%0 Conference Paper %B Proceedings of the 2008 international working conference on Mining software repositories %D 2008 %T Evaluation of source code copy detection methods on freebsd %A Chang, Hung-Fu %A Audris Mockus %K clone %K cloning %K code copying %K freebsd %K version control %X Studies have shown that substantial code reuse is common in open source and in commercial projects. However, the precise extent of reuse and its impact on productivity and quality are not well investigated in the open source context. Previously, we have introduced a simple-to-use method that needs only a set of file pathnames to identifies directories that share filenames and partially validated its performance on a set of closed-source projects. To evaluate this method and to improve reuse detection at the file level, we apply it and four additional file copy detection methods that utilize the underlying content of multiple versions of the source code on the FreeBSD project. The evaluation quantified unique advantages of each method and showed that the filename method detected roughly half of all reuse cases. We are still faced with a challenge to scale the content based methods to large repositories containing all versions of open source files. %B Proceedings of the 2008 international working conference on Mining software repositories %S MSR '08 %I ACM %C New York, NY, USA %P 61–66 %8 05/2008 %@ 978-1-60558-024-1 %U http://doi.acm.org/10.1145/1370750.1370766 %R http://doi.acm.org/10.1145/1370750.1370766 %> https://flosshub.org/sites/flosshub.org/files/p61-chang.pdf %0 Conference Paper %B Fourth International Workshop on Mining Software Repositories (MSR'07:ICSE Workshops 2007) %D 2007 %T Analysis of the Linux Kernel Evolution Using Code Clone Coverage %A Livieri, Simone %A Higo, Yoshiki %A Matsushita, Makoto %A Inoue, Katsuro %K ccfinder %K clone %K cloning %K kernel %K linux %K metrics %K source code %X Most studies of the evolution of software systems are based on the comparison of simple software metrics. In this paper, we present our preliminary investigation of the evolution of the Linux kernel using code-clone analysis and the code-clone coverage metrics. We examined 136 versions of the stable Linux kernel using a distributed extension of the code clone detection tool CCFinder. The result is shown as a heat map. %B Fourth International Workshop on Mining Software Repositories (MSR'07:ICSE Workshops 2007) %I IEEE %C Minneapolis, MN, USA %P 22 - 22 %@ 0-7695-2950-X %R 10.1109/MSR.2007.1 %> https://flosshub.org/sites/flosshub.org/files/28300022.pdf %0 Conference Paper %B Fourth International Workshop on Mining Software Repositories (MSR'07:ICSE Workshops 2007) %D 2007 %T Evaluating the Harmfulness of Cloning: A Change Based Experiment %A Lozano, Angela %A Wermelinger, Michel %A Nuseibeh, Bashar %K ccfinder %K clone %K clones %K clonetracker %K cloning %K ctags %K cvs %K dnsjava %K maintenance %K scm %K source code %X Cloning is considered a harmful practice for software maintenance because it requires consistent changes of the entities that share a cloned fragment. However this claim has not been refuted or confirmed empirically. Therefore, we have developed a prototype tool, CloneTracker, in order to study the rate of change of applications containing clones. This paper describes CloneTracker and illustrates its preliminary application on a case study. %B Fourth International Workshop on Mining Software Repositories (MSR'07:ICSE Workshops 2007) %I IEEE %C Minneapolis, MN, USA %P 18 - 18 %@ 0-7695-2950-X %R 10.1109/MSR.2007.8 %0 Conference Paper %B Proceedings of the 4th International Workshop on Principles of Software Evolution (IWPSE 2001) %D 2001 %T Growth, evolution, and structural change in open source software %A Michael Godfrey %A Tu, Qiang %K agile methods %K beagle %K cloning %K evolution %K fetchmail %K gcc %K growth %K kernel %K lehman's laws %K lines of code %K linux %K linux kernel %K loc %K open source software %K software architecture %K software evolution %K source code %K structural change %K supporting environments %K vim %X Our recent work has addressed how and why software systems evolve over time, with a particular emphasis on software architecture and open source software systems [2, 3, 6]. In this position paper, we present a short summary of two recent projects. First, we have performed a case study on the evolution of the Linux kernel [3], as well as some other open source software (OSS) systems. We have found that several OSS systems appear not to obey some of "Lehman's laws" of software evolution [5, 7], and that Linux in particular is continuing to grow at a geometric rate. Currently, we are working on a detailed study of the evolution of one of the subsystems of the Linux kernel: the SCSI drivers subsystem. We have found that cloning, which is usually considered to be an indicator of lazy development and poor process, is quite common and is even considered to be a useful practice. Second, we are developing a tool called Beagle to aid software maintainers in understanding how large systems have changed over time. Beagle integrates data from various static analysis and metrics tools and provides a query engine as well as navigable visualizations. Of particular note, Beagle aims to provide help in modelling long term evolution of systems that have undergone architectural and structural change. %B Proceedings of the 4th International Workshop on Principles of Software Evolution (IWPSE 2001) %S IWPSE '01 %I ACM %C New York, NY, USA %P 103–106 %@ 1-58113-508-4 %U http://doi.acm.org/10.1145/602461.602482 %R http://doi.acm.org/10.1145/602461.602482 %> https://flosshub.org/sites/flosshub.org/files/tu2001.pdf