diff --git a/tools/versioner/src/Preprocessor.h b/tools/versioner/src/Preprocessor.h
new file mode 100644
index 0000000..7be018b
--- /dev/null
+++ b/tools/versioner/src/Preprocessor.h
@@ -0,0 +1,24 @@
+/*
+ * Copyright 2016 The Android Open Source Project
+ *
+ * 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.
+ */
+
+#pragma once
+
+#include <string>
+
+class HeaderDatabase;
+
+bool preprocessHeaders(const std::string& preprocessor_output_path, const std::string& source_dir,
+                       HeaderDatabase* database);