Identifying clone removal opportunities based on co-evolution analysis

Previous research efforts have proposed various techniques for supporting code clone removal. They identify removal candidates based on the states of the source code in the latest version. However, those techniques suggest many code clones that are not suited for removal in addition to appropriate candidates. That is because the presence of code clones do not necessarily motivate developers to remove them if they are stable and do not require simultaneous modifications. In this paper, we propose a new technique that identifies removal candidates based on past records of code modifications. By using the proposed technique, we can identify code clones that actually required simultaneous modifications in the past.