Fortran C/C++ interoperability

Modern scientific applications require a well balanced approach to design. Many researchers are using a hybrid coding model that uses multiple programming languages. It is very common to see the core number crunching code of a scientific application being developed in Fortran, while C/C++ and even Python being used to design the driver program that handles everything else.

This repository contains example codes showing interoperability between C/C++ and Fortran.

work in progress ...

Code

 - BASIC
   '
   '- interop-0-1 : extern "C"
   '
   '- interop-1-1 : Call Fortran subroutine from C.
   '- interop-1-2 : Call C void function from Fortran.
   '
   '- interop-2-1 : Send integer and double digits to Fortran subroutine from C.
   '- interop-2-2 : Send integer and double digits to C void function from Fortran.

 - INTERMEDIATE
   '
   '- interop-3-1 : Send dynamic integer array to Fortran subroutine from C.
   '
   '- interop-4-1 : Send dynamic integer matrix to Fortran subroutine from C.
   '
   '- interop-5-1 : Send C struct to Fortran subroutine from C.
   '- interop-5-2 : Send C struct containing dynamic integer array to Fortran subroutine from C.
   '
   '- interop-6-1 : i.   Send dynamic integer array and matrix to Fortran subroutine from C.
                    ii.  Use c_f_pointer in Fortran to access integer array and matrix allocated in C.
                    iii. Store received data inside a derived type for better encapsulation.

 - PERFORMANCE
   '- perf-interop-5-2 : Performance analysis of interop-5-2 by observing the
                         generated assembly for arrays of integer and double
                         type and verifying if MAVX2 optimizations
                         was possible.

How to run code

Makefiles are provided along with the expected output in file output.txt.

Go to any directory, run make command to produce the executable a.out, then run the executable a.out.

$ cd interop-4-1
$ make
$ ./a.out