An SMT-based Approach for Generating Coverage Oriented Metamodel Instances

An effective technique for generating instances of a metamodel should quickly and automatically generate instances satisfying the metamodel's structural and OCL constraints. Ideally it should also produce quantitatively meaningful instances with respect to certain criteria, that is, instances which meet specified generic coverage criteria that help the modelers test or verify a metamodel at a general level. In this paper, the author presents an approach consisting of two techniques for coverage oriented metamodel instance generation. The first technique realises the standard coverage criteria defined for UML class diagrams, while the second technique focuses on generating instances satisfying graph-based criteria. With the author's approach, both kinds of criteria are translated to SMT formulas which are then investigated by an SMT solver. Each successful assignment is then interpreted as a metamodel instance that provably satisfies a coverage criteria or a graph property. The author has already integrated this approach into his existing tool to demonstrate the feasibility.