modernc.org/ccgo/v3@v3.16.14/lib/testdata/gcc-9.1.0/gcc/testsuite/gcc.c-torture/execute/frame-address.c (about)

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