1In order to build the fuzzer one needs to build HarfBuzz and 2harfbuzz/test/fuzzing/hb-fuzzer.cc with: 3 - Using the most recent Clang 4 - With -fsanitize=address (or =undefined, or a combination) 5 - With -fsanitize-coverage=edge[,8bit-counters,trace-cmp] 6 - With various defines that limit worst case exponential behavior. 7 See FUZZING_CPPFLAGS in harfbuzz/src/Makefile.am for the list. 8 - link against libFuzzer 9 10To run the fuzzer one needs to first obtain a test corpus as a directory 11containing interesting fonts. A good starting point is inside 12harfbuzz/test/shaping/fonts/fonts/. 13Then, run the fuzzer like this: 14 ./hb-fuzzer -max_len=2048 CORPUS_DIR 15Where max_len specifies the maximal length of font files to handle. 16The smaller the faster. 17 18For more details consult the following locations: 19 - http://llvm.org/docs/LibFuzzer.html or 20 - https://github.com/google/libfuzzer-bot/tree/master/harfbuzz 21 - https://github.com/harfbuzz/harfbuzz/issues/139 22