Unnamed repository; edit this file 'description' to name the repository.
Diffstat (limited to 'crates/hir-ty/src/lower.rs')
| -rw-r--r-- | crates/hir-ty/src/lower.rs | 124 |
1 files changed, 91 insertions, 33 deletions
diff --git a/crates/hir-ty/src/lower.rs b/crates/hir-ty/src/lower.rs index 223d705b15..22a85cf154 100644 --- a/crates/hir-ty/src/lower.rs +++ b/crates/hir-ty/src/lower.rs @@ -447,12 +447,31 @@ impl<'a> TyLoweringContext<'a> { .db .trait_data(trait_ref.hir_trait_id()) .associated_type_by_name(segment.name); + match found { Some(associated_ty) => { - // FIXME handle type parameters on the segment + // FIXME: `substs_from_path_segment()` pushes `TyKind::Error` for every parent + // generic params. It's inefficient to splice the `Substitution`s, so we may want + // that method to optionally take parent `Substitution` as we already know them at + // this point (`trait_ref.substitution`). + let substitution = self.substs_from_path_segment( + segment, + Some(associated_ty.into()), + false, + None, + ); + let len_self = + generics(self.db.upcast(), associated_ty.into()).len_self(); + let substitution = Substitution::from_iter( + Interner, + substitution + .iter(Interner) + .take(len_self) + .chain(trait_ref.substitution.iter(Interner)), + ); TyKind::Alias(AliasTy::Projection(ProjectionTy { associated_ty_id: to_assoc_type_id(associated_ty), - substitution: trait_ref.substitution, + substitution, })) .intern(Interner) } @@ -590,36 +609,48 @@ impl<'a> TyLoweringContext<'a> { res, Some(segment.name.clone()), move |name, t, associated_ty| { - if name == segment.name { - let substs = match self.type_param_mode { - ParamLoweringMode::Placeholder => { - // if we're lowering to placeholders, we have to put - // them in now - let generics = generics( - self.db.upcast(), - self.resolver - .generic_def() - .expect("there should be generics if there's a generic param"), - ); - let s = generics.placeholder_subst(self.db); - s.apply(t.substitution.clone(), Interner) - } - ParamLoweringMode::Variable => t.substitution.clone(), - }; - // We need to shift in the bound vars, since - // associated_type_shorthand_candidates does not do that - let substs = substs.shifted_in_from(Interner, self.in_binders); - // FIXME handle type parameters on the segment - Some( - TyKind::Alias(AliasTy::Projection(ProjectionTy { - associated_ty_id: to_assoc_type_id(associated_ty), - substitution: substs, - })) - .intern(Interner), - ) - } else { - None + if name != segment.name { + return None; } + + // FIXME: `substs_from_path_segment()` pushes `TyKind::Error` for every parent + // generic params. It's inefficient to splice the `Substitution`s, so we may want + // that method to optionally take parent `Substitution` as we already know them at + // this point (`t.substitution`). + let substs = self.substs_from_path_segment( + segment.clone(), + Some(associated_ty.into()), + false, + None, + ); + + let len_self = generics(self.db.upcast(), associated_ty.into()).len_self(); + + let substs = Substitution::from_iter( + Interner, + substs.iter(Interner).take(len_self).chain(t.substitution.iter(Interner)), + ); + + let substs = match self.type_param_mode { + ParamLoweringMode::Placeholder => { + // if we're lowering to placeholders, we have to put + // them in now + let generics = generics(self.db.upcast(), def); + let s = generics.placeholder_subst(self.db); + s.apply(substs, Interner) + } + ParamLoweringMode::Variable => substs, + }; + // We need to shift in the bound vars, since + // associated_type_shorthand_candidates does not do that + let substs = substs.shifted_in_from(Interner, self.in_binders); + Some( + TyKind::Alias(AliasTy::Projection(ProjectionTy { + associated_ty_id: to_assoc_type_id(associated_ty), + substitution: substs, + })) + .intern(Interner), + ) }, ); @@ -777,7 +808,15 @@ impl<'a> TyLoweringContext<'a> { // handle defaults. In expression or pattern path segments without // explicitly specified type arguments, missing type arguments are inferred // (i.e. defaults aren't used). - if !infer_args || had_explicit_args { + // Generic parameters for associated types are not supposed to have defaults, so we just + // ignore them. + let is_assoc_ty = if let GenericDefId::TypeAliasId(id) = def { + let container = id.lookup(self.db.upcast()).container; + matches!(container, ItemContainerId::TraitId(_)) + } else { + false + }; + if !is_assoc_ty && (!infer_args || had_explicit_args) { let defaults = self.db.generic_defaults(def); assert_eq!(total_len, defaults.len()); let parent_from = item_len - substs.len(); @@ -966,9 +1005,28 @@ impl<'a> TyLoweringContext<'a> { None => return SmallVec::new(), Some(t) => t, }; + // FIXME: `substs_from_path_segment()` pushes `TyKind::Error` for every parent + // generic params. It's inefficient to splice the `Substitution`s, so we may want + // that method to optionally take parent `Substitution` as we already know them at + // this point (`super_trait_ref.substitution`). + let substitution = self.substs_from_path_segment( + // FIXME: This is hack. We shouldn't really build `PathSegment` directly. + PathSegment { name: &binding.name, args_and_bindings: binding.args.as_deref() }, + Some(associated_ty.into()), + false, // this is not relevant + Some(super_trait_ref.self_type_parameter(Interner)), + ); + let self_params = generics(self.db.upcast(), associated_ty.into()).len_self(); + let substitution = Substitution::from_iter( + Interner, + substitution + .iter(Interner) + .take(self_params) + .chain(super_trait_ref.substitution.iter(Interner)), + ); let projection_ty = ProjectionTy { associated_ty_id: to_assoc_type_id(associated_ty), - substitution: super_trait_ref.substitution, + substitution, }; let mut preds: SmallVec<[_; 1]> = SmallVec::with_capacity( binding.type_ref.as_ref().map_or(0, |_| 1) + binding.bounds.len(), |