Error Intel Fortran calling C shared library function that receives an integer-CodePudding

I am trying to run a C function from a Linux shared library (.so) from Fortran. The function in C receives an integer number from the Fortran program. I am not getting an erroneous value in C when using the intel compiler (2021.3.0), yet gfortran works without any issues. There seems to be a type error that I can't identify. I am creating an abstract interface following the syntax for interoperability established here

Function in C:

int print_number(int n)
{
    printf("Hello world! %d\n", n);
    return 0;
}

Function in Fortran

! Interface with shared library
abstract interface
    !% -------------------------------------------------------------------------------
    !% Simulation
    !% -------------------------------------------------------------------------------
    integer function print_number(number)
        use, intrinsic :: iso_c_binding
        implicit none
        integer(c_int), value :: number
    end function print_number
end interface

The output when calling print_number(2):

Hello world! 734920112

I am attaching the files to reproduce the error here. First, execute ./compile.sh, then ./run_test

I would appreciate it a lot if someone could point out what I am doing wrong.

Thanks!

CodePudding user response：

You should not use an abstract interface for this, but the problem probably comes from not using bind(C).

Without bind(C) Intel Fortran compiles the function to expect a pointer (to a copy of something). To make it expect a value, use both value and bind(C).