u-tools/apps/tar/gnu/mbsinit.c

   1 /* -*- buffer-read-only: t -*- vi: set ro: */
   2 /* DO NOT EDIT! GENERATED AUTOMATICALLY! */
   3 /* Test for initial conversion state.
   4    Copyright (C) 2008-2011 Free Software Foundation, Inc.
   5    Written by Bruno Haible <bruno@clisp.org>, 2008.
   6
   7    This program is free software: you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  19
  20 #include <config.h>
  21
  22 /* Specification.  */
  23 #include <wchar.h>
  24
  25 #include "verify.h"
  26
  27 #if (defined _WIN32 || defined __WIN32__) && !defined __CYGWIN__
  28
  29 /* On native Windows, 'mbstate_t' is defined as 'int'.  */
  30
  31 int
  32 mbsinit (const mbstate_t *ps)
  33 {
  34   return ps == NULL || *ps == 0;
  35 }
  36
  37 #else
  38
  39 /* Platforms that lack mbsinit() also lack mbrlen(), mbrtowc(), mbsrtowcs()
  40    and wcrtomb(), wcsrtombs().
  41    We assume that
  42      - sizeof (mbstate_t) >= 4,
  43      - only stateless encodings are supported (such as UTF-8 and EUC-JP, but
  44        not ISO-2022 variants),
  45      - for each encoding, the number of bytes for a wide character is <= 4.
  46        (This maximum is attained for UTF-8, GB18030, EUC-TW.)
  47    We define the meaning of mbstate_t as follows:
  48      - In mb -> wc direction, mbstate_t's first byte contains the number of
  49        buffered bytes (in the range 0..3), followed by up to 3 buffered bytes.
  50      - In wc -> mb direction, mbstate_t contains no information. In other
  51        words, it is always in the initial state.  */
  52
  53 verify (sizeof (mbstate_t) >= 4);
  54
  55 int
  56 mbsinit (const mbstate_t *ps)
  57 {
  58   const char *pstate = (const char *)ps;
  59
  60   return pstate == NULL || pstate[0] == 0;
  61 }
  62
  63 #endif