Khaled Hosny 84dd65a874 [test] Remove timeout from test runners
See https://github.com/harfbuzz/harfbuzz/issues/2707#issuecomment-707744079

This wasn’t inconsistent as well, HB_TEST_SUBSET_FUZZER_TIMEOUT defaulted
to 12 in the test runner, but it was overridden to 50 in meson.build,
and then meson has its own test timeout.
2020-10-15 00:49:02 -07:00
..
2020-08-12 02:40:55 +04:30
2020-08-12 02:40:55 +04:30
2020-08-12 02:40:55 +04:30
2020-08-12 02:40:55 +04:30

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