Introduce Python-only extensions to the C API

Implements an incomplete version of Operation._add_control_input()
using a new extension to make sure the plumbing works.

This also adds header guards to c_api_internal.h, which were missing. For some reason the missing guards caused problems in the cmake build even though there doesn't appear to be any #include cycles.

PiperOrigin-RevId: 161705859

1 files changed, 30 insertions, 0 deletions

diff --git a/tensorflow/c/python_api.h b/tensorflow/c/python_api.h
new file mode 100644
index 0000000000..bb2b0fd8fd
--- /dev/null
+++ b/tensorflow/c/python_api.h
@@ -0,0 +1,30 @@
+/* Copyright 2017 The TensorFlow Authors. All Rights Reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+==============================================================================*/
+
+#ifndef THIRD_PARTY_TENSORFLOW_C_PYTHON_API_H_
+#define THIRD_PARTY_TENSORFLOW_C_PYTHON_API_H_
+
+#include "tensorflow/c/c_api.h"
+
+// These functions can be removed without notice. They exist to facilitate some
+// refactoring of graph construction code in the Python API.
+
+namespace tensorflow {
+
+void AddControlInput(TF_Graph* graph, TF_Operation* op, TF_Operation* input);
+
+}  // namespace tensorflow
+
+#endif  // THIRD_PARTY_TENSORFLOW_C_PYTHON_API_H_