[expat] working build & simple fuzzer from chrome.

expat/Dockerfile

@@ -16,5 +16,6 @@
 
 FROM ossfuzz/base-libfuzzer
 MAINTAINER mike.aizatsky@gmail.com
+RUN apt-get install -y autoconf automake libtool
 
-CMD /workspace/oss-fuzz/expat/build.sh
+CMD /src/oss-fuzz/expat/build.sh

expat/build.sh

@@ -1,8 +1,13 @@
 #!/bin/bash -ex
+. /env
 
-echo $pwd
+cd /workspace/expat
-
 ls -alR
 
 ./buildconf.sh
 ./configure
+make clean all
+
+$CXX $CXXFLAGS -std=c++11 -Ilib/ \
+    /src/oss-fuzz/expat/parse_fuzzer.cc -o /out/parse_fuzzer \
+    /work/libfuzzer/*.o .libs/libexpat.a

expat/parse_fuzzer.cc

@@ -0,0 +1,23 @@
+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include <vector>
+#include "expat.h"
+
+std::vector<const char*> kEncodings = {{"UTF-16", "UTF-8", "ISO-8859-1",
+                                        "US-ASCII", "UTF-16BE", "UTF-16LE",
+                                        "INVALIDENCODING"}};
+// Entry point for LibFuzzer.
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
+  const char* dataPtr = reinterpret_cast<const char*>(data);
+  for (int use_ns = 0; use_ns <= 1; ++use_ns) {
+    for (auto enc : kEncodings) {
+      XML_Parser parser =
+          use_ns ? XML_ParserCreateNS(enc, '\n') : XML_ParserCreate(enc);
+      XML_Parse(parser, dataPtr, size, true);
+      XML_ParserFree(parser);
+    }
+  }
+  return 0;
+}