Code Clone Detection

A code clone is a code fragment that is similar to another code fragment in the source code. The existence of code clones can have a negative impact on software development and maintenance. For example, if a developer makes changes to the source code to fix a bug without knowing that code clones exist, it is possible that the same bug exists in the code clones of the changed code fragment, but the developer is not always aware of their existence. If the developer is unaware of the existence, the bug cannot be completely removed and will remain in the source code.

For this reason, research on code clone detection has been conducted. I have been working on code clone detection and visualization of detected code clones. Recently, I have also studied evaluation methods for code clone detection techniques. Since it is currently impossible to detect all code clones in the source code, how to evaluate the recall of code clone detection results (i.e., the degree to which code clones that should be detected are not detected) is a major issue in this field, which I have also been working on recently.

Automated Program Repair

Debugging is a labor-intensive task in software development.
Some reports indicate that software developers spend more than 50% of their time debugging.
In recent years, APR (Automated Program Repair) has been attracting a great deal of attention as a debugging assistive technique.
Conventional debugging assistive techniques are designed to assist the developer in debugging, while APR is designed to identify the cause of bugs and correct them completely automatically.
If APR works well, developers do not need to debug at all.

However, research on APR is still in its infancy.
Currently, only a limited number of bugs can be fixed automatically, and it will be a long time before many bugs can be fixed by APR techniques.
This has led me to the conclusion that in order for APR techniques to play a major role in software development in the next few years, it is important not only to promote APR techniques but also to create an environment in which humans can develop software in which APR techniques can easily fix bugs.
Therefore, We are challenging to create an environment in which APR can play a dramatic role in software development and maintenance by introducing a new concept of software quality called Autorepairability.