Remove -Zinline-in-all-cgus and clean up tests/codegen-units/
Implementation of https://github.com/rust-lang/compiler-team/issues/814
I've taken some liberties with cleaning up the CGU partitioning tests, because that's the only place this flag was used and also mattered. I've often fought a lot with the contents of `tests/codegen-units` and it has never been clear to me when a test failure indicates a problem with my changes as opposed to a test just needing to be manually blessed. Hopefully the combination of the new README, new comments, and using `-Zprint-mono-items=lazy` in the partitioning tests improves that.
I've also deleted some of the `tests/run-make/sepcomp` tests. I think all the "sepcomp" tests have been obviated for years by better-designed (less flaky, clearer failures) test suites, but here I'm just deleting the ones I'm confident in.
Windows x86: Change i128 to return via the vector ABI
Clang and GCC both return `i128` in xmm0 on windows-msvc and windows-gnu. Currently, Rust returns the type on the stack. Add a calling convention adjustment so we also return scalar `i128`s using the vector ABI, which makes our `i128` compatible with C.
In the future, Clang may change to return `i128` on the stack for its `-msvc` targets (more at [1]). If this happens, the change here will need to be adjusted to only affect MinGW.
Link: https://github.com/rust-lang/rust/issues/134288 (does not fix) [1]
try-job: x86_64-msvc
try-job: x86_64-msvc-ext1
try-job: x86_64-mingw-1
try-job: x86_64-mingw-2
Add some tracing to core bootstrap logic
Follow-up to #135391.
### Summary
Add some initial tracing logging to bootstrap, focused on the core logic (in this PR).
Also:
- Adjusted tracing-tree style to not use indent lines (I found that more distracting than helpful).
- Avoid glob-importing `tracing` items.
- Improve the rustc-dev-guide docs on bootstrap tracing.
### Example output
```bash
$ BOOTSTRAP_TRACING=bootstrap=TRACE ./x check src/bootstrap
```

r? bootstrap
compiler_fence: fix example
The old example was wrong, an acquire fence is required in the signal handler. To make the point more clear, I changed the "data" variable to use non-atomic accesses.
Fixes https://github.com/rust-lang/rust/issues/133014
Fix tests on LLVM 20
For sparcv8plus.rs, duplicate the test for LLVM 19 and LLVM 20. LLVM 20 resolves one of the FIXME in the test.
For x86_64-bigint-add.rs split the check lines for LLVM 19 and LLVM 20. The difference in codegen here is due to a difference in unroll factor, which I believe is not what the test is interested in.
Fixes https://github.com/rust-lang/rust/issues/132957.
Fixes https://github.com/rust-lang/rust/issues/133754.
Get rid of `mir::Const::from_ty_const`
This function is strange, because it turns valtrees into `mir::Const::Value`, but the rest of the const variants stay as type system consts.
All of the callsites except for one in `instsimplify` (array length simplification of `ptr_metadata` call) just go through the valtree arm of the function, so it's easier to just create a `mir::Const` directly for those.
For the instsimplify case, if we have a type system const we should *keep* having a type system const, rather than turning it into a `mir::Const::Value`; it doesn't really matter in practice, though, bc `usize` has no padding, but it feels more principled.
It seems one can't overwrite a cache entry:
```
Failed to save: Unable to reserve cache with key linkcheck--0.8.1, another job may be creating this cache. More details: Cache already exists. Scope: refs/heads/master, Key: linkcheck--0.8.1, Version: 33f8fd511bed9c91c40778bc5c27cb58425caa894ab50f9c5705d83cb78660e0
Warning: Cache save failed.
```
A proper solution is to use `restore-keys`:
https://github.com/actions/cache/blob/main/tips-and-workarounds.md#update-a-cache
Reword resolve errors caused by likely missing crate in dep tree
Reword label and add `help`:
```
error[E0432]: unresolved import `some_novel_crate`
--> f704.rs:1:5
|
1 | use some_novel_crate::Type;
| ^^^^^^^^^^^^^^^^ use of unresolved module or unlinked crate `some_novel_crate`
|
= help: if you wanted to use a crate named `some_novel_crate`, use `cargo add some_novel_crate` to add it to your `Cargo.toml`
```
Fix#133137.
