lib/ucs2swapped.h

   1 /*
   2  * Copyright (C) 1999-2000 Free Software Foundation, Inc.
   3  * This file is part of the GNU LIBICONV Library.
   4  *
   5  * The GNU LIBICONV Library is free software; you can redistribute it
   6  * and/or modify it under the terms of the GNU Library General Public
   7  * License as published by the Free Software Foundation; either version 2
   8  * of the License, or (at your option) any later version.
   9  *
  10  * The GNU LIBICONV Library is distributed in the hope that it will be
  11  * useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * Library General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU Library General Public
  16  * License along with the GNU LIBICONV Library; see the file COPYING.LIB.
  17  * If not, write to the Free Software Foundation, Inc., 59 Temple Place -
  18  * Suite 330, Boston, MA 02111-1307, USA.
  19  */
  20
  21 /*
  22  * UCS-2-SWAPPED = UCS-2-INTERNAL with inverted endianness
  23  */
  24
  25 static int
  26 ucs2swapped_mbtowc (conv_t conv, ucs4_t *pwc, const unsigned char *s, int n)
  27 {
  28   /* This function assumes that 'unsigned short' has exactly 16 bits. */
  29   if (sizeof(unsigned short) != 2) abort();
  30
  31   if (n >= 2) {
  32     unsigned short x = *(const unsigned short *)s;
  33     x = (x >> 8) | (x << 8);
  34     if (x >= 0xd800 && x < 0xe000) {
  35       return RET_ILSEQ;
  36     } else {
  37       *pwc = x;
  38       return 2;
  39     }
  40   }
  41   return RET_TOOFEW(0);
  42 }
  43
  44 static int
  45 ucs2swapped_wctomb (conv_t conv, unsigned char *r, ucs4_t wc, int n)
  46 {
  47   /* This function assumes that 'unsigned short' has exactly 16 bits. */
  48   if (sizeof(unsigned short) != 2) abort();
  49
  50   if (wc < 0x10000 && !(wc >= 0xd800 && wc < 0xe000)) {
  51     if (n >= 2) {
  52       unsigned short x = wc;
  53       x = (x >> 8) | (x << 8);
  54       *(unsigned short *)r = x;
  55       return 2;
  56     } else
  57       return RET_TOOSMALL;
  58   } else
  59     return RET_ILSEQ;
  60 }