Array Abstractions from Proofs

stractions from Proofs Ranjit Jhala1 Kenneth L. McMillan2 1 UC San Diego 2 Cadence Berkeley Laboratories We present a technique for using infeasible program paths to automatically infer Range Predicates that describe properties of unbounded array segments. First, we build proofs showing the infeasibility of the paths, using axioms that precisely encode the high-level (but informal) rules with which programmers reason about arrays. Next, we mine the proofs for Craig Interpolants which correspond to predicates that refute the particular counterexample path. By embedding the predicate inference technique within a Counterexample-Guided AbstractionRefinement (CEGAR) loop, we obtain a method for verifying datasensitive safety properties whose precision is tailored in a program- and property-sensitive manner. Though the axioms used are simple, we show that the method suffices to prove a variety of array-manipulating programs that were previously beyond automatic model checkers.

• Type: Conference
• Year: 2007
• Where: CAV
• Authors: Ranjit Jhala, Kenneth L. McMillan
• Keywords: Cadence Berkeley Laboratories, CAV 2007, Formal Methods, Infeasible Program Paths, Unbounded Array Segments