@mapnik/mapnik/deps/protozero/FUZZING.md

Node.js bindings for Mapnik (mapnik.org)

To do fuzz testing using [AFL](https://lcamtuf.coredump.cx/afl/) compile with
the AFL compiler wrappers:

    mkdir build
    cd build
    CC=afl-clang CXX=afl-clang++ cmake ..
    mkdir testcase_dir

You need some data to start the fuzzing. In this case I am using all the test
messages from the unit tests:

    find ../test/t/ -name data-\*.pbf -a -not -empty -exec cp {} testcase_dir/ \;

Then do the actual fuzzing:

    afl-fuzz -i testcase_dir -o findings_dir -- tools/pbf-decoder -

See the AFL documentation for more information.

For increased speed, you can also use the dedicated pbf-fuzzer tool, which skips reading
data from files or stdin:

    clang++ -O2 -std=c++17 -g -DNDEBUG -Iinclude -fsanitize=address,fuzzer tools/pbf-fuzzer.cpp -o tools/pbf-fuzzer
    ./tools/pbf-fuzzer

or using AFL++

    afl-clang-fast++ -O2 -std=c++17 -g -DNDEBUG -Iinclude -fsanitize=address,fuzzer tools/pbf-fuzzer.cpp -o tools/pbf-fuzzer
    afl-fuzz -i testcase_dir -o findings_dir -- tools/pbf-fuzzer

This only checkes the reading side of Protozero!