Predicting change consistency in a clone group

Abstract

Abstract Code cloning has been accepted as one of the general code reuse methods in software development, thanks to the increasing demand in rapid software production. The introduction of clone groups and clone genealogies enable software developers to be aware of the presence of and changes to clones as a collective group; they also allow developers to understand how clone groups evolve throughout software life cycle. Due to similarity in codes within a clone group, a change in one piece of the code may require developers to make consistent change to other clones in the group. Failure in making such consistent change to a clone group when necessary is commonly known as “clone consistency-defect”, which can adversely impact software reusability. In this work, we propose an approach to predict the need for making consistent change in clones within a clone group at the time when changes have been made to one of its clones. We build a variant of clone genealogies to collect all consistent/inconsistent changes to clone groups, and extract three attribute sets from clone groups as input for predicting the need for consistent clone change. These three attribute sets are code attributes, context attributes and evolution attributes respectively. Together, they provide a holistic view about clone changes. We conduct experiments on four open source projects. Our experiments show that our approach has reasonable precision and recall in predicting whether a clone group requires (or is free of) consistent change. This holistic approach can aid developers in maintaining clone changes, and avoid potential consistency-defect, which can improve software quality and reusability.