Learn More
In software verification, Craig interpolation has proven to be a powerful technique for computing and refining abstractions. In this paper, we propose an interpolation-based software verification algorithm for checking safety properties of (possibly recursive) sequential programs. Our algorithm, called Whale, produces inter-procedural proofs of safety by(More)
In this paper, we present Ufo, a framework and a tool for verifying (and finding bugs in) sequential C programs. The framework is built on top of the LLVM compiler infrastructure and is targeted at researchers designing and experimenting with verification algorithms. It allows definition of different abstract post operators, refinement strategies and(More)
The rise in efficiency of Satisfiability Modulo Theories (SMT) solvers has created numerous uses for them in software verification, program synthesis, functional programming, refinement types, etc. In all of these applications, SMT solvers are used for generating satisfying assignments (e.g., a witness for a bug) or proving unsatisfiability/validity(e.g.,(More)
We describe a compositional approach to Craig interpolation based on the heuristic that simpler proofs of special cases are more likely to generalize. The method produces simple interpolants because it is able to summarize a large set of cases using one relatively simple fact. In particular, we present a method for finding such simple facts in the theory of(More)
interpretation (AI) is one of the most scalable automated approaches to program verification available today. To achieve efficiency, many steps of the analysis, e.g., joins and widening, lose precision. As a result, AI often produces false alarms, coming from the inability to find a safe inductive invariant even when it exists in a chosen abstract domain.(More)
The algorithms underlying Ufo are described in [1–3]. The Ufo tool is described in more detail in [4]. Ufo marries the power and efficiency of numerical Abstract Interpretation (AI) domains [6] with the generalizing ability of interpolation-based software verification in an abstraction refinement loop. More formally: given a program P , a safety property ϕ,(More)
Modularity is a central theme in any scalable program analysis. The core idea in a modular analysis is to build summaries at procedure boundaries, and use the summary of a procedure to analyze the effect of calling it at its calling context. There are two ways to perform a modular program analysis: (1) top-down and (2) bottomup. A bottom-up analysis(More)
Current approaches to software model checking can be divided into over-approximation-driven (OD) and under-approximation-driven (UD). OD approaches maintain an abstraction of the transition relation of a program and use abstract reachability to build an induc-tive invariant (or find a counterexample). At the other extreme, UD approaches attempt to construct(More)
Formal verification of hardware and software systems involves proving or disproving the correctness of the intended behaviour of the system with respect to a formal specification of the system. An effective means of automating this process is by representing properties to be verified in a temporal logic and exploiting model checking or theorem proving. In(More)