A Method for Passing Data Between C and Opaque Fortran 90 Pointers

摘要

This paper discusses a portable, standard conforming method for passing data arrays between C and Fortran 90. When Fortran introduced pointers in Fortran 90, they were made opaque, that is, programmers were not allowed access to their contents. This improved program safety, and Java made a similar choice for the same reason, and this works well so long as Fortran does not need to work with other languages. However, the real world is not so insular, and many large scientific projects involved a mixture of languages, most notably Fortran and C++. Java solved this problem by introducing a facility called native methods, which allow Java to natively communicate with C. Fortran followed a similar path by introducing interoperability with C as part of the Fortran 2003 standard.