Maximize API

[kyakdan]

Summary

Add a hill-climbing maximize() API to Jazzer that guides the fuzzer toward maximizing a value over time. This enables fuzzing scenarios where standard code coverage provides insufficient guidance, such as finding inputs that maximize some computed metric.

Changes

Jazzer.maximize() API

// Guide fuzzer to maximize 'value' within [0, 1023]
Jazzer.maximize(value, id);

// Convenience overload with auto-generated call-site ID (requires instrumentation)
Jazzer.maximize(value);

How it works: For each observed value v, sets coverage counters [0, 1023 - v] to 1. This creates incremental progress feedback - higher values trigger more "coverage," guiding the fuzzer toward the maximum. Corpus minimization naturally retains only the input producing the highest value.

Example

Added ReactorFuzzTest demonstrating the API on a chaotic feedback system where standard coverage is constant but the fuzzer needs to maximize a computed temperature value.