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.  The use of the function simply
       4     being unevaluated is not enough.  */
       5  /* Origin: Joseph Myers <jsm@polyomino.org.uk> */
       6  /* { dg-do compile } */
       7  /* { dg-options "-O2 -std=iso9899:1999 -pedantic-errors" } */
       8  
       9  /* Constraint violation (trivial case, where function is used).  */
      10  static void f0(void); /* { dg-error "used but never defined" } */
      11  void g0(void) { f0(); }
      12  
      13  /* Constraint violation.  */
      14  static void f1(void); /* { dg-error "used but never defined" } */
      15  void g1(void) { if (0) { f1(); } }
      16  
      17  /* Constraint violation.  */
      18  static int f2(void); /* { dg-error "used but never defined" } */
      19  void g2(void) { 0 ? f2() : 0; }
      20  
      21  /* OK.  */
      22  static int f3(void);
      23  void g3(void) { sizeof(f3()); }
      24  
      25  /* OK (VM type, not VLA).  */
      26  static int f4(void);
      27  void g4(void) { sizeof(int (*)[f4()]); }
      28  
      29  /* Constraint violation (VLA).  */
      30  static int f5(void); /* { dg-error "used but never defined" "VLA" } */
      31  void g5(void) { sizeof(int [0 ? f5() : 1]); }
      32  
      33  /* OK (non-constant sizeof inside constant sizeof).  */
      34  static int f6(void);
      35  void g6(void) { sizeof(sizeof(int [f6()])); }