A General Approach to Creating Fortran Interface for C++ Application Libraries

Summary

Incorporating various specialty libraries in different programming languages (FORTRAN and C/C++) with the main body of the source code remains a major challenge for developing scientific and engineering application software packages. The main difficulty originates from the fact that Fortran 90/95 pointers and C/C++ pointers are structurally different. In this paper, we present a technique that allows us to circumvent this difficulty without using any nonstandard features of these programming languages. This technique has helped us to develop a FORTRAN 90/95 interface for the GrACE library, which is written in C++ for facilitating spacial grid generation, adaptive mesh refinement, and load balance maintenance. The method outlined in this presentation provides a general guideline for the creation of the FORTRAN 90/95 interface for a C/C++ library. We show that this method is system independent and has low overhead cost, and can be easily extended to situations where building the C/C++ interface for a FORTRAN 90/95 application library is required.