Resource Usage Verification

We investigate how to automatically verify that resources such as files are not used improperly or unsafely by a program. We employ a mixture of compile-time analysis and run-time testing to verify that a program conforms to a resource usage policy specified by a deterministic finite state automata (DFA) which details allowed sequences of operations on resources. Our approach has four main phases. The first is to generate a context-free grammar which safely approximates the resource usage behaviour of the program. This, rather than the original program, is analysed in subsequent phases. The second phase checks whether the grammar satisfies the resource usage policy and, if not, where the problems arise. The third phase determines where to place a minimal set of run-time tests and the fourth determines how to instrument the program to compute the state information required for the tests.