2.10 Options for interoperability with other languages

-fc-prototypes

This option will generate C prototypes from BIND(C) variable declarations, types and procedure interfaces and writes them to standard output. ENUM is not yet supported.

The generated prototypes may need inclusion of an appropriate header, such as <stdint.h> or <stdlib.h>. For types which are not specified using the appropriate kind from the iso_c_binding module, a warning is added as a comment to the code.

For function pointers, a pointer to a function returning int 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 then uses #include "foo.h".