How to use macros to name unique variables?

main.c

#include <stdio.h>

#define TOKENPASTE2(x, y) x ## y
#define TOKENPASTE(x, y) TOKENPASTE2(x, y)
#define FOO TOKENPASTE(var_, __LINE__)
#define BAR __LINE__

void
main(void)
{
    int FOO = BAR; printf("hello world! %d %d\n", FOO, var_11);
    int FOO = BAR; printf("hello world! %d %d\n", FOO, var_12);
    int FOO = BAR; printf("hello world! %d %d\n", FOO, var_13);
}

// $ ( gcc -E main.c | egrep hello ); gcc -o main main.c && ./main
//     int var_11 = 11; printf("hello world! %d %d\n", var_11, var_11);
//     int var_12 = 12; printf("hello world! %d %d\n", var_12, var_12);
//     int var_13 = 13; printf("hello world! %d %d\n", var_13, var_13);
// hello world! 11 11
// hello world! 12 12
// hello world! 13 13