Function internal_function

compat/regex/regex_internal.c:209–272

   Note that this function assumes PSTR->VALID_LEN elements are already
   built and starts from PSTR->VALID_LEN.  */

static void
internal_function
build_wcs_buffer (re_string_t *pstr)
{
#ifdef _LIBC
  unsigned char buf[MB_LEN_MAX];
  assert (MB_LEN_MAX >= pstr->mb_cur_max);
#else
  unsigned char buf[64];
#endif
  mbstate_t prev_st;
  int byte_idx, end_idx, remain_len;
  size_t mbclen;

  /* Build the buffers from pstr->valid_len to either pstr->len or
     pstr->bufs_len.  */
  end_idx = (pstr->bufs_len > pstr->len) ? pstr->len : pstr->bufs_len;
  for (byte_idx = pstr->valid_len; byte_idx < end_idx;)
    {
      wchar_t wc;
      const char *p;

      remain_len = end_idx - byte_idx;
      prev_st = pstr->cur_state;
      /* Apply the translation if we need.  */
      if (BE (pstr->trans != NULL, 0))
	{
	  int i, ch;

	  for (i = 0; i < pstr->mb_cur_max && i < remain_len; ++i)
	    {
	      ch = pstr->raw_mbs [pstr->raw_mbs_idx + byte_idx + i];
	      buf[i] = pstr->mbs[byte_idx + i] = pstr->trans[ch];
	    }
	  p = (const char *) buf;
	}
      else
	p = (const char *) pstr->raw_mbs + pstr->raw_mbs_idx + byte_idx;
      mbclen = __mbrtowc (&wc, p, remain_len, &pstr->cur_state);
      if (BE (mbclen == (size_t) -2, 0))
	{
	  /* The buffer doesn't have enough space, finish to build.  */
	  pstr->cur_state = prev_st;
	  break;
	}
      else if (BE (mbclen == (size_t) -1 || mbclen == 0, 0))
	{
	  /* We treat these cases as a singlebyte character.  */
	  mbclen = 1;
	  wc = (wchar_t) pstr->raw_mbs[pstr->raw_mbs_idx + byte_idx];
	  if (BE (pstr->trans != NULL, 0))
	    wc = pstr->trans[wc];
	  pstr->cur_state = prev_st;
	}

      /* Write wide character and padding.  */
      pstr->wcs[byte_idx++] = wc;