jada.c

/* strtab.c */
#include <stdlib.h>
#include <stdio.h>

char *base = "";

#define STRING_ADDRESS(id) (base+id)
#define STRING_ID(address) (signed short)((address)-base)

signed short foo(void)
{
	char *c = "test";
	return STRING_ID(c);
}

signed short bar(void);

int main(void)
{
	char *a = "hello";
	char *b = "world";
	int id_a = STRING_ID(a);
	int id_b = STRING_ID(b);
	int id_c = foo();
	int id_d = bar();
	printf("string(%d)=%p (%s)\n", id_a, STRING_ADDRESS(id_a), STRING_ADDRESS(id_a));
	printf("string(%d)=%p (%s)\n", id_b, STRING_ADDRESS(id_b), STRING_ADDRESS(id_b));
	printf("string(%d)=%p (%s)\n", id_c, STRING_ADDRESS(id_c), STRING_ADDRESS(id_c));
	printf("string(%d)=%p (%s)\n", id_d, STRING_ADDRESS(id_d), STRING_ADDRESS(id_d));
	return 0;
}

/* bar.c */
extern char *base;

#define STRING_ADDRESS(id) (base+id)
#define STRING_ID(address) (signed short)((address)-base)

signed short bar(void)
{
	char *d = "barstring";
	return STRING_ID(d);
}

Can you explain what you would use this for?