Commit-time incremental analysis

Most changes to large systems that have been deployed are quite small compared to the size of the entire system. While standard summary-based analyses reduce the code that is reanalysed, they, nevertheless, analyse code that is not changed. For example, a backward summary-based analysis, will examine all the callers of the changed code even if the callers themselves have not changed. In this paper we present a novel approach of having summaries of the callers (called forward summaries) that enables one to analyse only the changed code. An evaluation of this approach on two representative examples, demonstrates that the overheads associated with the generation of the forward summaries is recovered by performing just one or two incremental analyses. Thus this technique can be used at commit-time where only the changed code is available.