pull in fuzzers, add CI scripts later

ChangeLog

@@ -9,6 +9,9 @@ Deprecated and removed features:
 * lh_table_lookup() has been removed, use lh_table_lookup_ex() instead.
 * Remove TRUE and FALSE defines, use 1 and 0 instead.
 
+Build changes:
+--------------
+* Add a top level fuzz directory for fuzzers run by OSS-Fuzz
 
 0.13 (up to commit 5dae561, 2017/11/29)
 =================================

fuzz/README.md

@@ -0,0 +1,6 @@
+# Fuzzers
+
+This directory contains fuzzers that
+target [llvm's LibFuzzer](https://llvm.org/docs/LibFuzzer.html). They are built
+and run automatically by
+Google's [OSS-Fuzz](https://github.com/google/oss-fuzz/) infrastructure.

fuzz/build.sh

@@ -0,0 +1,30 @@
+#!/bin/bash -eu
+# Copyright 2018 Google Inc.
+#
+# 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.
+#
+################################################################################
+
+./autogen.sh
+./configure --enable-static --disable-shared
+make -j$(nproc) all
+ar rc json_c.a *.o
+
+cp $SRC/*.dict $OUT/
+
+for f in $SRC/*_fuzzer.cc; do
+    fuzzer=$(basename "$f" _fuzzer.cc)
+    $CXX $CXXFLAGS -std=c++11 -I$SRC/json-c \
+         $SRC/${fuzzer}_fuzzer.cc -o $OUT/${fuzzer}_fuzzer \
+         -lFuzzingEngine $SRC/json-c/json_c.a
+done

fuzz/tokener_parse_ex_fuzzer.cc

@@ -0,0 +1,13 @@
+#include <stdint.h>
+
+#include <json.h>
+
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
+  const char *data1 = reinterpret_cast<const char *>(data);
+  json_tokener *tok = json_tokener_new();
+  json_object *obj = json_tokener_parse_ex(tok, data1, size);
+
+  json_object_put(obj);
+  json_tokener_free(tok);
+  return 0;
+}

fuzz/tokener_parse_ex_fuzzer.dict

@@ -0,0 +1,18 @@
+"{"
+"}"
+","
+"["
+"]"
+","
+":"
+"e"
+"e+"
+"e-"
+"E"
+"E+"
+"E-"
+"\""
+"null"
+"1"
+"1.234"
+"3e4"