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Fix capturing duplicated lifetimes via parent

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This commit is contained in:
Michael Goulet 2024-04-17 21:30:41 -04:00
parent d1a0fa5ed3
commit 5daf58ffc1
3 changed files with 96 additions and 7 deletions
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37
compiler/rustc_hir_analysis/src/check/check.rs
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@ -492,6 +492,7 @@ fn check_opaque_precise_captures<'tcx>(tcx: TyCtxt<'tcx>, opaque_def_id: LocalDe
};
let mut expected_captures = UnordSet::default();
let mut shadowed_captures = UnordSet::default();
let mut seen_params = UnordMap::default();
let mut prev_non_lifetime_param = None;
for arg in precise_capturing_args {
@ -530,6 +531,21 @@ fn check_opaque_precise_captures<'tcx>(tcx: TyCtxt<'tcx>, opaque_def_id: LocalDe
match tcx.named_bound_var(hir_id) {
Some(ResolvedArg::EarlyBound(def_id)) => {
expected_captures.insert(def_id);
// Make sure we allow capturing these lifetimes through `Self` and
// `T::Assoc` projection syntax, too. These will occur when we only
// see lifetimes are captured after hir-lowering -- this aligns with
// the cases that were stabilized with the `impl_trait_projection`
// feature -- see <https://github.com/rust-lang/rust/pull/115659>.
if let DefKind::LifetimeParam = tcx.def_kind(def_id)
&& let ty::ReEarlyParam(ty::EarlyParamRegion { def_id, .. })
| ty::ReLateParam(ty::LateParamRegion {
bound_region: ty::BoundRegionKind::BrNamed(def_id, _),
..
}) = *tcx.map_opaque_lifetime_to_parent_lifetime(def_id.expect_local())
{
shadowed_captures.insert(def_id);
}
}
_ => {
tcx.dcx().span_delayed_bug(
@ -555,23 +571,30 @@ fn check_opaque_precise_captures<'tcx>(tcx: TyCtxt<'tcx>, opaque_def_id: LocalDe
);
continue;
}
// If a param is shadowed by a early-bound (duplicated) lifetime, then
// it may or may not be captured as invariant, depending on if it shows
// up through `Self` or `T::Assoc` syntax.
if shadowed_captures.contains(&param.def_id) {
continue;
}
match param.kind {
ty::GenericParamDefKind::Lifetime => {
// Check if the lifetime param was captured but isn't named in the precise captures list.
if variances[param.index as usize] == ty::Invariant {
let param_span =
if let ty::ReEarlyParam(ty::EarlyParamRegion { def_id, .. })
let param_span = if let DefKind::OpaqueTy =
tcx.def_kind(tcx.parent(param.def_id))
&& let ty::ReEarlyParam(ty::EarlyParamRegion { def_id, .. })
| ty::ReLateParam(ty::LateParamRegion {
bound_region: ty::BoundRegionKind::BrNamed(def_id, _),
..
}) = *tcx
.map_opaque_lifetime_to_parent_lifetime(param.def_id.expect_local())
{
Some(tcx.def_span(def_id))
} else {
None
};
{
Some(tcx.def_span(def_id))
} else {
None
};
// FIXME(precise_capturing): Structured suggestion for this would be useful
tcx.dcx().emit_err(errors::LifetimeNotCaptured {
use_span: tcx.def_span(param.def_id),