Correctness Witness Validation by Abstract Interpretation

TL;DR

This paper introduces the unassume abstract operation to validate correctness witnesses via abstract interpretation, improving verification efficiency and enabling verification of properties previously unverified.

Contribution

It presents a novel unassume operator that incorporates witnesses into abstract interpretation, enhancing precision and performance in program verification.

Findings

Witnesses reduce CPU time by 7% to 47%.

Witness-guided analysis verifies properties unprovable alone.

Augmented interpreter accelerates fixpoint convergence.

Abstract

Witnesses record automated program analysis results and make them exchangeable. To validate correctness witnesses through abstract interpretation, we introduce a novel abstract operation unassume. This operator incorporates witness invariants into the abstract program state. Given suitable invariants, the unassume operation can accelerate fixpoint convergence and yield more precise results. We demonstrate the feasibility of this approach by augmenting an abstract interpreter with unassume operators and evaluating the impact of incorporating witnesses on performance and precision. Using manually crafted witnesses, we can confirm verification results for multi-threaded programs with a reduction in effort ranging from 7% to 47% in CPU time. More intriguingly, we discover that using witnesses from model checkers can guide our analyzer to verify program properties that it could not verify on its own.