5 files changed, 52 insertions, 29 deletions

diff --git a/crates/ra_hir/src/db.rs b/crates/ra_hir/src/db.rs
index 17cb63868..a5bfef91f 100644
--- a/crates/ra_hir/src/db.rs
+++ b/crates/ra_hir/src/db.rs
@@ -2,7 +2,7 @@
 
 use std::sync::Arc;
 
-use hir_def::{GenericDefId, LocalStructFieldId, TraitId, VariantId};
+use hir_def::{GenericDefId, ImplId, LocalStructFieldId, TraitId, VariantId};
 use ra_arena::map::ArenaMap;
 use ra_db::{salsa, CrateId};
 
@@ -13,7 +13,7 @@ use crate::{
         CallableDef, FnSig, GenericPredicate, InferenceResult, Substs, Ty, TyDefId, TypeCtor,
         ValueTyDefId,
     },
-    DefWithBody, ImplBlock,
+    DefWithBody,
 };
 
 pub use hir_def::db::{
@@ -63,7 +63,7 @@ pub trait HirDatabase: DefDatabase {
     fn impls_in_crate(&self, krate: CrateId) -> Arc<CrateImplBlocks>;
 
     #[salsa::invoke(crate::ty::traits::impls_for_trait_query)]
-    fn impls_for_trait(&self, krate: CrateId, trait_: TraitId) -> Arc<[ImplBlock]>;
+    fn impls_for_trait(&self, krate: CrateId, trait_: TraitId) -> Arc<[ImplId]>;
 
     /// This provides the Chalk trait solver instance. Because Chalk always
     /// works from a specific crate, this query is keyed on the crate; and
diff --git a/crates/ra_hir/src/ty/infer/coerce.rs b/crates/ra_hir/src/ty/infer/coerce.rs
index 5ed4470af..cf45ede7c 100644
--- a/crates/ra_hir/src/ty/infer/coerce.rs
+++ b/crates/ra_hir/src/ty/infer/coerce.rs
@@ -4,13 +4,17 @@
 //!
 //! See: https://doc.rust-lang.org/nomicon/coercions.html
 
-use hir_def::{lang_item::LangItemTarget, resolver::Resolver, AdtId};
+use hir_def::{
+    lang_item::LangItemTarget,
+    resolver::{HasResolver, Resolver},
+    AdtId,
+};
 use rustc_hash::FxHashMap;
 use test_utils::tested_by;
 
 use crate::{
     db::HirDatabase,
-    ty::{autoderef, Substs, Ty, TypeCtor, TypeWalk},
+    ty::{autoderef, Substs, TraitRef, Ty, TypeCtor, TypeWalk},
     Mutability,
 };
 
@@ -57,9 +61,18 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
 
         impls
             .iter()
-            .filter_map(|impl_block| {
+            .filter_map(|&impl_id| {
+                let impl_data = db.impl_data(impl_id);
+                let resolver = impl_id.resolver(db);
+                let target_ty = Ty::from_hir(db, &resolver, &impl_data.target_type);
+
                 // `CoerseUnsized` has one generic parameter for the target type.
-                let trait_ref = impl_block.target_trait_ref(db)?;
+                let trait_ref = TraitRef::from_hir(
+                    db,
+                    &resolver,
+                    impl_data.target_trait.as_ref()?,
+                    Some(target_ty),
+                )?;
                 let cur_from_ty = trait_ref.substs.0.get(0)?;
                 let cur_to_ty = trait_ref.substs.0.get(1)?;
 
diff --git a/crates/ra_hir/src/ty/method_resolution.rs b/crates/ra_hir/src/ty/method_resolution.rs
index 92645e2a5..7df2649c9 100644
--- a/crates/ra_hir/src/ty/method_resolution.rs
+++ b/crates/ra_hir/src/ty/method_resolution.rs
@@ -62,7 +62,7 @@ impl CrateImplBlocks {
                 let impl_data = db.impl_data(impl_id);
                 let resolver = impl_id.resolver(db);
 
-                let target_ty = { Ty::from_hir(db, &resolver, &impl_data.target_type) };
+                let target_ty = Ty::from_hir(db, &resolver, &impl_data.target_type);
 
                 match &impl_data.target_trait {
                     Some(trait_ref) => {
diff --git a/crates/ra_hir/src/ty/traits.rs b/crates/ra_hir/src/ty/traits.rs
index 39b489a4c..93cb32869 100644
--- a/crates/ra_hir/src/ty/traits.rs
+++ b/crates/ra_hir/src/ty/traits.rs
@@ -2,13 +2,13 @@
 use std::sync::{Arc, Mutex};
 
 use chalk_ir::{cast::Cast, family::ChalkIr};
-use hir_def::{expr::ExprId, DefWithBodyId, TraitId};
+use hir_def::{expr::ExprId, DefWithBodyId, ImplId, TraitId, TypeAliasId};
 use log::debug;
 use ra_db::{impl_intern_key, salsa, CrateId};
 use ra_prof::profile;
 use rustc_hash::FxHashSet;
 
-use crate::{db::HirDatabase, ImplBlock, TypeAlias};
+use crate::{db::HirDatabase, ImplBlock};
 
 use super::{Canonical, GenericPredicate, HirDisplay, ProjectionTy, TraitRef, Ty, TypeWalk};
 
