1 In order to build the fuzzer one needs to build HarfBuzz and
2 harfbuzz/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
10 To run the fuzzer one needs to first obtain a test corpus as a directory
11 containing interesting fonts. A good starting point is inside
12 harfbuzz/test/shaping/fonts/fonts/.
13 Then, run the fuzzer like this:
14 ./hb-fuzzer -max_len=2048 CORPUS_DIR
15 Where max_len specifies the maximal length of font files to handle.
16 The smaller the faster.
18 For 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/behdad/harfbuzz/issues/139