lib/unistr/u16-uctomb.c

   1 /* Store a character in UTF-16 string.
   2    Copyright (C) 2002, 2005-2006, 2009-2021 Free Software Foundation, Inc.
   3    Written by Bruno Haible <bruno@clisp.org>, 2002.
   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 #if defined IN_LIBUNISTRING
  21 /* Tell unistr.h to declare u16_uctomb as 'extern', not 'static inline'.  */
  22 # include "unistring-notinline.h"
  23 #endif
  24
  25 /* Specification.  */
  26 #include "unistr.h"
  27
  28 #if !HAVE_INLINE
  29
  30 int
  31 u16_uctomb (uint16_t *s, ucs4_t uc, ptrdiff_t n)
  32 {
  33   if (uc < 0xd800)
  34     {
  35       if (n > 0)
  36         {
  37           s[0] = uc;
  38           return 1;
  39         }
  40       /* else return -2, below.  */
  41     }
  42   else if (uc < 0x10000)
  43     {
  44       if (uc >= 0xe000)
  45         {
  46           if (n >= 1)
  47             {
  48               s[0] = uc;
  49               return 1;
  50             }
  51         }
  52       else
  53         return -1;
  54     }
  55   else
  56     {
  57       if (uc < 0x110000)
  58         {
  59           if (n >= 2)
  60             {
  61               s[0] = 0xd800 + ((uc - 0x10000) >> 10);
  62               s[1] = 0xdc00 + ((uc - 0x10000) & 0x3ff);
  63               return 2;
  64             }
  65         }
  66       else
  67         return -1;
  68     }
  69   return -2;
  70 }
  71
  72 #endif