A Comprehensive Study on Code Clones in Automated Driving Software

With the continuous improvement of artificial intelligence technology, autonomous driving technology has been greatly developed. Hence automated driving software has drawn more and more attention from both researchers and practitioners. Code clone is a commonly used to speed up the development cycle in software development, but many studies have shown that code clones may affect software maintainability. Currently, there is little research investigating code clones in automated driving software. To bridge this gap, we conduct a comprehensive experience study on the code clones in automated driving software. Through the analysis of Apollo and Autoware, we have presented that code clones are prevalent in automated driving software. about 30% of code lines are involved in code clones and more than 50% of files contain code clones. Moreover, a notable portion of these code clones has caused bugs and co-modifications. Due to the high complexity of autonomous driving, the automated driving software is often designed to be modular, with each module responsible for a single task. When considering each module individually, we have found that Perception, Planning, Canbus, and Sensing modules are more likely to encounter code clones, and more likely to have bug-prone and co-modified clones. Finally, we have shown that there exist cross-module clones to propagate bugs and co-modifications in different modules, which undermine the software's modularity.