1  /* It is a constraint violation for a static function to be declared
       2     but not defined if it is used except in a sizeof expression whose
       3     result is an integer constant.  In GNU C, we need to consider
       4     __typeof__ and __alignof__ as well.  __alignof__ always returns a
       5     constant, so static functions can always be used therein.
       6     __typeof__ evaluates its argument iff it has variably modified
       7     type.  */
       8  /* Origin: Joseph Myers <jsm@polyomino.org.uk> */
       9  /* { dg-do compile } */
      10  /* { dg-options "-O2 -std=gnu99 -pedantic-errors" } */
      11  
      12  /* __alignof__, OK.  */
      13  static int f0(void); 
      14  void g0(void) { __alignof__(f0()); }
      15  
      16  /* __typeof__ not variably modified, OK.  */
      17  static int f1(void);
      18  void g1(void) { __typeof__(f1()) x; }
      19  
      20  /* __typeof__ variably modified, not OK.  */
      21  static int f2(void); /* { dg-error "used but never defined" } */
      22  void g2(void) { __typeof__(int [f2()]) x; }
      23  
      24  /* __typeof__ variably modified, not OK.  */
      25  static int f3(void); /* { dg-error "used but never defined" } */
      26  void g3(void) { __typeof__(int (*)[f3()]) x; }
      27  
      28  /* Integer sizeof of VM typeof, OK.  */
      29  static int f4(void);
      30  void g4(void) { sizeof(__typeof__(int (*)[f3()])); }