Push clauses for auto traits on opaque types

Author: matthewjasper

chalk-solve/src/clauses.rs

@@ -75,8 +75,10 @@ fn constituent_types<I: Interner>(db: &dyn RustIrDatabase<I>, ty: &TyKind<I>) ->
         TyKind::Alias(_) => panic!("this function should not be called for alias"),
         TyKind::Foreign(_) => panic!("constituent_types of foreign types are unknown!"),
         TyKind::Error => Vec::new(),
-        TyKind::OpaqueType(_, _) => unimplemented!(),
-        TyKind::AssociatedType(_, _) => unimplemented!(),
+        TyKind::OpaqueType(_, _) => panic!("constituent_types of opaque types are unknown!"),
+        TyKind::AssociatedType(_, _) => {
+            panic!("constituent_types of associated types are unknown!")
+        }
     }
 }
 
@@ -176,12 +178,16 @@ pub fn push_auto_trait_impls<I: Interner>(
             Ok(())
         }
 
-        // Unimplemented
-        TyKind::OpaqueType(_, _) => Ok(()),
-        TyKind::AssociatedType(_, _) => Ok(()),
+        TyKind::OpaqueType(opaque_ty_id, _) => {
+            push_auto_trait_impls_opaque(builder, auto_trait_id, *opaque_ty_id);
+            Ok(())
+        }
 
         // No auto traits
-        TyKind::Placeholder(_) | TyKind::Dyn(_) | TyKind::Alias(_) => Ok(()),
+        TyKind::AssociatedType(_, _)
+        | TyKind::Placeholder(_)
+        | TyKind::Dyn(_)
+        | TyKind::Alias(_) => Ok(()),
 
         // app_ty implements AutoTrait if all constituents of app_ty implement AutoTrait
         _ => {

tests/test/opaque_types.rs

@@ -205,3 +205,40 @@ fn opaque_auto_traits() {
         }
     }
 }
+
+#[test]
+fn opaque_auto_traits_indirect() {
+    test! {
+        program {
+            struct Bar { }
+            struct Baz { }
+            trait Trait { }
+
+            impl Trait for Bar { }
+            impl Trait for Baz { }
+
+            #[auto]
+            trait Send { }
+            trait SendDerived where Self: Send { }
+
+            impl<T> SendDerived for T where T: Send { }
+
+            impl !Send for Baz { }
+
+            opaque type Opaque1: Trait = Bar;
+            opaque type Opaque2: Trait = Baz;
+        }
+
+        goal {
+            Opaque1: SendDerived
+        } yields {
+            "Unique"
+        }
+
+        goal {
+            Opaque2: SendDerived
+        } yields {
+            "No possible solution"
+        }
+    }
+}