Abstract

Abstract. Specifications are necessary in order to find software bugs using program verification tools. This paper presents a novel automatic specification mining algorithm that uses information about error handling to learn temporal safety rules. Our algorithm is based on the observation that programs often make mistakes along exceptional control-flow paths, even when they behave correctly on normal execution paths. We show that this focus improves the effectiveness of the miner for discovering specifications beneficial for bug finding. We present quantitative results comparing our technique to four existing miners. We highlight assumptions made by various miners that are not always born out in practice. Additionally, we apply our algorithm to existing Java programs and analyze its ability to learn specifications that find bugs in those programs. In our experiments, we find filtering candidate specifications to be more important than ranking them. We find 430 bugs in 1 million lines of code. Notably, we find 250 more bugs using per-program specifications learned by our algorithm than with generic specifications that apply to all programs. 1

Citations