Add a new incremental parsing API

Change-Id: I6b921766836d58df0281fb23b2add3f62a478e14

webm_parser/fuzzing/webm_fuzzer.cc

@@ -0,0 +1,76 @@
+// Copyright (c) 2016 The WebM project authors. All Rights Reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the LICENSE file in the root of the source
+// tree. An additional intellectual property rights grant can be found
+// in the file PATENTS.  All contributing project authors may
+// be found in the AUTHORS file in the root of the source tree.
+#include <cassert>
+#include <cstdint>
+#include <cstdio>
+#include <cstdlib>
+#include <iostream>
+#include <new>
+#include <vector>
+
+#include "webm/buffer_reader.h"
+#include "webm/callback.h"
+#include "webm/file_reader.h"
+#include "webm/reader.h"
+#include "webm/status.h"
+#include "webm/webm_parser.h"
+
+using webm::BufferReader;
+using webm::Callback;
+using webm::FileReader;
+using webm::Reader;
+using webm::Status;
+using webm::WebmParser;
+
+static int Run(Reader* reader) {
+  Callback callback;
+  WebmParser parser;
+
+#if WEBM_FUZZER_SEEK_FIRST
+  parser.DidSeek();
+#endif
+
+  Status status(-1);
+  try {
+    status = parser.Feed(&callback, reader);
+  } catch (std::bad_alloc&) {
+    // Failed allocations are okay. MSan doesn't throw std::bad_alloc, but
+    // someday it might.
+  }
+
+  // BufferReader/FileReader should never return either of the following codes,
+  // which means the parser never should too:
+  assert(status.code != Status::kWouldBlock);
+  assert(status.code != Status::kOkPartial);
+
+  // Only the following ranges have status codes defined:
+  assert((-1030 <= status.code && status.code <= -1025) ||
+         (-3 <= status.code && status.code <= 0));
+
+  return 0;
+}
+
+extern "C" int LLVMFuzzerTestOneInput(const std::uint8_t* data,
+                                      std::size_t size) {
+  BufferReader reader(std::vector<std::uint8_t>(data, data + size));
+  return Run(&reader);
+}
+
+#if __AFL_COMPILER
+int main(int argc, char* argv[]) {
+  FILE* file = (argc == 2) ? std::fopen(argv[1], "rb")
+                           : std::freopen(nullptr, "rb", stdin);
+  if (!file) {
+    std::cerr << "File cannot be opened\n";
+    return EXIT_FAILURE;
+  }
+
+  FileReader reader(file);
+  return Run(&reader);
+}
+#endif