Formal specification and analysis of functional properties of graph rewriting‐based model transformation

Abstract

SUMMARY Model processing programs are regularly used when working with models or synthetizing the code from them; therefore, their verification has become an essential component of constructing reliable software in model‐based software engineering. Models are usually formalized and visualized as graphs; therefore, model processing programs based on algebraic graph rewriting systems—such programs are called model transformations—are often applied, and their verification has become an important research area. The goal of our research is to support offline transformation analysis by automated methods, where offline means that only the definition of the program itself, the language definitions of its source and target models are used during the analysis. Therefore, the results are independent from concrete source models, and the analysis needs to be performed only once. Based on previous work, this paper provides the synthesis and of a set of individual components and improves them to provide a complete verification solution: (i) a language is introduced to specify the properties to be verified; (ii) a formalism to describe model transformations in a declarative way; and (iii) automated algorithms that can analyse the declarative transformations as well as the properties expressed by the language. Besides its theoretical basis, the implementation of a verification framework is presented, and its operation is illustrated on a case study. Although the formal verification of model transformation properties is algorithmically undecidable in general, our goal is to provide a practically usable, scoped framework that can largely facilitate the manual verification of model transformations. Copyright © 2013 John Wiley & Sons, Ltd.

Formalised EMFTVM bytecode language for sound verification of model transformations

“…The execution semantics of rule scheduling in SimpleGT requires that it should be able to match rules with their own output, i.e. re-matching after each apply 4 : 4 For simplicity, we do not consider the inheritance of transformation rules [69].…”

“…Asztalos et al [4] use category theory to describe graph rewriting systems. This approach is implemented in the VMTS verification framework, but it is not targeted to a specific graph rewriting-based MT language.…”

Specification and Verification of Graph-Based Model Transformation Properties

“…These properties can be compiled into OCL and injected into any OMG-based transformation implementation (e.g., ATL) for automated verification. The property languages used by Asztalos et al [5] and AGG [20] are similar to ours; i.e., their graph-based property languages are used in their native graphical format and properties are contracts that can be used to build propositional formulae. The difference is that both studies [5,20] do not introduce a construct equivalent to our free variables which allows contracts in the same formula to refer to a specific element.…”

“…(ii) We used our prover to verify a simple and an industrial transformation. (iii) We demonstrated several property kinds that our prover can conclusively verify (unlike [5]) as opposed to verifying specific property kinds, e.g., forbidden patterns [8]. (iv) Verification is based on generating the symbolic executions.…”

“…Asztalos et al [5] implemented a VMTS-based verification tool for in-place transformations. VMTS transformations are expressed as graphical rules scheduled by a control flow graph.…”