Skip `if-let-rescope` lint unless requested by migration
Tracked by #124085
Related to https://github.com/rust-lang/rust/pull/131984#issuecomment-2448329667
Given that `if-let-rescope` is a lint to be enabled globally by an edition migration, there is no point in extracting the precise lint level on the HIR expression. This mitigates the performance regression discovered by the earlier perf-run.
cc `@Kobzol` `@rylev` `@traviscross` I propose a `rust-timer` run to measure how much performance that we can recover from the mitigation. 🙇
Allow `arena_cache` queries to return `Option<&'tcx T>`
Currently, `arena_cache` queries always have to return `&'tcx T`[^deref]. This means that if an arena-cached query wants to return an optional value, it has to return `&'tcx Option<T>`, which has a few negative consequences:
- It goes against normal Rust style, where `Option<&T>` is preferred over `&Option<T>`.
- Callers that actually want an `Option<&T>` have to manually call `.as_ref()` on the query result.
- When the query result is `None`, a full-sized `Option<T>` still needs to be stored in the arena.
This PR solves that problem by introducing a helper trait `ArenaCached` that is implemented for both `&T` and `Option<&T>`, and takes care of bridging between the provided type, the arena-allocated type, and the declared query return type.
---
To demonstrate that this works, I have converted the two existing arena-cached queries that currently return `&Option<T>`: `mir_coroutine_witnesses` and `diagnostic_hir_wf_check`. Only the query declarations need to be modified; existing providers and callers continue to work with the new query return type.
(My real goal is to apply this to `coverage_ids_info`, which will return Option as of #135873, but that PR hasn't landed yet.)
[^deref]: Technically they could return other types that implement `Deref`, but it's hard to imagine this working well with anything other than `&T`.
rustc_codegen_llvm: remove outdated asm-to-obj codegen note
Remove comment about missing integrated assembler handling, which was removed in commit 02840ca.
Get rid of RunCompiler
The various `set_*` methods that have been removed can be replaced by setting the respective fields in the `Callbacks::config` implementation. `set_using_internal_features` was often forgotten and it's equivalent is now done automatically.
handle global trait bounds defining assoc types
This also fixes the compare-mode for
- tests/ui/coherence/coherent-due-to-fulfill.rs
- tests/ui/codegen/mono-impossible-2.rs
- tests/ui/trivial-bounds/trivial-bounds-inconsistent-projection.rs
- tests/ui/nll/issue-61320-normalize.rs
I first considered the alternative to always prefer where-bounds during normalization, regardless of how the trait goal has been proven by changing `fn merge_candidates` instead. ecda83b30f/compiler/rustc_next_trait_solver/src/solve/assembly/mod.rs (L785)
This approach is more restrictive than behavior of the old solver to avoid mismatches between trait and normalization goals. This may be breaking in case the where-bound adds unnecessary region constraints and we currently don't ever try to normalize an associated type. I would like to detect these cases and change the approach to exactly match the old solver if required. I want to minimize cases where attempting to normalize in more places causes code to break.
r? `@compiler-errors`
Add missing check for async body when suggesting await on futures.
Currently the compiler suggests adding `.await` to resolve some type conflicts without checking if the conflict happens in an async context. This can lead to the compiler suggesting `.await` in function signatures where it is invalid. Example:
```rs
trait A {
fn a() -> impl Future<Output = ()>;
}
struct B;
impl A for B {
fn a() -> impl Future<Output = impl Future<Output = ()>> {
async { async { () } }
}
}
```
```
error[E0271]: expected `impl Future<Output = impl Future<Output = ()>>` to be a future that resolves to `()`, but it resolves to `impl Future<Output = ()>`
--> bug.rs:6:15
|
6 | fn a() -> impl Future<Output = impl Future<Output = ()>> {
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected `()`, found future
|
note: calling an async function returns a future
--> bug.rs:6:15
|
6 | fn a() -> impl Future<Output = impl Future<Output = ()>> {
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
note: required by a bound in `A::{synthetic#0}`
--> bug.rs:2:27
|
2 | fn a() -> impl Future<Output = ()>;
| ^^^^^^^^^^^ required by this bound in `A::{synthetic#0}`
help: consider `await`ing on the `Future`
|
6 | fn a() -> impl Future<Output = impl Future<Output = ()>>.await {
| ++++++
```
The documentation of suggest_await_on_expect_found (`compiler/rustc_trait_selection/src/error_reporting/infer/suggest.rs:156`) even mentions such a check but does not actually implement it.
This PR adds that check to ensure `.await` is only suggested within async blocks.
There were 3 unit tests whose expected output needed to be changed because they had the suggestion outside of async. One of them (`tests/ui/async-await/dont-suggest-missing-await.rs`) actually tests that exact problem but expects it to be present.
