Extracting Interactive Actor-Based Dataflow Models from Legacy C Code

Graphical actor-based models provide an abstract overview of the flow of data in a system. They are well-established for the model-driven engineering (MDE) of complex software systems and are supported by numerous commercial and academic tools, such as Simulink, LabVIEW or Ptolemy. In MDE, engineers concentrate on constructing and simulating such models, before application code (or at least a large fraction thereof) is synthesized automatically. However, a significant fraction of today's legacy system has been coded directly, often using the C language. High-level models that give a quick, accurate overview of how components interact are often out of date or do not exist. This makes it challenging to maintain or extend legacy software, in particular for new team members. To address this problem, we here propose to reverse the classic synthesis path of MDE and to synthesize actor-based dataflow models automatically from source code. Here functions in the code get synthesized into nodes that represent actors manipulating data. Second, we propose to harness the modeling-pragmatic approach, which considers visual models not as static artefacts, but allows interactive, flexible views that also link back to textual descriptions. Thus we propose to synthesize actor models that can vary in level of detail and that allow navigation in the source code. To validate and evaluate our proposals, we implemented these concepts for C analysis in the open source, Eclipse-based KIELER project and conducted a small survey.