lib/ucs2swapped.h

   1 /*
   2  * Copyright (C) 1999-2001, 2016 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 Lesser General Public
   7  * License as published by the Free Software Foundation; either version 2.1
   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  * Lesser General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU Lesser General Public
  16  * License along with the GNU LIBICONV Library; see the file COPYING.LIB.
  17  * If not, see <https://www.gnu.org/licenses/>.
  18  */
  19
  20 /*
  21  * UCS-2-SWAPPED = UCS-2-INTERNAL with inverted endianness
  22  */
  23
  24 static int
  25 ucs2swapped_mbtowc (conv_t conv, ucs4_t *pwc, const unsigned char *s, size_t n)
  26 {
  27   /* This function assumes that 'unsigned short' has exactly 16 bits. */
  28   if (sizeof(unsigned short) != 2) abort();
  29
  30   if (n >= 2) {
  31     unsigned short x = *(const unsigned short *)s;
  32     x = (x >> 8) | (x << 8);
  33     if (x >= 0xd800 && x < 0xe000) {
  34       return RET_ILSEQ;
  35     } else {
  36       *pwc = x;
  37       return 2;
  38     }
  39   }
  40   return RET_TOOFEW(0);
  41 }
  42
  43 static int
  44 ucs2swapped_wctomb (conv_t conv, unsigned char *r, ucs4_t wc, size_t n)
  45 {
  46   /* This function assumes that 'unsigned short' has exactly 16 bits. */
  47   if (sizeof(unsigned short) != 2) abort();
  48
  49   if (wc < 0x10000 && !(wc >= 0xd800 && wc < 0xe000)) {
  50     if (n >= 2) {
  51       unsigned short x = wc;
  52       x = (x >> 8) | (x << 8);
  53       *(unsigned short *)r = x;
  54       return 2;
  55     } else
  56       return RET_TOOSMALL;
  57   } else
  58     return RET_ILUNI;
  59 }