A Case for Structural Clones

In previous work, we introduced the concept of structural clone as recurring configurations of simple clones (i.e., similar code fragments). We also described a technique for detection of certain types of structural clones. The premise of our approach is that structural clones can provide a higher level and more useful view of the similarity situation in software than simple clones alone. In this paper, we set up a ground for systematic analysis of the structural clone phenomenon: We define structural clones more formally and more generally than we did before. We show how structural clone analysis extends the benefits of analysis based on simple clones only in areas of program understanding, maintenance, reuse, refactoring, and plagiarism detection.