The Sustainability Face of Automated Program Repair Tools

Automated program repair (APR) aims to automatize the process of repairing software bugs in order to reduce the cost of maintaining software programs. While APR accuracy has significantly improved in recent years, its energy impact remains unstudied. The field of green software research aims to measure the energy consumption required to develop, maintain, and use software products. Our main goal is to define the foundation for measuring the energy consumption of the APR activity. We state that an environmentally sustainable (or green) APR tool achieves a good balance between the ability to correctly repair bugs and the amount of energy consumed during such process. We measure the energy consumption of 10 traditional APR tools for Java and 11 fine-tuned large-language models (LLM) trying to repair real bugs from Defects4J. The results of this study show the existing tradeoff between energy consumption and repairability. In particular, APR tools such as TBar and RepairLlama repair more bugs than other approaches at the expense of a higher energy consumption. Other tools, such as SimFix and the LLM CodeT5-large, provide a good tradeoff between energy consumption and repairability. We also present guidelines consisting of a set of recommendations for developing greener APR.