Beyond Basic Specifications? A Systematic Study of Logical Constructs in LLM-based Specification Generation
Formal specifications play a pivotal role in accurately characterizing program behaviors and ensuring software correctness. In recent years, leveraging large language models (LLMs) for the automatic generation of program specifications has emerged as a promising avenue for enhancing verification efficiency. However, existing research has been predominantly confined to generating specifications based on basic syntactic constructs, falling short of meeting the demands for high-level abstraction in complex program verification. Consequently, we propose incorporating logical constructs into existing LLM-based specification generation framework. Nevertheless, there remains a lack of systematic investigation into whether LLMs can effectively generate such complex constructs. To this end, we conduct an empirical study aimed at exploring the impact of various types of syntactic constructs on specification generation framework. Specifically, we define four syntactic configurations with varying levels of abstraction and perform extensive evaluations on mainstream program verification datasets, employing a diverse set of representative LLMs. Experimental results first confirm that LLMs are capable of generating valid logical constructs. Further analysis reveals that the synergistic use of logical constructs and basic syntactic constructs leads to improvements in both verification capability and robustness, without significantly increasing verification overhead. Additionally, we uncover the distinct advantages of two refinement paradigms. To the best of our knowledge, this is the first systematic work exploring the feasibility of utilizing LLMs for generating high-level logical constructs, providing an empirical basis and guidance for the future construction of automated program verification framework with enhanced abstraction capabilities.