diff options
Diffstat (limited to 'compiler/rustc_borrowck/src/region_infer/opaque_types.rs')
| -rw-r--r-- | compiler/rustc_borrowck/src/region_infer/opaque_types.rs | 119 |
1 files changed, 70 insertions, 49 deletions
diff --git a/compiler/rustc_borrowck/src/region_infer/opaque_types.rs b/compiler/rustc_borrowck/src/region_infer/opaque_types.rs index 465f353aa..516a08077 100644 --- a/compiler/rustc_borrowck/src/region_infer/opaque_types.rs +++ b/compiler/rustc_borrowck/src/region_infer/opaque_types.rs @@ -1,18 +1,16 @@ -use rustc_data_structures::fx::FxHashMap; +use rustc_data_structures::fx::{FxHashMap, FxIndexSet}; use rustc_data_structures::vec_map::VecMap; use rustc_hir::def_id::LocalDefId; use rustc_hir::OpaqueTyOrigin; use rustc_infer::infer::TyCtxtInferExt as _; use rustc_infer::infer::{DefiningAnchor, InferCtxt}; -use rustc_infer::traits::{Obligation, ObligationCause, TraitEngine}; +use rustc_infer::traits::{Obligation, ObligationCause}; use rustc_middle::ty::subst::{GenericArgKind, InternalSubsts}; use rustc_middle::ty::visit::TypeVisitable; -use rustc_middle::ty::{ - self, OpaqueHiddenType, OpaqueTypeKey, ToPredicate, Ty, TyCtxt, TypeFoldable, -}; +use rustc_middle::ty::{self, OpaqueHiddenType, OpaqueTypeKey, Ty, TyCtxt, TypeFoldable}; use rustc_span::Span; use rustc_trait_selection::traits::error_reporting::TypeErrCtxtExt as _; -use rustc_trait_selection::traits::TraitEngineExt as _; +use rustc_trait_selection::traits::ObligationCtxt; use super::RegionInferenceContext; @@ -63,17 +61,21 @@ impl<'tcx> RegionInferenceContext<'tcx> { opaque_ty_decls: VecMap<OpaqueTypeKey<'tcx>, (OpaqueHiddenType<'tcx>, OpaqueTyOrigin)>, ) -> VecMap<LocalDefId, OpaqueHiddenType<'tcx>> { let mut result: VecMap<LocalDefId, OpaqueHiddenType<'tcx>> = VecMap::new(); + + let member_constraints: FxHashMap<_, _> = self + .member_constraints + .all_indices() + .map(|ci| (self.member_constraints[ci].key, ci)) + .collect(); + debug!(?member_constraints); + for (opaque_type_key, (concrete_type, origin)) in opaque_ty_decls { let substs = opaque_type_key.substs; debug!(?concrete_type, ?substs); let mut subst_regions = vec![self.universal_regions.fr_static]; - let universal_substs = infcx.tcx.fold_regions(substs, |region, _| { - if let ty::RePlaceholder(..) = region.kind() { - // Higher kinded regions don't need remapping, they don't refer to anything outside of this the substs. - return region; - } - let vid = self.to_region_vid(region); + + let to_universal_region = |vid, subst_regions: &mut Vec<_>| { trace!(?vid); let scc = self.constraint_sccs.scc(vid); trace!(?scc); @@ -94,10 +96,33 @@ impl<'tcx> RegionInferenceContext<'tcx> { infcx.tcx.lifetimes.re_static } } + }; + + // Start by inserting universal regions from the member_constraint choice regions. + // This will ensure they get precedence when folding the regions in the concrete type. + if let Some(&ci) = member_constraints.get(&opaque_type_key) { + for &vid in self.member_constraints.choice_regions(ci) { + to_universal_region(vid, &mut subst_regions); + } + } + debug!(?subst_regions); + + // Next, insert universal regions from substs, so we can translate regions that appear + // in them but are not subject to member constraints, for instance closure substs. + let universal_substs = infcx.tcx.fold_regions(substs, |region, _| { + if let ty::RePlaceholder(..) = region.kind() { + // Higher kinded regions don't need remapping, they don't refer to anything outside of this the substs. + return region; + } + let vid = self.to_region_vid(region); + to_universal_region(vid, &mut subst_regions) }); + debug!(?universal_substs); + debug!