Enhancing Bug-Inducing Commit Identification: A Fine-Grained Semantic Analysis Approach

The SZZ algorithm and its variants have been extensively utilized for identifying bug-inducing commits based on bug-fixing commits. However, these algorithms face challenges when there are no deletion lines in the bug-fixing commit. Previous studies have attempted to address this issue by tracing back all lines in the block that encapsulates the added lines. However, this method is too coarse-grained and suffers from low precision. To address this issue, we propose a novel method in this paper called Sem-SZZ, which is based on fine-grained semantic analysis. Initially, we observe that a significant number of bug-inducing commits can be identified by tracing back the unmodified lines near added lines, resulting in improved precision and F1-score. Building on this observation, we conduct a more fine-grained semantic analysis. We begin by performing program slicing to extract the program part near the added lines. Subsequently, we compare the program's states between the previous version and the current version, focusing on data flow and control flow differences based on the extracted program part. Finally, we extract statements contributing to the bug based on these differences and utilize them to locate bug-inducing commits. We also extend our approach to fit the scenario where the bug-fixing commits contain deleted lines. Experimental results demonstrate that Sem-SZZ outperforms the state-of-the-art methods in identifying bug-inducing commits, regardless of whether the bug-fixing commit contains deleted lines.