root/maint/gnulib/lib/unistr/u16-mbtouc-unsafe.c

/* */

DEFINITIONS

1. u16_mbtouc_unsafe

   1 /* Look at first character in UTF-16 string.
   2    Copyright (C) 1999-2002, 2006-2007, 2009-2021 Free Software Foundation, Inc.
   3    Written by Bruno Haible <bruno@clisp.org>, 2001.
   4 
   5    This file is free software.
   6    It is dual-licensed under "the GNU LGPLv3+ or the GNU GPLv2+".
   7    You can redistribute it and/or modify it under either
   8      - the terms of the GNU Lesser General Public License as published
   9        by the Free Software Foundation; either version 3, or (at your
  10        option) any later version, or
  11      - the terms of the GNU General Public License as published by the
  12        Free Software Foundation; either version 2, or (at your option)
  13        any later version, or
  14      - the same dual license "the GNU LGPLv3+ or the GNU GPLv2+".
  15 
  16    This file is distributed in the hope that it will be useful,
  17    but WITHOUT ANY WARRANTY; without even the implied warranty of
  18    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  19    Lesser General Public License and the GNU General Public License
  20    for more details.
  21 
  22    You should have received a copy of the GNU Lesser General Public
  23    License and of the GNU General Public License along with this
  24    program.  If not, see <https://www.gnu.org/licenses/>.  */
  25 
  26 #include <config.h>
  27 
  28 #if defined IN_LIBUNISTRING
  29 /* Tell unistr.h to declare u16_mbtouc_unsafe as 'extern', not
  30    'static inline'.  */
  31 # include "unistring-notinline.h"
  32 #endif
  33 
  34 /* Specification.  */
  35 #include "unistr.h"
  36 
  37 #if !HAVE_INLINE
  38 
  39 int
  40 u16_mbtouc_unsafe (ucs4_t *puc, const uint16_t *s, size_t n)
     /*  */
  41 {
  42   uint16_t c = *s;
  43 
  44   if (c < 0xd800 || c >= 0xe000)
  45     {
  46       *puc = c;
  47       return 1;
  48     }
  49   if (c < 0xdc00)
  50     {
  51       if (n >= 2)
  52         {
  53           if (s[1] >= 0xdc00 && s[1] < 0xe000)
  54             {
  55               *puc = 0x10000 + ((c - 0xd800) << 10) + (s[1] - 0xdc00);
  56               return 2;
  57             }
  58           /* invalid multibyte character */
  59         }
  60       else
  61         {
  62           /* incomplete multibyte character */
  63         }
  64     }
  65   /* invalid multibyte character */
  66   *puc = 0xfffd;
  67   return 1;
  68 }
  69 
  70 #endif

/* */