Migrating Esope to Fortran 2008 Using Model Transformations

Legacy programming languages such as FORTRAN 77 still play a vital role in many industrial applications. Maintaining and modernizing these languages is challenging, especially when migrating to newer standards such as Fortran 2008. This is exacerbated in the presence of legacy proprietary extensions on such legacy languages, because their semantics are often based on old context (limits of legacy language, domain logic,...). This paper presents an approach for automatically migrating FORTRAN 77 with a proprietary extension, named Esope, to Fortran 2008. We introduce a tool that converts Esope source code to Fortran 2008. While supporting readability of the generated code, we want to maintain the level of abstraction provided by Esope. Our method uses model-driven engineering techniques, with transformations to generate a target model from which we export easy-to-read Fortran 2008 source code. We discuss the advantages, limitations, and maintainability considerations of our approach and provide insights into its scalability and adaptability to evolving requirements.