(?subst_regions); - subst_regions.sort(); - subst_regions.dedup(); + // Deduplicate the set of regions while keeping the chosen order. + let subst_regions = subst_regions.into_iter().collect::<FxIndexSet<_>>(); + debug!(?subst_regions); let universal_concrete_type = infcx.tcx.fold_regions(concrete_type, |region, _| match *region { @@ -108,8 +133,7 @@ impl<'tcx> RegionInferenceContext<'tcx> { .unwrap_or(infcx.tcx.lifetimes.re_erased), _ => region, }); - - debug!(?universal_concrete_type, ?universal_substs); + debug!(?universal_concrete_type); let opaque_type_key = OpaqueTypeKey { def_id: opaque_type_key.def_id, substs: universal_substs }; @@ -221,12 +245,12 @@ impl<'tcx> InferCtxtExt<'tcx> for InferCtxt<'tcx> { instantiated_ty: OpaqueHiddenType<'tcx>, origin: OpaqueTyOrigin, ) -> Ty<'tcx> { - if self.is_tainted_by_errors() { - return self.tcx.ty_error(); + if let Some(e) = self.tainted_by_errors() { + return self.tcx.ty_error_with_guaranteed(e); } let definition_ty = instantiated_ty - .remap_generic_params_to_declaration_params(opaque_type_key, self.tcx, false, origin) + .remap_generic_params_to_declaration_params(opaque_type_key, self.tcx, false) .ty; if !check_opaque_type_parameter_valid( @@ -252,48 +276,45 @@ impl<'tcx> InferCtxtExt<'tcx> for InferCtxt<'tcx> { // type-alias-impl-trait/issue-67844-nested-opaque.rs let infcx = self.tcx.infer_ctxt().with_opaque_type_inference(DefiningAnchor::Bubble).build(); + let ocx = ObligationCtxt::new(&infcx); // Require the hidden type to be well-formed with only the generics of the opaque type. // 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(definition_ty.into())) - .to_predicate(infcx.tcx); - let mut fulfillment_cx = <dyn TraitEngine<'tcx>>::new(infcx.tcx); + let predicate = ty::Binder::dummy(ty::PredicateKind::WellFormed(definition_ty.into())); let id_substs = InternalSubsts::identity_for_item(self.tcx, def_id.to_def_id()); // Require that the hidden type actually fulfills all the bounds of the opaque type, even without // the bounds that the function supplies. let opaque_ty = self.tcx.mk_opaque(def_id.to_def_id(), id_substs); - match infcx - .at(&ObligationCause::misc(instantiated_ty.span, body_id), param_env) - .eq(opaque_ty, definition_ty) - { - Ok(infer_ok) => { - for obligation in infer_ok.obligations { - fulfillment_cx.register_predicate_obligation(&infcx, obligation); - } - } - Err(err) => { - infcx - .err_ctxt() - .report_mismatched_types( - &ObligationCause::misc(instantiated_ty.span, body_id), - opaque_ty, - definition_ty, - err, - ) - .emit(); - } + if let Err(err) = ocx.eq( + &ObligationCause::misc(instantiated_ty.span, body_id), + param_env, + opaque_ty, + definition_ty, + ) { + infcx + .err_ctxt() + .report_mismatched_types( + &ObligationCause::misc(instantiated_ty.span, body_id), + opaque_ty, + definition_ty, + err, + ) + .emit(); } - fulfillment_cx.register_predicate_obligation( - &infcx, - Obligation::misc(instantiated_ty.span, body_id, param_env, predicate), - ); + ocx.register_obligation(Obligation::misc( + infcx.tcx, + instantiated_ty.span, + body_id, + param_env, + predicate, + )); // Check that all obligations are satisfied by the implementation's // version. - let errors = fulfillment_cx.select_all_or_error(&infcx); + let errors = ocx.select_all_or_error(); // This is still required for many(half of the tests in ui/type-alias-impl-trait) // tests to pass @@ -302,8 +323,8 @@ impl<'tcx> InferCtxtExt<'tcx> for InferCtxt<'tcx> { if errors.is_empty() { definition_ty } else { - infcx.err_ctxt().report_fulfillment_errors(&errors, None, false); - self.tcx.ty_error() + let reported = infcx.err_ctxt().report_fulfillment_errors(&errors, None); + self.tcx.ty_error_with_guaranteed(reported) } } } |