diff options
Diffstat (limited to 'compiler/rustc_ty_utils/src/implied_bounds.rs')
| -rw-r--r-- | compiler/rustc_ty_utils/src/implied_bounds.rs | 131 |
1 files changed, 67 insertions, 64 deletions
diff --git a/compiler/rustc_ty_utils/src/implied_bounds.rs b/compiler/rustc_ty_utils/src/implied_bounds.rs index ec2e0daaf..5c34df1ed 100644 --- a/compiler/rustc_ty_utils/src/implied_bounds.rs +++ b/compiler/rustc_ty_utils/src/implied_bounds.rs @@ -50,73 +50,76 @@ fn assumed_wf_types<'tcx>(tcx: TyCtxt<'tcx>, def_id: LocalDefId) -> &'tcx [(Ty<' let mut impl_spans = impl_spans(tcx, def_id); tcx.arena.alloc_from_iter(tys.into_iter().map(|ty| (ty, impl_spans.next().unwrap()))) } - DefKind::AssocTy if let Some(data) = tcx.opt_rpitit_info(def_id.to_def_id()) => match data { - ty::ImplTraitInTraitData::Trait { fn_def_id, .. } => { - // We need to remap all of the late-bound lifetimes in theassumed wf types - // of the fn (which are represented as ReFree) to the early-bound lifetimes - // of the RPITIT (which are represented by ReEarlyBound owned by the opaque). - // Luckily, this is very easy to do because we already have that mapping - // stored in the HIR of this RPITIT. - // - // Side-note: We don't really need to do this remapping for early-bound - // lifetimes because they're already "linked" by the bidirectional outlives - // predicates we insert in the `explicit_predicates_of` query for RPITITs. - let mut mapping = FxHashMap::default(); - let generics = tcx.generics_of(def_id); + DefKind::AssocTy if let Some(data) = tcx.opt_rpitit_info(def_id.to_def_id()) => { + match data { + ty::ImplTraitInTraitData::Trait { fn_def_id, .. } => { + // We need to remap all of the late-bound lifetimes in theassumed wf types + // of the fn (which are represented as ReFree) to the early-bound lifetimes + // of the RPITIT (which are represented by ReEarlyBound owned by the opaque). + // Luckily, this is very easy to do because we already have that mapping + // stored in the HIR of this RPITIT. + // + // Side-note: We don't really need to do this remapping for early-bound + // lifetimes because they're already "linked" by the bidirectional outlives + // predicates we insert in the `explicit_predicates_of` query for RPITITs. + let mut mapping = FxHashMap::default(); + let generics = tcx.generics_of(def_id); - // For each captured opaque lifetime, if it's late-bound (`ReFree` in this case, - // since it has been liberated), map it back to the early-bound lifetime of - // the GAT. Since RPITITs also have all of the fn's generics, we slice only - // the end of the list corresponding to the opaque's generics. - for param in &generics.params[tcx.generics_of(fn_def_id).params.len()..] { - let orig_lt = tcx.map_rpit_lifetime_to_fn_lifetime(param.def_id.expect_local()); - if matches!(*orig_lt, ty::ReFree(..)) { - mapping.insert( - orig_lt, - ty::Region::new_early_bound( - tcx, - ty::EarlyBoundRegion { - def_id: param.def_id, - index: param.index, - name: param.name, - }, - ), - ); + // For each captured opaque lifetime, if it's late-bound (`ReFree` in this case, + // since it has been liberated), map it back to the early-bound lifetime of + // the GAT. Since RPITITs also have all of the fn's generics, we slice only + // the end of the list corresponding to the opaque's generics. + for param in &generics.params[tcx.generics_of(fn_def_id).params.len()..] { + let orig_lt = + tcx.map_rpit_lifetime_to_fn_lifetime(param.def_id.expect_local()); + if matches!(*orig_lt, ty::ReFree(..)) { + mapping.insert( + orig_lt, + ty::Region::new_early_bound( + tcx, + ty::EarlyBoundRegion { + def_id: param.def_id, + index: param.index, + name: param.name, + }, + ), + ); + } } + // FIXME: This could use a real folder, I guess. + let remapped_wf_tys = tcx.fold_regions( + tcx.assumed_wf_types(fn_def_id.expect_local()).to_vec(), + |region, _| { + // If `region` is a `ReFree` that is captured by the + // opaque, remap it to its corresponding the early- + // bound region. + if let Some(remapped_region) = mapping.get(®ion) { + *remapped_region + } else { + region + } + }, + ); + tcx.arena.alloc_from_iter(remapped_wf_tys) + } + // Assumed wf types for RPITITs in an impl just inherit (and instantiate) + // the assumed wf types of the trait's RPITIT GAT. + ty::ImplTraitInTraitData::Impl { .. } => { + let impl_def_id = tcx.local_parent(def_id); + let rpitit_def_id = tcx.associated_item(def_id).trait_item_def_id.unwrap(); + let args = ty::GenericArgs::identity_for_item(tcx, def_id).rebase_onto( + tcx, + impl_def_id.to_def_id(), + tcx.impl_trait_ref(impl_def_id).unwrap().instantiate_identity().args, + ); + tcx.arena.alloc_from_iter( + ty::EarlyBinder::bind(tcx.assumed_wf_types_for_rpitit(rpitit_def_id)) + .iter_instantiated_copied(tcx, args) + .chain(tcx.assumed_wf_types(impl_def_id).into_iter().copied()), + ) } - // FIXME: This could use a real folder, I guess. - let remapped_wf_tys = tcx.fold_regions( - tcx.assumed_wf_types(fn_def_id.expect_local()).to_vec(), - |region, _| { - // If `region` is a `ReFree` that is captured by the - // opaque, remap it to its corresponding the early- - // bound region. - if let Some(remapped_region) = mapping.get(®ion) { - *remapped_region - } else { - region - } - }, - ); - tcx.arena.alloc_from_iter(remapped_wf_tys) - } - // Assumed wf types for RPITITs in an impl just inherit (and instantiate) - // the assumed wf types of the trait's RPITIT GAT. - ty::ImplTraitInTraitData::Impl { .. } => { - let impl_def_id = tcx.local_parent(def_id); - let rpitit_def_id = tcx.associated_item(def_id).trait_item_def_id.unwrap(); - let args = ty::GenericArgs::identity_for_item(tcx, def_id).rebase_onto( - tcx, - impl_def_id.to_def_id(), - tcx.impl_trait_ref(impl_def_id).unwrap().instantiate_identity().args, - ); - tcx.arena.alloc_from_iter( - ty::EarlyBinder::bind(tcx.assumed_wf_types_for_rpitit(rpitit_def_id)) - .iter_instantiated_copied(tcx, args) - .chain(tcx.assumed_wf_types(impl_def_id).into_iter().copied()), - ) } - }, + } DefKind::AssocConst | DefKind::AssocTy => tcx.assumed_wf_types(tcx.local_parent(def_id)), DefKind::OpaqueTy => match tcx.def_kind(tcx.local_parent(def_id)) { DefKind::TyAlias => ty::List::empty(), @@ -154,7 +157,7 @@ fn assumed_wf_types<'tcx>(tcx: TyCtxt<'tcx>, def_id: LocalDefId) -> &'tcx [(Ty<' | DefKind::LifetimeParam | DefKind::GlobalAsm | DefKind::Closure - | DefKind::Generator => ty::List::empty(), + | DefKind::Coroutine => ty::List::empty(), } } |