root/lib/libiconv_modules/EUC/citrus_euc.c
/*      $NetBSD: citrus_euc.c,v 1.14 2009/01/11 02:46:24 christos Exp $ */

/*-
 * Copyright (c)2002 Citrus Project,
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Paul Borman at Krystal Technologies.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/types.h>

#include <assert.h>
#include <errno.h>
#include <limits.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <wchar.h>

#include "citrus_namespace.h"
#include "citrus_bcs.h"
#include "citrus_types.h"
#include "citrus_module.h"
#include "citrus_stdenc.h"
#include "citrus_euc.h"


/* ----------------------------------------------------------------------
 * private stuffs used by templates
 */

typedef struct {
        int      chlen;
        char     ch[3];
} _EUCState;

typedef struct {
        wchar_t          bits[4];
        wchar_t          mask;
        unsigned         count[4];
        unsigned         mb_cur_max;
} _EUCEncodingInfo;

#define _SS2    0x008e
#define _SS3    0x008f

#define _CEI_TO_EI(_cei_)               (&(_cei_)->ei)
#define _CEI_TO_STATE(_cei_, _func_)    (_cei_)->states.s_##_func_

#define _FUNCNAME(m)                    _citrus_EUC_##m
#define _ENCODING_INFO                  _EUCEncodingInfo
#define _ENCODING_STATE                 _EUCState
#define _ENCODING_MB_CUR_MAX(_ei_)      (_ei_)->mb_cur_max
#define _ENCODING_IS_STATE_DEPENDENT    0
#define _STATE_NEEDS_EXPLICIT_INIT(_ps_)        0


static __inline int
_citrus_EUC_cs(unsigned int c)
{

        c &= 0xff;

        return ((c & 0x80) ? c == _SS3 ? 3 : c == _SS2 ? 2 : 1 : 0);
}

static __inline int
_citrus_EUC_parse_variable(_EUCEncodingInfo *ei, const void *var,
    size_t lenvar __unused)
{
        char *e;
        const char *v;
        int x;

        /* parse variable string */
        if (!var)
                return (EFTYPE);

        v = (const char *)var;

        while (*v == ' ' || *v == '\t')
                ++v;

        ei->mb_cur_max = 1;
        for (x = 0; x < 4; ++x) {
                ei->count[x] = (int)_bcs_strtol(v, (char **)&e, 0);
                if (v == e || !(v = e) || ei->count[x] < 1 || ei->count[x] > 4) {
                        return (EFTYPE);
                }
                if (ei->mb_cur_max < ei->count[x])
                        ei->mb_cur_max = ei->count[x];
                while (*v == ' ' || *v == '\t')
                        ++v;
                ei->bits[x] = (int)_bcs_strtol(v, (char **)&e, 0);
                if (v == e || !(v = e)) {
                        return (EFTYPE);
                }
                while (*v == ' ' || *v == '\t')
                        ++v;
        }
        ei->mask = (int)_bcs_strtol(v, (char **)&e, 0);
        if (v == e || !(v = e)) {
                return (EFTYPE);
        }

        return (0);
}


static __inline void
/*ARGSUSED*/
_citrus_EUC_init_state(_EUCEncodingInfo *ei __unused, _EUCState *s)
{

        memset(s, 0, sizeof(*s));
}

#if 0
static __inline void
/*ARGSUSED*/
_citrus_EUC_pack_state(_EUCEncodingInfo *ei __unused, void *pspriv,
    const _EUCState *s)
{

        memcpy(pspriv, (const void *)s, sizeof(*s));
}

static __inline void
/*ARGSUSED*/
_citrus_EUC_unpack_state(_EUCEncodingInfo *ei __unused, _EUCState *s,
    const void *pspriv)
{

        memcpy((void *)s, pspriv, sizeof(*s));
}
#endif

static int
_citrus_EUC_mbrtowc_priv(_EUCEncodingInfo *ei, wchar_t *pwc, char **s,
    size_t n, _EUCState *psenc, size_t *nresult)
{
        wchar_t wchar;
        int c, chlenbak, cs, len;
        char *s0, *s1 = NULL;

        s0 = *s;

        if (s0 == NULL) {
                _citrus_EUC_init_state(ei, psenc);
                *nresult = 0; /* state independent */
                return (0);
        }

        chlenbak = psenc->chlen;

