From 36882e882c3de9be4381c266af6049b08fe2326c Mon Sep 17 00:00:00 2001
From: "A. Unique TensorFlower" <gardener@tensorflow.org>
Date: Mon, 9 Apr 2018 13:24:03 -0700
Subject: [PATCH] Add a utility that can detect the class that defined a
 method. This is useful when converting a e.g. a custom Keras model, to avoid
 recompiling the base model methods.

PiperOrigin-RevId: 192177117
---
 tensorflow/contrib/autograph/pyct/inspect_utils.py | 12 +++++++++++
 .../contrib/autograph/pyct/inspect_utils_test.py   | 24 ++++++++++++++++++++++
 2 files changed, 36 insertions(+)

diff --git a/tensorflow/contrib/autograph/pyct/inspect_utils.py b/tensorflow/contrib/autograph/pyct/inspect_utils.py
index 30a5961..386a6d2 100644
--- a/tensorflow/contrib/autograph/pyct/inspect_utils.py
+++ b/tensorflow/contrib/autograph/pyct/inspect_utils.py
@@ -50,6 +50,18 @@ def getnamespace(f):
   return namespace
 
 
+def getdefiningclass(m, owner_class):
+  """Resolves the class (e.g. one of the superclasses) that defined a method."""
+  m = six.get_unbound_function(m)
+  last_defining = owner_class
+  for superclass in tf_inspect.getmro(owner_class):
+    if hasattr(superclass, m.__name__):
+      superclass_m = getattr(superclass, m.__name__)
+      if six.get_unbound_function(superclass_m) == m:
+        last_defining = superclass
+  return last_defining
+
+
 def getmethodclass(m):
   """Resolves a function's owner, e.g. a method's class.
 
diff --git a/tensorflow/contrib/autograph/pyct/inspect_utils_test.py b/tensorflow/contrib/autograph/pyct/inspect_utils_test.py
index eda3fc1..58f827b 100644
--- a/tensorflow/contrib/autograph/pyct/inspect_utils_test.py
+++ b/tensorflow/contrib/autograph/pyct/inspect_utils_test.py
@@ -234,6 +234,30 @@ class InspectUtilsTest(test.TestCase):
     c = TestCallable()
     self.assertEqual(inspect_utils.getmethodclass(c), TestCallable)
 
+  def test_getdefiningclass(self):
+    class Superclass(object):
+
+      def foo(self):
+        pass
+
+      def bar(self):
+        pass
+
+    class Subclass(Superclass):
+
+      def foo(self):
+        pass
+
+      def baz(self):
+        pass
+
+    self.assertTrue(
+        inspect_utils.getdefiningclass(Subclass.foo, Subclass) is Subclass)
+    self.assertTrue(
+        inspect_utils.getdefiningclass(Subclass.bar, Subclass) is Superclass)
+    self.assertTrue(
+        inspect_utils.getdefiningclass(Subclass.baz, Subclass) is Subclass)
+
 
 if __name__ == '__main__':
   test.main()
-- 
2.7.4