Improve the warning messages for the `#[diagnostic::on_unimplemented]`
This commit improves warnings emitted for malformed on unimplemented attributes by:
* Improving the span of the warnings
* Adding a label message to them
* Separating the messages for missing and unexpected options
* Adding a help message that says which options are supported
r? `@compiler-errors`
I'm happy to work on further improvements, so feel free to make suggestions.
Return multiple object-safety violation errors and code improvements to the object-safety check
See individual commits for more information. Split off of #114260, since it turned out that the main intent of that PR was wrong.
r? oli-obk
Rollup of 7 pull requests
Successful merges:
- #117111 (Remove support for alias `-Z instrument-coverage`)
- #117141 (Require target features to match exactly during inlining)
- #117152 (Fix unwrap suggestion for async fn)
- #117154 (implement C ABI lowering for CSKY)
- #117159 (Work around the fact that `check_mod_type_wf` may spuriously return `ErrorGuaranteed`)
- #117163 (compiletest: Display compilation errors in mir-opt tests)
- #117173 (Make `Iterator` a lang item)
r? `@ghost`
`@rustbot` modify labels: rollup
Make `Iterator` a lang item
r? `@compiler-errors`
pulled out of https://github.com/rust-lang/rust/pull/116447
We're doing this change on its own, because iterator was the one diagnostic item that was load bearing on us correctly emitting errors about `diagnostic_item` mis-uses. It was used in some diagnostics as an early abort, before the actual checks of the diagnostic, so effectively the compiler was *unconditionally* checking for the iterator diagnostic item, even if it didn't emit any diagnostics. Changing those uses to use the lang item, caused us not to invoke the `all_diagnostic_items` query anymore, which then caused us to miss some issues around diagnostic items until they were actually used.
The reason we keep the diagnostic item around is that clippy uses it a lot and having `Iterator` be a lang item and a diagnostic item at the same time doesn't cost us anything, but makes clippy's internal code simpler
compiletest: Display compilation errors in mir-opt tests
Previously when compilation failed the `check_mir_dump` would panic first, so we would never display the compiler output.
Work around the fact that `check_mod_type_wf` may spuriously return `ErrorGuaranteed`
Even if that error is only emitted by `check_mod_item_types`.
fixes https://github.com/rust-lang/rust/issues/117153
A cleaner refactoring would merge/chain these queries in ways that ensure we only actually get an `ErrorGuaranteed` if there was an error emitted.
Fix unwrap suggestion for async fn
Use `body_fn_sig` to get the expected return type of the function instead of `ret_coercion` in `FnCtxt`. This avoids accessing the `ret_coercion` when it's already mutably borrowed (e.g. when checking `return` expressions).
Fixes#117144
r? `@chenyukang`
Require target features to match exactly during inlining
In general it is not correct to inline a callee with a target features
that are subset of the callee. Require target features to match exactly
during inlining.
The exact match could be potentially relaxed, but this would require
identifying specific feature that are allowed to differ, those that need
to match, and those that can be present in caller but not in callee.
This resolves MIR part of #116573. For other concerns with respect to
the previous implementation also see areInlineCompatible in LLVM.
Remove support for alias `-Z instrument-coverage`
This flag was stabilized in rustc 1.60.0 (2022-04-07) as `-C instrument-coverage`, but the old unstable flag was kept around (with a warning) as an alias to ease migration.
It should now be reasonable to remove the somewhat tricky code that implemented that alias.
Fixes#116980.
Fix some coroutine sentences that don't make sense anymore.
These happened during the `generator` -> `coroutine` rename.
Found thanks to `@pthariensflame` for their thorough review of the `generator` -> `coroutine` rename https://github.com/rust-lang/rust/pull/116958#issuecomment-1777756937
Merge `impl_wf_inference` (`check_mod_impl_wf`) check into coherence checking
Problem here is that we call `collect_impl_trait_in_trait_types` when checking `check_mod_impl_wf` which is performed before coherence. Due to the `tcx.sess.track_errors`, since we end up reporting an error, we never actually proceed to coherence checking, where we would be emitting a more useful impl overlap error.
This change means that we may report more errors in some cases, but can at least proceed far enough to leave a useful message for overlapping traits with RPITITs in them.
Fixes#116982
r? types
Remove fold code and add `Const::internal()` to StableMIR
We are not planning to support user generated constant in the foreseeable future, so we are cleaning up the fold logic and user created type for now. Users should use `Instance::resolve` in order to trigger monomorphization.
The Instance::resolve was however incomplete, since we weren't handling internalizing constants yet. Thus, I added that.
I decided to keep the `Const` fields private in case we decide to translate them lazily.
Modernize rustc_builtin_macros generics helpers
- Rustfmt-compatible formatting for the code snippets in comments
- Eliminate an _"Extra scope required"_ obsoleted by NLL
Uplift `ClauseKind` and `PredicateKind` into `rustc_type_ir`
Uplift `ClauseKind` and `PredicateKind` into `rustc_type_ir`.
Blocked on #116951
r? `@ghost`
Get rid of `'tcx` lifetime on `ConstVid`, `EffectVid`
These are simply newtyped numbers, so don't really have a reason (per se) to have a lifetime -- `TyVid` and `RegionVid` do not, for example.
The only consequence of this is that we need to use a new key type for `UnifyKey` that mentions `'tcx`. This is already done for `RegionVid`, with `RegionVidKey<'tcx>`, but this `UnifyKey` trait implementation may have been the original reason to give `ConstVid` a lifetime. See the changes to `compiler/rustc_middle/src/infer/unify_key.rs` specifically.
I consider the code cleaner this way, though -- we removed quite a few unnecessary `'tcx` in the process. This also makes it easier to uplift these two ids to `rustc_type_ir`, which I plan on doing in a follow-up PR.
r? `@BoxyUwU`
We are not planning to support user generated constant in the
foreseeable future, so we are removing the Fold logic for now in
favor of the Instance::resolve logic.
The Instance::resolve was however incomplete, since we weren't handling
internalizing constants yet. Thus, I added that.
I decided to keep the Const fields private in case we decide to
translate them lazily.
