gcc/testsuite/gcc.c-torture/execute/20000917-1.c

   1 /* This bug exists in gcc-2.95, egcs-1.1.2, gcc-2.7.2 and probably
   2    every other version as well.  */
   3
   4 typedef struct int3 { int a, b, c; } int3;
   5
   6 int3
   7 one (void)
   8 {
   9   return (int3) { 1, 1, 1 };
  10 }
  11
  12 int3
  13 zero (void)
  14 {
  15   return (int3) { 0, 0, 0 };
  16 }
  17
  18 int
  19 main (void)
  20 {
  21   int3 a;
  22
  23   /* gcc allocates a temporary for the inner expression statement
  24      to store the return value of `one'.
  25
  26      gcc frees the temporaries for the inner expression statement.
  27
  28      gcc realloates the same temporary slot to store the return
  29      value of `zero'.
  30
  31      gcc expands the call to zero ahead of the expansion of the
  32      statement expressions.  The temporary gets the value of `zero'.
  33
  34      gcc expands statement expressions and the stale temporary is
  35      clobbered with the value of `one'.  The bad value is copied from
  36      the temporary into *&a.  */
  37
  38   *({ ({ one (); &a; }); }) = zero ();
  39   if (a.a && a.b && a.c)
  40     abort ();
  41   exit (0);
  42 }