gcc/testsuite/gcc.dg/pr25682.c

   1 /* PR c/25682 */
   2 /* { dg-do compile } */
   3 /* { dg-options "-ansi" } */
   4 /* Test whether we don't ICE on questionable constructs where offsetof
   5    should have been used instead.  */
   6
   7 struct S
   8 {
   9   char a[4];
  10   int b;
  11 };
  12
  13 char c[(char *) &((struct S *) 0)->b - (char *) 0]; /* { dg-warning "variably modified" } */
  14 char d[(__UINTPTR_TYPE__) &((struct S *) 8)->b]; /* { dg-warning "variably modified" } */
  15 char e[sizeof (c) == __builtin_offsetof (struct S, b) ? 1 : -1];
  16 char f[sizeof (d) == __builtin_offsetof (struct S, b) + 8 ? 1 : -1];
  17
  18 extern void bar (char *, char *);
  19
  20 void
  21 foo (void)
  22 {
  23   char g[(char *) &((struct S *) 0)->b - (char *) 0];
  24   char h[(__UINTPTR_TYPE__) &((struct S *) 8)->b];
  25   char i[sizeof (g) == __builtin_offsetof (struct S, b) ? 1 : -1];
  26   char j[sizeof (h) == __builtin_offsetof (struct S, b) + 8 ? 1 : -1];
  27   bar (g, h);
  28 }