For anyone interested there is something called fuzzing that uses usually code coverage based heuristics to generate data to find bugs.

For example LLVM's lib fuzzer uses instrumentation to track code coverage and mutates data to find invalid behaviour.

https://llvm.org/docs/LibFuzzer.html

It uses a compiler pass to insert code to branch points functions calls etc. I think it uses genetic algorithms to increase coverage by changing the data.

There are others that work in similar ways one of them is. https://github.com/google/AFL