1  /* Test C2x noreturn attribute: valid uses.  */
       2  /* { dg-do compile } */
       3  /* { dg-options "-std=c2x -pedantic-errors" } */
       4  
       5  [[noreturn]] void exit (int);
       6  
       7  [[__noreturn__]] int f1 (void);
       8  
       9  [[_Noreturn]] void f2 (void);
      10  
      11  [[___Noreturn__]] static void f3 (void) { exit (0); }
      12  
      13  /* Returning from a noreturn function is undefined at runtime, not a
      14     constraint violation, but recommended practice is to diagnose if
      15     such a return appears possible.  */
      16  
      17  [[noreturn]] int
      18  f4 (void)
      19  {
      20    return 1; /* { dg-warning "has a 'return' statement" } */
      21    /* { dg-warning "does return" "second warning" { target *-*-* } .-1 } */
      22  }
      23  
      24  [[__noreturn__]] void
      25  f5 (void)
      26  {
      27    return; /* { dg-warning "has a 'return' statement" } */
      28    /* { dg-warning "does return" "second warning" { target *-*-* } .-1 } */
      29  }
      30  
      31  [[_Noreturn]] void
      32  f6 (void)
      33  {
      34  } /* { dg-warning "does return" } */
      35  
      36  [[___Noreturn__]] void
      37  f7 (int a)
      38  {
      39    if (a)
      40      exit (0);
      41  } /* { dg-warning "does return" } */
      42  
      43  /* Declarations need not all have the attribute (buf if the first does not,
      44     there is undefined behavior).  */
      45  
      46  void f2 (void);
      47  
      48  /* Duplicate attribute, and use with _Noreturn, is OK.  */
      49  [[noreturn]] [[noreturn]] [[noreturn, __noreturn__]] void _Noreturn f9 (void);
      50  
      51  /* The attribute does not affect type compatibility.  */
      52  
      53  void (*fp) (void) = f5;
      54  
      55  /* Unlike the function specifier, the attribute may be used on main.  */
      56  [[noreturn]] int main ();