Automatic Repair of Quantum Programs via Unitary Operation

With the continuous advancement of quantum computing (QC), the demand for high-quality quantum programs (QPs) is growing. In order to avoid program failure, in software engineering, the technology of automatic program repair (APR) employs appropriate patches to remove potential bugs without the intervention of a human. However, the method tailored for repairing defective QPs is still absent. This paper proposes a new APR method named \(\texttt {UnitAR} \) that can repair QPs via unitary operation automatically. Based on the characteristics of superposition and entanglement in QC, the paper constructs an algebraic model and adopts a generate-and-validate approach for the repair procedure. Furthermore, the paper presents two schemes that can respectively promote the efficiency of generating patches and guarantee the effectiveness of applying patches. For the purpose of evaluating the proposed method, the paper selects 29 mutated versions as well as 5 real-world buggy programs as the objects, and introduces two traditional APR approaches \(\texttt {GenProg} \) and \(\texttt {TBar} \) as baselines. According to the experiments, \(\texttt {UnitAR} \) can fix 23 buggy programs, and this method demonstrates the highest efficiency and effectiveness among 3 APR approaches. Besides, the experimental results further manifest the crucial roles of two constituents involved in the framework of \(\texttt {UnitAR} \).