diff options
Diffstat (limited to 'compiler/rustc_hir_analysis')
| -rw-r--r-- | compiler/rustc_hir_analysis/src/check/check.rs | 20 |
1 files changed, 15 insertions, 5 deletions
diff --git a/compiler/rustc_hir_analysis/src/check/check.rs b/compiler/rustc_hir_analysis/src/check/check.rs index 7cee9779c5f..c3583eeb430 100644 --- a/compiler/rustc_hir_analysis/src/check/check.rs +++ b/compiler/rustc_hir_analysis/src/check/check.rs @@ -732,8 +732,6 @@ fn check_opaque_meets_bounds<'tcx>( span: Span, origin: &hir::OpaqueTyOrigin, ) { - let hidden_type = tcx.bound_type_of(def_id.to_def_id()).subst(tcx, substs); - let hir_id = tcx.hir().local_def_id_to_hir_id(def_id); let defining_use_anchor = match *origin { hir::OpaqueTyOrigin::FnReturn(did) | hir::OpaqueTyOrigin::AsyncFn(did) => did, @@ -748,14 +746,26 @@ fn check_opaque_meets_bounds<'tcx>( let ocx = ObligationCtxt::new(&infcx); let opaque_ty = tcx.mk_opaque(def_id.to_def_id(), substs); + // `ReErased` regions appear in the "parent_substs" of closures/generators. + // We're ignoring them here and replacing them with fresh region variables. + // See tests in ui/type-alias-impl-trait/closure_{parent_substs,wf_outlives}.rs. + // + // FIXME: Consider wrapping the hidden type in an existential `Binder` and instantiating it + // here rather than using ReErased. + let hidden_ty = tcx.bound_type_of(def_id.to_def_id()).subst(tcx, substs); + let hidden_ty = tcx.fold_regions(hidden_ty, |re, _dbi| match re.kind() { + ty::ReErased => infcx.next_region_var(RegionVariableOrigin::MiscVariable(span)), + _ => re, + }); + let misc_cause = traits::ObligationCause::misc(span, hir_id); - match infcx.at(&misc_cause, param_env).eq(opaque_ty, hidden_type) { + match infcx.at(&misc_cause, param_env).eq(opaque_ty, hidden_ty) { Ok(infer_ok) => ocx.register_infer_ok_obligations(infer_ok), Err(ty_err) => { tcx.sess.delay_span_bug( span, - &format!("could not unify `{hidden_type}` with revealed type:\n{ty_err}"), + &format!("could not unify `{hidden_ty}` with revealed type:\n{ty_err}"), ); } } @@ -764,7 +774,7 @@ fn check_opaque_meets_bounds<'tcx>( // Defining use functions may have more bounds than the opaque type, which is ok, as long as the // hidden type is well formed even without those bounds. let predicate = - ty::Binder::dummy(ty::PredicateKind::WellFormed(hidden_type.into())).to_predicate(tcx); + ty::Binder::dummy(ty::PredicateKind::WellFormed(hidden_ty.into())).to_predicate(tcx); ocx.register_obligation(Obligation::new(misc_cause, param_env, predicate)); // Check that all obligations are satisfied by the implementation's |