Semantic Foundations for Model-Integrated Computing A panel at the First OMG MIC Workshop Arlington, VA October 14, 2004 Jeff Gray, University of Alabama at Birmingham

Issues on DSML Semantic Foundations Panel Position  Transformations (horizontal or vertical) are the “heart and soul” of any model-driven approach  Towards consistency across various meta layers: 1. Transformations performed on the metamodel, in response to changes in domain requirements 2. Transformations performed on instance models, in response to system changes 3. Testing the correctness of transformations in the presence of metamodel changes

1. Effect of Changing Domain Semantics The evolution of the models and interpreters in terms of metamodel changes ∆ MM : The changes made to the meta-models ∆ M : The changes reflected in the domain models ∆ I : The changes reflected in the model interpreters Interpreter 1 Model 1 Meta-model 1 Define Interpret Interpreter n Model n Meta-model n Define Interpret Interpreter 0 Model 0 Meta-model 0 Define Interpret ∆ M 1 ∆ MM 1 ∆ I 1 ∆ M 2 ∆ MM 2 ∆ I 2 ∆ M n ∆ MM n ∆ I n …… BASED ONBASED ON

1. Model-Driven Program Transformation on Interpreter Source void CComponent::InvokeEx(CBuilder &builder) { Interpreter aInterpreter; CString fileName; if(!aInterpreter.selectSpecAspects(fileName)) { return; } … } void CComponent::InvokeEx(CBuilder &builder) { Interpreter aInterpreter; CString fileName; char *specFile = new char[fileName.GetLength()]; strcpy(specFile, fileName); …. } Interpreters Interpreters ’ Meta-model’Meta-model model Models Model Xform Engine Models’ model Modeling Tool APIModeling Tool API’

2. Ensuring Fidelity Between Models and Legacy Source Model-Driven Evolution of Legacy Systems  Must model-driven approaches be applied to only “greenfield” systems?; difference between translation/synthesis versus transformation of code  Workshop at OMG-sponsored EDOC conference: Intersection of MIC and the OMG ADM/KDM Preliminary concepts: see last talk

3. Testing the Correctness of Transformations Addressing the “ad-hoc” nature of transformations by adding some degree of confidence in correctness of semantic preservation; transformation specification can be erroneous  Terminating and confluent?  Property preserving? Formal proof of transformation correctness versus testing Parallel Argument:  Formal verification of compilers (except for a few safety-critical domains) is not the norm  Instead, whenever a new compiler is released (or language definition changes), a compiler is tested on a large suite of sample code Side benefit - Regression testing in presence of:  Transformation changes  Metamodel changes  Instance model changes

3. Testing the Correctness of Transformations