70 lines
2.3 KiB
C
70 lines
2.3 KiB
C
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/* Test for initial conversion state.
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Copyright (C) 2008-2023 Free Software Foundation, Inc.
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Written by Bruno Haible <bruno@clisp.org>, 2008.
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This file is free software: you can redistribute it and/or modify
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it under the terms of the GNU Lesser General Public License as
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published by the Free Software Foundation; either version 2.1 of the
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License, or (at your option) any later version.
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This file is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public License
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along with this program. If not, see <https://www.gnu.org/licenses/>. */
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#include <config.h>
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/* Specification. */
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#include <wchar.h>
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#if GNULIB_defined_mbstate_t
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/* Platforms that lack mbsinit() also lack mbrlen(), mbrtowc(), mbsrtowcs()
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and wcrtomb(), wcsrtombs().
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We assume that
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- sizeof (mbstate_t) >= 4,
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- only stateless encodings are supported (such as UTF-8 and EUC-JP, but
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not ISO-2022 variants),
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- for each encoding, the number of bytes for a wide character is <= 4.
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(This maximum is attained for UTF-8, GB18030, EUC-TW.)
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We define the meaning of mbstate_t as follows:
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- In mb -> wc direction, mbstate_t's first byte contains the number of
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buffered bytes (in the range 0..3), followed by up to 3 buffered bytes.
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See mbrtowc.c.
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- In wc -> mb direction, mbstate_t contains no information. In other
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words, it is always in the initial state. */
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static_assert (sizeof (mbstate_t) >= 4);
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int
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mbsinit (const mbstate_t *ps)
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{
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const char *pstate = (const char *)ps;
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return pstate == NULL || pstate[0] == 0;
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}
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#else
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int
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mbsinit (const mbstate_t *ps)
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{
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# if defined _WIN32 && !defined __CYGWIN__
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/* Native Windows. */
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/* MSVC defines 'mbstate_t' as an 8-byte struct; the first 4 bytes matter.
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On mingw, 'mbstate_t' is sometimes defined as 'int', sometimes defined as
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an 8-byte struct, of which the first 4 bytes matter. */
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return ps == NULL || *(const unsigned int *)ps == 0;
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# else
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/* Minix, HP-UX 11.00, Solaris 2.6, Interix, ... */
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/* Maybe this definition works, maybe not... */
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return ps == NULL || *(const char *)ps == 0;
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# endif
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}
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#endif
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