Code Generation by Model Transformation

June 08, 2010

The journal version of our ICMT 2008 paper has finally and officially been published in the Software and Systems Modeling journal.

Zef Hemel, Lennart C. L. Kats, Danny M. Groenewegen, Eelco Visser. Code generation by model transformation: a case study in transformation modularity. Software and Systems Modeling, 9(3):375-402, June 2010.

The big contribution with respect to the earlier paper is a new approach to type checking with Stratego. Instead of defining a type checker as a single traversal that takes care of name resolution, type analysis, error checking and generation of error messages, these aspects are defined separately and can also be used separately. This allows a much cleaner style for defining type checkers and it enables a smooth combination of type analysis and normalizing transformations. The style also turned out to work very well in Spoofax setting where analyses such as name resolution are used for multiple purposes in the IDE.

The paper is published under the open access regime, so you can read it even without subscription to the journal.

Abstract The realization of model-driven software development requires effective techniques for implementing code generators for domain-specific languages. This paper identifies techniques for improving separation of concerns in the implementation of generators. The core technique is code generation by model transformation, that is, the generation of a structured representation (model) of the target program instead of plain text. This approach enables the transformation of code after generation, which in turn enables the extension of the target language with features that allow better modularity in code generation rules. The technique can also be applied to ‘internal code generation’ for the translation of high-level extensions of a DSL to lower-level constructs within the same DSL using model-to-model transformations. This paper refines our earlier description of code generation by model transformation with an improved architecture for the composition of model-to-model normalization rules, solving the problem of combining type analysis and transformation. Instead of coarse-grained stages that alternate between normalization and type analysis, we have developed a new style of type analysis that can be integrated with normalizing transformations in a fine-grained manner. The normalization strategy has a simple extension interface and integrates non-local, context-sensitive transformation rules. We have applied the techniques in a realistic case study of domain-specific language engineering, i.e. the code generator for WebDSL, using Stratego, a high-level transformation language that integrates model-to-model, model-to-code, and code-to-code transformations.