lib/unistr/u16-mbtouc-unsafe-aux.c

   1 /* Conversion UTF-16 to UCS-4.
   2    Copyright (C) 2001-2002, 2006-2007, 2009-2021 Free Software Foundation, Inc.
   3    Written by Bruno Haible <bruno@clisp.org>, 2001.
   4
   5    This program is free software: you can redistribute it and/or modify it
   6    under the terms of the GNU Lesser General Public License as published
   7    by the Free Software Foundation; either version 3 of the License, or
   8    (at your option) any later version.
   9
  10    This program is distributed in the hope that it will be useful,
  11    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 License
  16    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
  17
  18 #include <config.h>
  19
  20 /* Specification.  */
  21 #include "unistr.h"
  22
  23 #if defined IN_LIBUNISTRING || HAVE_INLINE
  24
  25 int
  26 u16_mbtouc_unsafe_aux (ucs4_t *puc, const uint16_t *s, size_t n)
  27 {
  28   uint16_t c = *s;
  29
  30   if (c < 0xdc00)
  31     {
  32       if (n >= 2)
  33         {
  34           if (s[1] >= 0xdc00 && s[1] < 0xe000)
  35             {
  36               *puc = 0x10000 + ((c - 0xd800) << 10) + (s[1] - 0xdc00);
  37               return 2;
  38             }
  39           /* invalid multibyte character */
  40         }
  41       else
  42         {
  43           /* incomplete multibyte character */
  44         }
  45     }
  46   /* invalid multibyte character */
  47   *puc = 0xfffd;
  48   return 1;
  49 }
  50
  51 #endif