stabilize `const_extern_fn`
closes https://github.com/rust-lang/rust/issues/64926
tracking issue: https://github.com/rust-lang/rust/issues/64926
reference PR: https://github.com/rust-lang/reference/pull/1596
## Stabilizaton Report
### Summary
Using `const extern "Rust"` and `const extern "C"` was already stabilized (since version 1.62.0, see https://github.com/rust-lang/rust/pull/95346). This PR stabilizes the other calling conventions: it is now possible to write `const unsafe extern "calling-convention" fn` and `const extern "calling-convention" fn` for any supported calling convention:
```rust
const extern "C-unwind" fn foo1(val: u8) -> u8 { val + 1}
const extern "stdcall" fn foo2(val: u8) -> u8 { val + 1}
const unsafe extern "C-unwind" fn bar1(val: bool) -> bool { !val }
const unsafe extern "stdcall" fn bar2(val: bool) -> bool { !val }
```
This can be used to const-ify an `extern fn`, or conversely, to make a `const fn` callable from external code.
r? T-lang
cc `@RalfJung`
ci: add a runner for vanilla LLVM 19
Ubuntu 24.10 has `llvm-19` packages that we can start testing with.
The `Dockerfile` is otherwise the same as the `llvm-18` runner.
simd_shuffle: require index argument to be a vector
Remove some codegen hacks by forcing the SIMD shuffle `index` argument to be a vector, which means (thanks to https://github.com/rust-lang/rust/pull/128537) that it will automatically be passed as an immediate in LLVM. The only special-casing we still have is for the extra sanity-checks we add that ensure that the indices are all in-bounds. (And the GCC backend needs to do a bunch of work since the Rust intrinsic is modeled after what LLVM expects, which seems to be quite different from what GCC expects.)
Fixes https://github.com/rust-lang/rust/issues/128738, see that issue for more context.
Rollup of 5 pull requests
Successful merges:
- #130138 (bootstrap: Print more debug info when `find_initial_libdir` fails)
- #130199 (Don't call closure_by_move_body_def_id on FnOnce async closures in MIR validation)
- #130302 (add llvm-bitcode-linker and llvm-tools bins to ci-rustc's sysroot)
- #130306 (avoid updating LLVM submodule during bootstrap unit tests)
- #130317 (`ProjectionElem` and `UnOp`/`BinOp` dont need to be `PartialOrd`/`Ord`)
r? `@ghost`
`@rustbot` modify labels: rollup
avoid updating LLVM submodule during bootstrap unit tests
To test this, make sure you don't have `src/llvm-project` fetched and then set `llvm.download-ci-llvm=true` and run `x test bootstrap`.
bootstrap: Print more debug info when `find_initial_libdir` fails
From looking at the failure messages printed by #129775, my hypothesis is that `rustc --print=sysroot` sometimes prints the wrong path when the rustc executable is hardlinked in multiple places, at least on my macOS system.
However, currently I don't have any concrete evidence of this actually happening. This PR therefore expands on #129775 by printing even more information on failure (including the actual rustc path), in the hope that when the failure next occurs we can confirm or reject the hypothesis that `rustc --print=sysroot` is printing the wrong path.
[bootstrap] Add support for building gcc and libgccjit
As `@eholk` summarized below:
> From my understanding, this change would add libgccjit as an optional component to the Rust distribution. This library is licensed under GPLv2 and currently we do not have any other components under that license so it would be a new license, and one that is generally more restrictive than the other licenses we use.
It'll greatly improve the experience for anyone wanting to work on the GCC backend from the compiler.
Should help with https://github.com/rust-lang/rust/issues/124172.
Will unblock #124353.
r? `@Kobzol`
Rollup of 6 pull requests
Successful merges:
- #129320 (Fix crash when labeling arguments for call_once and friends)
- #130266 (target: default to the medium code model on LoongArch targets)
- #130297 (Dataflow cleanups)
- #130299 (Add set_dcx to ParseSess)
- #130301 (some fixes for clashing_extern_declarations lint)
- #130305 (Clippy: consider msrv for const context for const_float_bits_conv)
r? `@ghost`
`@rustbot` modify labels: rollup
Clippy: consider msrv for const context for const_float_bits_conv
When `const_float_bits_conv` was stabilized for 1.83.0, clippy lints started to be triggered in const context ignoring MSRV. This PR makes the lints trigger in const context only when the MSRV meets 1.83.0.