Add `#[optimize(none)]`
cc #54882
This extends the `optimize` attribute to add `none`, which corresponds to the LLVM `OptimizeNone` attribute.
Not sure if an MCP is required for this, happy to file one if so.
Update cargo
5 commits in 045bf21b36a2e1f3ed85e38278d1c3cc4305e134..cecde95c119a456c30e57d3e4b31fff5a7d83df4
2025-01-17 14:59:36 +0000 to 2025-01-24 17:15:24 +0000
- Remove unused `-C link-arg=-fuse-ld=lld` (rust-lang/cargo#15097)
- Remove `unsafe` by using `LazyLock` (rust-lang/cargo#15096)
- Print globs when workspace members can't be found (rust-lang/cargo#15093)
- Make --allow-dirty imply --allow-staged (rust-lang/cargo#15013)
- fix(config): When merging, replace rather than combining specific configuration keys (rust-lang/cargo#15066)
Rollup of 9 pull requests
Successful merges:
- #135415 (Add `File already exists` error doc to `hard_link` function)
- #135581 (Separate Builder methods from tcx)
- #135728 (document order of items in iterator from drain)
- #135749 (Do not assume const params are printed after type params)
- #135829 (Rustc dev guide subtree update)
- #135938 (Add memory layout documentation to generic NonZero<T>)
- #135949 (Use short type string in E0308 secondary span label)
- #135976 (Don't drop types with no drop glue when building drops for tailcalls)
- #135998 ([rustdoc] Fix indent of trait items on mobile)
r? `@ghost`
`@rustbot` modify labels: rollup
Don't drop types with no drop glue when building drops for tailcalls
this is required as otherwise drops of `&mut` refs count as a usage of a
'two-phase temporary' causing an ICE.
fixes#128097
The underlying issue is that the current code generates drops for `&mut` which are later counted as a second use of a two-phase temporary:
`bat t.rs -p`
```rust
#![expect(incomplete_features)]
#![feature(explicit_tail_calls)]
fn f(x: &mut ()) {
let _y = String::new();
become f(x);
}
fn main() {}
```
`rustc t.rs -Zdump_mir=f`
```text
error: internal compiler error: compiler/rustc_borrowck/src/borrow_set.rs:298:17: found two uses for 2-phase borrow temporary _4: bb2[1] and bb3[0]
--> t.rs:6:5
|
6 | become f(x);
| ^^^^^^^^^^^
thread 'rustc' panicked at compiler/rustc_borrowck/src/borrow_set.rs:298:17:
Box<dyn Any>
stack backtrace:
[REDACTED]
error: aborting due to 1 previous error
```
`bat ./mir_dump/t.f.-------.renumber.0.mir -p -lrust`
```rust
// MIR for `f` 0 renumber
fn f(_1: &mut ()) -> () {
debug x => _1;
let mut _0: ();
let mut _2: !;
let _3: std::string::String;
let mut _4: &mut ();
scope 1 {
debug _y => _3;
}
bb0: {
StorageLive(_3);
_3 = String::new() -> [return: bb1, unwind: bb4];
}
bb1: {
FakeRead(ForLet(None), _3);
StorageLive(_4);
_4 = &mut (*_1);
drop(_3) -> [return: bb2, unwind: bb3];
}
bb2: {
StorageDead(_3);
tailcall f(Spanned { node: move _4, span: t.rs:6:14: 6:15 (#0) });
}
bb3 (cleanup): {
drop(_4) -> [return: bb4, unwind terminate(cleanup)];
}
bb4 (cleanup): {
resume;
}
}
```
Note how `_4 is moved into the tail call in `bb2` and dropped in `bb3`.
This PR adds a check that the locals we drop need dropping.
r? `@oli-obk` (feel free to reassign, I'm not sure who would be a good reviewer, but thought you might have an idea)
cc `@beepster4096,` since you wrote the original drop implementation.
Use short type string in E0308 secondary span label
We were previously printing the full type on the "this expression has type" label.
