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remove unnecessary eval_verify_bound

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This commit is contained in:
lcnr 2024-12-03 18:42:09 +01:00
parent 96e51d9482
commit baf4bb7100
1 changed files with 1 additions and 18 deletions
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19
compiler/rustc_borrowck/src/region_infer/mod.rs
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@ -973,7 +973,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
propagated_outlives_requirements: &mut Vec<ClosureOutlivesRequirement<'tcx>>, propagated_outlives_requirements: &mut Vec<ClosureOutlivesRequirement<'tcx>>,
) -> bool { ) -> bool {
let tcx = infcx.tcx; let tcx = infcx.tcx;
let TypeTest { generic_kind, lower_bound, span: blame_span, ref verify_bound } = *type_test; let TypeTest { generic_kind, lower_bound, span: blame_span, verify_bound: _ } = *type_test;
let generic_ty = generic_kind.to_ty(tcx); let generic_ty = generic_kind.to_ty(tcx);
let Some(subject) = self.try_promote_type_test_subject(infcx, generic_ty) else { let Some(subject) = self.try_promote_type_test_subject(infcx, generic_ty) else {
@ -1013,23 +1013,6 @@ impl<'tcx> RegionInferenceContext<'tcx> {
// `ClosureOutlivesRequirement`. // `ClosureOutlivesRequirement`.
for ur in self.scc_values.universal_regions_outlived_by(r_scc) { for ur in self.scc_values.universal_regions_outlived_by(r_scc) {
debug!("universal_region_outlived_by ur={:?}", ur); debug!("universal_region_outlived_by ur={:?}", ur);
// Check whether we can already prove that the "subject" outlives `ur`.
// If so, we don't have to propagate this requirement to our caller.
//
// To continue the example from the function, if we are trying to promote
// a requirement that `T: 'X`, and we know that `'X = '1 + '2` (i.e., the union
// `'1` and `'2`), then in this loop `ur` will be `'1` (and `'2`). So here
// we check whether `T: '1` is something we *can* prove. If so, no need
// to propagate that requirement.
//
// This is needed because -- particularly in the case
// where `ur` is a local bound -- we are sometimes in a
// position to prove things that our caller cannot. See
// #53570 for an example.
if self.eval_verify_bound(infcx, generic_ty, ur, &verify_bound) {
continue;
}
let non_local_ub = self.universal_region_relations.non_local_upper_bounds(ur); let non_local_ub = self.universal_region_relations.non_local_upper_bounds(ur);
debug!(?non_local_ub); debug!(?non_local_ub);