Automated techniques for higher-order program verification

Abstract

interpretation techniques are used to derive a control-flow analysis for a simple higher-order functional language. The analysis approximates the interprocedural control-flow of both function calls and returns in the presence of first-class functions and tail-call optimization. The analysis is systematically derived by abstract interpretation of the stack-based CaEK abstract machine of Flanagan et al. using a series of Galois connections. The analysis induces an equivalent constraint-based formulation, thereby providing a rational reconstruction of a constraintbased, higher-order CFA from abstract interpretation principles. Joint work with Jan Midtgaard. CFA2: Pushdown Flow Analysis for Higher-Order Languages Dimitrios Vardoulakis (Northeastern University) Flow analysis is a valuable tool for creating better programming languages; its applications span optimization, debugging, verification and program understanding. Despite its apparent usefulness, flow analysis of higher-order programs has not been made practical. The reason is that existing analyses do not model function call and return well: they remember only a bounded number of pending calls because they approximate programs with control-flow graphs. Call/return mismatch results in imprecision and increases the analysis time. In this talk I will describe CFA, a flow analysis that provides unbounded call/return matching in