ALBFL: A Novel Neural Ranking Model for Software Fault Localization via Combining Static and Dynamic Features

Automatic fault localization plays a significant role in assisting developers to fix software bugs efficiently. Although existing approaches, e.g., static methods and dynamic ones, have greatly alleviated this problem by analyzing static features in source code and diagnosing dynamic behaviors in software running state respectively, the fault localization accuracy still does not meet user requirements. To improve the fault locating ability with statement granularity, this paper proposes ALBFL, a novel neural ranking model that involves the attention mechanism and the LambdaRank model, which can integrate the static and dynamic features and achieve very high accuracy for identifying software faults. ALBFL first introduces a transformer encoder to learn the semantic features from software source code. Also, it leverages other static statistical features and dynamic features, i.e., eleven Spectrum-Based Fault Localization (SBFL) features, three mutation features, to evaluate software together. Specially, the two types of features are integrated through a self-attention layer, and fed into the LambdaRank model so as to rank a list of possible fault statements. Finally, thorough experiments are conducted on 5 open-source projects with 357 faulty programs in Defects4J. The results show that ALBFL outperforms 11 traditional SBFL methods (by three times) and 2 state-of-the-art approaches (by 13%) on ranking faulty statements in the first position.