gcc/testsuite/gcc.dg/pr25682.c

   1 /* PR c/25682 */
   2 /* { dg-do compile } */
   3 /* { dg-options "-ansi" } */
   4 /* { dg-require-effective-target alloca } */
   5 /* Test whether we don't ICE on questionable constructs where offsetof
   6    should have been used instead.  */
   7
   8 struct S
   9 {
  10   char a[4];
  11   int b;
  12 };
  13
  14 char c[(char *) &((struct S *) 0)->b - (char *) 0]; /* { dg-warning "variably modified" } */
  15 char d[(__UINTPTR_TYPE__) &((struct S *) 8)->b]; /* { dg-warning "variably modified" } */
  16 char e[sizeof (c) == __builtin_offsetof (struct S, b) ? 1 : -1];
  17 char f[sizeof (d) == __builtin_offsetof (struct S, b) + 8 ? 1 : -1];
  18
  19 extern void bar (char *, char *);
  20
  21 void
  22 foo (void)
  23 {
  24   char g[(char *) &((struct S *) 0)->b - (char *) 0];
  25   char h[(__UINTPTR_TYPE__) &((struct S *) 8)->b];
  26   char i[sizeof (g) == __builtin_offsetof (struct S, b) ? 1 : -1];
  27   char j[sizeof (h) == __builtin_offsetof (struct S, b) + 8 ? 1 : -1];
  28   bar (g, h);
  29 }