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 void abort (void);
   5 void exit (int);
   6
   7 typedef struct int3 { int a, b, c; } int3;
   8
   9 int3
  10 one (void)
  11 {
  12   return (int3) { 1, 1, 1 };
  13 }
  14
  15 int3
  16 zero (void)
  17 {
  18   return (int3) { 0, 0, 0 };
  19 }
  20
  21 int
  22 main (void)
  23 {
  24   int3 a;
  25
  26   /* gcc allocates a temporary for the inner expression statement
  27      to store the return value of `one'.
  28
  29      gcc frees the temporaries for the inner expression statement.
  30
  31      gcc realloates the same temporary slot to store the return
  32      value of `zero'.
  33
  34      gcc expands the call to zero ahead of the expansion of the
  35      statement expressions.  The temporary gets the value of `zero'.
  36
  37      gcc expands statement expressions and the stale temporary is
  38      clobbered with the value of `one'.  The bad value is copied from
  39      the temporary into *&a.  */
  40
  41   *({ ({ one (); &a; }); }) = zero ();
  42   if (a.a && a.b && a.c)
  43     abort ();
  44   exit (0);
  45 }