Calling a VS2019 C++ function from Intel Fortran

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C++

FORTAN

I've tried to build a project inside VS2019 IDE, where I call from a routine C++ a routine Intel Fortran passing some structures and inside the routine Intel Fortran I call a routine C++, but I've some problems in linking because the link does not recognize the routine called by C++ module. Previously I've been able to call the routine Fortran from the routine C++ and passing some structs without any error.
In particular I've got the following error:
Severity Code Description Project File Line Suppression State
Error error LNK2019: unresolved external symbol _Gprintf referenced in function _ADD1 Source1.obj

Thanks awfully in advance for your support.

What I have tried:

C++ code:

#include <iostream>

extern "C" {
    typedef struct
    {
        short int   nstream;
        short int   nunit;
        short int   ncomp;
    }  GENERALtype;
    typedef struct
    {
        float tau;
    } PItype;
}
extern "C" {
    __declspec(dllexport) void ADD1(GENERALtype* general, PItype* pi);
}

extern "C" {
    void Gprintf(short int msgcod, char *text) {
        printf("%d - %s\n", msgcod, text);
    }
}

int main()
{
    GENERALtype GENERAL;
    PItype PI;
    PI.tau = 2;
    ADD1(&GENERAL,&PI);
    
    std::cout << GENERAL.nstream;
    std::cout << GENERAL.nunit;
    std::cout << GENERAL.ncomp;
    std::cout << PI.tau;
}

Fortran Module containing the data exchanged with C++ by Fortran routine called by C++ (ADD1)

module extdata
    use, intrinsic :: iso_c_binding
    implicit none
    TYPE, BIND(C) :: GENERALtype
         INTEGER(C_SHORT) :: nstream, nunit, ncomp
    END TYPE GENERALtype
    TYPE, BIND(C) :: PItype
         REAL(C_FLOAT) :: tau
    END TYPE PItype
end module extdata

Fortran Module containg the routine ADD1 and the interface of C++ routine called by ADD1:

module FortranSub
          use, intrinsic :: iso_c_binding,only : C_SHORT, C_CHAR, 
     *    C_NULL_CHAR
          implicit none
          interface
          subroutine Gprintf(codemsg, string) 
     *     bind(C, name ='Gprintf')
           use, intrinsic :: iso_c_binding,only : C_SHORT, C_CHAR
              implicit none
              integer(C_SHORT), intent(in) :: codemsg
              character(KIND=C_CHAR), intent(in) :: string(*)
           end subroutine Gprintf
          end interface 
      contains    
          subroutine ADD1(GENERAL,PI) bind(C,name="ADD1")
          !DEC$ ATTRIBUTES DLLEXPORT :: ADD1
          use, intrinsic :: iso_c_binding
          use extdata
          TYPE (GENERALtype) GENERAL
          TYPE (PItype) PI
*          
          GENERAL%nstream=5
          GENERAL%nunit=1
          GENERAL%ncomp=3          
          PI%tau = 3.14159*PI%tau
          call Gprintf(69,C_CHAR_"Passaggio Stringa"//C_NULL_CHAR)
          return
          end subroutine
      end module FortranSub