Randomized generation and misc. fixes #499
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There isn't a flag to set the seed in fsm or re yet. Update callers, add a 0 seed argument to default to the existing behavior. Also, no end states means nothing to do, so exit right away.
It fills up the fuzzer logs with lots of uninteresting output.
src/libfsm/gen.c
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| (void)seed; | ||
| if (randomized) { | ||
| srand(seed); | ||
| } |
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Not sure about calling srand() in library code, because of its state being side-effect to the caller's own uses. I don't want to include our own prng. What do you think of moving the srand() invocation to the caller?
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Good point. Should the interface just have bool randomized (or int, since nothing else in that header uses bool), note that it uses rand specifically, and encourage the caller to seed with srand? It doesn't need to be a good PRNG, just something that has more variation than always choosing the first printable character.
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Probably that's simplest, yes. Let's document that we call rand(), and the caller can seed beforehand.
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Updated in cf8fc65.
Instead of taking a seed argument, just treat `int randomized` like a flag. (I'd use `bool`, but the header consistently uses `int` for boolean arguments.)
| @@ -1047,7 +1047,7 @@ main(int argc, char *argv[]) | |||
| } | |||
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| if (generate_bounds > 0) { | |||
| if (!fsm_generate_matches(fsm, generate_bounds, fsm_generate_cb_printf_escaped, &opt)) { | |||
| if (!fsm_generate_matches(fsm, generate_bounds, 0, fsm_generate_cb_printf_escaped, &opt)) { | |||
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would make sense to expose this to the cli of course (and also for fsm(1)), but that can wait
Instead of always using the first character in a label set, pseudorandomly pick one using
rand()if a non-zero seed is provided. This adds an extra argument tofsm_generate_matches, for the seed.Also:
TRACK_TIMESto 0 whenBUILD_FOR_FUZZERis set, because it fills up the fuzzer logs with lots of uninteresting messages about things taking longer when subjected to weird random inputs.fsm_trim's integrity checks whenEXPENSIVE_CHECKSis set.