developers or users.
I don't see any legal issues here.
> The target must not introduce license incompatibilities.
> Anything added to the Rust repository must be under the standard Rust license (MIT OR Apache-2.0).
> The target must not cause the Rust tools or libraries built for any other host (even when supporting cross-compilation to the target) to depend on any new dependency less permissive than the Rust licensing policy. This applies whether the dependency is a Rust crate that would require adding new license exceptions (as specified by the tidy tool in the rust-lang/rust repository), or whether the dependency is a native library or binary. In other words, the introduction of the target must not cause a user installing or running a version of Rust or the Rust tools to be subject to any new license requirements.
> If the target supports building host tools (such as rustc or cargo), those host tools must not depend on proprietary (non-FOSS) libraries, other than ordinary runtime libraries supplied by the platform and commonly used by other binaries built for the target. For instance, rustc built for the target may depend on a common proprietary C runtime library or console output library, but must not depend on a proprietary code generation library or code optimization library. Rust's license permits such combinations, but the Rust project has no interest in maintaining such combinations within the scope of Rust itself, even at tier 3.
> Targets should not require proprietary (non-FOSS) components to link a functional binary or library.
> "onerous" here is an intentionally subjective term. At a minimum, "onerous" legal/licensing terms include but are not limited to: non-disclosure requirements, non-compete requirements, contributor license agreements (CLAs) or equivalent, "non-commercial"/"research-only"/etc terms, requirements conditional on the employer or employment of any particular Rust developers, revocable terms, any requirements that create liability for the Rust project or its developers or users, or any requirements that adversely affect the livelihood or prospects of the Rust project or its developers or users.
I see no issues with any of the above.
> Neither this policy nor any decisions made regarding targets shall create any binding agreement or estoppel by any party. If any member of an approving Rust team serves as one of the maintainers of a target, or has any legal or employment requirement (explicit or implicit) that might affect their decisions regarding a target, they must recuse themselves from any approval decisions regarding the target's tier status, though they may otherwise participate in discussions.
> This requirement does not prevent part or all of this policy from being cited in an explicit contract or work agreement (e.g. to implement or maintain support for a target). This requirement exists to ensure that a developer or team responsible for reviewing and approving a target does not face any legal threats or obligations that would prevent them from freely exercising their judgment in such approval, even if such judgment involves subjective matters or goes beyond the letter of these requirements.
Only relevant to those making approval decisions.
> Tier 3 targets should attempt to implement as much of the standard libraries as possible and appropriate (core for most targets, alloc for targets that can support dynamic memory allocation, std for targets with an operating system or equivalent layer of system-provided functionality), but may leave some code unimplemented (either unavailable or stubbed out as appropriate), whether because the target makes it impossible to implement or challenging to implement. The authors of pull requests are not obligated to avoid calling any portions of the standard library on the basis of a tier 3 target not implementing those portions.
core and alloc can be used. std support will be added in a subsequent PR.
> The target must provide documentation for the Rust community explaining how to build for the target, using cross-compilation if possible. If the target supports running tests (even if they do not pass), the documentation must explain how to run tests for the target, using emulation if possible or dedicated hardware if necessary.
Use --target= option to cross compile, just like any target. Tests can be run using the WatchOS simulator (see https://developer.apple.com/documentation/xcode/running-your-app-in-the-simulator-or-on-a-device).
> Tier 3 targets must not impose burden on the authors of pull requests, or other developers in the community, to maintain the target. In particular, do not post comments (automated or manual) on a PR that derail or suggest a block on the PR based on a tier 3 target. Do not send automated messages or notifications (via any medium, including via `@)` to a PR author or others involved with a PR regarding a tier 3 target, unless they have opted into such messages.
> Backlinks such as those generated by the issue/PR tracker when linking to an issue or PR are not considered a violation of this policy, within reason. However, such messages (even on a separate repository) must not generate notifications to anyone involved with a PR who has not requested such notifications.
I don't foresee this being a problem.
> Patches adding or updating tier 3 targets must not break any existing tier 2 or tier 1 target, and must not knowingly break another tier 3 target without approval of either the compiler team or the maintainers of the other tier 3 target.
> In particular, this may come up when working on closely related targets, such as variations of the same architecture with different features. Avoid introducing unconditional uses of features that another variation of the target may not have; use conditional compilation or runtime detection, as appropriate, to let each target run code supported by that target.
No other targets should be affected by the pull request.
r? compiler-team
ci: docker: dist-various-1: Include RISC-V C compilers
The compiler-builtins for RISC-V are missing some key functions, such as __bswapsi2 [1].
We can't just pull in the LLVM compiler-rt builtins as the rust-lang/rust distribution container doesn't have a C compiler [2].
This patch adds RISC-V C compilers to the CI Dockerfile as the first step towards enabling LLVM compiler-rt builtins for RISC-V Rust.
1: https://github.com/rust-lang/compiler-builtins/issues/350
2: e4f46b91ca
Fixes#16110.
The way rust desugars doc comments when expanding macros
is rendering it as raw strings delimited with hashes.
Rust-analyzer wasn't aware of this, so the desugared doc
comments wouldn't match correctly when on the LHS of macro
declarations.
This PR fixes this by porting the code used by rustc: 4cfdbd328b/compiler/rustc_ast/src/tokenstream.rs (L6837)
Desugar `yield` in `async gen` correctly, ensure `gen` always returns unit
1. Ensure `async gen` blocks desugar `yield $expr` to `task_context = yield async_gen_ready($expr)`. Previously we were not assigning the `task_context` correctly, meaning that `yield` expressions in async generators returned type `ResumeTy` instead of `()`, and that we were not storing the `task_context` (which is probably unsound if we were reading the old task-context which has an invalidated borrow or something...)
2. Ensure that all `(async?) gen` blocks and `(async?) gen` fns return unit. Previously we were only checking this for `gen fn`, meaning that `gen {}` and `async gen {}` and `async gen fn` were allowed to return values that weren't unit. This is why #119058 was an ICE rather than an E0308.
Fixes#119058.
fix `x clean` for cross-compiled artifacts
```toml
build = "x86_64-unknown-linux-gnu"
host = ["arm-unknown-linux-gnueabihf"]
target = ["arm-unknown-linux-gnueabihf"]
```
On `x86_64-unknown-linux-gnu`, after cross-compiling with the sample configuration above, artifacts under `build/x86_64-unknown-linux-gnu` never gets cleaned with `x clean`. This PR fixes that.
Document unstable linker flags in the unstable book
This PR:
- removes the unstable linker flavors from the stable documentation
- documents the unstable `-C linker-flavor` values in the unstable book (including the ones previously described as stable)
- documents the unstable `-C link-self-contained` components in the unstable book
I don't know if these have some common reviewers, but if not r? `@petrochenkov` as the most knowledgeable person in this area. Please feel free to reassign, I know that you are quite busy.
Fix ICE `ProjectionKinds Deref and Field were mismatched`
Fix#118144
Removed the check that ICEd if the sequence of projection kinds were different across captures. Instead we now sort based only on `Field` projection kinds.