lib/utf16le.h

   1 /*
   2  * Copyright (C) 1999-2001, 2008, 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  * UTF-16LE
  22  */
  23
  24 /* Specification: RFC 2781 */
  25
  26 static int
  27 utf16le_mbtowc (conv_t conv, ucs4_t *pwc, const unsigned char *s, size_t n)
  28 {
  29   int count = 0;
  30   if (n >= 2) {
  31     ucs4_t wc = s[0] + (s[1] << 8);
  32     if (wc >= 0xd800 && wc < 0xdc00) {
  33       if (n >= 4) {
  34         ucs4_t wc2 = s[2] + (s[3] << 8);
  35         if (!(wc2 >= 0xdc00 && wc2 < 0xe000))
  36           goto ilseq;
  37         *pwc = 0x10000 + ((wc - 0xd800) << 10) + (wc2 - 0xdc00);
  38         return count+4;
  39       }
  40     } else if (wc >= 0xdc00 && wc < 0xe000) {
  41       goto ilseq;
  42     } else {
  43       *pwc = wc;
  44       return count+2;
  45     }
  46   }
  47   return RET_TOOFEW(count);
  48
  49 ilseq:
  50   return RET_SHIFT_ILSEQ(count);
  51 }
  52
  53 static int
  54 utf16le_wctomb (conv_t conv, unsigned char *r, ucs4_t wc, size_t n)
  55 {
  56   if (!(wc >= 0xd800 && wc < 0xe000)) {
  57     if (wc < 0x10000) {
  58       if (n >= 2) {
  59         r[0] = (unsigned char) wc;
  60         r[1] = (unsigned char) (wc >> 8);
  61         return 2;
  62       } else
  63         return RET_TOOSMALL;
  64     }
  65     else if (wc < 0x110000) {
  66       if (n >= 4) {
  67         ucs4_t wc1 = 0xd800 + ((wc - 0x10000) >> 10);
  68         ucs4_t wc2 = 0xdc00 + ((wc - 0x10000) & 0x3ff);
  69         r[0] = (unsigned char) wc1;
  70         r[1] = (unsigned char) (wc1 >> 8);
  71         r[2] = (unsigned char) wc2;
  72         r[3] = (unsigned char) (wc2 >> 8);
  73         return 4;
  74       } else
  75         return RET_TOOSMALL;
  76     }
  77   }
  78   return RET_ILUNI;
  79 }