@@ -79,7 +79,7 @@ pub(crate) fn impls_for_trait_query(
     db: &impl HirDatabase,
     krate: CrateId,
     trait_: TraitId,
-) -> Arc<[ImplBlock]> {
+) -> Arc<[ImplId]> {
     let mut impls = FxHashSet::default();
     // We call the query recursively here. On the one hand, this means we can
     // reuse results from queries for different crates; on the other hand, this
@@ -90,7 +90,7 @@ pub(crate) fn impls_for_trait_query(
         impls.extend(db.impls_for_trait(dep.crate_id, trait_).iter());
     }
     let crate_impl_blocks = db.impls_in_crate(krate);
-    impls.extend(crate_impl_blocks.lookup_impl_blocks_for_trait(trait_).map(ImplBlock::from));
+    impls.extend(crate_impl_blocks.lookup_impl_blocks_for_trait(trait_));
     impls.into_iter().collect()
 }
 
@@ -317,7 +317,7 @@ impl_intern_key!(GlobalImplId);
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub enum AssocTyValue {
     /// A normal assoc type value from an impl block.
-    TypeAlias(TypeAlias),
+    TypeAlias(TypeAliasId),
     /// The output type of the Fn trait implementation.
     ClosureFnTraitImplOutput(ClosureFnTraitImplData),
 }
diff --git a/crates/ra_hir/src/ty/traits/chalk.rs b/crates/ra_hir/src/ty/traits/chalk.rs
index 49fa95508..7b2e530a2 100644
--- a/crates/ra_hir/src/ty/traits/chalk.rs
+++ b/crates/ra_hir/src/ty/traits/chalk.rs
@@ -11,7 +11,8 @@ use chalk_rust_ir::{AssociatedTyDatum, AssociatedTyValue, ImplDatum, StructDatum
 use ra_db::CrateId;
 
 use hir_def::{
-    lang_item::LangItemTarget, AstItemDef, ContainerId, GenericDefId, Lookup, TraitId, TypeAliasId,
+    lang_item::LangItemTarget, resolver::HasResolver, AstItemDef, ContainerId, GenericDefId,
+    Lookup, TraitId, TypeAliasId,
 };
 use hir_expand::name;
 
@@ -22,7 +23,7 @@ use crate::{
     db::HirDatabase,
     ty::display::HirDisplay,
     ty::{ApplicationTy, GenericPredicate, ProjectionTy, Substs, TraitRef, Ty, TypeCtor, TypeWalk},
-    ImplBlock, TypeAlias,
+    ImplBlock,
 };
 
 /// This represents a trait whose name we could not resolve.
@@ -452,7 +453,7 @@ where
             .impls_for_trait(self.krate, trait_.into())
             .iter()
             .copied()
-            .map(Impl::ImplBlock)
+            .map(|it| Impl::ImplBlock(it.into()))
             .map(|impl_| impl_.to_chalk(self.db))
             .collect();
 
@@ -670,7 +671,7 @@ fn impl_block_datum(
             // don't include associated types that don't exist in the trait
             trait_data.associated_type_by_name(&type_alias.name(db)).is_some()
         })
-        .map(|type_alias| AssocTyValue::TypeAlias(type_alias).to_chalk(db))
+        .map(|type_alias| AssocTyValue::TypeAlias(type_alias.id).to_chalk(db))
         .collect();
     debug!("impl_datum: {:?}", impl_datum_bound);
     let impl_datum = ImplDatum {
@@ -773,24 +774,33 @@ pub(crate) fn associated_ty_value_query(
 fn type_alias_associated_ty_value(
     db: &impl HirDatabase,
     _krate: CrateId,
-    type_alias: TypeAlias,
+    type_alias: TypeAliasId,
 ) -> Arc<AssociatedTyValue<ChalkIr>> {
-    let impl_block = type_alias.impl_block(db).expect("assoc ty value should be in impl");
-    let impl_id = Impl::ImplBlock(impl_block).to_chalk(db);
-    let trait_ = impl_block
-        .target_trait_ref(db)
-        .expect("assoc ty value should not exist") // we don't return any assoc ty values if the impl'd trait can't be resolved
-        .trait_;
+    let type_alias_data = db.type_alias_data(type_alias);
+    let impl_id = match type_alias.lookup(db).container {
+        ContainerId::ImplId(it) => it,
+        _ => panic!("assoc ty value should be in impl"),
+    };
+
+    let impl_data = db.impl_data(impl_id);
+    let resolver = impl_id.resolver(db);
+    let target_ty = Ty::from_hir(db, &resolver, &impl_data.target_type);
+    let target_trait = impl_data
+        .target_trait
+        .as_ref()
+        .and_then(|trait_ref| TraitRef::from_hir(db, &resolver, &trait_ref, Some(target_ty)))
+        .expect("assoc ty value should not exist"); // we don't return any assoc ty values if the impl'd trait can't be resolved
+
     let assoc_ty = db
-        .trait_data(trait_)
-        .associated_type_by_name(&type_alias.name(db))
+        .trait_data(target_trait.trait_)
+        .associated_type_by_name(&type_alias_data.name)
         .expect("assoc ty value should not exist"); // validated when building the impl data as well
-    let generic_params = db.generic_params(impl_block.id.into());
+    let generic_params = db.generic_params(impl_id.into());
     let bound_vars = Substs::bound_vars(&generic_params);
-    let ty = db.ty(type_alias.id.into()).subst(&bound_vars);
+    let ty = db.ty(type_alias.into()).subst(&bound_vars);
     let value_bound = chalk_rust_ir::AssociatedTyValueBound { ty: ty.to_chalk(db) };
     let value = chalk_rust_ir::AssociatedTyValue {
-        impl_id,
+        impl_id: Impl::ImplBlock(impl_id.into()).to_chalk(db),
         associated_ty_id: assoc_ty.to_chalk(db),
         value: make_binders(value_bound, bound_vars.len()),
     };