harfbuzz/test/fuzzing
Ebrahim Byagowi 84163c83d3 [draw] Skip commands and paths not contributing anything
They aren't contributing to rendering and making issue for stroking, let's skip them
ourselves as Skia does also https://skia-review.googlesource.com/c/skia/+/268166

They are useful for extracting extents and so which that functionality won't be effected by this change.
2020-02-26 16:09:28 +03:30
..
fonts [fuzz] minor fuzzer case move, oops 2020-02-12 19:19:37 +03:30
sets [fuzz] minor, move two fuzzer cases to their correct place 2020-02-12 19:17:18 +03:30
CMakeLists.txt Remove remains of get-codepoint-fuzzer 2018-10-11 17:31:29 -04:00
hb-draw-fuzzer.cc [draw] Skip commands and paths not contributing anything 2020-02-26 16:09:28 +03:30
hb-fuzzer.hh [fuzzer] Separate main() into a new file 2016-12-20 20:50:38 -06:00
hb-set-fuzzer.cc [fuzz] minor style fixes 2020-02-12 19:30:31 +03:30
hb-shape-fuzzer.cc [fuzz] Practice variations on font object 2020-02-25 21:16:57 +03:30
hb-subset-fuzzer.cc [fuzz] Don't fail when blob is empty 2019-07-11 14:31:55 +04:30
main.cc [fuzz] make the custom loader to handle multiple files 2020-02-24 23:01:02 +03:30
Makefile.am [draw] Add a fuzzer 2020-02-25 19:09:44 +03:30
README Move all references of old url to the new address (#622) 2017-11-20 14:49:22 -05:00
run-shape-fuzzer-tests.py Remove python2 support from tests/utils scripts 2020-02-19 16:17:45 +03:30
run-subset-fuzzer-tests.py Remove python2 support from tests/utils scripts 2020-02-19 16:17:45 +03:30

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