Mark `simplify_aggregate_to_copy` mir-opt as unsound
Mark the `simplify_aggregate_to_copy` mir-opt added in #128299 as unsound as it seems to miscompile the MCVE reported in https://github.com/rust-lang/rust/issues/132353. The mir-opt can be re-enabled once this case is fixed.
```rs
fn pop_min(mut score2head: Vec<Option<usize>>) -> Option<usize> {
loop {
if let Some(col) = score2head[0] {
score2head[0] = None;
return Some(col);
}
}
}
fn main() {
let min = pop_min(vec![Some(1)]);
println!("min: {:?}", min);
// panic happens here on beta in release mode
// but not in debug mode
min.unwrap();
}
```
This MCVE is included as a `run-pass` ui regression test in the first commit. I built the ui test with a nightly manually, and can reproduce the behavioral difference with `-C opt-level=0` and `-C opt-level=1`. Locally, this ui test will fail unless it was run on a compiler built with the second commit marking the mir-opt as unsound thus disabling it by default.
This PR **partially reverts** commit e7386b3, reversing changes made to 02b1be1. The mir-opt implementation is just marked as unsound but **not** reverted to make reland reviews easier. Test changes are **reverted if they were not pure additions**. Tests added by the original PR received `-Z unsound-mir-opts` compile-flags.
cc `@DianQK` `@cjgillot` (PR author and reviewer of #128299)
Rollup of 5 pull requests
Successful merges:
- #130693 (Add `minicore` test auxiliary and support `//@ add-core-stubs` directive in ui/assembly/codegen tests)
- #132316 (CI: use free runners for 3 fast windows jobs)
- #132354 (Add `lp64e` RISC-V ABI)
- #132395 (coverage: Avoid ICE when `coverage_cx` is unexpectedly unavailable)
- #132396 (CI: use free runners for x86_64-gnu-tools and x86_64-rust-for-linux)
r? `@ghost`
`@rustbot` modify labels: rollup
We haven't been compressing dylib metadata for a while now. Removing
decompression support will regress error messages about an incompatible
rustc version being used, but dylibs are pretty rare anyway.
coverage: Avoid ICE when `coverage_cx` is unexpectedly unavailable
In #132124, `coverage_cx()` was changed to panic if the context was unavailable, under the assumption that it would always be available whenever coverage instrumentation is enabled.
However, there have been reports of this change causing ICEs in `polars` CI.
I don't yet understand why this is happening, but for now it seems wisest to revert that part of the change, restoring the two early returns that had been replaced with panics.
Add `lp64e` RISC-V ABI
This PR adds support for the `lp64e` RISC-V ABI, which is the 64-bit equivalent of the `ilp32e` ABI that is already supported.
For reference, this ABI was originally added to LLVM in [this PR](https://reviews.llvm.org/D70401).
Add `minicore` test auxiliary and support `//@ add-core-stubs` directive in ui/assembly/codegen tests
Context: [Real cross-compiling tests instead of `#![no_core]` silliness #130375](https://github.com/rust-lang/rust/issues/130375)
MCP: https://github.com/rust-lang/compiler-team/issues/786
Tracking issue: https://github.com/rust-lang/rust/issues/131485
This prototype PR is subject to further changes based on feedback.
### New `minicore` test auxiliary and `//@ add-core-stubs` compiletest directive
This PR introduces a prototype implementation of a `minicore` auxiliary test helper that provides `core` stubs for `#![no_core]` ui/assembly/codegen tests that need to build but not run on both the host platform and the cross-compiled target platform.
Key summary:
- `tests/auxiliary/minicore.rs` contains stub definitions of `core` items intended for consumption by `check-pass`/`build-pass` tests that want the typical prelude items like `Copy` to be stubbed out under `#![no_core]` scenarios, so that the test can be built (not run) for cross-compiled target platforms. Such tests don't want nor need full `-Z build-std` (e.g. `tests/ui/abi/compatibility.rs`).
- `minicore` is intended for `core` items **only**, not `std`- or `alloc`-exclusive items. If stubs for `alloc` or `std` are wanted, they should be provided by an additional directive and test auxiliary, and not be conflated with `minicore` or `core` stubs. This is because a wider range of tests can benefit from `core`-only stubs.
### Implementation
- The `minicore` auxiliary is a single source file `tests/auxiliary/minicore.rs`.
- The path to `minicore` is made avaiable from bootstrap to compiletest via the `--minicore-path` compiletest flag.
- `minicore` is then built on-demand via the `//@ add-core-stubs` compiletest directive, for each test revision for the given target platform (this distinction is important for when host platform != target platform in cross-compilation scenario).
- `minicore` is then made available to the test as an [extern prelude].
[extern prelude]: https://doc.rust-lang.org/reference/names/preludes.html#extern-prelude
### Example usage
```rs
// tests/ui/abi/my-abi-test.rs
//@ check-pass
//@ add-core-stubs
//@ compile-flags: --target i686-unknown-linux-gnu
//@ needs-llvm-components: x86
#![feature(no_core, lang_items)]
#![no_std]
#![no_core]
#![allow(unused, internal_features)]
extern crate minicore;
use minicore::*;
#[lang = "clone"]
pub trait Clone: Sized { // `Sized` is provided by `minicore`
fn clone(&self) -> Self;
}
```
### Implementation steps
- [x] 1. Add an initial `minicore` test auxiliary.
- [x] 2. Build `minicore` in bootstrap.
- [x] 3. Setup a `--minicore-path` compiletest cli flag and pass `minicore` build artifact path from bootstrap to compiletest.
- [x] 4. Assert `add-core-stubs` is mutually incompatible with tests that require to be `run`, as the stubs are only good for tests that only need to be built (i.e. no `run-{pass,fail}`).
- [x] 5. Add some self-tests to sanity check the behavior.
- [x] 6. Ensure that `tests/auxiliary/minicore.rs` is input stamped, i.e. modifying `tests/auxiliary/minicore.rs` should invalidate test cache and force the test to be rerun.
### Known limitations
- The current `minicore` is very minimal, because this PR is intended to focus on supporting the test infrastructure first. Further stubs could be added in follow-up PRs and/or on a as-needed basis.
try-job: aarch64-apple
try-job: armhf-gnu
try-job: x86_64-msvc
try-job: test-various
try-job: dist-various-1
The initial `minicore` is intentionally super minimal and contains an
incomplete subset of `core` items, and explicitly not items from `alloc`
or `std`-only items.
Remove region from adjustments
It's not necessary to store this region, because it's only used in THIR and MemCat/ExprUse, both of which already basically only deal with erased regions anyways.
Rollup of 4 pull requests
Successful merges:
- #132347 (Remove `ValueAnalysis` and `ValueAnalysisWrapper`.)
- #132365 (pass `RUSTC_HOST_FLAGS` at once without the for loop)
- #132366 (Do not enforce `~const` constness effects in typeck if `rustc_do_not_const_check`)
- #132376 (Annotate `input` reference tests)
r? `@ghost`
`@rustbot` modify labels: rollup
Do not enforce `~const` constness effects in typeck if `rustc_do_not_const_check`
Fixes a slight inconsistency between HIR and MIR enforcement of `~const` :D
r? `@rust-lang/project-const-traits`
Remove `ValueAnalysis` and `ValueAnalysisWrapper`.
They represent a lot of abstraction and indirection, but they're only used for `ConstAnalysis`, and apparently won't be used for any other analyses in the future. This commit inlines and removes them, which makes `ConstAnalysis` easier to read and understand.
r? `@cjgillot`
