Lower bounds on trait definition, and resolve assoc types from super traits

5 files changed, 26 insertions, 23 deletions

diff --git a/crates/ra_hir/src/ty/autoderef.rs b/crates/ra_hir/src/ty/autoderef.rs
index 08f52a53b..caa17f64e 100644
--- a/crates/ra_hir/src/ty/autoderef.rs
+++ b/crates/ra_hir/src/ty/autoderef.rs
@@ -8,7 +8,7 @@ use std::iter::successors;
 use log::{info, warn};
 
 use super::{traits::Solution, Canonical, Ty, TypeWalk};
-use crate::{HasGenericParams, HirDatabase, Name, Resolver};
+use crate::{name, HasGenericParams, HirDatabase, Resolver};
 
 const AUTODEREF_RECURSION_LIMIT: usize = 10;
 
@@ -42,7 +42,7 @@ fn deref_by_trait(
         crate::lang_item::LangItemTarget::Trait(t) => t,
         _ => return None,
     };
-    let target = deref_trait.associated_type_by_name(db, Name::target())?;
+    let target = deref_trait.associated_type_by_name(db, &name::TARGET)?;
 
     if target.generic_params(db).count_params_including_parent() != 1 {
         // the Target type + Deref trait should only have one generic parameter,
diff --git a/crates/ra_hir/src/ty/infer.rs b/crates/ra_hir/src/ty/infer.rs
index ec3b7ffef..0e6ebd365 100644
--- a/crates/ra_hir/src/ty/infer.rs
+++ b/crates/ra_hir/src/ty/infer.rs
@@ -1453,7 +1453,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
 
         match self.resolver.resolve_path_segments(self.db, &into_iter_path).into_fully_resolved() {
             PerNs { types: Some(Def(Trait(trait_))), .. } => {
-                Some(trait_.associated_type_by_name(self.db, name::ITEM)?)
+                Some(trait_.associated_type_by_name(self.db, &name::ITEM)?)
             }
             _ => None,
         }
@@ -1471,7 +1471,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
 
         match self.resolver.resolve_path_segments(self.db, &ops_try_path).into_fully_resolved() {
             PerNs { types: Some(Def(Trait(trait_))), .. } => {
-                Some(trait_.associated_type_by_name(self.db, name::OK)?)
+                Some(trait_.associated_type_by_name(self.db, &name::OK)?)
             }
             _ => None,
         }
@@ -1493,7 +1493,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
             .into_fully_resolved()
         {
             PerNs { types: Some(Def(Trait(trait_))), .. } => {
-                Some(trait_.associated_type_by_name(self.db, name::OUTPUT)?)
+                Some(trait_.associated_type_by_name(self.db, &name::OUTPUT)?)
             }
             _ => None,
         }
diff --git a/crates/ra_hir/src/ty/lower.rs b/crates/ra_hir/src/ty/lower.rs
index f6f0137cf..480bae740 100644
--- a/crates/ra_hir/src/ty/lower.rs
+++ b/crates/ra_hir/src/ty/lower.rs
@@ -132,14 +132,16 @@ impl Ty {
             if let Some(remaining_index) = remaining_index {
                 if remaining_index == path.segments.len() - 1 {
                     let segment = &path.segments[remaining_index];
-                    let associated_ty =
-                        match trait_ref.trait_.associated_type_by_name(db, segment.name.clone()) {
-                            Some(t) => t,
-                            None => {
-                                // associated type not found
-                                return Ty::Unknown;
-                            }
-                        };
+                    let associated_ty = match trait_ref
+                        .trait_
+                        .associated_type_by_name_including_super_traits(db, &segment.name)
+                    {
+                        Some(t) => t,
+                        None => {
+                            // associated type not found
+                            return Ty::Unknown;
+                        }
+                    };
                     // FIXME handle type parameters on the segment
                     Ty::Projection(ProjectionTy { associated_ty, parameters: trait_ref.substs })
                 } else {
@@ -387,10 +389,11 @@ fn assoc_type_bindings_from_type_bound<'a>(
         .flat_map(|segment| segment.args_and_bindings.iter())
         .flat_map(|args_and_bindings| args_and_bindings.bindings.iter())
         .map(move |(name, type_ref)| {
-            let associated_ty = match trait_ref.trait_.associated_type_by_name(db, name.clone()) {
-                None => return GenericPredicate::Error,
-                Some(t) => t,
-            };
+            let associated_ty =
+                match trait_ref.trait_.associated_type_by_name_including_super_traits(db, &name) {
+                    None => return GenericPredicate::Error,
+                    Some(t) => t,
+                };
             let projection_ty =
                 ProjectionTy { associated_ty, parameters: trait_ref.substs.clone() };
             let ty = Ty::from_hir(db, resolver, type_ref);
diff --git a/crates/ra_hir/src/ty/tests.rs b/crates/ra_hir/src/ty/tests.rs
index cb5540cb6..17c4e3556 100644
--- a/crates/ra_hir/src/ty/tests.rs
+++ b/crates/ra_hir/src/ty/tests.rs
@@ -3720,11 +3720,11 @@ fn test() {
     [157; 160) '{t}': T
     [158; 159) 't': T
     [259; 280) '{     ...S)); }': ()
-    [265; 269) 'get2': fn get2<{unknown}, S<{unknown}>>(T) -> U
-    [265; 277) 'get2(set(S))': {unknown}
-    [270; 273) 'set': fn set<S<{unknown}>>(T) -> T
-    [270; 276) 'set(S)': S<{unknown}>
-    [274; 275) 'S': S<{unknown}>
+    [265; 269) 'get2': fn get2<u64, S<u64>>(T) -> U
+    [265; 277) 'get2(set(S))': u64
+    [270; 273) 'set': fn set<S<u64>>(T) -> T
+    [270; 276) 'set(S)': S<u64>
+    [274; 275) 'S': S<u64>
     "###
     );
 }
diff --git a/crates/ra_hir/src/ty/traits/chalk.rs b/crates/ra_hir/src/ty/traits/chalk.rs
index c201c5e50..cfe0cab16 100644
--- a/crates/ra_hir/src/ty/traits/chalk.rs
+++ b/crates/ra_hir/src/ty/traits/chalk.rs
@@ -636,7 +636,7 @@ pub(crate) fn impl_datum_query(
             _ => None,
         })
         .filter_map(|t| {
-            let assoc_ty = trait_.associated_type_by_name(db, t.name(db))?;
+            let assoc_ty = trait_.associated_type_by_name(db, &t.name(db))?;
             let ty = db.type_for_def(t.into(), crate::Namespace::Types).subst(&bound_vars);
             Some(chalk_rust_ir::AssociatedTyValue {
                 impl_id,