Method start

hail-fuzz/src/havoc.rs:30–66

(fuzzer: &mut Fuzzer)

impl StageData for HavocStage {
    fn start(fuzzer: &mut Fuzzer) -> Result<Self, StageExit> {
        fuzzer.copy_current_input();

        let (Some(id), data) = (fuzzer.input_id, &fuzzer.state.input)
        else {
            return Err(StageExit::Unsupported);
        };

        let streams = get_non_empty_streams(data);
        if streams.is_empty() {
            // Must have at least one non-empty stream.
            return Err(StageExit::Skip);
        }

        let stream_distr = get_stream_weights(fuzzer, id, &streams);
        let mutator = HavocMutator::new();
        let attempts = calculate_energy(fuzzer) as u32;
        let log2_max_mutations = log2_max_mutations(fuzzer);
        let max_mutations = max_mutations(fuzzer);

        fuzzer.corpus[id].metadata.havoc_rounds += 1;

        tracing::trace!(
            "[{id}] havoc for {attempts} attempts with {} max mutations",
            2_u64.pow(log2_max_mutations)
        );
        Ok(Self {
            attempts,
            streams,
            stream_distr,
            mutator,
            log2_max_mutations,
            max_mutations,
            streams_to_extend: HashMap::new(),
            saved: false,
        })
    }

    fn fuzz_one(&mut self, fuzzer: &mut Fuzzer) -> Option<VmExit> {
        self.attempts = self.attempts.checked_sub(1)?;