A technique to detect multi-grained code clones

It is said that the presence of code clones makes software maintenance more difficult. For such a reason, it is important to understand how code clones are distributed in source code. A variety of code clone detection tools has been developed before now. Recently, some researchers have detected code clones from a large set of source code to find library candidates or overlooked bugs. In general, the smaller the granularity of the detection target is, the longer the detection time. On the other hand, the larger the granularity of the detection target is, the fewer detectable code clones are. In this paper, we propose a technique that detects in order from coarse code clones to fine-grained ones. In the coarse-tofine- grained-detections, code fragments detected as code clones at a certain granularity are excluded from detection targets of more fine-grained detections. Our proposed technique can detect code clones faster than fine-grained detection techniques. Besides, it can detect more code clones than coarse detection techniques.