gcc/testsuite/gcc.dg/builtin-object-size-9.c

   1 /* { dg-do run } */
   2 /* { dg-options "-O2" } */
   3
   4 typedef __SIZE_TYPE__ size_t;
   5 extern void *malloc (size_t);
   6 extern void free (void *);
   7 extern void abort (void);
   8
   9 union U
  10 {
  11   struct S { int a; int b; } s;
  12   int t;
  13 };
  14
  15 struct T
  16 {
  17   int c;
  18   char d[1];
  19 };
  20
  21 int
  22 main (void)
  23 {
  24   union U *u = malloc (sizeof (struct S) + sizeof (struct T) + 6);
  25   struct T *t = (struct T *) (&u->s + 1);
  26   if (__builtin_object_size (t->d, 1)
  27       != sizeof (struct T) + 6 - __builtin_offsetof (struct T, d))
  28     abort ();
  29   free (u);
  30   return 0;
  31 }