1  /* Test null pointer constants: typedefs for void should be OK but not
       2     qualified void.  */
       3  /* Origin: Joseph Myers <joseph@codesourcery.com> */
       4  /* { dg-do compile } */
       5  /* { dg-options "-std=iso9899:1990 -pedantic-errors" } */
       6  
       7  typedef void V;
       8  int *p;
       9  long *q;
      10  int j;
      11  void (*fp)(void);
      12  
      13  void
      14  f (void)
      15  {
      16    /* (V *)0 is a null pointer constant, so the assignment should be
      17       diagnosed.  */
      18    q = (j ? p : (V *)0); /* { dg-error "5:assignment to 'long int \\*' from incompatible pointer type 'int \\*'" } */
      19    q = (j ? p : (void *)0); /* { dg-error "5:assignment to 'long int \\*' from incompatible pointer type 'int \\*'" } */
      20    /* And this conversion should be valid.  */
      21    (void (*)(void))(V *)0;
      22    (void (*)(void))(void *)0;
      23    /* Pointers to qualified void are not valid null pointer
      24       constants.  */
      25    fp = (const void *)0; /* { dg-error "6:ISO C forbids assignment between function pointer and 'void \\*'" } */
      26    fp = (void *)0;
      27    fp = (V *)0;
      28    fp = 0;
      29    fp == 0;
      30    0 == fp;
      31    fp == (void *)0;
      32    (void *)0 == fp;
      33    fp == (V *)0;
      34    (V *)0 == fp;
      35    fp == (V *)1; /* { dg-error "6:ISO C forbids comparison of 'void \\*' with function pointer" } */
      36    (V *)1 == fp; /* { dg-error "10:ISO C forbids comparison of 'void \\*' with function pointer" } */
      37    fp == (const void *)0; /* { dg-error "6:ISO C forbids comparison of 'void \\*' with function pointer" } */
      38    (const void *)0 == fp; /* { dg-error "19:ISO C forbids comparison of 'void \\*' with function pointer" } */
      39  }