check_match: improve diagnostics for `let A = 2;` with `const A: i32 = 3`
For example:
```
error[E0005]: refutable pattern in local binding: `std::i32::MIN..=1i32` and `3i32..=std::i32::MAX` not covered
--> $DIR/const-pat-non-exaustive-let-new-var.rs:2:9
|
LL | let A = 3;
| ^
| |
| interpreted as a constant pattern, not a new variable
| help: introduce a variable instead: `a_var`
...
LL | const A: i32 = 2;
| ----------------- constant defined here
```
r? @estebank
cc @matthiaskrgr @rpjohnst
hir: Disallow `target_feature` on constants
Fixes#64768.
This PR fixes an ICE when `#[target_feature]` is applied to constants by disallowing this with the same error as when `#[target_feature]` is applied to other places it shouldn't be.
I couldn't see anything in the [RFC](https://github.com/rust-lang/rfcs/blob/master/text/2045-target-feature.md) that suggested that `#[target_feature]` should be applicable to constants or any tests that suggested it should, though I might have missed something - if this is desirable in future, it remains possible to remove this error (but for the time being, I think this error is better than an ICE).
I also added some extra cases to the test for other places where `#[target_feature]` should not be permitted.
cc @gnzlbg
Account for tail expressions when pointing at return type
When there's a type mismatch we make an effort to check if it was
caused by a function's return type. This logic now makes sure to
only point at the return type if the error happens in a tail
expression.
Turn `walk_parent_nodes` method into an iterator.
CC #39968, CC #40799.
When there's a type mismatch we make an effort to check if it was
caused by a function's return type. This logic now makes sure to
only point at the return type if the error happens in a tail
expression.
Rename `*.node` to `*.kind`, and `hair::Pattern*` to `hair::Pat*`
In both `ast::Expr` and `hir::Expr`:
- Rename `Expr.node` to `Expr.kind`.
- Rename `Pat.node` to `Pat.kind`.
- Rename `ImplItem.node` to `ImplItem.kind`.
- Rename `Lit.node` to `Lit.kind`.
- Rename `TraitItem.node` to `TraitItem.kind`.
- Rename `Ty.node` to `Ty.kind`.
- Rename `Stmt.node` to `Stmt.kind`.
- Rename `Item.node` to `Item.kind`.
- Rename `ForeignItem.node` to `ForeignItem.kind`.
- Rename `MetaItem.node` to `MetaItem.kind`.
Also:
- Rename `hair::FieldPattern` to `hair::FieldPat`.
- Rename `hair::PatternKind` to `hair::PatKind`.
- Rename `hair::PatternRange` to `hair::PatRange`.
- Rename `PatternContext` to `PatCtxt`.
- Rename `PatternTypeProjection` to `PatTyProj`.
- Rename `hair::Pattern` to `hair::Pat`.
These two sets of changes are grouped together to aid with merging. The only changes are renamings.
r? @petrochenkov
Fix issue #64732
Based on issue #64732, when creating a byte literal with single quotes,
the suggestion message would indicate that you meant to write a `str` literal,
but we actually meant to write a byte string literal.
So I changed the unescape_error_reporting.rs to decide whether to print out
"if you meant to write a `str` literal, use double quotes",
or "if you meant to write a byte string literal, use double quotes".
Fixes#64732.
reserve `impl<T> From<!> for T`
this is necessary for never-type stabilization.
cc #57012#35121
I think we wanted a crater run for this @nikomatsakis?
r? @nikomatsakis
or-patterns: Push `PatKind/PatternKind::Or` at top level to HIR & HAIR
Following up on work in https://github.com/rust-lang/rust/pull/64111, https://github.com/rust-lang/rust/pull/63693, and https://github.com/rust-lang/rust/pull/61708, in this PR:
- We change `hair::Arm.patterns: Vec<Pattern<'_>>` into `hir::Arm.pattern: Pattern<'_>`.
- `fn hair::Arm::top_pats_hack` is introduced as a temporary crutch in MIR building to avoid more changes.
