diff options
3 files changed, 25 insertions, 54 deletions
diff --git a/src/librustc_typeck/check/compare_method.rs b/src/librustc_typeck/check/compare_method.rs index fac87866b80..bf415406675 100644 --- a/src/librustc_typeck/check/compare_method.rs +++ b/src/librustc_typeck/check/compare_method.rs @@ -6,15 +6,14 @@ use rustc_hir::{GenericParamKind, ImplItemKind, TraitItemKind}; use rustc_infer::infer::{self, InferOk, TyCtxtInferExt}; use rustc_middle::ty; use rustc_middle::ty::error::{ExpectedFound, TypeError}; -use rustc_middle::ty::subst::{InternalSubsts, Subst, SubstsRef}; +use rustc_middle::ty::subst::{InternalSubsts, Subst}; use rustc_middle::ty::util::ExplicitSelf; -use rustc_middle::ty::{GenericParamDefKind, ToPredicate, TyCtxt, WithConstness}; +use rustc_middle::ty::{GenericParamDefKind, ToPredicate, TyCtxt}; use rustc_span::Span; use rustc_trait_selection::traits::error_reporting::InferCtxtExt; use rustc_trait_selection::traits::{self, ObligationCause, ObligationCauseCode, Reveal}; use super::{potentially_plural_count, FnCtxt, Inherited}; -use std::iter; /// Checks that a method from an impl conforms to the signature of /// the same method as declared in the trait. @@ -1240,22 +1239,6 @@ fn compare_projection_bounds<'tcx>( ty::ParamEnv::new(tcx.intern_predicates(&predicates), Reveal::UserFacing, None) }; - // Map the predicate from the trait to the corresponding one for the impl. - // For example: - // - // trait X<A> { type Y<'a>: PartialEq<A> } impl X for T { type Y<'a> = &'a S; } - // impl<'x> X<&'x u32> for () { type Y<'c> = &'c u32; } - // - // For the `for<'a> <<Self as X<A>>::Y<'a>: PartialEq<A>` bound, this - // function would translate and partially normalize - // `[<Self as X<A>>::Y<'a>, A]` to `[&'a u32, &'x u32]`. - let translate_predicate_substs = move |predicate_substs: SubstsRef<'tcx>| { - tcx.mk_substs( - iter::once(impl_ty_value.into()) - .chain(predicate_substs[1..].iter().map(|s| s.subst(tcx, rebased_substs))), - ) - }; - tcx.infer_ctxt().enter(move |infcx| { let inh = Inherited::new(infcx, impl_ty.def_id.expect_local()); let infcx = &inh.infcx; @@ -1270,39 +1253,10 @@ fn compare_projection_bounds<'tcx>( ); let predicates = tcx.projection_predicates(trait_ty.def_id); - debug!("compare_projection_bounds: projection_predicates={:?}", predicates); for predicate in predicates { - let concrete_ty_predicate = match predicate.kind() { - ty::PredicateKind::Trait(poly_tr, c) => poly_tr - .map_bound(|tr| { - let trait_substs = translate_predicate_substs(tr.trait_ref.substs); - ty::TraitRef { def_id: tr.def_id(), substs: trait_substs } - }) - .with_constness(*c) - .to_predicate(tcx), - ty::PredicateKind::Projection(poly_projection) => poly_projection - .map_bound(|projection| { - let projection_substs = - translate_predicate_substs(projection.projection_ty.substs); - ty::ProjectionPredicate { - projection_ty: ty::ProjectionTy { - substs: projection_substs, - item_def_id: projection.projection_ty.item_def_id, - }, - ty: projection.ty.subst(tcx, rebased_substs), - } - }) - .to_predicate(tcx), - ty::PredicateKind::TypeOutlives(poly_outlives) => poly_outlives - .map_bound(|outlives| { - ty::OutlivesPredicate(impl_ty_value, outlives.1.subst(tcx, rebased_substs)) - }) - .to_predicate(tcx), - _ => bug!("unexepected projection predicate kind: `{:?}`", predicate), - }; - + let concrete_ty_predicate = predicate.subst(tcx, rebased_substs); debug!("compare_projection_bounds: concrete predicate = {:?}", concrete_ty_predicate); let traits::Normalized { value: normalized_predicate, obligations } = traits::normalize( @@ -1311,7 +1265,6 @@ fn compare_projection_bounds<'tcx>( normalize_cause.clone(), &concrete_ty_predicate, ); - debug!("compare_projection_bounds: normalized predicate = {:?}", normalized_predicate); inh.register_predicates(obligations); diff --git a/src/test/ui/generic-associated-types/unsatisfied-outlives-bound.rs b/src/test/ui/generic-associated-types/unsatisfied-outlives-bound.rs index 7510c58d574..4831a8c63e8 100644 --- a/src/test/ui/generic-associated-types/unsatisfied-outlives-bound.rs +++ b/src/test/ui/generic-associated-types/unsatisfied-outlives-bound.rs @@ -7,7 +7,7 @@ trait ATy { impl<'b> ATy for &'b () { type Item<'a> = &'b (); - //~^ ERROR does not fulfill the required lifetime + //~^ ERROR cannot infer an appropriate lifetime } trait StaticTy { diff --git a/src/test/ui/generic-associated-types/unsatisfied-outlives-bound.stderr b/src/test/ui/generic-associated-types/unsatisfied-outlives-bound.stderr index 5d612284a21..80f69becc2c 100644 --- a/src/test/ui/generic-associated-types/unsatisfied-outlives-bound.stderr +++ b/src/test/ui/generic-associated-types/unsatisfied-outlives-bound.stderr @@ -1,14 +1,31 @@ -error[E0477]: the type `&'b ()` does not fulfill the required lifetime +error[E0495]: cannot infer an appropriate lifetime for lifetime parameter `'b` due to conflicting requirements --> $DIR/unsatisfied-outlives-bound.rs:9:5 | LL | type Item<'a> = &'b (); | ^^^^^^^^^^^^^^^^^^^^^^^ | -note: type must outlive the lifetime `'a` as defined on the associated item at 9:15 +note: first, the lifetime cannot outlive the lifetime `'b` as defined on the impl at 8:6... + --> $DIR/unsatisfied-outlives-bound.rs:8:6 + | +LL | impl<'b> ATy for &'b () { + | ^^ +note: ...so that the types are compatible + --> $DIR/unsatisfied-outlives-bound.rs:9:5 + | +LL | type Item<'a> = &'b (); + | ^^^^^^^^^^^^^^^^^^^^^^^ + = note: expected `ATy` + found `ATy` +note: but, the lifetime must be valid for the lifetime `'a` as defined on the associated item at 9:15... --> $DIR/unsatisfied-outlives-bound.rs:9:15 | LL | type Item<'a> = &'b (); | ^^ +note: ...so that the type `&()` will meet its required lifetime bounds + --> $DIR/unsatisfied-outlives-bound.rs:9:5 + | +LL | type Item<'a> = &'b (); + | ^^^^^^^^^^^^^^^^^^^^^^^ error[E0477]: the type `&'a ()` does not fulfill the required lifetime --> $DIR/unsatisfied-outlives-bound.rs:18:5 @@ -20,4 +37,5 @@ LL | type Item<'a> = &'a (); error: aborting due to 2 previous errors -For more information about this error, try `rustc --explain E0477`. +Some errors have detailed explanations: E0477, E0495. +For more information about an error, try `rustc --explain E0477`. |