Fuzzing and Delta-Debugging SMT Solvers

SMT solvers are widely used as core engines in many applications. Therefore, robustness and correctness are essential criteria. Current testing techniques used by developers of SMT solvers do not satisfy the high demand for correct and robust solvers, as our testing experiments show. To improve this situation, we propose to complement traditional testing techniques with grammar-based blackbox fuzz testing, combined with delta-debugging. We demonstrate the effectiveness of our approach and report on critical bugs and incorrect results which we found in current state-of-the-art SMT solvers for bit-vectors and arrays.