Typestate-like analysis of multiple interacting objects

Practical API Protocol Checking with Access Permissions

“…This paper shows that our approach at least matches the most recently proposed global analyses that we are aware of in precision when verifying iterator usage in PMD [10,30] with extremely low developer overhead. Another previous global typestate analysis has also been used with varying precision to check simple iterator protocols, but in a di erent corpus of client programs [19].…”

“…(A similar problem, called concurrent modi cation, exists with iterators [4].) There are no automated modular protocol checkers that we know of that can handle these protocols, although recent global protocol checking approaches can [10,30].…”

“…In the next section this case study is used for direct comparison with state-of-the-art global protocol analyses [10,30], which typically focus on simple protocols such as the well-known iterator protocol. Iterators are widely used in PMD, and most iterations in PMD are over Java Collections (see section 4.1), but PMD implements a few iterator classes over its own data structures as well.…”

“…These approaches di er signi cantly in the way protocols are speci ed, including typestates [33,15,26,19,17,7], type quali ers [20], size properties [13], direct constraints on ordering [24,10,30], type re nements [29,14], rst-order [27,2] or separation logic [32], and various temporal logics [23]. In these approaches, like in ours, usage rules of the API(s) of interest have to be codi ed by a developer.…”

“…While model checkers [23] typically have severe limitations in scaling to larger programs, approaches based on abstract interpretations have been shown to scale quite well in practice. Sound (see below) approaches rely on a global aliasing analysis [1,19,10,30] and become imprecise when alias information becomes imprecise.…”