RetCom: Information Retrieval-Enhanced Automatic Source-Code Summarization

With the purpose of saving the developing time of software engineers and promoting the work efficiency of programs, the research on automated source-code summarization (SCS) has become necessary in recent years, i.e. generating language descriptions for source code. To date, there exist two categories of SCS methods: information retrieval (IR)-based SCS and neural-based SCS. The latter is the mainstream method at present, however, this line of work suffers from the drawback of incapability to generate low-frequency words, which potentially degrades the performance. To tackle this predicament, we in this paper propose an IR-enhanced neural SCS method RetCom to improve the prediction of low-frequency words through leveraging both structural-level and semantic-level code retrievals. Furthermore, we figure out a token-level contextdependent mixture network to fuse different information sources, i.e. original code, structurally most similar code, and semantically most similar code. Finally, extensive experiments are performed to validate our proposed RetCom using two real-world datasets. Compared to several baseline methods, the experimental results show that our method does validly capture more low-frequency words to conduct a superior performance.