Preparing source code for gRPC upgrade.

Change: 128472309

Author: tensorflower-gardener

tensorflow/core/distributed_runtime/rpc/grpc_serialization_traits.h

@@ -80,10 +80,25 @@ class GrpcBufferWriter GRPC_FINAL
 
 class GrpcBufferReader GRPC_FINAL
     : public ::grpc::protobuf::io::ZeroCopyInputStream {
+  typedef void (CoreCodegenInterface::*OldReaderInitAPI)(
+      grpc_byte_buffer_reader* reader, grpc_byte_buffer* buffer);
+  typedef int (CoreCodegenInterface::*NewReaderInitAPI)(
+      grpc_byte_buffer_reader* reader, grpc_byte_buffer* buffer);
+  void ReaderInit(OldReaderInitAPI ptr, grpc_byte_buffer_reader* reader,
+                  grpc_byte_buffer* buffer) {
+    (g_core_codegen_interface->*ptr)(reader, buffer);
+  }
+  void ReaderInit(NewReaderInitAPI ptr, grpc_byte_buffer_reader* reader,
+                  grpc_byte_buffer* buffer) {
+    int result = (g_core_codegen_interface->*ptr)(reader, buffer);
+    (void)result;
+  }
+
  public:
   explicit GrpcBufferReader(grpc_byte_buffer* buffer)
       : byte_count_(0), backup_count_(0) {
-    g_core_codegen_interface->grpc_byte_buffer_reader_init(&reader_, buffer);
+    ReaderInit(&CoreCodegenInterface::grpc_byte_buffer_reader_init, &reader_,
+               buffer);
   }
   ~GrpcBufferReader() GRPC_OVERRIDE {
     g_core_codegen_interface->grpc_byte_buffer_reader_destroy(&reader_);

tensorflow/core/distributed_runtime/rpc/grpc_tensor_coding_test.cc

@@ -35,7 +35,7 @@ class GrpcTensorCodingTest : public ::testing::Test {
 
     // Make a string
     std::vector<::grpc::Slice> slices;
-    buf.Dump(&slices);
+    (void)buf.Dump(&slices);
     string tmp;
     for (const auto& s : slices) {
       tmp.append(reinterpret_cast<const char*>(s.begin()), s.size());