Targeted program transformations for symbolic execution

Abstract

Semantics-preserving program transformations, such as refactorings and optimisations, can have a significant impact on the effectiveness of symbolic execution testing and analysis. Furthermore, semantics-preserving transformations that increase the performance of native execution can in fact decrease the scalability of symbolic execution. Similarly, semantics-altering transformations, such as type changes and object size modifications, can often lead to substantial improvements in the testing effectiveness achieved by symbolic execution in the original program. As a result, we argue that one should treat program transformations as first-class ingredients of scalable symbolic execution, alongside widely-accepted aspects such as search heuristics and constraint solving optimisations. First, we propose to understand the impact of existing program transformations on symbolic execution, to increase scalability and improve experimental design and reproducibility. Second, we argue for the design of testability transformations specifically targeted toward more scalable symbolic execution.