[HW6] How to find coverage info with `gcov`?

[leejy12]

Hello, I want to see if I understood the problems correctly.

In Problem 1(c)(iii), it asks to find the test input with best graph coverage. After running afl-fuzz for 30 minutes, it generated 664 test inputs. Then do I have to check coverage for each of those inputs?

Step-by-step

1. Compile grep.c for AFL and gcov.

   $ afl-clang-lto grep.c -o grep
   $ gcc -O0 -coverage grep.c -o grep-cov

2. Fuzz with 3 seeds (4580, 4581, 4582), 30 minutes each.

   $ afl-fuzz -V 1800 -s 4580 -i <input_seeds> -o <output_dir> -- ./grep .... @@

3. Run grep-cov with all test inputs (hundreds!) in <output_dir> and find the best one.

Is my understanding correct?

[3-24]

Yes, you need to run each inputs with grep-cov binary, and find the best input that reaches highest coverage.

[leejy12]

Thank you!