A Summary on the Stability of Code Clones and Current Research Trends

Abstract

Code clones are exactly or nearly similar code pieces in the source code files of a software system. These mainly get created because of the frequent copy/paste activities of the programmers during development. Many studies have been done on realizing the impacts of code clones on software evolution and maintenance. We performed a comprehensive study on clone stability in order to understand whether clone or non-clone code in a software system is more change-prone. Intuitively, code pieces with higher change-proneness (lower stability) will require higher maintenance effort and cost during software evolution. According to our study, code clones are more change-prone than non-clone code in general and thus, code clones are likely to require a higher maintenance effort and cost. We suggest that code clones should be managed with proper tool support so that we can get rid of their negative impacts and can get benefited from their positive impacts. This document provides a brief summary of our study on clone stability. It also discusses the studies that were done mostly after the publication of our study. Finally, it mentions some possible future works on the basis of the findings of the existing studies.