Merge associated types with the other alias types

Author: oli-obk

compiler/rustc_privacy/src/lib.rs

@@ -207,19 +207,7 @@ where
                     }
                 }
             }
-            ty::Alias(ty::Projection, proj) => {
-                if V::SKIP_ASSOC_TYS {
-                    // Visitors searching for minimal visibility/reachability want to
-                    // conservatively approximate associated types like `<Type as Trait>::Alias`
-                    // as visible/reachable even if both `Type` and `Trait` are private.
-                    // Ideally, associated types should be substituted in the same way as
-                    // free type aliases, but this isn't done yet.
-                    return ControlFlow::Continue(());
-                }
-                // This will also visit args if necessary, so we don't need to recurse.
-                return self.visit_projection_ty(proj);
-            }
-            ty::Alias(kind @ (ty::Inherent | ty::Weak), data) => {
+            ty::Alias(kind @ (ty::Inherent | ty::Weak | ty::Projection), data) => {
                 if V::SKIP_ASSOC_TYS {
                     // Visitors searching for minimal visibility/reachability want to
                     // conservatively approximate associated types like `Type::Alias`
@@ -229,15 +217,15 @@ where
                     return ControlFlow::Continue(());
                 }
 
-                self.def_id_visitor.visit_def_id(
-                    data.def_id,
-                    match kind {
-                        ty::Inherent => "associated type",
-                        ty::Weak => "type alias",
-                        _ => unreachable!(),
-                    },
-                    &LazyDefPathStr { def_id: data.def_id, tcx },
-                )?;
+                let (def_id, kind) = match kind {
+                    ty::Inherent => (data.def_id, "associated type"),
+                    ty::Weak => (data.def_id, "type alias"),
+                    // Trait associated types don't have visibility, they are
+                    // visible if their parent trait is.
+                    ty::Projection => (tcx.parent(data.def_id), "trait"),
+                    _ => unreachable!(),
+                };
+                self.def_id_visitor.visit_def_id(def_id, kind, &LazyDefPathStr { def_id, tcx })?;
 
                 // This will also visit args if necessary, so we don't need to recurse.
                 return if V::SHALLOW {