c-preprocessor/_test/inputs/test25.in

#define VAR0 1
#define TEST_IF 5

int main() {
#if 0
    printf("No\n");
#elif 0
    printf("Maybe\n");
#elif VAR0
    printf("ABC\n");
#else
    printf("Yes\n");
#endif

#if TEST_IF
    printf("#defines working in #ifs\n");
#endif

    int y = VAR0 + 1;
    printf("%d\n", VAR0);

    return 0;
}