#define CFG_USED(type, name, stuff) \
        { .compFunc = compare_ ## type; /* */ },
#define CFG_UNUSED(type, name, stuff)   /* unused */

#define CFG_ADD(type, name, stuff)  CFG_USE_ ## type (type,name,stuff)

#ifdef USING_int
#define CFG_USE_int CFG_USED
#else
#define CFG_USE_int CFG_UNUSED
#endif

##</code><code>##

/tmp>cat testing.c
#include <stdio.h>
#include <stdlib.h>

static inline int compare_short(const void * a, const void * b)
{
        if (*(short *)a < *(short *)b) return -1;
        if (*(short *)a > *(short *)b) return 1;
        return 0;
}

static inline int compare_int(const void * a, const void * b)
{
        if (*(int *)a < *(int *)b) return -1;
        if (*(int *)a > *(int *)b) return 1;
        return 0;
}

static int foo[5]={47,11,0,8,15};

int main(int argc, char ** argv)
{
        qsort(foo,sizeof(foo)/sizeof(foo[0]),sizeof(foo[0]),&compare_int);
}

/tmp>CFLAGS="-Wall -pedantic" make testing
cc -Wall -pedantic    testing.c   -o testing

/tmp>cc --version
cc (GCC) 5.3.0
Copyright (C) 2015 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

/tmp>


##</code><code>##

static foo compare_foo(void *a, void *b) { return _inline_cmpfunc_foo(a, b); }

##</code><code>##

#define CFG_ADD(TYPE,NAME,STUFF) \
    static int compare_ ## NAME(const void * a, const void * b) \
    { \
        return _inline_cmpfunc_ ## TYPE(a,b); \
    }