Norihiro Yoshida
ABSTRACT
We have been doing code clone analysis with industry collaborators for a long time, and have been always asked a question, "OK, I understand my system contains a lot of code clones, but how slim will it be after merging redundant code clones?" As a software system evolves for long period, it would increasingly contain many code clones due to quick bug fix and new feature addition. Industry collaborators would recognize decay of initial design simplicity, and try to evaluate current system from the view point of maintenance effort and cost. As one of resources for the evaluation, the estimated code size by merging code clone is very important for them. In this paper, we formulate this issue as "slimming" problem, and present three different slimming methods, Basic, Complete, and Heuristic Methods, each of which gives a lower bound, upper bound, and modest reduction rates, respectively. Application of these methods to OSS systems written in C/C++ showed that the reduction rate is at most 5.7% of the total size, and to a commercial COBOL system, it is at most 15.4%. For this approach, we have gotten initial but very positive feedback from industry collaborators.
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Index Terms
- How slim will my system be?: estimating refactored code size by merging clones
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A metric-based approach to identifying refactoring opportunities for merging code clones in a Java software system
A code clone is a code fragment that has other code fragments identical or similar to it in the source code. The presence of code clones is generally regarded as one factor that makes software maintenance more difficult. For example, if a code fragment ...
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WRT '12: Proceedings of the Fifth Workshop on Refactoring ToolsAlthough code clone (i.e. a code fragment that has similar or identical fragments) is regarded as one of the most typical bad smells, tools for identification of clone refactoring (i.e. merge code clones into a single method) are not commonly used. To ...
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