Fixes https://github.com/rust-lang/rust-clippy/issues/13383.
skip target sanity check when it's a `local-rebuild`
Running the stage0 target sanity check on the newly built compiler can result in errors and incorrect assumptions.
Resolves#130242
- Replace non-standard names like 's, 'p, 'rg, 'ck, 'parent, 'this, and
'me with vanilla 'a. These are cases where the original name isn't
really any more informative than 'a.
- Replace names like 'cx, 'mir, and 'body with vanilla 'a when the lifetime
applies to multiple fields and so the original lifetime name isn't
really accurate.
- Put 'tcx last in lifetime lists, and 'a before 'b.
Re-run coverage tests if `coverage-dump` was modified
If the `coverage-dump` tool was modified, coverage tests should not be treated as up-to-date, because the tool's output might have changed.
Bootstrap already handles rebuilding the tool itself if its sources were changed, so all compiletest needs to do here is include the binary in the list of files whose timestamps are checked.
This should have no effect on non-coverage tests, because bootstrap won't pass the `--coverage-dump-path` flag, so the path in compiletest's config will be None.
Properly report error on `const gen fn`
Fixes#130232
Also removes some (what I thought were unused) functions, and fixes a bug in clippy where we considered `gen fn` to be the same as `fn` because it was only built to consider asyncness.
Add test for S_OBJNAME & update test for LF_BUILDINFO cl and cmd
Update the unit test for checking cl and cmd in LF_BUILDINFO. With llvm-pdbutil we can now more specifically check if the string appears at the right location instead of just checking whether the string exists at all.
Context: https://github.com/rust-lang/rust/issues/96475
Fix default/minimum deployment target for Aarch64 simulator targets
The minimum that `rustc` encoded did not match [the version in Clang](https://github.com/llvm/llvm-project/blob/llvmorg-18.1.8/llvm/lib/TargetParser/Triple.cpp#L1900-L1932), and that meant that that when linking, Clang ended up bumping the version. See https://github.com/rust-lang/rust/issues/129432 for more motivation behind this change.
Specifically, this PR sets the correct deployment target of the following targets:
- `aarch64-apple-ios-sim` from 10.0 to 14.0
- `aarch64-apple-tvos-sim` from 10.0 to 14.0
- `aarch64-apple-watchos-sim` from 5.0 to 7.0
- `aarch64-apple-ios-macabi` from 13.1 to 14.0
I have chosen not to document the `-sim` changes in the platform support docs, as it is fundamentally uninteresting; the normal targets (e.g. `aarch64-apple-ios`) still have the same deployment target, and that's what developers should actually target.
r? compiler
CC `@BlackHoleFox`
Running the stage0 target sanity check on the newly built compiler can result
in errors and incorrect assumptions.
Signed-off-by: onur-ozkan <work@onurozkan.dev>
Add -Z small-data-threshold
This flag allows specifying the threshold size above which LLVM should not consider placing small objects in a `.sdata` or `.sbss` section.
Support is indicated in the target options via the
small-data-threshold-support target option, which can indicate either an
LLVM argument or an LLVM module flag. To avoid duplicate specifications
in a large number of targets, the default value for support is
DefaultForArch, which is translated to a concrete value according to the
target's architecture.
miri: fix overflow detection for unsigned pointer offset
This is the Miri part of https://github.com/rust-lang/rust/pull/130229. This is already UB in codegen so we better make Miri detect it; updating the docs may take time if we have to follow some approval process, but let's make Miri match reality ASAP.
r? ``@scottmcm``
refactor merge base logic and fix `x fmt`
When remote upstream is not configured, using [get_git_modified_files](38e3a5771c/src/tools/build_helper/src/git.rs (L114)) to find modified files fails because [get_rust_lang_rust_remote](38e3a5771c/src/tools/build_helper/src/git.rs (L46-L48)) can not resolve "rust-lang/rust" from the git output. The changes in this PR makes bootstrap to find the latest bors commit, treating it as the "closest upstream commit" so that the change tracker logic can use it to find the diffs.
In addition, [skips formatting](e392454483) if there are no modified files.
Fixes#130147
This flag allows specifying the threshold size above which LLVM should
not consider placing small objects in a .sdata or .sbss section.
Support is indicated in the target options via the
small-data-threshold-support target option, which can indicate either an
LLVM argument or an LLVM module flag. To avoid duplicate specifications
in a large number of targets, the default value for support is
DefaultForArch, which is translated to a concrete value according to the
target's architecture.
