Enable the minifier fuzzer (fixes #530) (#694)

This enables the minify fuzzer, which has been disabled because it did not pass the oss-fuzz instrumentation test. Now it does, after changes in simdjson (https://github.com/lemire/simdjson/issues/186).

 * get minify running (api change)
 * disable benchmarks when compiling fuzzers
 * catch exceptions from the minify fuzzer
 * enable repeated corpus creation without recursive inclusion of zip
 * remove leftover comment

fuzz/CMakeLists.txt

@@ -27,7 +27,7 @@ set(SIMDJSON_FUZZ_LDFLAGS "" CACHE STRING "LDFLAGS for the fuzz targets")
 
 set(SOURCES
   fuzz_parser.cpp
-#  fuzz_minify.cpp   # <--- does not pass the build check test on oss-fuzz, says "partially instrumented". help needed!
+  fuzz_minify.cpp
   fuzz_dump.cpp
   fuzz_print_json.cpp
   fuzz_dump_raw_tape.cpp

fuzz/fuzz_minify.cpp

@@ -4,11 +4,18 @@
 #include <string>
 extern "C" int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size) {
 
-  auto begin = (const char *)Data;
-  auto end = begin + Size;
+    auto begin = (const char *)Data;
+    auto end = begin + Size;
 
-  std::string str(begin, end);
+    std::string str(begin, end);
 
-  simdjson::json_minify(str.data(), str.size(), str.data());
-  return 0;
+    try {
+        simdjson::dom::parser parser;
+        simdjson::dom::element doc = parser.parse(str);
+        std::string minified=simdjson::minify(doc);
+        (void)minified;
+    } catch (...) {
+
+    }
+    return 0;
 }

fuzz/ossfuzz.sh

@@ -30,6 +30,7 @@ cmake .. \
 -DCMAKE_BUILD_TYPE=Debug \
 -DSIMDJSON_BUILD_STATIC=On \
 -DENABLE_FUZZING=On \
+-DSIMDJSON_COMPETITION=Off \
 -DSIMDJSON_FUZZ_LINKMAIN=Off \
 -DSIMDJSON_FUZZ_LDFLAGS=$LIB_FUZZING_ENGINE
 
@@ -38,6 +39,6 @@ cmake --build .
 cp fuzz/fuzz_* $OUT
 
 # all corpora are equal, they all take json as input
-for f in $OUT/fuzz* ; do
+for f in $(ls $OUT/fuzz* |grep -v '.zip$') ; do
    cp ../corpus.zip $OUT/$(basename $f).zip
 done