Added include guard to mock headers (#31909)

* Added include guard to mock headers

* Fix test

src/compiler/cpp_generator.cc

@@ -2147,6 +2147,7 @@ std::string GetMockPrologue(grpc_generator::File* file,
     std::map<std::string, std::string> vars;
 
     vars["filename"] = file->filename();
+    vars["filename_identifier"] = FilenameIdentifier(file->filename());
     vars["filename_base"] = file->filename_without_ext();
     vars["message_header_ext"] = params.message_header_extension.empty()
                                      ? kCppGeneratorMessageHeaderExt
@@ -2158,6 +2159,9 @@ std::string GetMockPrologue(grpc_generator::File* file,
                    "// If you make any local change, they will be lost.\n");
     printer->Print(vars, "// source: $filename$\n\n");
 
+    printer->Print(vars, "#ifndef GRPC_MOCK_$filename_identifier$__INCLUDED\n");
+    printer->Print(vars, "#define GRPC_MOCK_$filename_identifier$__INCLUDED\n");
+    printer->Print(vars, "\n");
     printer->Print(vars, "#include \"$filename_base$$message_header_ext$\"\n");
     printer->Print(vars, "#include \"$filename_base$$service_header_ext$\"\n");
     if (params.include_import_headers) {
@@ -2350,20 +2354,27 @@ std::string GetMockServices(grpc_generator::File* file,
 
 std::string GetMockEpilogue(grpc_generator::File* file,
                             const Parameters& /*params*/) {
-  std::string temp;
-
-  if (!file->package().empty()) {
-    std::vector<std::string> parts = file->package_parts();
+  std::string output;
+  {
+    // Scope the output stream so it closes and finalizes output to the string.
+    auto printer = file->CreatePrinter(&output);
+    std::map<std::string, std::string> vars;
+    vars["filename_identifier"] = FilenameIdentifier(file->filename());
 
-    for (auto part = parts.begin(); part != parts.end(); part++) {
-      temp.append("} // namespace ");
-      temp.append(*part);
-      temp.append("\n");
+    if (!file->package().empty()) {
+      std::vector<std::string> parts = file->package_parts();
+      for (auto part = parts.rbegin(); part != parts.rend(); part++) {
+        vars["part"] = *part;
+        printer->Print(vars, "}  // namespace $part$\n");
+      }
+      printer->Print(vars, "\n");
     }
-    temp.append("\n");
-  }
 
-  return temp;
+    printer->Print(vars, "\n");
+    printer->Print(vars,
+                   "#endif  // GRPC_MOCK_$filename_identifier$__INCLUDED\n");
+  }
+  return output;
 }
 
 }  // namespace grpc_cpp_generator

test/cpp/codegen/compiler_test_mock_golden

@@ -2,6 +2,9 @@
 // If you make any local change, they will be lost.
 // source: src/proto/grpc/testing/compiler_test.proto
 
+#ifndef GRPC_MOCK_src_2fproto_2fgrpc_2ftesting_2fcompiler_5ftest_2eproto__INCLUDED
+#define GRPC_MOCK_src_2fproto_2fgrpc_2ftesting_2fcompiler_5ftest_2eproto__INCLUDED
+
 #include "src/proto/grpc/testing/compiler_test.pb.h"
 #include "src/proto/grpc/testing/compiler_test.grpc.pb.h"
 
@@ -34,6 +37,8 @@ class MockServiceBStub : public ServiceB::StubInterface {
   MOCK_METHOD3(PrepareAsyncMethodB1Raw, ::grpc::ClientAsyncResponseReaderInterface< ::grpc::testing::Response>*(::grpc::ClientContext* context, const ::grpc::testing::Request& request, ::grpc::CompletionQueue* cq));
 };
 
-} // namespace grpc
-} // namespace testing
+}  // namespace testing
+}  // namespace grpc
+
 
+#endif  // GRPC_MOCK_src_2fproto_2fgrpc_2ftesting_2fcompiler_5ftest_2eproto__INCLUDED