Store #[stable] attribute's `since` value in structured form
Followup to https://github.com/rust-lang/rust/pull/116773#pullrequestreview-1680913901.
Prior to this PR, if you wrote an improper `since` version in a `stable` attribute, such as `#[stable(feature = "foo", since = "wat.0")]`, rustc would emit a diagnostic saying **_'since' must be a Rust version number, such as "1.31.0"_** and then throw out the whole `stable` attribute as if it weren't there. This strategy had 2 problems, both fixed in this PR:
1. If there was also a `#[deprecated]` attribute on the same item, rustc would want to enforce that the stabilization version is older than the deprecation version. This involved reparsing the `stable` attribute's `since` version, with a diagnostic **_invalid stability version found_** if it failed to parse. Of course this diagnostic was unreachable because an invalid `since` version would have already caused the `stable` attribute to be thrown out. This PR deletes that unreachable diagnostic.
2. By throwing out the `stable` attribute when `since` is invalid, you'd end up with a second diagnostic saying **_function has missing stability attribute_** even though your function is not missing a stability attribute. This PR preserves the `stable` attribute even when `since` cannot be parsed, avoiding the misleading second diagnostic.
Followups I plan to try next:
- Do the same for the `since` value of `#[deprecated]`.
- See whether it makes sense to also preserve `stable` and/or `unstable` attributes when they contain an invalid `feature`. What redundant/misleading diagnostics can this eliminate? What problems arise from not having a usable feature name for some API, in the situation that we're already failing compilation, so not concerned about anything that happens in downstream code?
Mark .rmeta files as /SAFESEH on x86 Windows.
Chrome links .rlibs with /WHOLEARCHIVE or -Wl,--whole-archive to prevent the linker from discarding static initializers. This works well, except on Windows x86, where lld complains:
error: /safeseh: lib.rmeta is not compatible with SEH
The fix is simply to mark the .rmeta as SAFESEH aware. This is trivially true, since the metadata file does not contain any executable code.
Stop telling people to submit bugs for internal feature ICEs
This keeps track of usage of internal features, and changes the message to instead tell them that using internal features is not supported.
I thought about several ways to do this but now used the explicit threading of an `Arc<AtomicBool>` through `Session`. This is not exactly incremental-safe, but this is fine, as this is set during macro expansion, which is pre-incremental, and also only affects the output of ICEs, at which point incremental correctness doesn't matter much anyways.
See [MCP 620.](https://github.com/rust-lang/compiler-team/issues/596)
The latest locals() method in stable MIR returns slices instead of vecs.
This commit also includes fixes to the existing tests that previously
referenced the private locals field.
The word internal has connotations about information that's not exposed.
It's more accurate to say that the remaining locals apply only to the
inner part of the function, so I'm renaming them to inner locals.
Rename AsyncCoroutineKind to CoroutineSource
pulled out of https://github.com/rust-lang/rust/pull/116447
Also refactors the printing infra of `CoroutineSource` to be ready for easily extending it with a `Gen` variant for `gen` blocks
Uplift `Canonical` to `rustc_type_ir`
I plan on moving the new trait solver's canonicalizer into either `rustc_type_ir` or a child crate. One dependency on this is lifting `Canonical<V>` to `rustc_type_ir` so we can actually name the canonicalized values.
I may also later lift `CanonicalVarInfo` into the new trait solver. I can't really tell what other changes need to be done, but I'm just putting this up sooner than later since I'm almost certain it'll need to be done regardless of other design choices.
There are a couple of warts introduced by this PR, since we no longer can define inherent `Canonical` impls in `rustc_middle` -- see the changes to:
* `compiler/rustc_trait_selection/src/traits/query/normalize.rs`
* `compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs`
r? lcnr
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
This keeps track of usage of internal features, and changes the message
to instead tell them that using internal features is not supported.
See MCP 620.
This is particularly helpful for the ui tests, but also could be helpful
for Stable MIR users who just want all the locals without needing to
concatenate responses
This commit hides the arg_count field in Body and instead exposes more
stable and user-friendly methods to get the return and argument locals.
As a result, Body instances must now be constructed using the `new`
function.
This field allows SMIR consumers to identify which locals correspond to
argument locals. It simply exposes the arg_count field from the MIR
representation.
HIR typeck tries to figure out which casts are trivial by doing them as
coercions and seeing whether this works. Since HIR typeck is oblivious
of lifetimes, this doesn't work for pointer casts that only change the
lifetime of the pointee, which are, as borrowck will tell you, not
trivial.
This change makes it so that raw pointer casts are never considered
trivial.
This also incidentally fixes the "trivial cast" lint false positive on
the same code. Unfortunately, "trivial cast" lints are now never emitted
on raw pointer casts, even if they truly are trivial. This could be
fixed by also doing the lint in borrowck for raw pointers specifically.
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
When encountering code like `f::<f::<f::<f::<f::<f::<f::<f::<...` with
unmatched closing angle brackets, add a linear check that avoids the
exponential behavior of the parse recovery mechanism.
Fix#117080.
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
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.
