Add support for hasattr on ListVariable (#110438)

cdzhan · pytorchmergebot · commit fa8e4ea2122f · 2023-10-08T05:34:00.000Z
Fixes #109502 Pull Request resolved: #110438 Approved by: https://github.com/jansel
diff --git a/test/dynamo/test_misc.py b/test/dynamo/test_misc.py
@@ -6706,6 +6706,32 @@ def fn(x):
         compiled_out = compiled_fn(x)
         self.assertTrue(same(fn_out, compiled_out))
 
+    def test_list_hasattr1(self):
+        def fn(x):
+            if hasattr(x, "foo"):
+                return x[0] + 1
+            return x[0] - 1
+
+        compiled_fn = torch.compile(backend="eager", fullgraph=True)(fn)
+
+        x = [torch.randn(3)]
+        fn_out = fn(x)
+        compiled_out = compiled_fn(x)
+        self.assertTrue(same(fn_out, compiled_out))
+
+    def test_list_hasattr2(self):
+        def fn():
+            x = [torch.zeros(3)]
+            if hasattr(x, "__len__"):
+                return x[0] + 1
+            return x[0] - 1
+
+        compiled_fn = torch.compile(backend="eager", fullgraph=True)(fn)
+
+        fn_out = fn()
+        compiled_out = compiled_fn()
+        self.assertTrue(same(fn_out, compiled_out))
+
     def test_torch_objects_as_keys(self):
         remap = {torch.float16: torch.float32}
 
diff --git a/torch/_dynamo/variables/lists.py b/torch/_dynamo/variables/lists.py
@@ -380,6 +380,12 @@ def call_method(
         else:
             return super().call_method(tx, name, args, kwargs)
 
+    def call_hasattr(self, tx, name: str) -> "VariableTracker":
+        if self.python_type() is not list:
+            return super().call_hasattr(tx, name)
+        options = VariableTracker.propagate(self)
+        return variables.ConstantVariable.create(hasattr([], name), **options)
+
 
 class DequeVariable(CommonListMethodsVariable):
     def python_type(self):
