[C API]: Bugfix for TF_AddGradients.

TF_AddGradients could create nodes in the graph with names that conflicted with
other nodes in the graph. This would most clearly happen if TF_AddGradients()
was called twice on the same graph, and could also happen if there were other
nodes in the graph that happened to have "gradients" as a prefix of their name.

Fix that.

The added test in c_api_test.cc would fail in the call to TF_SessionRun() with
  Node 'gradients/OnesLike' is not unique
without the changes to c_api.cc and c_api_internal.h

While at it, also fixed a possible name collision bug when using the C++ API
to constructor graphs (using Scope).

Thanks @karllessard for pointing this out.

PiperOrigin-RevId: 202087996

1 files changed, 7 insertions, 0 deletions

diff --git a/tensorflow/c/c_test_util.cc b/tensorflow/c/c_test_util.cc
index f3b28c1708..24eb6c069b 100644
--- a/tensorflow/c/c_test_util.cc
+++ b/tensorflow/c/c_test_util.cc
@@ -216,6 +216,13 @@ TF_Operation* Min(TF_Operation* l, TF_Operation* r, TF_Graph* graph,
   return MinWithDevice(l, r, graph, /*op_device=*/"", s, name);
 }
 
+TF_Operation* Mul(TF_Operation* l, TF_Operation* r, TF_Graph* graph,
+                  TF_Status* s, const char* name) {
+  TF_Operation* op;
+  BinaryOpHelper("Mul", l, r, graph, s, name, &op, "", true);
+  return op;
+}
+
 TF_Operation* Add(TF_Output l, TF_Output r, TF_Graph* graph, TF_Status* s,
                   const char* name) {
   TF_OperationDescription* desc = TF_NewOperation(graph, "AddN", name);