Gemini: maintenance support environment based on code clone analysis

Maintaining software systems is becoming a more complex and difficult task, as the scale becomes larger. It is generally said that code cloning is one of the factors that make software maintenance difficult. A code clone is a code portion in source files that is identical or similar to another. If some faults are found in a code clone, it is necessary to correct the faults in its all code clones. However for large scale software, it is very difficult to correct them completely. We develop a maintenance support environment, called Gemini, which visualizes the code clone information from a code clone detection tool, CCFinder. Using Gemini, we can specify a set of distinctive code clones through the GUI (scatter plot and metrics graph about code clones), and refer the fragments of source code corresponding to the clone on the plot or graph.