Restore: Retrospective Fault Localization Enhancing Automated Program Repair
Tongtong Xu, Liushan Chen, Yu Pei, Tian Yao Zhang, Minxue Pan, Carlo A. Furia · IEEE Transactions on Software Engineering · 2020
Fault localization is a crucial step of automated program repair, because accurately identifying program locations that are most closely implicated with a fault greatly affects the effectiveness of the patching process. An ideal fault localization technique would provide precise information while requiring moderate computational resources—to best support an efficient search for correct fixes. In contrast, most automated program repair tools use standard fault localization techniques—which are not tightly integrated with the overall program repair process, and hence deliver only subpar efficiency. In this paper, we presentretrospective fault localization: a novel fault localization technique geared to the requirements of automated program repair. A key idea of retrospective fault localization is to reuse the outcome of failed patch validation to support mutation-based dynamic analysis—providing accurate fault localization information without incurring onerous computational costs. We implemented retrospective fault localization in a tool calledRestore—based on theJaidJava program repair system. Experiments involving faults from theDefects4Jstandard benchmark indicate that retrospective fault localization can boost automated program repair:Restoreefficiently explores a large fix space, delivering state-of-the-art effectiveness (41Defects4Jbugs correctly fixed, 8 of which no other automated repair tool for Java can fix) while simultaneously boosting performance (speedup over 3 compared toJaid). Retrospective fault localization is applicable to any automated program repair techniques that rely on fault localization and dynamic validation of patches.