1  /* Test for constant expressions: cases involving VLAs and typeof.  */
       2  /* Origin: Joseph Myers <joseph@codesourcery.com> */
       3  /* { dg-do compile } */
       4  /* { dg-options "-std=gnu99 -pedantic-errors" } */
       5  
       6  /* It appears address constants may contain casts to variably modified
       7     types.  Whether they should be permitted was discussed in
       8     <http://groups.google.com/group/comp.std.c/msg/923eee5ab690fd98>
       9     <LV7g2Vy3ARF$Ew9Q@romana.davros.org>; since static pointers to VLAs
      10     are definitely permitted within functions and may be initialized
      11     and such initialization involves implicit conversion to a variably
      12     modified type, allowing explicit casts seems appropriate.  Thus,
      13     GCC allows them as long as the "evaluated" size expressions do not
      14     contain the various operators not permitted to be evaluated in a
      15     constant expression, and as long as the result is genuinely
      16     constant (meaning that pointer arithmetic using the size of the VLA
      17     is generally not permitted).  */
      18  
      19  static int sa[100];
      20  
      21  int
      22  f (int m, int n)
      23  {
      24    static int (*a1)[n] = &sa;
      25    static int (*a2)[n] = (__typeof__(int (*)[n]))sa;
      26    static int (*a3)[n] = (__typeof__(int (*)[(int){m++}]))sa; /* { dg-error "constant" } */
      27    static int (*a4)[n] = (__typeof__((int (*)[n])sa))sa;
      28    static int (*a5)[n] = (__typeof__((int (*)[m++])sa))sa; /* { dg-error "constant" } */
      29    static int (*a6)[n] = (__typeof__((int (*)[100])(int (*)[m++])sa))sa;
      30    static int (*a7)[n] = (__typeof__((int (*)[n])sa + m++))sa; /* { dg-error "constant" } */
      31    return n;
      32  }