Use C API to implement Operation.name property

This name property is used in many existing tests including those that
already run with C API enabled (math_ops_test, framework_ops_test,
session_test, session_partial_run_test, math_ops_test_gpu, etc).

PiperOrigin-RevId: 159645767

tensorflow/python/client/tf_session.i

@@ -63,6 +63,11 @@ tensorflow::ImportNumpy();
 // Constants used by TensorHandle (get_session_handle).
 %constant const char* TENSOR_HANDLE_KEY = tensorflow::SessionState::kTensorHandleResourceTypeName;
 
+// Convert TF_OperationName output to unicode python string
+%typemap(out) const char* TF_OperationName {
+  $result = PyUnicode_FromString($1);
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // BEGIN TYPEMAPS FOR tensorflow::TF_Run_wrapper()
 ////////////////////////////////////////////////////////////////////////////////

tensorflow/python/framework/ops.py

@@ -1350,7 +1350,13 @@ def _set_control_flow_context(self, context):
   @property
   def name(self):
     """The full name of this operation."""
-    return self._node_def.name
+    if _USE_C_API:
+      # TODO(iga): Remove this assert after converting to C API by default.
+      # Just being a bit paranoid here.
+      assert self._node_def.name == c_api.TF_OperationName(self._c_op)
+      return c_api.TF_OperationName(self._c_op)
+    else:
+      return self._node_def.name
 
   @property
   def _id(self):