Identifying Relevant Changes for Incremental Verification of Evolving Software Systems

Modern software verification tools are moving towards incremental verification of program properties to ensure safety of evolving software systems. These tools analyze each and every change in the code. However, not every change in the program impacts verification outcome of program properties. Moreover, analyzing these irrelevant changes adds to cost of incremental verification. To address this, we are proposing a light-weight pre-analysis phase that identifies relevant changes with respect to program properties before applying any incremental verification technique. To identify such relevant changes, we present the Relevant Change Identification Technique (RCIT). RCIT uses a variant of the Strongly Live Variables (SLV) analysis to compute variables that are influencing the verification outcome of program properties. RCIT, then uses these variables to identify relevant changes. We evaluated RCIT on the changes made in five versions of open source applications with respect to two type of program properties - array index out of bound and zero division. RCIT identifies 59% of the actual changes as irrelevant.