An approach to formal verication of real time concurrent Ada programs

Abstract

The SPARK system provides static analysis tools for a highly restricted sequential Ada subset, including a proof checking tool for verifying partial correctness properties. Recently, SPARK Ada has been extended to include much of the Ravenscar Tasking Pro le which supports construction of high integrity real time systems. However, the veri cation machinery has not been changed, and can only handle purely sequential properties of the code. This paper sketches an approach to reasoning about the concurrent and real-time aspects that SPARK cannot handle. The approach involves compiling an abstract model of the Ada program that can be embedded in a general purpose theorem prover (e.g. PVS). The compilation makes heavy use of SPARK's existing static analysis tools.