bjoernager/rust
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Handle ty::Opaque correctly

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This commit is contained in:
Nadrieril 2023-10-27 05:10:58 +02:00
parent d5070e32ea
commit 3fa2e71ce1
2 changed files with 33 additions and 11 deletions
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17
compiler/rustc_mir_build/src/thir/pattern/usefulness.rs
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@ -883,7 +883,22 @@ impl<'p, 'tcx> PatternColumn<'p, 'tcx> {
self.patterns.is_empty()
}
fn head_ty(&self) -> Option<Ty<'tcx>> {
self.patterns.get(0).map(|p| p.ty())
if self.patterns.len() == 0 {
return None;
}
// If the type is opaque and it is revealed anywhere in the column, we take the revealed
// version. Otherwise we could encounter constructors for the revealed type and crash.
let is_opaque = |ty: Ty<'tcx>| matches!(ty.kind(), ty::Alias(ty::Opaque, ..));
let first_ty = self.patterns[0].ty();
if is_opaque(first_ty) {
for pat in &self.patterns {
let ty = pat.ty();
if !is_opaque(ty) {
return Some(ty);
}
}
}
Some(first_ty)
}
fn analyze_ctors(&self, pcx: &PatCtxt<'_, 'p, 'tcx>) -> SplitConstructorSet<'tcx> {