bjoernager/rust
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Use fewer delayed bugs.

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For some cases where it's clear that an error has already occurred,
e.g.:
- there's a comment stating exactly that, or
- things like HIR lowering, where we are lowering an error kind

The commit also tweaks some comments around delayed bug sites.
This commit is contained in:
Nicholas Nethercote 2024-02-14 15:17:15 +11:00
parent bb89df6903
commit 05849e8c2f
23 changed files with 88 additions and 90 deletions
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22
compiler/rustc_mir_build/src/check_unsafety.rs
View file

@ -33,7 +33,7 @@ struct UnsafetyVisitor<'a, 'tcx> {
body_target_features: &'tcx [Symbol],
/// When inside the LHS of an assignment to a field, this is the type
/// of the LHS and the span of the assignment expression.
assignment_info: Option<(Ty<'tcx>, Span)>,
assignment_info: Option<Ty<'tcx>>,
in_union_destructure: bool,
param_env: ParamEnv<'tcx>,
inside_adt: bool,
@ -473,10 +473,15 @@ impl<'a, 'tcx> Visitor<'a, 'tcx> for UnsafetyVisitor<'a, 'tcx> {
if let ty::Adt(adt_def, _) = lhs.ty.kind()
&& adt_def.is_union()
{
if let Some((assigned_ty, assignment_span)) = self.assignment_info {
if let Some(assigned_ty) = self.assignment_info {
if assigned_ty.needs_drop(self.tcx, self.param_env) {
// This would be unsafe, but should be outright impossible since we reject such unions.
self.tcx.dcx().span_delayed_bug(assignment_span, format!("union fields that need dropping should be impossible: {assigned_ty}"));
// This would be unsafe, but should be outright impossible since we
// reject such unions.
assert!(
self.tcx.dcx().has_errors().is_some(),
"union fields that need dropping should be impossible: \
{assigned_ty}"
);
}
} else {
self.requires_unsafe(expr.span, AccessToUnionField);
@ -492,14 +497,15 @@ impl<'a, 'tcx> Visitor<'a, 'tcx> for UnsafetyVisitor<'a, 'tcx> {
self.requires_unsafe(expr.span, MutationOfLayoutConstrainedField);
}
// Second, check for accesses to union fields
// don't have any special handling for AssignOp since it causes a read *and* write to lhs
// Second, check for accesses to union fields. Don't have any
// special handling for AssignOp since it causes a read *and*
// write to lhs.
if matches!(expr.kind, ExprKind::Assign { .. }) {
self.assignment_info = Some((lhs.ty, expr.span));
self.assignment_info = Some(lhs.ty);
visit::walk_expr(self, lhs);
self.assignment_info = None;
visit::walk_expr(self, &self.thir()[rhs]);
return; // we have already visited everything by now
return; // We have already visited everything by now.
}
}
ExprKind::Borrow { borrow_kind, arg } => {

3
compiler/rustc_mir_build/src/thir/pattern/const_to_pat.rs
View file

@ -153,8 +153,7 @@ impl<'tcx> ConstToPat<'tcx> {
// a hard error when we don't have a valtree or when we find something in
// the valtree that is not structural; then this can all be made a lot simpler.
let structural =
traits::search_for_structural_match_violation(self.span, self.tcx(), cv.ty());
let structural = traits::search_for_structural_match_violation(self.tcx(), cv.ty());
debug!(
"search_for_structural_match_violation cv.ty: {:?} returned: {:?}",
cv.ty(),