5 files changed, 9 insertions, 18 deletions

diff --git a/crates/hir_ty/src/display.rs b/crates/hir_ty/src/display.rs
index 666bb1f9d..4a25a49e3 100644
--- a/crates/hir_ty/src/display.rs
+++ b/crates/hir_ty/src/display.rs
@@ -471,14 +471,9 @@ impl HirDisplay for Ty {
                     projection_ty.hir_fmt(f)?;
                 }
             }
-            Ty::ForeignType(type_alias, parameters) => {
+            Ty::ForeignType(type_alias) => {
                 let type_alias = f.db.type_alias_data(*type_alias);
                 write!(f, "{}", type_alias.name)?;
-                if parameters.len() > 0 {
-                    write!(f, "<")?;
-                    f.write_joined(&*parameters.0, ", ")?;
-                    write!(f, ">")?;
-                }
             }
             Ty::OpaqueType(opaque_ty_id, parameters) => {
                 match opaque_ty_id {
diff --git a/crates/hir_ty/src/lib.rs b/crates/hir_ty/src/lib.rs
index 3d134453f..4c0ebcfe3 100644
--- a/crates/hir_ty/src/lib.rs
+++ b/crates/hir_ty/src/lib.rs
@@ -169,7 +169,7 @@ pub enum Ty {
     Closure { def: DefWithBodyId, expr: ExprId, substs: Substs },
 
     /// Represents a foreign type declared in external blocks.
-    ForeignType(TypeAliasId, Substs),
+    ForeignType(TypeAliasId),
 
     /// A pointer to a function.  Written as `fn() -> i32`.
     ///
@@ -755,7 +755,6 @@ impl Ty {
             | Ty::Tuple(_, substs)
             | Ty::OpaqueType(_, substs)
             | Ty::AssociatedType(_, substs)
-            | Ty::ForeignType(_, substs)
             | Ty::Closure { substs, .. } => {
                 assert_eq!(substs.len(), new_substs.len());
                 *substs = new_substs;
@@ -779,7 +778,6 @@ impl Ty {
             | Ty::Tuple(_, substs)
             | Ty::OpaqueType(_, substs)
             | Ty::AssociatedType(_, substs)
-            | Ty::ForeignType(_, substs)
             | Ty::Closure { substs, .. } => Some(substs),
             _ => None,
         }
@@ -797,7 +795,6 @@ impl Ty {
             | Ty::Tuple(_, substs)
             | Ty::OpaqueType(_, substs)
             | Ty::AssociatedType(_, substs)
-            | Ty::ForeignType(_, substs)
             | Ty::Closure { substs, .. } => Some(substs),
             _ => None,
         }
diff --git a/crates/hir_ty/src/lower.rs b/crates/hir_ty/src/lower.rs
index 8295f4c31..84734bc0b 100644
--- a/crates/hir_ty/src/lower.rs
+++ b/crates/hir_ty/src/lower.rs
@@ -1100,10 +1100,10 @@ fn type_for_type_alias(db: &dyn HirDatabase, t: TypeAliasId) -> Binders<Ty> {
     let resolver = t.resolver(db.upcast());
     let ctx =
         TyLoweringContext::new(db, &resolver).with_type_param_mode(TypeParamLoweringMode::Variable);
-    let substs = Substs::bound_vars(&generics, DebruijnIndex::INNERMOST);
     if db.type_alias_data(t).is_extern {
-        Binders::new(substs.len(), Ty::ForeignType(t, substs))
+        Binders::new(0, Ty::ForeignType(t))
     } else {
+        let substs = Substs::bound_vars(&generics, DebruijnIndex::INNERMOST);
         let type_ref = &db.type_alias_data(t).type_ref;
         let inner = Ty::from_hir(&ctx, type_ref.as_ref().unwrap_or(&TypeRef::Error));
         Binders::new(substs.len(), inner)
diff --git a/crates/hir_ty/src/method_resolution.rs b/crates/hir_ty/src/method_resolution.rs
index 422e61f0a..ff8ce5599 100644
--- a/crates/hir_ty/src/method_resolution.rs
+++ b/crates/hir_ty/src/method_resolution.rs
@@ -235,7 +235,7 @@ impl Ty {
             Ty::Adt(def_id, _) => {
                 return mod_to_crate_ids(def_id.module(db.upcast()));
             }
-            Ty::ForeignType(type_alias_id, _) => {
+            Ty::ForeignType(type_alias_id) => {
                 return mod_to_crate_ids(type_alias_id.lookup(db.upcast()).module(db.upcast()));
             }
             Ty::Scalar(Scalar::Bool) => lang_item_crate!("bool"),
diff --git a/crates/hir_ty/src/traits/chalk/mapping.rs b/crates/hir_ty/src/traits/chalk/mapping.rs
index 09e5a82b8..c17c19638 100644
--- a/crates/hir_ty/src/traits/chalk/mapping.rs
+++ b/crates/hir_ty/src/traits/chalk/mapping.rs
@@ -55,7 +55,7 @@ impl ToChalk for Ty {
                 chalk_ir::TyKind::OpaqueType(id, substitution).intern(&Interner)
             }
 
-            Ty::ForeignType(type_alias, _) => {
+            Ty::ForeignType(type_alias) => {
                 let foreign_type = TypeAliasAsForeignType(type_alias);
                 let foreign_type_id = foreign_type.to_chalk(db);
                 chalk_ir::TyKind::Foreign(foreign_type_id).intern(&Interner)
@@ -221,10 +221,9 @@ impl ToChalk for Ty {
                 Ty::Closure { def, expr, substs: from_chalk(db, subst) }
             }
 
-            chalk_ir::TyKind::Foreign(foreign_def_id) => Ty::ForeignType(
-                from_chalk::<TypeAliasAsForeignType, _>(db, foreign_def_id).0,
-                Substs::empty(),
-            ),
+            chalk_ir::TyKind::Foreign(foreign_def_id) => {
+                Ty::ForeignType(from_chalk::<TypeAliasAsForeignType, _>(db, foreign_def_id).0)
+            }
             chalk_ir::TyKind::Generator(_, _) => unimplemented!(), // FIXME
             chalk_ir::TyKind::GeneratorWitness(_, _) => unimplemented!(), // FIXME
         }