Move ossfuzz directory and use Makefile.am

.travis.yml

@@ -21,4 +21,4 @@ script:
   - if [ "$JANSSON_BUILD_METHOD" = "autotools" ]; then autoreconf -f -i && CFLAGS=-Werror ./configure && make check; fi
   - if [ "$JANSSON_BUILD_METHOD" = "cmake" ]; then mkdir build && cd build && cmake $JANSSON_CMAKE_OPTIONS .. && cmake --build . && ctest --output-on-failure; fi
   - if [ "$JANSSON_BUILD_METHOD" = "coverage" ]; then mkdir build && cd build && cmake $JANSSON_CMAKE_OPTIONS .. && cmake --build . && cmake --build . --target coveralls; fi
-  - if [ "$JANSSON_BUILD_METHOD" = "fuzzer" ]; then ./ossfuzz/travisoss.sh; fi
+  - if [ "$JANSSON_BUILD_METHOD" = "fuzzer" ]; then ./test/ossfuzz/travisoss.sh; fi

Makefile.am

@@ -8,15 +8,3 @@ dvi:
 
 pkgconfigdir = $(libdir)/pkgconfig
 pkgconfig_DATA = jansson.pc
-
-
-# Add fuzzing support
-LIB_FUZZING_ENGINE ?= standaloneengine.o
-
-ossfuzz/%.o: ossfuzz/%.cc
-	$(CXX) -c -Isrc $(CXXFLAGS) $< -o $@
-
-.PHONY: json_load_fuzzer
-json_load_fuzzer: ossfuzz/json_load_fuzzer.o src/.libs/libjansson.a
-	$(CXX) -c $(CXXFLAGS) ossfuzz/standaloneengine.cc -o standaloneengine.o
-	$(CXX) $(CXXFLAGS) $(LIB_FUZZING_ENGINE) $^ -o $@$(EXT)

configure.ac

@@ -9,6 +9,7 @@ AC_CONFIG_HEADERS([jansson_private_config.h])
 
 # Checks for programs.
 AC_PROG_CC
+AC_PROG_CXX
 AC_PROG_LIBTOOL
 AM_CONDITIONAL([GCC], [test x$GCC = xyes])
 
@@ -136,6 +137,19 @@ fi
 AS_IF([test "x$with_Bsymbolic" = "xyes"], [JSON_BSYMBOLIC_LDFLAGS=-Wl[,]-Bsymbolic-functions])
 AC_SUBST(JSON_BSYMBOLIC_LDFLAGS)
 
+
+AC_ARG_ENABLE([ossfuzzers],
+  [AS_HELP_STRING([--enable-ossfuzzers],
+    [Whether to generate the fuzzers for OSS-Fuzz])],
+  [have_ossfuzzers=yes], [have_ossfuzzers=no])
+AM_CONDITIONAL([USE_OSSFUZZERS], [test "x$have_ossfuzzers" = "xyes"])
+
+
+AC_SUBST([LIB_FUZZING_ENGINE])
+AM_CONDITIONAL([USE_OSSFUZZ_FLAG], [test "x$LIB_FUZZING_ENGINE" = "x-fsanitize=fuzzer"])
+AM_CONDITIONAL([USE_OSSFUZZ_STATIC], [test -f "x$LIB_FUZZING_ENGINE"])
+
+
 if test x$GCC = xyes; then
     AC_MSG_CHECKING(for -Wno-format-truncation)
     wnoformat_truncation="-Wno-format-truncation"
@@ -156,6 +170,7 @@ AC_CONFIG_FILES([
         src/jansson_config.h
         test/Makefile
         test/bin/Makefile
+        test/ossfuzz/Makefile
         test/suites/Makefile
         test/suites/api/Makefile
 ])

ossfuzz/json_load_fuzzer.cc

@@ -1,11 +0,0 @@
-#include <stdint.h>
-
-#include "jansson.h"
-
-extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
-  json_error_t error;
-  auto jobj = json_loadb(reinterpret_cast<const char *>(data), size, 0, &error);
-  if (jobj)
-    json_decref(jobj);
-  return 0;
-}

test/Makefile.am

@@ -1,4 +1,4 @@
-SUBDIRS = bin suites
+SUBDIRS = bin suites ossfuzz
 EXTRA_DIST = scripts run-suites
 
 TESTS = run-suites

test/ossfuzz/.gitignore

@@ -0,0 +1 @@
+json_load_dump_fuzzer

test/ossfuzz/Makefile.am

@@ -0,0 +1,32 @@
+AM_CPPFLAGS = -I$(top_builddir)/src -I$(top_srcdir)/src
+LDADD = $(top_builddir)/src/libjansson.la
+
+if USE_OSSFUZZ_FLAG
+FUZZ_FLAG = $(LIB_FUZZING_ENGINE)
+else
+if USE_OSSFUZZ_STATIC
+LDADD += $(LIB_FUZZING_ENGINE)
+FUZZ_FLAG =
+else
+LDADD += libstandaloneengine.a
+FUZZ_FLAG =
+endif
+endif
+
+noinst_PROGRAMS =
+noinst_LIBRARIES =
+
+if USE_OSSFUZZERS
+noinst_PROGRAMS += \
+	json_load_dump_fuzzer
+
+noinst_LIBRARIES += \
+	libstandaloneengine.a
+endif
+
+json_load_dump_fuzzer_SOURCES = json_load_dump_fuzzer.cc testinput.h
+json_load_dump_fuzzer_CXXFLAGS = $(AM_CXXFLAGS) $(FUZZ_FLAG)
+json_load_dump_fuzzer_LDFLAGS = $(AM_LDFLAGS) -static
+
+libstandaloneengine_a_SOURCES = standaloneengine.cc
+libstandaloneengine_a_CXXFLAGS = $(AM_CXXFLAGS)

test/ossfuzz/json_load_dump_fuzzer.cc

@@ -0,0 +1,47 @@
+#include <stdint.h>
+#include <sys/types.h>
+
+#include "jansson.h"
+
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size)
+{
+  json_error_t error;
+
+  if (size < sizeof(size_t) + sizeof(size_t))
+  {
+    return 0;
+  }
+
+  // Use the first sizeof(size_t) bytes as load flags.
+  size_t load_flags = *(const size_t*)data;
+  data += sizeof(size_t);
+  size -= sizeof(size_t);
+
+  // Use the next sizeof(size_t) bytes as dump flags.
+  size_t dump_flags = *(const size_t*)data;
+  data += sizeof(size_t);
+  size -= sizeof(size_t);
+
+  // Attempt to load the remainder of the data with the given load flags.
+  const char* text = reinterpret_cast<const char *>(data);
+  json_t* jobj = json_loadb(text, size, load_flags, &error);
+
+  if (jobj == NULL)
+  {
+    return 0;
+  }
+
+  // Attempt to dump the loaded json object with the given dump flags.
+  char* out = json_dumps(jobj, dump_flags);
+  if (out)
+  {
+    free(out);
+  }
+
+  if (jobj)
+  {
+    json_decref(jobj);
+  }
+
+  return 0;
+}

test/ossfuzz/ossfuzz.sh

@@ -20,9 +20,8 @@ apt-get -y install automake libtool
 
 # Compile the fuzzer.
 autoreconf -i
-./configure
+./configure --enable-ossfuzzers
 make
-make json_load_fuzzer
 
 # Copy the fuzzer to the output directory.
-cp -v json_load_fuzzer $OUT/
+cp -v test/ossfuzz/json_load_dump_fuzzer $OUT/