Improving Process of Source Code Modification Focusing on Repeated Code

摘要

There are various kinds of repeated code such as consecutive if-else statements or case entries in program source code. Such repeated code sometimes require simultaneous modifications on all of its elements. Applying the same modifications to many places on source code is a burdensome work and introduces new bugs if some places to be modified are overlooked. For these reasons, it is necessary to support modifications on repeated code. Appropriate supports for repeated code can improve process of source code modification. In this paper, as a first step for supporting modifications on repeated code, we investigate how repeated code are modified during software evolution. As a result, we revealed that, 73-89% of repeated code were modified at least once in their life and 31-58% of modifications on repeated code were simultaneous ones for all of their elements.