Symbolic Game Semantics for Model Checking Program Families

Program families can produce a (potentially huge) number of related programs from a common code base. Many such programs are safety critical. However, most verification techniques are designed to work on the level of single programs, and thus are too costly to apply to the entire program family. In this paper, we propose an efficient game semantics based approach for verifying open program families, i.e. program families with free (undefined) identifiers. We use symbolic representation of algorithmic game semantics, where concrete values are replaced with symbolic ones. In this way, we can compactly represent program families with infinite integers as so-called (finite-state) featured symbolic automata. Specifically designed model checking algorithms are then employed to verify safety of all programs from a family at once and pinpoint those programs that are unsafe (respectively, safe). We present a prototype tool implementing this approach, and we illustrate it with several examples.