diff options
Diffstat (limited to 'compiler/rustc_trait_selection/src/traits/object_safety.rs')
| -rw-r--r-- | compiler/rustc_trait_selection/src/traits/object_safety.rs | 76 |
1 files changed, 47 insertions, 29 deletions
diff --git a/compiler/rustc_trait_selection/src/traits/object_safety.rs b/compiler/rustc_trait_selection/src/traits/object_safety.rs index 4eacb5211..b8ad1925e 100644 --- a/compiler/rustc_trait_selection/src/traits/object_safety.rs +++ b/compiler/rustc_trait_selection/src/traits/object_safety.rs @@ -8,20 +8,19 @@ //! - not reference the erased type `Self` except for in this receiver; //! - not have generic type parameters. -use super::{elaborate_predicates, elaborate_trait_ref}; +use super::elaborate; use crate::infer::TyCtxtInferExt; use crate::traits::query::evaluate_obligation::InferCtxtExt; use crate::traits::{self, Obligation, ObligationCause}; -use hir::def::DefKind; use rustc_errors::{DelayDm, FatalError, MultiSpan}; use rustc_hir as hir; use rustc_hir::def_id::DefId; use rustc_middle::ty::subst::{GenericArg, InternalSubsts}; -use rustc_middle::ty::ToPredicate; use rustc_middle::ty::{ self, EarlyBinder, Ty, TyCtxt, TypeSuperVisitable, TypeVisitable, TypeVisitor, }; +use rustc_middle::ty::{ToPredicate, TypeVisitableExt}; use rustc_session::lint::builtin::WHERE_CLAUSES_OBJECT_SAFETY; use rustc_span::symbol::Symbol; use rustc_span::Span; @@ -140,6 +139,10 @@ fn object_safety_violations_for_trait( if !spans.is_empty() { violations.push(ObjectSafetyViolation::SupertraitSelf(spans)); } + let spans = super_predicates_have_non_lifetime_binders(tcx, trait_def_id); + if !spans.is_empty() { + violations.push(ObjectSafetyViolation::SupertraitNonLifetimeBinder(spans)); + } violations.extend( tcx.associated_items(trait_def_id) @@ -157,6 +160,7 @@ fn object_safety_violations_for_trait( .in_definition_order() .filter(|item| item.kind == ty::AssocKind::Type) .filter(|item| !tcx.generics_of(item.def_id).params.is_empty()) + .filter(|item| tcx.opt_rpitit_info(item.def_id).is_none()) .map(|item| { let ident = item.ident(tcx); ObjectSafetyViolation::GAT(ident.name, ident.span) @@ -331,7 +335,7 @@ fn predicate_references_self<'tcx>( has_self_ty(&ty.into()).then_some(sp) } - ty::PredicateKind::AliasEq(..) => bug!("`AliasEq` not allowed as assumption"), + ty::PredicateKind::AliasRelate(..) => bug!("`AliasRelate` not allowed as assumption"), ty::PredicateKind::WellFormed(..) | ty::PredicateKind::ObjectSafe(..) @@ -348,6 +352,21 @@ fn predicate_references_self<'tcx>( } } +fn super_predicates_have_non_lifetime_binders( + tcx: TyCtxt<'_>, + trait_def_id: DefId, +) -> SmallVec<[Span; 1]> { + // If non_lifetime_binders is disabled, then exit early + if !tcx.features().non_lifetime_binders { + return SmallVec::new(); + } + tcx.super_predicates_of(trait_def_id) + .predicates + .iter() + .filter_map(|(pred, span)| pred.has_non_region_late_bound().then_some(*span)) + .collect() +} + fn trait_has_sized_self(tcx: TyCtxt<'_>, trait_def_id: DefId) -> bool { generics_require_sized_self(tcx, trait_def_id) } @@ -360,26 +379,24 @@ fn generics_require_sized_self(tcx: TyCtxt<'_>, def_id: DefId) -> bool { // Search for a predicate like `Self : Sized` amongst the trait bounds. let predicates = tcx.predicates_of(def_id); let predicates = predicates.instantiate_identity(tcx).predicates; - elaborate_predicates(tcx, predicates.into_iter()).any(|obligation| { - match obligation.predicate.kind().skip_binder() { - ty::PredicateKind::Clause(ty::Clause::Trait(ref trait_pred)) => { - trait_pred.def_id() == sized_def_id && trait_pred.self_ty().is_param(0) - } - ty::PredicateKind::Clause(ty::Clause::Projection(..)) - | ty::PredicateKind::Clause(ty::Clause::ConstArgHasType(..)) - | ty::PredicateKind::Subtype(..) - | ty::PredicateKind::Coerce(..) - | ty::PredicateKind::Clause(ty::Clause::RegionOutlives(..)) - | ty::PredicateKind::WellFormed(..) - | ty::PredicateKind::ObjectSafe(..) - | ty::PredicateKind::ClosureKind(..) - | ty::PredicateKind::Clause(ty::Clause::TypeOutlives(..)) - | ty::PredicateKind::ConstEvaluatable(..) - | ty::PredicateKind::ConstEquate(..) - | ty::PredicateKind::AliasEq(..) - | ty::PredicateKind::Ambiguous - | ty::PredicateKind::TypeWellFormedFromEnv(..) => false, + elaborate(tcx, predicates.into_iter()).any(|pred| match pred.kind().skip_binder() { + ty::PredicateKind::Clause(ty::Clause::Trait(ref trait_pred)) => { + trait_pred.def_id() == sized_def_id && trait_pred.self_ty().is_param(0) } + ty::PredicateKind::Clause(ty::Clause::Projection(..)) + | ty::PredicateKind::Clause(ty::Clause::ConstArgHasType(..)) + | ty::PredicateKind::Subtype(..) + | ty::PredicateKind::Coerce(..) + | ty::PredicateKind::Clause(ty::Clause::RegionOutlives(..)) + | ty::PredicateKind::WellFormed(..) + | ty::PredicateKind::ObjectSafe(..) + | ty::PredicateKind::ClosureKind(..) + | ty::PredicateKind::Clause(ty::Clause::TypeOutlives(..)) + | ty::PredicateKind::ConstEvaluatable(..) + | ty::PredicateKind::ConstEquate(..) + | ty::PredicateKind::AliasRelate(..) + | ty::PredicateKind::Ambiguous + | ty::PredicateKind::TypeWellFormedFromEnv(..) => false, }) } @@ -649,10 +666,11 @@ fn object_ty_for_trait<'tcx>( }); debug!(?trait_predicate); - let mut elaborated_predicates: Vec<_> = elaborate_trait_ref(tcx, trait_ref) - .filter_map(|obligation| { - debug!(?obligation); - let pred = obligation.predicate.to_opt_poly_projection_pred()?; + let pred: ty::Predicate<'tcx> = trait_ref.to_predicate(tcx); + let mut elaborated_predicates: Vec<_> = elaborate(tcx, [pred]) + .filter_map(|pred| { + debug!(?pred); + let pred = pred.to_opt_poly_projection_pred()?; Some(pred.map_bound(|p| { ty::ExistentialPredicate::Projection(ty::ExistentialProjection::erase_self_ty( tcx, p, @@ -854,7 +872,7 @@ fn contains_illegal_self_type_reference<'tcx, T: TypeVisitable<TyCtxt<'tcx>>>( } } ty::Alias(ty::Projection, ref data) - if self.tcx.def_kind(data.def_id) == DefKind::ImplTraitPlaceholder => + if self.tcx.is_impl_trait_in_trait(data.def_id) => { // We'll deny these later in their own pass ControlFlow::Continue(()) @@ -921,7 +939,7 @@ pub fn contains_illegal_impl_trait_in_trait<'tcx>( ty.skip_binder().walk().find_map(|arg| { if let ty::GenericArgKind::Type(ty) = arg.unpack() && let ty::Alias(ty::Projection, proj) = ty.kind() - && tcx.def_kind(proj.def_id) == DefKind::ImplTraitPlaceholder + && tcx.is_impl_trait_in_trait(proj.def_id) { Some(MethodViolationCode::ReferencesImplTraitInTrait(tcx.def_span(proj.def_id))) } else { |