1 int check_fa_work (const char *, const char *) __attribute__((noinline));
2 int check_fa_mid (const char *) __attribute__((noinline));
3 int check_fa (char *) __attribute__((noinline));
4 int how_much (void) __attribute__((noinline));
5 
check_fa_work(const char * c,const char * f)6 int check_fa_work (const char *c, const char *f)
7 {
8   const char d = 0;
9 
10   if (c >= &d)
11     return c >= f && f >= &d;
12   else
13     return c <= f && f <= &d;
14 }
15 
check_fa_mid(const char * c)16 int check_fa_mid (const char *c)
17 {
18   const char *f = __builtin_frame_address (0);
19 
20   /* Prevent a tail call to check_fa_work, eliding the current stack frame.  */
21   return check_fa_work (c, f) != 0;
22 }
23 
check_fa(char * unused)24 int check_fa (char *unused)
25 {
26   const char c = 0;
27 
28   /* Prevent a tail call to check_fa_mid, eliding the current stack frame.  */
29   return check_fa_mid (&c) != 0;
30 }
31 
how_much(void)32 int how_much (void)
33 {
34 	return 8;
35 }
36 
main(void)37 int main (void)
38 {
39   char *unused = __builtin_alloca (how_much ());
40 
41   if (!check_fa(unused))
42     abort();
43   return 0;
44 }
45