```
error[E0308]: mismatched types
--> $DIR/secondary-label-with-long-type.rs:8:9
|
LL | let () = x;
| ^^ - this expression has type `((..., ..., ..., ...), ..., ..., ...)`
| |
| expected `((..., ..., ..., ...), ..., ..., ...)`, found `()`
|
= note: expected tuple `((..., ..., ..., ...), ..., ..., ...)`
found unit type `()`
= note: the full type name has been written to '$TEST_BUILD_DIR/diagnostic-width/secondary-label-with-long-type/secondary-label-with-long-type.long-type-3987761834644699448.txt'
= note: consider using `--verbose` to print the full type name to the console
```
Reported in a comment of #135919.
Add memory layout documentation to generic NonZero<T>
The documentation I've added is based on the same Layout documentation that appears on the other `NonZero*` types. For example see [the Layout docs on `NonZeroI8`](https://doc.rust-lang.org/std/num/type.NonZeroI8.html#layout-1).
Separate Builder methods from tcx
As part of the autodiff upstreaming we noticed, that it would be nice to have various builder methods available without the TypeContext, which prevents the normal CodegenCx to be passed around between threads.
We introduce a SimpleCx which just owns the llvm module and llvm context, to encapsulate them.
The previous CodegenCx now implements deref and forwards access to the llvm module or context to it's SimpleCx sub-struct. This gives us a bit more flexibility, because now we can pass (or construct) the SimpleCx in locations where we don't have enough information to construct a CodegenCx, or are not able to pass it around due to the tcx lifetimes (and it not implementing send/sync).
This also introduces an SBuilder, similar to the SimpleCx. The SBuilder uses a SimpleCx, whereas the existing Builder uses the larger CodegenCx. I will push updates to make implementations generic (where possible) to be implemented once and work for either of the two. I'll also clean up the leftover code.
`call` is a bit tricky, because it requires a tcx, I probably need to duplicate it after all.
Tracking:
- https://github.com/rust-lang/rust/issues/124509
Add `File already exists` error doc to `hard_link` function
## Description
If the link path already exists, the error `AlreadyExists` is returned. This commit adds this error to the docs.
I tested it with the current rust master version, this error was returned when there is already a link for the file is present.
This was the error returned:
```
[harshit:../Desktop/rust_compiler_testing/hard_link (master|…5)] cargo +stage1 run
Compiling hard_link v0.1.0 (/home/harshit/Desktop/rust_compiler_testing/hard_link)
Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.12s
Running `target/debug/hard_link`
Err(Os { code: 17, kind: AlreadyExists, message: "File exists" })
```
This is my first PR on rust, any suggestions on which issue I can take next are most welcome 😄Fixes#130117
Rollup of 6 pull requests
Successful merges:
- #135873 (coverage: Prepare for upcoming changes to counter creation)
- #135926 (Implement `needs-subprocess` directive, and cleanup a bunch of tests to use `needs-{subprocess,threads}`)
- #135950 (Tidy Python improvements)
- #135956 (Make `Vec::pop_if` a bit more presentable)
- #135966 ([AIX] Allow different sized load and store in `tests/assembly/powerpc64-struct-abi.rs`)
- #135983 (Doc difference between extend and extend_from_slice)
r? `@ghost`
`@rustbot` modify labels: rollup
[AIX] Allow different sized load and store in `tests/assembly/powerpc64-struct-abi.rs`
Sometimes in the llvm backend generates 2 different copy assembly sequence.
1. `lxvd2x` followed immediately by `stxvd2x` (Load VSX Vector 2 Dword, Store VSX Vector 2 Dword) is semantically equivalent to;
2. `lxvw4x` followed immediately by `stxvw4x` (Load VSX Vector 4 Word, Store VSX Vector 4 Word)
Tidy Python improvements
Fixes display of Python formatting diffs in tidy, and refactors the code to make it simpler and more robust. Also documents Python formatting and linting in the Rustc dev guide.
Fixes: https://github.com/rust-lang/rust/issues/135942
r? `@onur-ozkan`