Reland torch.ops API change machinery with the core functionality disabled (#71785)

Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/71785

see https://github.com/pytorch/pytorch/pull/67254
ghstack-source-id: 147648699

Test Plan: github CI

Reviewed By: albanD

Differential Revision: D33777229

fbshipit-source-id: 517b36be9743025eb40d708d380dae62e3663184
(cherry picked from commit a637e695694d3fd615dbe821394bfe53d41b6901)

test/test_per_overload_api.py

@@ -0,0 +1,67 @@
+# Owner(s): ["module: unknown"]
+# import torch
+# import copy
+from torch.testing._internal.common_utils import TestCase, run_tests
+
+class TestPerOverloadAPI(TestCase):
+    # def test_basics_opoverloadpacket(self):
+    #     # add is ony used as an example here. It is ok to update the test
+    #     # if the semantics of add are modified in the future.
+    #     add_packet = torch.ops.aten.add
+
+    #     # class attributes
+    #     self.assertEqual(add_packet.op_name, 'add')
+    #     self.assertEqual(add_packet.qualified_op_name, 'aten.add')
+
+    #     # callable
+    #     self.assertEqual(add_packet(torch.tensor(2), torch.tensor(3)), torch.tensor(5))
+
+    #     # correct module
+    #     self.assertEqual(add_packet.__module__, add_packet.op.__module__)
+
+    #     # caching
+    #     another_add_packet = torch.ops.aten.add
+    #     self.assertEqual(id(add_packet), id(another_add_packet))
+
+    #     # deepcopy is a no-op
+    #     self.assertEqual(id(add_packet), id(copy.deepcopy(add_packet)))
+
+    #     # pretty print
+    #     self.assertEqual(str(add_packet), "OpOverloadPacket(op='aten.add')")
+
+    #     self.assertRaises(AttributeError, lambda: add_packet.foo)
+
+    # def test_basics_opoverload(self):
+    #     add_packet = torch.ops.aten.add
+    #     add_tensoroverload = add_packet.Tensor
+
+    #     # class attributes
+    #     self.assertEqual(add_tensoroverload.name, 'aten.add')
+    #     self.assertEqual(add_tensoroverload.overload_name, 'Tensor')
+    #     self.assertEqual(add_tensoroverload.overload_packet, add_packet)
+
+    #     # deepcopy is a no-op
+    #     self.assertEqual(id(add_tensoroverload), id(copy.deepcopy(add_tensoroverload)))
+
+    #     # caching
+    #     another_add_tensoroverload = torch.ops.aten.add.Tensor
+    #     self.assertEqual(id(add_tensoroverload), id(another_add_tensoroverload))
+
+    #     # pretty print
+    #     self.assertEqual(str(add_tensoroverload), "OpOverload(op='aten.add', overload='Tensor')")
+
+    #     # callable
+    #     self.assertEqual(add_tensoroverload(torch.tensor(2), torch.tensor(3)), torch.tensor(5))
+
+    #     a = torch.tensor(2)
+    #     b = torch.tensor(0)
+    #     torch.ops.aten.add.out(a, a, out=b)
+    #     self.assertEqual(b, torch.tensor(4))
+
+    #     self.assertRaises(RuntimeError, lambda: add_tensoroverload(a, a, out=b))
+
+    def do_nothing(self):
+        return
+
+if __name__ == '__main__':
+    run_tests()