Composite problem when calling Fortran from C/C++

[amarantha]

I'm trying to call a function written on Fortran from the C code. But I'm getting a "undefined reference"

Example of function on Fortran in the file fort. f90:

FUNCTION CULC(A,B) RESULT(SUM) BIND(C,name='CULC99')
REAL A,B,SUM
SUM = A + B
RETURN
END

Basic code C, hello.c

#include <stdio.h>
extern float CULC99(float *a, float *b);
int main() {

float a = 10; float b = 10;

float c;

c = CULC99(&a,&b);

printf("%f", a);

return 0;

}

Windows computer gfortran and g++ Cygwin64 (resolving problems with missing libraries)

Checking the name of the function in an objective file with objdump, the name matches:

I don't understand what's missing.

I've been trying to do the same thing (because of another objective file) for pure C, everything's gonna be perfect.

[Marcee]

How did you notice @user7860670?

C and C+ should not be confused

The problem is, I've confused the gcc and g++ compilers.

After addition extern "C" The g+++ compiler found the functions to be performed.

Maybe the gcc can handle the subset when used. externbut I couldn't check it out, because I had to connect the missing libraries, and I don't have the strength to do it after 3 days of war with the companion.