Automated Program Repair Using Donor Code Generation Based on Features of Targeted Systems

In recent years, automated program repair techniques have attracted attention. In the conventional techniques, a defect is fixed by rewriting statements containing the defect using expressions (donor code) that appear in another part of the source code. If donor code required to fix the defect does not exist in the source code, the conventional techniques cannot repair the defect. In this study, a technique is proposed, which fixes defects even in the above-mentioned case. In the proposed technique, developers' knowledge that specific expressions are often used in the system is specified as the commonly used expression pattern in advance, and expressions commonly used in the system are generated as donor code according to the pattern. As a result of applying the proposed technique to 48 defects detected and fixed during the development of an actual product, the number of defects that could be fixed by the conventional technique was nine, and the number increased by two to eleven in the proposed technique.