There's no real need for Fuzzer, Replayer and Shrinker to use the
opaque pointer design pattern. This change removes it, paving the way
for making some upcoming changes to Fuzzer easier.
This change adds the notion of "overflow ids", which can be used
during shrinking to facilitate applying transformations that would
otherwise have become inapplicable due to earlier transformations
being removed.
Fixes an issue with the shrinker, where the message consumer set for
the shrinker was not being passed on to the replay object that the
shrinker creates. This meant that messages generated during replay
would cause an exception to be thrown.
To aid in debugging issues in spirv-fuzz, this change adds an option whereby the SPIR-V module is validated after each transformation is applied during replay. This can assist in finding a transformation that erroneously makes the module invalid, so that said transformation can be debugged.
Adds to spirv-fuzz the option to shrink a sequence of transformations
that lead to an interesting binary to be generated, to find a smaller
sub-sequence of transformations that still lead to an interesting (but
hopefully simpler) binary being generated. The notion of what counts
as "interesting" comes from a user-provided script, the
"interestingness function", similar to the way the spirv-reduce tool
works. The shrinking process will give up after a maximum number of
steps, which can be configured on the command line.
Tests for the combination of fuzzing and shrinking are included, using
a variety of interestingness functions.
