fix optional type promotion for classes (#21593)

suo · facebook-github-bot · commit 4fb302eb34e9 · 2019-06-10T12:51:00.000-07:00
Summary: Pull Request resolved: #21593 ghimport-source-id: f68730618bccf2326218e08d0a2a70171fdd8921 Differential Revision: D15741471 Pulled By: suo fbshipit-source-id: 7ac1a0f6d9d2ff4bc819caff43a7a5b6d37cbc98
diff --git a/aten/src/ATen/core/jit_type.h b/aten/src/ATen/core/jit_type.h
@@ -1380,12 +1380,6 @@ struct CAFFE2_API ClassType : public Type {
     return false;
   }
 
-  bool isSubtypeOf(const TypePtr rhs) const override {
-    // XXX: We do not have inheritance implemented, only types that are the
-    // same can subtype from each other.
-    return *this == *rhs;
-  }
-
   std::string str() const override {
     return std::string("ClassType<") + name_.name() + ">";
   }
diff --git a/test/test_jit.py b/test/test_jit.py
@@ -16050,6 +16050,17 @@ def copy(self):
                 other.stack = list(self.stack)
                 return other
 
+    def test_optional_type_promotion(self):
+        # should not throw
+        @torch.jit.script  # noqa: B903
+        class Tree(object):
+            def __init__(self):
+                self.parent = torch.jit.annotate(Optional[Tree], None)
+
+            def add_child(self, child):
+                # type: (Tree) -> None
+                child.parent = torch.jit.annotate(Optional[Tree], self)
+
 
 class TestLogging(JitTestCase):
     def test_bump_numeric_counter(self):

Original file line number	Diff line number	Diff line change
`@@ -1380,12 +1380,6 @@ struct CAFFE2_API ClassType : public Type {`
`1380`	`1380`	`return false;`
`1381`	`1381`	`}`
`1382`	`1382`
`1383`		`- bool isSubtypeOf(const TypePtr rhs) const override {`
`1384`		`- // XXX: We do not have inheritance implemented, only types that are the`
`1385`		`- // same can subtype from each other.`
`1386`		`- return this == rhs;`
`1387`		`- }`
`1388`		`-`
`1389`	`1383`	`std::string str() const override {`
`1390`	`1384`	`return std::string("ClassType<") + name_.name() + ">";`
`1391`	`1385`	`}`