harfbuzz/test/fuzzing
Ebrahim Byagowi a470b0b205 Minor, disable strict-aliasing warning in set fuzzer
../test/fuzzing/hb-set-fuzzer.cc: In function ‘int LLVMFuzzerTestOneInput(const uint8_t*, size_t)’:
../test/fuzzing/hb-set-fuzzer.cc:38:82: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
   38 |   const instructions_t &instructions = reinterpret_cast<const instructions_t &> (data);
      |

And it is already disabled at project level so let's disable it here also.
2020-07-05 10:49:10 +04:30
..
fonts Fix bug 2020-04-21 16:51:55 -07:00
sets [fuzz] minor, move two fuzzer cases to their correct place 2020-02-12 19:17:18 +03:30
Makefile.am Remove cmake testing and add meson build bot 2020-03-11 20:15:10 +03:30
README
hb-draw-fuzzer.cc [tests] Enable more gid misc calls on draw fuzzer 2020-05-21 07:00:40 +04:30
hb-fuzzer.hh
hb-set-fuzzer.cc Minor, disable strict-aliasing warning in set fuzzer 2020-07-05 10:49:10 +04:30
hb-shape-fuzzer.cc [fuzzer] Make some use for test_font API calls 2020-06-20 22:06:11 +04:30
hb-subset-fuzzer.cc [fuzz] Don't fail when blob is empty 2019-07-11 14:31:55 +04:30
main.cc [fuzz] minor don't abort main.cc when the file was empty or not found 2020-02-26 16:15:17 +03:30
meson.build [meson] Mark longer tests with slow 2020-06-21 08:47:10 +04:30
run-draw-fuzzer-tests.py [py] minor, replace os.environ.get with os.getenv 2020-07-04 16:16:15 +04:30
run-shape-fuzzer-tests.py [py] minor, replace os.environ.get with os.getenv 2020-07-04 16:16:15 +04:30
run-subset-fuzzer-tests.py [py] minor, replace os.environ.get with os.getenv 2020-07-04 16:16:15 +04:30

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/harfbuzz/harfbuzz/issues/139