gistfile1.c

__fortify_function wchar_t *
__NTH (wcpcpy (wchar_t *__restrict __dest, const wchar_t *__restrict __src))
{
  if (__bos (__dest) != (size_t) -1)
    return __wcpcpy_chk (__dest, __src, __bos (__dest) / sizeof (wchar_t));
  return __wcpcpy_alias (__dest, __src);
}

gistfile2.c

/* Copy SRC to DEST, returning the address of the terminating L'\0' in
   DEST.  Check for overflows.  */
wchar_t *
__wcpcpy_chk (wchar_t *dest, const wchar_t *src, size_t destlen)
{
  wchar_t *wcp = (wchar_t *) dest - 1;
  wint_t c;
  const ptrdiff_t off = src - dest + 1;

  do
    {
      if (__builtin_expect (destlen-- == 0, 0))
  __chk_fail ();
      c = wcp[off];
      *++wcp = c;
    }
  while (c != L'\0');

  return wcp;
}