gcc/testsuite/gcc.dg/nrv1.c

   1 /* Test that the NRV optimization doesn't cause a1 to change too soon.  This
   2    is equivalent to c++/19317.  */
   3 /* { dg-do run } */
   4
   5 void abort (void);
   6
   7 struct A
   8 {
   9   int i[100];
  10 };
  11
  12 struct A a1;
  13
  14 struct A f ()
  15 {
  16   struct A a2;
  17   a2.i[0] = 42;
  18   /* a1.i[0] should still be 0 until we return. */
  19   if (a1.i[0] != 0)
  20     abort ();
  21   return a2;
  22 }
  23
  24 int main()
  25 {
  26   a1 = f();
  27   return 0;
  28 }