Turn `stdarch` into a Josh subtree
In a similar vein as https://github.com/rust-lang/rust/pull/141229, this PR makes the `stdarch` repository a Josh subtree (it was previously a submodule). The initial commit of `stdarch` upon this is based is `5a7342fc16b208b1b16624e886937ed8509a6506`, which is the previous commit SHA of the `stdarch` submodule. The sync was performed according to https://hackmd.io/7pOuxnkdQDaL1Y1FQr65xg.
This was decided in https://github.com/rust-lang/stdarch/issues/1655.
Test pull PR on my fork: https://github.com/Kobzol/stdarch/pull/1
Test push PR on my fork: https://github.com/Kobzol/rust/pull/59
I plan to use the same Rust (miri-inspired) tooling that we use for `rustc-dev-guide` to enable pulls/pushes on stdarch.
Note that this repository currently doesn't have any stdarch-specific tests, so before that, the subtree should only be modified through this repository only when dealing with changes that contain "cyclical dependencies" between stdarch and rustc. The long term vision is to integrate stdarch into rust-lang/rust completely.
CC `@Amanieu`
try-job: aarch64-apple
try-job: aarch64-gnu
try-job: `x86_64-msvc-*`
try-job: x86_64-gnu
try-job: x86_64-gnu-aux
Rollup of 7 pull requests
Successful merges:
- rust-lang/rust#142146 (Withdraw the claim `extern "C-cmse-nonsecure-*"` always matches `extern "C"`)
- rust-lang/rust#142200 (`tests/ui`: A New Order [8/N])
- rust-lang/rust#142724 (Add runtime check to avoid overwrite arg in `Diag`)
- rust-lang/rust#142809 (Add PrintTAFn flag for targeted type analysis printing)
- rust-lang/rust#142976 (Check CoerceUnsized impl validity before coercing)
- rust-lang/rust#142992 (Convert some ABI tests to use `extern "rust-invalid"`)
- rust-lang/rust#143000 (Make `Sub`, `Mul`, `Div` and `Rem` `const_traits`)
r? `@ghost`
`@rustbot` modify labels: rollup
Add PrintTAFn flag for targeted type analysis printing
## Summary
This PR adds a new `PrintTAFn` flag to the `-Z autodiff` option that allows printing type analysis information for a specific function, rather than all functions.
## Changes
### New Flag
- Added `PrintTAFn=<function_name>` option to `-Z autodiff`
- Usage: `-Z autodiff=Enable,PrintTAFn=my_function_name`
### Implementation Details
- **Rust side**: Added `PrintTAFn(String)` variant to `AutoDiff` enum
- **Parser**: Updated `parse_autodiff` to handle `PrintTAFn=<function_name>` syntax with proper error handling
- **FFI**: Added `set_print_type_fun` function to interface with Enzyme's `FunctionToAnalyze` command line option
- **Documentation**: Updated help text and documentation for the new flag
### Files Modified
- `compiler/rustc_session/src/config.rs`: Added `PrintTAFn(String)` variant
- `compiler/rustc_session/src/options.rs`: Updated parser and help text (now shows `PrintTAFn` in the list)
- `compiler/rustc_codegen_llvm/src/llvm/enzyme_ffi.rs`: Added FFI function and static variable
- `compiler/rustc_codegen_llvm/src/back/lto.rs`: Added handling for new flag
- `src/doc/rustc-dev-guide/src/autodiff/flags.md`: Updated documentation
- `src/doc/unstable-book/src/compiler-flags/autodiff.md`: Updated documentation
## Testing
The flag can be tested with:
```bash
rustc +enzyme -Z autodiff=Enable,PrintTAFn=square test.rs
```
This will print type analysis information only for the function named "square" instead of all functions.
## Error Handling
The parser includes proper error handling:
- Missing argument: `PrintTAFn` without `=<function_name>` will show an error
- Unknown options: Invalid autodiff options will be reported
r? ```@ZuseZ4```
Add runtime check to avoid overwrite arg in `Diag`
## Origin PR description
At first, I set up a `debug_assert` check for the arg method to make sure that `args` in `Diag` aren't easily overwritten, and I added the `remove_arg()` method, so that if you do need to overwrite an arg, then you can explicitly call `remove_arg()` to remove it first, then call `arg()` to overwrite it.
For the code before the rust-lang/rust#142015 change, it won't compile because it will report an error
```
arg `instance`already exists.
```
This PR also modifies all diagnostics that fail the check to pass the check. There are two cases of check failure:
1. ~~Between *the parent diagnostic and the subdiagnostic*, or *between the subdiagnostics* have the same field between them. In this case, I renamed the conflicting fields.~~
2. ~~For subdiagnostics stored in `Vec`, the rendering may iteratively write the same arg over and over again. In this case, I changed the auto-generation with `derive(SubDiagnostic)` to manually implementing `SubDiagnostic` and manually rendered it with `eagerly_translate()`, similar to https://github.com/rust-lang/rust/issues/142031#issuecomment-2984812090, and after rendering it I manually deleted useless arg with the newly added `remove_arg` method.~~
## Final Decision
After trying and discussing, we made a final decision.
For `#[derive(Subdiagnostic)]`, This PR made two changes:
1. After the subdiagnostic is rendered, remove all args of this subdiagnostic, which allows for usage like `Vec<Subdiag>`.
2. Store `diag.args` before setting arguments, so that you can restore the contents of the main diagnostic after deleting the arguments after subdiagnostic is rendered, to avoid deleting the main diagnostic's arg when they have the same name args.
Withdraw the claim `extern "C-cmse-nonsecure-*"` always matches `extern "C"`
We currently claim that `extern "C-cmse-nonsecure-*"` ABIs will always match `extern "C"`, but that seems... **optimistic** when one considers that `extern "C"` is ambiguous enough to be redefined in ways we may not want the Cortex M Security Extensions ABIs to mirror. If some configuration, feature, or other platform quirk that applied to Arm CPUs with CMSE would modify the `extern "C"` ABI, it does not seem like we should guarantee that also applies to the `extern "cmse-nonsecure-*"` ABIs. Anything involving target modifiers that might affect register availability or usage could make us liars if, for instance, clang decides those apply to normal C functions but not ones with the CMSE attributes, but we still want to have interop with the C compiler.
We simply do not control enough of the factors involved to both force these ABIs to match and still provide useful interop, so we shouldn't implicitly promise they do. We should leave this judgement call to the decisions of platform experts who can afford to keep up with the latest news from Cambridge, instead of enshrining today's hopeful guess forever in Rust's permitted ABIs.
It's a bit weird anyways.
- The attributes are `__attribute__((cmse_nonsecure_call))` and `__attribute__((cmse_nonsecure_entry))`, so the obvious choice is `extern "cmse-nonsecure-call"` and `extern "cmse-nonsecure-entry"`.
- We do not prefix any other ABI that reflects (or even *is*) a C ABI with "C-", with the exception of the Rust-defined `extern "C-unwind`", e.g. we do not have `extern "C-aapcs"` or `extern "C-sysv64"`.
Tracking issues:
- rust-lang/rust#75835
- rust-lang/rust#81391
Remove dead instructions in terminate blocks
Terminate blocks look pretty in the IR I've looked at, so no actual perf delta from this. But it seems reasonable to note produce unused IR.
In order to expose edition dependent divergences in some tests in the test suite, add explicit `edition` annotations. Some of these tests might require additional work to *avoid* the divergences, as they might have been unintentional. These are not exhaustive changes, purely opportunistic while looking at something else.
