Cleaning up copy–paste clones with interactive merging

Research output: Contribution to journalArticle


Copy-paste-modify is a form of software reuse in which developers explicitly duplicate source code. This duplicated source code, amounting to a code clone, is adapted for a new purpose. Copy-paste-modify is popular among software developers, however, empirical evidence shows that it complicates software maintenance and increases the frequency of bugs. To allow developers to use copy-paste-modify without having to worry about these concerns, we propose an approach that automatically merges similar pieces of code by creating suitable abstractions. Because different kinds of abstractions may be beneficial in different contexts, our approach offers multiple abstraction mechanisms, which were selected based on a study of popular open-source repositories. To demonstrate the feasibility of our approach, we have designed and implemented a prototype merging tool for C++ and evaluated it on a number of code clones exhibiting some variation, i.e., near-miss clones, in popular Open Source packages. We observed that maintainers find our algorithmically created abstractions to be largely preferable to the existing duplicated code.


External organisations
  • Sorbonne Paris Cité Université
  • Itemis AG
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Software Engineering


  • Clone management, Program analysis, Source code analysis, Static analysis
Original languageEnglish
Pages (from-to)627-673
JournalAutomated Software Engineering
Issue number3
Early online date2018 Jul 9
Publication statusPublished - 2018 Sep
Publication categoryResearch