scc

 1#if defined(FOO)
 2int a;
 3#elif !defined(FOO) && defined(BAR)
 4int b;
 5#elif !defined(FOO) && !defined(BAR)
 6int c;
 7#else
 8int d;
 9#endif
10
11int
12main(void)
13{
14	return c;
15}