[dynamo][dicts] Support hasattr on dicts (#134590)

Fixes - https://github.com/pytorch/pytorch/issues/134577

Pull Request resolved: https://github.com/pytorch/pytorch/pull/134590
Approved by: https://github.com/Skylion007
ghstack dependencies: #134610

test/dynamo/test_functions.py

@@ -1683,6 +1683,22 @@ class FunctionTests(torch._dynamo.test_case.TestCase):
         tmp = {1: "D", 10: "B", 3: "E", 0: "F"}
         return x + 1, sorted(tmp), sorted(tmp, reverse=True)
 
+    def test_dict_hasattr(self):
+        def fn(x):
+            if hasattr(x, "to"):
+                return x.to("cpu")
+            if hasattr(x, "items"):
+                return torch.cos(x["a"])
+            return x
+
+        opt_fn = torch.compile(fn, backend="eager", fullgraph=True)
+
+        x = dict(a=torch.randn(3))
+        self.assertEqual(fn(x), opt_fn(x))
+
+        x = torch.randn(4)
+        self.assertEqual(fn(x), opt_fn(x))
+
     @make_test
     def test_list_clear(a, b):
         tmp = [a + 1, a + 2]

torch/_dynamo/variables/dicts.py

@@ -355,6 +355,15 @@ class ConstDictVariable(VariableTracker):
     def unpack_var_sequence(self, tx):
         return [x.vt for x in self.items.keys()]
 
+    def call_hasattr(self, tx, name):
+        # dict not allow setting arbitrary attributes. To check for hasattr, we can just check the __dict__ of the dict.
+        # OrderedDict though requires side effects tracking because it supports arbitrary setattr.
+        if self.user_cls is dict:
+            if name in self.user_cls.__dict__:
+                return ConstantVariable.create(True)
+            return ConstantVariable.create(False)
+        unimplemented(f"hasattr on {self.user_cls} is not supported")
+
 
 class DefaultDictVariable(ConstDictVariable):
     def __init__(self, items, user_cls, default_factory=None, **kwargs) -> None: