diff options
5 files changed, 128 insertions, 117 deletions
diff --git a/compiler/rustc_hir_analysis/src/astconv/mod.rs b/compiler/rustc_hir_analysis/src/astconv/mod.rs index 94b182e09f6..b9a4806e6c2 100644 --- a/compiler/rustc_hir_analysis/src/astconv/mod.rs +++ b/compiler/rustc_hir_analysis/src/astconv/mod.rs @@ -26,12 +26,13 @@ use rustc_hir::def::{CtorOf, DefKind, Namespace, Res}; use rustc_hir::def_id::{DefId, LocalDefId}; use rustc_hir::intravisit::{walk_generics, Visitor as _}; use rustc_hir::{GenericArg, GenericArgs, OpaqueTyOrigin}; -use rustc_infer::infer::{InferCtxt, InferOk, TyCtxtInferExt}; +use rustc_infer::infer::{InferCtxt, TyCtxtInferExt}; use rustc_infer::traits::ObligationCause; use rustc_middle::middle::stability::AllowUnstable; use rustc_middle::ty::GenericParamDefKind; use rustc_middle::ty::{ - self, Const, GenericArgKind, GenericArgsRef, IsSuggestable, Ty, TyCtxt, TypeVisitableExt, + self, Const, GenericArgKind, GenericArgsRef, IsSuggestable, ParamEnv, Ty, TyCtxt, + TypeVisitableExt, }; use rustc_session::lint::builtin::AMBIGUOUS_ASSOCIATED_ITEMS; use rustc_span::edit_distance::find_best_match_for_name; @@ -39,8 +40,7 @@ use rustc_span::symbol::{kw, Ident, Symbol}; 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 rustc_trait_selection::traits::{self, ObligationCtxt}; use std::fmt::Display; use std::slice; @@ -1606,133 +1606,110 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o { // FIXME(inherent_associated_types): Acquiring the ParamEnv this early leads to cycle errors // when inside of an ADT (#108491) or where clause. let param_env = tcx.param_env(block.owner); - 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<TyCtxt<'tcx>> for BoundVarEraser<'tcx> { - fn interner(&self) -> TyCtxt<'tcx> { - self.tcx - } + 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 } - } + let (impl_, (assoc_item, def_scope)) = + crate::traits::project::with_replaced_escaping_bound_vars( + infcx, + &mut universes, + self_ty, + |self_ty| { + self.select_inherent_assoc_type_candidates( + infcx, name, span, self_ty, param_env, candidates, + ) + }, + )?; + + 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())), + ); - 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 ty = Ty::new_alias(tcx, ty::Inherent, ty::AliasTy::new(tcx, assoc_item, args)); - fn fold_const( - &mut self, - ct: ty::Const<'tcx>, - ) -> <TyCtxt<'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), - } - } - } + Ok(Some((ty, assoc_item))) + } - let InferOk { value: self_ty, obligations } = - infcx.at(&cause, param_env).normalize(self_ty); + fn select_inherent_assoc_type_candidates( + &self, + infcx: &InferCtxt<'tcx>, + name: Ident, + span: Span, + self_ty: Ty<'tcx>, + param_env: ParamEnv<'tcx>, + candidates: Vec<(DefId, (DefId, DefId))>, + ) -> Result<(DefId, (DefId, DefId)), ErrorGuaranteed> { + let tcx = self.tcx(); + let mut fulfillment_errors = Vec::new(); - 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; - } + let applicable_candidates: Vec<_> = candidates + .iter() + .copied() + .filter(|&(impl_, _)| { + infcx.probe(|_| { + let ocx = ObligationCtxt::new(infcx); + let self_ty = ocx.normalize(&ObligationCause::dummy(), param_env, self_ty); + + 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(&ObligationCause::dummy(), 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; + } - // 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); + // 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(&ObligationCause::dummy(), param_env, impl_bounds); + let impl_obligations = traits::predicates_for_generics( + |_, _| ObligationCause::dummy(), + param_env, + impl_bounds, + ); + ocx.register_obligations(impl_obligations); - let mut errors = ocx.select_where_possible(); - if !errors.is_empty() { - fulfillment_errors.append(&mut errors); - return false; - } + let mut errors = ocx.select_where_possible(); + if !errors.is_empty() { + fulfillment_errors.append(&mut errors); + return false; + } - true - }) + true }) - .collect() - }); + }) + .collect(); - if applicable_candidates.len() > 1 { - return Err(self.complain_about_ambiguous_inherent_assoc_type( + match &applicable_candidates[..] { + &[] => Err(self.complain_about_inherent_assoc_type_not_found( name, - applicable_candidates.into_iter().map(|(_, (candidate, _))| candidate).collect(), + self_ty, + candidates, + fulfillment_errors, 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)); + &[applicable_candidate] => Ok(applicable_candidate), - return Ok(Some((ty, assoc_item))); + &[_, ..] => Err(self.complain_about_ambiguous_inherent_assoc_type( + name, + applicable_candidates.into_iter().map(|(_, (candidate, _))| candidate).collect(), + span, + )), } - - Err(self.complain_about_inherent_assoc_type_not_found( - name, - self_ty, - candidates, - fulfillment_errors, - span, - )) } fn lookup_assoc_ty( diff --git a/compiler/rustc_trait_selection/src/traits/project.rs b/compiler/rustc_trait_selection/src/traits/project.rs index 8f5afdf0a1f..3be14951703 100644 --- a/compiler/rustc_trait_selection/src/traits/project.rs +++ b/compiler/rustc_trait_selection/src/traits/project.rs @@ -1454,7 +1454,18 @@ pub fn compute_inherent_assoc_ty_args<'a, 'b, 'tcx>( // Infer the generic parameters of the impl by unifying the // impl type with the self type of the projection. - let self_ty = alias_ty.self_ty(); + let mut self_ty = alias_ty.self_ty(); + if !selcx.infcx.next_trait_solver() { + self_ty = normalize_with_depth_to( + selcx, + param_env, + cause.clone(), + depth + 1, + self_ty, + obligations, + ); + } + match selcx.infcx.at(&cause, param_env).eq(DefineOpaqueTypes::No, impl_ty, self_ty) { Ok(mut ok) => obligations.append(&mut ok.obligations), Err(_) => { diff --git a/tests/ui/associated-inherent-types/assoc-inherent-late-bound.rs b/tests/ui/associated-inherent-types/assoc-inherent-late-bound.rs new file mode 100644 index 00000000000..b6993f66fe7 --- /dev/null +++ b/tests/ui/associated-inherent-types/assoc-inherent-late-bound.rs @@ -0,0 +1,14 @@ +// check-pass + +#![feature(inherent_associated_types)] +#![allow(incomplete_features)] + +struct Foo<T>(T); + +impl<'a> Foo<fn(&'a ())> { + type Assoc = &'a (); +} + +fn bar(_: for<'a> fn(Foo<fn(Foo<fn(&'static ())>::Assoc)>::Assoc)) {} + +fn main() {} diff --git a/tests/ui/associated-inherent-types/issue-111404-1.rs b/tests/ui/associated-inherent-types/issue-111404-1.rs index f4ad5d7ff6c..dd62e59f07d 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(&'a ())> { fn bar(_: fn(Foo<for<'b> fn(Foo<fn(&'b ())>::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 2c78e3a1fb7..cf4d4a5f19b 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<for<'b> fn(Foo<fn(&'b ())>::Assoc)>::Assoc)) {} | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ -error: aborting due to 1 previous error +error: higher-ranked subtype error + --> $DIR/issue-111404-1.rs:10:1 + | +LL | fn bar(_: fn(Foo<for<'b> fn(Foo<fn(&'b ())>::Assoc)>::Assoc)) {} + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | + = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no` + +error: aborting due to 2 previous errors |