diff --git a/compiler/rustc_hir_analysis/src/astconv/mod.rs b/compiler/rustc_hir_analysis/src/astconv/mod.rs index d9d13c4c315b4..1d4b5d71fc427 100644 --- a/compiler/rustc_hir_analysis/src/astconv/mod.rs +++ b/compiler/rustc_hir_analysis/src/astconv/mod.rs @@ -40,7 +40,6 @@ use rustc_span::{sym, BytePos, Span, DUMMY_SP}; use rustc_target::spec::abi; use rustc_trait_selection::traits::wf::object_region_bounds; use rustc_trait_selection::traits::{self, NormalizeExt, ObligationCtxt}; -use rustc_type_ir::fold::{TypeFoldable, TypeFolder, TypeSuperFoldable}; use std::fmt::Display; use std::slice; @@ -1609,130 +1608,111 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o { let cause = ObligationCause::misc(span, block.owner.def_id); let mut fulfillment_errors = Vec::new(); - let mut applicable_candidates: Vec<_> = infcx.probe(|_| { - // Regions are not considered during selection. - let self_ty = self_ty - .fold_with(&mut BoundVarEraser { tcx, universe: infcx.create_next_universe() }); - - struct BoundVarEraser<'tcx> { - tcx: TyCtxt<'tcx>, - universe: ty::UniverseIndex, - } - - // FIXME(non_lifetime_binders): Don't assign the same universe to each placeholder. - impl<'tcx> TypeFolder> for BoundVarEraser<'tcx> { - fn interner(&self) -> TyCtxt<'tcx> { - self.tcx - } + infcx.probe(|_| { + let mut universes = if self_ty.has_escaping_bound_vars() { + vec![None; self_ty.outer_exclusive_binder().as_usize()] + } else { + vec![] + }; - fn fold_region(&mut self, r: ty::Region<'tcx>) -> ty::Region<'tcx> { - // FIXME(@lcnr): This is broken, erasing bound regions - // impacts selection as it results in different types. - if r.is_bound() { self.tcx.lifetimes.re_erased } else { r } - } + crate::traits::project::with_replaced_escaping_bound_vars( + infcx, + &mut universes, + self_ty, + |self_ty| { + let InferOk { value: self_ty, obligations } = + infcx.at(&cause, param_env).normalize(self_ty); - fn fold_ty(&mut self, ty: Ty<'tcx>) -> Ty<'tcx> { - match *ty.kind() { - ty::Bound(_, bv) => Ty::new_placeholder( - self.tcx, - ty::PlaceholderType { universe: self.universe, bound: bv }, - ), - _ => ty.super_fold_with(self), - } - } + let mut applicable_candidates: Vec<_> = candidates + .iter() + .copied() + .filter(|&(impl_, _)| { + infcx.probe(|_| { + let ocx = ObligationCtxt::new(&infcx); + ocx.register_obligations(obligations.clone()); + + let impl_args = infcx.fresh_args_for_item(span, impl_); + let impl_ty = tcx.type_of(impl_).instantiate(tcx, impl_args); + let impl_ty = ocx.normalize(&cause, param_env, impl_ty); + + // Check that the self types can be related. + if ocx + .eq(&ObligationCause::dummy(), param_env, impl_ty, self_ty) + .is_err() + { + return false; + } - fn fold_const( - &mut self, - ct: ty::Const<'tcx>, - ) -> as rustc_type_ir::Interner>::Const { - assert!(!ct.ty().has_escaping_bound_vars()); - - match ct.kind() { - ty::ConstKind::Bound(_, bv) => ty::Const::new_placeholder( - self.tcx, - ty::PlaceholderConst { universe: self.universe, bound: bv }, - ct.ty(), - ), - _ => ct.super_fold_with(self), - } - } - } + // Check whether the impl imposes obligations we have to worry about. + let impl_bounds = + tcx.predicates_of(impl_).instantiate(tcx, impl_args); + let impl_bounds = ocx.normalize(&cause, param_env, impl_bounds); + let impl_obligations = traits::predicates_for_generics( + |_, _| cause.clone(), + param_env, + impl_bounds, + ); + ocx.register_obligations(impl_obligations); - let InferOk { value: self_ty, obligations } = - infcx.at(&cause, param_env).normalize(self_ty); + let mut errors = ocx.select_where_possible(); + if !errors.is_empty() { + fulfillment_errors.append(&mut errors); + return false; + } - candidates - .iter() - .copied() - .filter(|&(impl_, _)| { - infcx.probe(|_| { - let ocx = ObligationCtxt::new(&infcx); - ocx.register_obligations(obligations.clone()); - - let impl_args = infcx.fresh_args_for_item(span, impl_); - let impl_ty = tcx.type_of(impl_).instantiate(tcx, impl_args); - let impl_ty = ocx.normalize(&cause, param_env, impl_ty); - - // Check that the self types can be related. - if ocx.eq(&ObligationCause::dummy(), param_env, impl_ty, self_ty).is_err() { - return