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 | 70 |
1 files changed, 58 insertions, 12 deletions
diff --git a/crates/hir_ty/src/lower.rs b/crates/hir_ty/src/lower.rs index 3734eb1013..d5f3940149 100644 --- a/crates/hir_ty/src/lower.rs +++ b/crates/hir_ty/src/lower.rs @@ -30,6 +30,7 @@ use smallvec::SmallVec; use stdx::impl_from; use syntax::ast; +use crate::all_super_traits; use crate::{ consteval, db::HirDatabase, @@ -531,9 +532,10 @@ impl<'a> TyLoweringContext<'a> { fn select_associated_type(&self, res: Option<TypeNs>, segment: PathSegment<'_>) -> Ty { if let Some(res) = res { - let ty = associated_type_shorthand_candidates( + let ty = named_associated_type_shorthand_candidates( self.db, res, + Some(segment.name.clone()), move |name, t, associated_ty| { if name == segment.name { let substs = match self.type_param_mode { @@ -555,16 +557,16 @@ impl<'a> TyLoweringContext<'a> { // 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 - return Some( + Some( TyKind::Alias(AliasTy::Projection(ProjectionTy { associated_ty_id: to_assoc_type_id(associated_ty), substitution: substs, })) .intern(&Interner), - ); + ) + } else { + None } - - None }, ); @@ -935,6 +937,15 @@ pub fn callable_item_sig(db: &dyn HirDatabase, def: CallableDefId) -> PolyFnSig pub fn associated_type_shorthand_candidates<R>( db: &dyn HirDatabase, res: TypeNs, + cb: impl FnMut(&Name, &TraitRef, TypeAliasId) -> Option<R>, +) -> Option<R> { + named_associated_type_shorthand_candidates(db, res, None, cb) +} + +fn named_associated_type_shorthand_candidates<R>( + db: &dyn HirDatabase, + res: TypeNs, + assoc_name: Option<Name>, mut cb: impl FnMut(&Name, &TraitRef, TypeAliasId) -> Option<R>, ) -> Option<R> { let mut search = |t| { @@ -959,7 +970,7 @@ pub fn associated_type_shorthand_candidates<R>( db.impl_trait(impl_id)?.into_value_and_skipped_binders().0, ), TypeNs::GenericParam(param_id) => { - let predicates = db.generic_predicates_for_param(param_id); + let predicates = db.generic_predicates_for_param(param_id, assoc_name); let res = predicates.iter().find_map(|pred| match pred.skip_binders().skip_binders() { // FIXME: how to correctly handle higher-ranked bounds here? WhereClause::Implemented(tr) => search( @@ -1022,6 +1033,7 @@ pub(crate) fn field_types_query( pub(crate) fn generic_predicates_for_param_query( db: &dyn HirDatabase, param_id: TypeParamId, + assoc_name: Option<Name>, ) -> Arc<[Binders<QuantifiedWhereClause>]> { let resolver = param_id.parent.resolver(db.upcast()); let ctx = @@ -1031,13 +1043,46 @@ pub(crate) fn generic_predicates_for_param_query( .where_predicates_in_scope() // we have to filter out all other predicates *first*, before attempting to lower them .filter(|pred| match pred { - WherePredicate::ForLifetime { target, .. } - | WherePredicate::TypeBound { target, .. } => match target { - WherePredicateTypeTarget::TypeRef(type_ref) => { - ctx.lower_ty_only_param(type_ref) == Some(param_id) + WherePredicate::ForLifetime { target, bound, .. } + | WherePredicate::TypeBound { target, bound, .. } => { + match target { + WherePredicateTypeTarget::TypeRef(type_ref) => { + if ctx.lower_ty_only_param(type_ref) != Some(param_id) { + return false; + } + } + WherePredicateTypeTarget::TypeParam(local_id) => { + if *local_id != param_id.local_id { + return false; + } + } + }; + + match &**bound { + TypeBound::ForLifetime(_, path) | TypeBound::Path(path, _) => { + // Only lower the bound if the trait could possibly define the associated + // type we're looking for. + + let assoc_name = match &assoc_name { + Some(it) => it, + None => return true, + }; + let tr = match resolver + .resolve_path_in_type_ns_fully(db.upcast(), path.mod_path()) + { + Some(TypeNs::TraitId(tr)) => tr, + _ => return false, + }; + + all_super_traits(db.upcast(), tr).iter().any(|tr| { + db.trait_data(*tr).items.iter().any(|(name, item)| { + matches!(item, AssocItemId::TypeAliasId(_)) && name == assoc_name + }) + }) + } + TypeBound::Lifetime(_) | TypeBound::Error => false, } - WherePredicateTypeTarget::TypeParam(local_id) => *local_id == param_id.local_id, - }, + } WherePredicate::Lifetime { .. } => false, }) .flat_map(|pred| ctx.lower_where_predicate(pred, true).map(|p| make_binders(&generics, p))) @@ -1056,6 +1101,7 @@ pub(crate) fn generic_predicates_for_param_recover( _db: &dyn HirDatabase, _cycle: &[String], _param_id: &TypeParamId, + _assoc_name: &Option<Name>, ) -> Arc<[Binders<QuantifiedWhereClause>]> { Arc::new([]) } |