This option will generate C prototypes from
declarations, types and procedure interfaces and writes them to
ENUM is not yet supported.
The generated prototypes may need inclusion of an appropriate header,
<stdlib.h>. For types which are
not specified using the appropriate kind from the
module, a warning is added as a comment to the code.
For function pointers, a pointer to a function returning
without an explicit argument list is generated.
Example of use:
$ gfortran -fc-prototypes -fsyntax-only foo.f90 > foo.h
where the C code intended for interoperating with the Fortran code