Thanks to `@llenck` for initially noticing the bug and helping with fixing it
Implement `ByteStr` and `ByteString` types
Approved ACP: https://github.com/rust-lang/libs-team/issues/502
Tracking issue: https://github.com/rust-lang/rust/issues/134915
These types represent human-readable strings that are conventionally,
but not always, UTF-8. The `Debug` impl prints non-UTF-8 bytes using
escape sequences, and the `Display` impl uses the Unicode replacement
character.
This is a minimal implementation of these types and associated trait
impls. It does not add any helper methods to other types such as `[u8]`
or `Vec<u8>`.
I've omitted a few implementations of `AsRef`, `AsMut`, and `Borrow`,
when those would be the second implementation for a type (counting the
`T` impl), to avoid potential inference failures. We can attempt to add
more impls later in standalone commits, and run them through crater.
In addition to the `bstr` feature, I've added a `bstr_internals` feature
for APIs provided by `core` for use by `alloc` but not currently
intended for stabilization.
This API and its implementation are based *heavily* on the `bstr` crate
by Andrew Gallant (`@BurntSushi).`
r? `@BurntSushi`
Rollup of 9 pull requests
Successful merges:
- #134746 (Don't ICE in coerce when autoderef fails to structurally normalize non-WF type in new solver)
- #135552 ([AIX] Lint on structs that have a different alignment in AIX's C ABI)
- #135779 (CI: free disk on linux arm runner)
- #135790 (Update windows-gnu targets to set `DebuginfoKind::DWARF`)
- #135879 (fix outdated file path ref in llvm)
- #135883 (Remove erroneous `unsafe` in `BTreeSet::upper_bound_mut`)
- #135884 (remove implied end of slice)
- #135887 (improvements on `build_steps::test` implementation)
- #135898 (rustdoc-json-types: Finalize dyn compatibility renaming)
r? `@ghost`
`@rustbot` modify labels: rollup
Refactor `fmt::Display` impls in rustdoc
This PR does a couple of things, with the intention of cleaning up and streamlining some of the `fmt::Display` impls in rustdoc:
1. Use the unstable [`fmt::from_fn`](https://github.com/rust-lang/rust/issues/117729) instead of open-coding it.
2. ~~Replace bespoke implementations of `Itertools::format` with the method itself.~~
4. Some more minor cleanups - DRY, remove unnecessary calls to `Symbol::as_str()`, replace some `format!()` calls with lazier options
The changes are mostly cosmetic but some of them might have a slight positive effect on performance.
rustdoc-json-types: Finalize dyn compatibility renaming
Followup to #131595.
Part of #130852.
Inspired by #135858 (does the same thing but for the rustdoc-types docs).
r? ````@fmease````
Update windows-gnu targets to set `DebuginfoKind::DWARF`
These targets have always used DWARF debuginfo and not CodeView/PDB debuginfo like the MSVC Windows targets. However, their target definitions claim to use `DebuginfoKind::PDB` probably to ensure that we do not try to allow the use of split-DWARF debuginfo.
This does not appear to be necessary since the targets set their supported split debug info to `Off`. I've looked at all of the uses of these properties and this patch does not appear to cause any functional changes in compiler behavior. I also added UI tests to attempt to validate there is no change in the behavior of these options on stable compilers.
cc ````@mati865```` since you mentioned this in #135739
cc ````@davidtwco```` for split-dwarf
[AIX] Lint on structs that have a different alignment in AIX's C ABI
This PR adds a linting diagnostic on AIX for repr(C) structs that are required to follow
the power alignment rule. A repr(C) struct needs to follow the power alignment rule if
the struct:
- Has a floating-point data type (greater than 4-bytes) as its first member, or
- The first member of the struct is an aggregate, whose recursively first member is a
floating-point data type (greater than 4-bytes).
The power alignment rule for eligible structs is currently unimplemented, so a linting
diagnostic is produced when such a struct is encountered.
tests: Port `jobserver-error` to rmake.rs
Part of #121876.
This PR ports `tests/run-make/jobserver-error` to rmake.rs, and is basically #128789 slightly adjusted.
The complexity involved here is mostly how to get `/dev/null/` piping to fd 3 working with std `Command`, whereas with a shell this is much easier (as is evident with the `Makefile` version).
Supersedes #128789.
This PR is co-authored with `@Oneirical` and `@coolreader18.`
try-job: aarch64-gnu
try-job: i686-gnu-1
try-job: x86_64-gnu-debug
try-job: x86_64-gnu-llvm-18-1
- Convert `run-pass` to `check-pass`, the test is about closure
inference based on expected type, does not need to run-pass.
- Dropped unnecessary ignores.
