Anti-patterns in search-based program repair

Abstract

Search-based program repair automatically searches for a program fix within a given repair space. This may be accomplished by retrofitting a generic search algorithm for program repair as evidenced by the GenProg tool, or by building a customized search algorithm for program repair as in SPR. Unfortunately, automated program repair approaches may produce patches that may be rejected by programmers, because of which past works have suggested using human-written patches to produce templates to guide program repair. In this work, we take the position that we will not provide templates to guide the repair search because that may unduly restrict the repair space and attempt to overfit the repairs into one of the provided templates. Instead, we suggest the use of a set of anti-patterns --- a set of generic forbidden transformations that can be enforced on top of any search-based repair tool. We show that by enforcing our anti-patterns, we obtain repairs that localize the correct lines or functions, involve less deletion of program functionality, and are mostly obtained more efficiently. Since our set of anti-patterns are generic, we have integrated them into existing search based repair tools, including GenProg and SPR, thereby allowing us to obtain higher quality program patches with minimal effort.