The paper introduces a technique to symbolically execute hierarchically composed models based on communicating state machines. The technique is modular and starts with non-composite models, which are symbolically executed. The results of the execution, symbolic execution trees, are then composed according to the communication topology. The composite symbolic execution trees may be composed further reflecting hierarchical structure of the analyzed model. The technique supports reuse, meaning that already generated symbolic execution trees, composite or not, are used any time they are required in the composition. For illustration, the technique is applied to analyze UML-RT models and the paper shows several analyses options such as reachability checking or test case generation. The presentation of the technique is formal, but we also report on the implementation and we present some experimental results.
展开▼
