Add function gradient support to C API

Also, change the internal representation of TF_Function and
rename TF_GraphAddFunction to TF_GraphAddFunctionCopy to make it
clear that a copy of the function is added to the graph. Any
subsequent modifications to the function will not be reflected
in the copy added to the graph.

PiperOrigin-RevId: 169187793

1 files changed, 20 insertions, 0 deletions

diff --git a/tensorflow/c/c_test_util.cc b/tensorflow/c/c_test_util.cc
index d1f99fe1ef..a380375db0 100644
--- a/tensorflow/c/c_test_util.cc
+++ b/tensorflow/c/c_test_util.cc
@@ -16,6 +16,7 @@ limitations under the License.
 #include "tensorflow/c/c_test_util.h"
 
 #include "tensorflow/core/framework/function.pb.h"
+#include "tensorflow/core/framework/op_def.pb.h"
 #include "tensorflow/core/framework/tensor.pb.h"
 #include "tensorflow/core/lib/strings/strcat.h"
 #include "tensorflow/core/platform/logging.h"
@@ -339,6 +340,25 @@ bool GetAttrValue(TF_Operation* oper, const char* attr_name,
   return ret;
 }
 
+std::vector<std::pair<string, string>> GetGradDefs(
+    const tensorflow::GraphDef& graph_def) {
+  std::vector<std::pair<string, string>> grads;
+  for (const tensorflow::GradientDef& grad : graph_def.library().gradient()) {
+    grads.emplace_back(grad.function_name(), grad.gradient_func());
+  }
+  std::sort(grads.begin(), grads.end());
+  return grads;
+}
+
+std::vector<string> GetFuncNames(const tensorflow::GraphDef& graph_def) {
+  std::vector<string> names;
+  for (const tensorflow::FunctionDef& func : graph_def.library().function()) {
+    names.push_back(func.signature().name());
+  }
+  std::sort(names.begin(), names.end());
+  return names;
+}
+
 CSession::CSession(TF_Graph* graph, TF_Status* s) {
   TF_SessionOptions* opts = TF_NewSessionOptions();
   session_ = TF_NewSession(graph, opts, s);