- We change `hir::Arm.pats: HirVec<P<Pat>>` into `hir::Arm.pat: P<Pat>`.
- The hacks in `rustc::hir::lowering` are removed since the representation hack is no longer necessary.
- In some places, `fn hir::Arm::top_pats_hack` is introduced to leave some things as future work.
- Misc changes: HIR pretty printing is adjusted to behave uniformly wrt. top/inner levels, rvalue promotion is adjusted, regionck, and dead_code is also.
- Type checking is adjusted to uniformly handle or-patterns at top/inner levels.
To make things compile, `p_0 | ... | p_n` is redefined as a "reference pattern" in [`fn is_non_ref_pat`](https://doc.rust-lang.org/nightly/nightly-rustc/rustc_typeck/check/struct.FnCtxt.html#method.is_non_ref_pat) for now. This is done so that reference types are not eagerly stripped from the `expected: Ty<'tcx>`.
- Liveness is adjusted wrt. the `unused_variables` and `unused_assignments` lints to handle top/inner levels uniformly and the handling of `fn` parameters, `let` locals, and `match` arms are unified in this respect. This is not tested for now as exhaustiveness checks are reachable and will ICE.
- In `check_match`, checking `@` and by-move bindings is adjusted. However, exhaustiveness checking is not adjusted the moment and is handled by @dlrobertson in https://github.com/rust-lang/rust/pull/63688.
- AST borrowck (`construct.rs`) is not adjusted as AST borrowck will be removed soon.
r? @matthewjasper
cc @dlrobertson @varkor @oli-obk
Don't emit explain with json short messages.
This fixes an issue where `--error-format=json --json=diagnostic-short` would emit the "For more information about this error" message, which doesn't match the behavior of `--error-format=short` which explicitly excludes it.
Remove blanket silencing of "type annotation needed" errors
Remove blanket check for existence of other errors before emitting "type annotation needed" errors, and add some eager checks to avoid adding obligations when they refer to types that reference `[type error]` in order to reduce unneeded errors.
Fix#64084.
rustc: Fix mixing crates with different `share_generics`
This commit addresses #64319 by removing the `dylib` crate type from the
list of crate type that exports generic symbols. The bug in #64319
arises because a `dylib` crate type was trying to export a symbol in an
uptream crate but it miscalculated the symbol name of the uptream
symbol. This isn't really necessary, though, since `dylib` crates aren't
that heavily used, so we can just conservatively say that the `dylib`
crate type never exports generic symbols, forcibly removing them from
the exported symbol lists if were to otherwise find them.
The fix here happens in two places:
* First is in the `local_crate_exports_generics` method, indicating that
it's now `false` for the `Dylib` crate type. Only rlibs actually
export generics at this point.
* Next is when we load exported symbols from upstream crate. If, for our
compilation session, the crate may be included from a dynamic library,
then its generic symbols are removed. When the crate was linked into a
dynamic library its symbols weren't exported, so we can't consider
them a candidate to link against.
Overally this should avoid situations where we incorrectly calculate the
upstream symbol names in the face of differnet `share_generics` options,
ultimately...
Closes#64319
Recover on `const X = 42;` and infer type + Error Stash API
Here we:
1. Introduce a notion of the "error stash".
This is a map in the `Handler` to which you can `err.stash(...)` away your diagnostics and then steal them in a later "phase" of the compiler (e.g. stash in parser, steal in typeck) to enrich them with more information that isn't available in the previous "phase".
I believe I've covered all the bases to make sure these diagnostics are actually emitted eventually even under `#[cfg(FALSE)]` but please check my logic.
2. Recover when parsing `[const | static mut?] $ident = $expr;` which has a missing type.
Use the "error stash" to stash away the error and later steal the error in typeck where we emit the error as `MachineApplicable` with the actual inferred type. This builds on https://github.com/rust-lang/rust/pull/62804.
cc https://github.com/rust-lang/rfcs/pull/2545
r? @estebank
Remove blanket check for existence of other errors before emitting
"type annotation needed" errors, and add some eager checks to avoid
adding obligations when they refer to types that reference
`[type error]` in order to reduce unneded errors.
