Passing parameters to a C function

Hello,

I have a question about passing parameters to a C function. Imagine the
example by PostgreSQL:

PG_FUNCTION_INFO_V1(complex_add);

Datum

complex_add(PG_FUNCTION_ARGS)

{

Complex *a = (Complex *) PG_GETARG_POINTER(0);

Complex *b = (Complex *) PG_GETARG_POINTER(1);

Complex *result;

result = (Complex *) palloc(sizeof(Complex));

result->x = a->x + b->x;

result->y = a->y + b->y;

PG_RETURN_POINTER(result);

}

So, in the same .C file I have to write another function that calls this
one, for example:

void

test_main()

{

Complex *a;

Complex *b;

a = complex_in("(4.01, 3.77 )");

printf("a = %s\n", complex_out(a));

b = complex_in("(1.0,2.0)");

printf("b = %s\n", complex_out(b));

printf("a + b = %s\n", complex_out(complex_add(a,b)));

}

But using version 1 calling convention it won't work! So, how can I pass the
'a' and 'b' variables in complex_add(?, ?)?

Thanks in advance!