lib/btoc32.c

   1 /* Convert unibyte character to 32-bit wide character.
   2    Copyright (C) 2020 Free Software Foundation, Inc.
   3
   4    This program is free software: you can redistribute it and/or modify
   5    it under the terms of the GNU General Public License as published by
   6    the Free Software Foundation; either version 3 of the License, or
   7    (at your option) any later version.
   8
   9    This program is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12    GNU General Public License for more details.
  13
  14    You should have received a copy of the GNU General Public License
  15    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
  16
  17 /* Written by Bruno Haible <bruno@clisp.org>, 2020.  */
  18
  19 #include <config.h>
  20
  21 /* Specification.  */
  22 #include <uchar.h>
  23
  24 #include <stdio.h>
  25 #include <string.h>
  26
  27 wint_t
  28 btoc32 (int c)
  29 {
  30 #if HAVE_WORKING_MBRTOC32 && !defined __GLIBC__
  31   /* The char32_t encoding of a multibyte character may be different than its
  32      wchar_t encoding.  */
  33   if (c != EOF)
  34     {
  35       mbstate_t state;
  36       char s[1];
  37       char32_t wc;
  38
  39       memset (&state, '\0', sizeof (mbstate_t));
  40       s[0] = (unsigned char) c;
  41       if (mbrtoc32 (&wc, s, 1, &state) <= 1)
  42         return wc;
  43     }
  44   return WEOF;
  45 #else
  46   /* In all known locale encodings, unibyte characters correspond only to
  47      characters in the BMP.  */
  48   return btowc (c);
  49 #endif
  50 }