[fuzzer] split main() into FuzzerDriver() that takes a callback as a parameter and a tiny main() in a separate file

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229882 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Fuzzer/FuzzerInterface.h

@@ -0,0 +1,25 @@
+//===- FuzzerInterface.h - Interface header for the Fuzzer ------*- C++ -* ===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+// Define the interface between the Fuzzer and the library being tested.
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_FUZZER_INTERFACE_H
+#define LLVM_FUZZER_INTERFACE_H
+
+#include <cstddef>
+#include <cstdint>
+
+namespace fuzzer {
+
+typedef void (*UserCallback)(const uint8_t *data, size_t size);
+int FuzzerDriver(int argc, char **argv, UserCallback Callback);
+
+}  // namespace fuzzer
+
+#endif  // LLVM_FUZZER_INTERFACE_H