Incorrect optimization for function__libc_message on C-SKY

[Mao Han <han_mao at c-sky dot com>]

Hi,

I've got some probelm with the optimization of __libc_message on C-SKY.
__libc_message show nothing when MALLOC_CHECK_=3 is set.

./include/stdio.h:101
enum __libc_message_action
{
  do_message    = 0,            /* Print message.  */
  do_abort      = 1 << 0,       /* Abort.  */
  do_backtrace  = 1 << 1        /* Backtrace.  */
};

sysdeps/posix/libc_fatal.c:175
if ((action & do_abort))
    {
      if ((action & do_backtrace))
        BEFORE_ABORT (do_abort, written, fd);

      /* Kill the application.  */
      abort ();

The type of action is enum __libc_message_action, the C-SKY compiler
think the action can not be both do_abort and do_backtrace at the
same time, this path is supposed to be inaccessible.

./sysdeps/unix/sysv/linux/libc_fatal.c:41
static void
backtrace_and_maps (int do_abort, bool written, int fd)
{
  if (do_abort > 1 && written)
    {
      void *addrs[64];
#define naddrs (sizeof (addrs) / sizeof (addrs[0]))
      int n = __backtrace (addrs, naddrs);

backtrace_and_maps is called with BEFORE_ABORT (do_abort, written, fd);
do_abort equals to 1, and the function also check do_abort > 1, so the
entire backtrace_and_maps is optimized.

Some one can explain the excepted logic here?

Thanks
Mao Han