Structural code clone detection on object oriented software using software metrics

Unnecessary repeated codes clones have not been well documented and are difficult to maintain. Detected bugs must be fixed in all occurences in these types of codes. Code clones may become an important problem in software development cycle and they must be fixed in all occurrences. This condition increases significantly software maintenance costs and required effort/duration for understanding the code. Many techniques have been proposed in order to minimize or prevent the code cloning problems in contemporary literature. The main focus of these techniques is on the detection of clones. In such studies, code cloning is studied under two main categories. While the repetition of code fragments arising from the code similarity is called as simple clone in the software, codes built with the same structure are called as structural clone in the system architecture. Simple clone detection techniques fail to determine the reasons of code repetition whether it is due to design or not, as they do not look at the code from a wider perspective for repetitive code snippets. Structural code clone detection techniques reveal the high level similarities, increase the reusability and simplify the software for filling the deficiency of simple clone detection techniques. The structural code clone detection techniques are based on existing simple code clone techniques in the literature. In this thesis, the most suitable metrics for metric based structural code clone detection and detection methodology based on these metrics are proposed. The proposed methodology has been implemented as a plugin for Sonar that is an open source quality management tool. In conclusion,this thesis evaluates the proposed methodology and proves that metric based structural code clone detection gives the successful results.