harfbuzz

History

Behdad Esfahbod a0688e8e7b Ouch, finish previous change		2016-12-20 20:52:50 -06:00
..
hb-fuzzer.cc	Ouch, finish previous change	2016-12-20 20:52:50 -06:00
hb-fuzzer.hh	[fuzzer] Separate main() into a new file	2016-12-20 20:50:38 -06:00
main.cc	[fuzzer] Separate main() into a new file	2016-12-20 20:50:38 -06:00
Makefile.am	Ouch, finish previous change	2016-12-20 20:52:50 -06:00
README	Enable building a bounded version of the library for fuzzing	2015-11-18 16:27:32 -08:00

README

In order to build the fuzzer one needs to build HarfBuzz and
harfbuzz/test/fuzzing/hb-fuzzer.cc with:
  - Using the most recent Clang
  - With -fsanitize=address (or =undefined, or a combination)
  - With -fsanitize-coverage=edge[,8bit-counters,trace-cmp]
  - With various defines that limit worst case exponential behavior.
    See FUZZING_CPPFLAGS in harfbuzz/src/Makefile.am for the list.
  - link against libFuzzer

To run the fuzzer one needs to first obtain a test corpus as a directory
containing interesting fonts.  A good starting point is inside
harfbuzz/test/shaping/fonts/fonts/.
Then, run the fuzzer like this:
   ./hb-fuzzer -max_len=2048 CORPUS_DIR
Where max_len specifies the maximal length of font files to handle.
The smaller the faster.

For more details consult the following locations:
  - http://llvm.org/docs/LibFuzzer.html or
  - https://github.com/google/libfuzzer-bot/tree/master/harfbuzz
  - https://github.com/behdad/harfbuzz/issues/139