Evolution of Code Clone Ratios throughout Development History of Open-Source C and C plus plus Programs

A code clone is a fragment of code which is duplicated throughout the source code of a project. Code clones have been shown to make a project less maintainable because all code clones will share potential bugs and problems. Unlike other code clone research, this study analyzes the code clone ratios over the entire development lifetime of three open-source projects written in C/C++ to understand code clone growth in software over development and potential developer habits which could affect this growth. The study utilizes CCFinderX and Git to detect clone metrics across development history. The results from each project show very low, stable ratios across development history, with the code clone ratios only fluctuating greatly during the beginning of development mostly and very little refactoring occurring. This study goes further into the potential cause of low ratios and different fluctuations at different periods of development.