false; - } + true + }) + }) + .collect(); + + if applicable_candidates.len() > 1 { + return Err(self.complain_about_ambiguous_inherent_assoc_type( + name, + applicable_candidates + .into_iter() + .map(|(_, (candidate, _))| candidate) + .collect(), + span, + )); + } - // Check whether the impl imposes obligations we have to worry about. - let impl_bounds = tcx.predicates_of(impl_).instantiate(tcx, impl_args); - let impl_bounds = ocx.normalize(&cause, param_env, impl_bounds); - let impl_obligations = traits::predicates_for_generics( - |_, _| cause.clone(), - param_env, - impl_bounds, + if let Some((impl_, (assoc_item, def_scope))) = applicable_candidates.pop() { + self.check_assoc_ty(assoc_item, name, def_scope, block, span); + + // FIXME(fmease): Currently creating throwaway `parent_args` to please + // `create_args_for_associated_item`. Modify the latter instead (or sth. similar) to + // not require the parent args logic. + let parent_args = ty::GenericArgs::identity_for_item(tcx, impl_); + let args = self.create_args_for_associated_item( + span, + assoc_item, + segment, + parent_args, + ); + let args = tcx.mk_args_from_iter( + std::iter::once(ty::GenericArg::from(self_ty)) + .chain(args.into_iter().skip(parent_args.len())), ); - ocx.register_obligations(impl_obligations); - - let mut errors = ocx.select_where_possible(); - if !errors.is_empty() { - fulfillment_errors.append(&mut errors); - return false; - } - - true - }) - }) - .collect() - }); - - if applicable_candidates.len() > 1 { - return Err(self.complain_about_ambiguous_inherent_assoc_type( - name, - applicable_candidates.into_iter().map(|(_, (candidate, _))| candidate).collect(), - span, - )); - } - - if let Some((impl_, (assoc_item, def_scope))) = applicable_candidates.pop() { - self.check_assoc_ty(assoc_item, name, def_scope, block, span); - - // FIXME(fmease): Currently creating throwaway `parent_args` to please - // `create_args_for_associated_item`. Modify the latter instead (or sth. similar) to - // not require the parent args logic. - let parent_args = ty::GenericArgs::identity_for_item(tcx, impl_); - let args = self.create_args_for_associated_item(span, assoc_item, segment, parent_args); - let args = tcx.mk_args_from_iter( - std::iter::once(ty::GenericArg::from(self_ty)) - .chain(args.into_iter().skip(parent_args.len())), - ); - let ty = Ty::new_alias(tcx, ty::Inherent, ty::AliasTy::new(tcx, assoc_item, args)); + let ty = Ty::new_alias( + tcx, + ty::Inherent, + ty::AliasTy::new(tcx, assoc_item, args), + ); - return Ok(Some((ty, assoc_item))); - } + return Ok(Some((ty, assoc_item))); + } - Err(self.complain_about_inherent_assoc_type_not_found( - name, - self_ty, - candidates, - fulfillment_errors, - span, - )) + Err(self.complain_about_inherent_assoc_type_not_found( + name, + self_ty, + candidates, + fulfillment_errors, + span, + )) + }, + ) + }) } fn lookup_assoc_ty( diff --git a/tests/ui/associated-inherent-types/issue-111404-1.rs b/tests/ui/associated-inherent-types/issue-111404-1.rs index f4ad5d7ff6c03..dd62e59f07d22 100644 --- a/tests/ui/associated-inherent-types/issue-111404-1.rs +++ b/tests/ui/associated-inherent-types/issue-111404-1.rs @@ -9,5 +9,6 @@ impl<'a> Foo { fn bar(_: fn(Foo fn(Foo::Assoc)>::Assoc)) {} //~^ ERROR higher-ranked subtype error +//~| ERROR higher-ranked subtype error fn main() {} diff --git a/tests/ui/associated-inherent-types/issue-111404-1.stderr b/tests/ui/associated-inherent-types/issue-111404-1.stderr index c55f1432389c7..cf4d4a5f19b12 100644 --- a/tests/ui/associated-inherent-types/issue-111404-1.stderr +++ b/tests/ui/associated-inherent-types/issue-111404-1.stderr @@ -4,5 +4,13 @@ error: higher-ranked subtype error LL | fn bar(_: fn(Foo fn(Foo::Assoc)>::Assoc)) {} | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ -error: aborting due to previous error +error: higher-ranked subtype error + --> $DIR/issue-111404-1.rs:10:1 + | +LL | fn bar(_: fn(Foo fn(Foo::Assoc)>::Assoc)) {} + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | + = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no` + +error: aborting due to 2 previous errors