        /* make sure we have the first byte in the buffer */
        switch (psenc->chlen) {
        case 0:
                if (n < 1)
                        goto restart;
                psenc->ch[0] = *s0++;
                psenc->chlen = 1;
                n--;
                break;
        case 1:
        case 2:
                break;
        default:
                /* illgeal state */
                goto encoding_error;
        }

        c = ei->count[cs = _citrus_EUC_cs(psenc->ch[0] & 0xff)];
        if (c == 0)
                goto encoding_error;
        while (psenc->chlen < c) {
                if (n < 1)
                        goto restart;
                psenc->ch[psenc->chlen] = *s0++;
                psenc->chlen++;
                n--;
        }
        *s = s0;

        switch (cs) {
        case 3:
        case 2:
                /* skip SS2/SS3 */
                len = c - 1;
                s1 = &psenc->ch[1];
                break;
        case 1:
        case 0:
                len = c;
                s1 = &psenc->ch[0];
                break;
        default:
                goto encoding_error;
        }
        wchar = 0;
        while (len-- > 0)
                wchar = (wchar << 8) | (*s1++ & 0xff);
        wchar = (wchar & ~ei->mask) | ei->bits[cs];

        psenc->chlen = 0;
        if (pwc)
                *pwc = wchar;
        *nresult = wchar ? (size_t)(c - chlenbak) : 0;
        return (0);

encoding_error:
        psenc->chlen = 0;
        *nresult = (size_t)-1;
        return (EILSEQ);

restart:
        *nresult = (size_t)-2;
        *s = s0;
        return (0);
}

static int
_citrus_EUC_wcrtomb_priv(_EUCEncodingInfo *ei, char *s, size_t n, wchar_t wc,
    _EUCState *psenc __unused, size_t *nresult)
{
        wchar_t m, nm;
        unsigned int cs;
        int ret;
        short i;

        m = wc & ei->mask;
        nm = wc & ~m;

        for (cs = 0; cs < sizeof(ei->count) / sizeof(ei->count[0]); cs++)
                if (m == ei->bits[cs])
                        break;
        /* fallback case - not sure if it is necessary */
        if (cs == sizeof(ei->count) / sizeof(ei->count[0]))
                cs = 1;

        i = ei->count[cs];
        if (n < (unsigned)i) {
                ret = E2BIG;
                goto err;
        }
        m = (cs) ? 0x80 : 0x00;
        switch (cs) {
        case 2:
                *s++ = _SS2;
                i--;
                break;
        case 3:
                *s++ = _SS3;
                i--;
                break;
        }

        while (i-- > 0)
                *s++ = ((nm >> (i << 3)) & 0xff) | m;

        *nresult = (size_t)ei->count[cs];
        return (0);

err:
        *nresult = (size_t)-1;
        return (ret);
}

static __inline int
/*ARGSUSED*/
_citrus_EUC_stdenc_wctocs(_EUCEncodingInfo * __restrict ei,
    _csid_t * __restrict csid, _index_t * __restrict idx, wchar_t wc)
{
        wchar_t m, nm;

        m = wc & ei->mask;
        nm = wc & ~m;

        *csid = (_citrus_csid_t)m;
        *idx  = (_citrus_index_t)nm;

        return (0);
}

static __inline int
/*ARGSUSED*/
_citrus_EUC_stdenc_cstowc(_EUCEncodingInfo * __restrict ei,
    wchar_t * __restrict wc, _csid_t csid, _index_t idx)
{

        if ((csid & ~ei->mask) != 0 || (idx & ei->mask) != 0)
                return (EINVAL);

        *wc = (wchar_t)csid | (wchar_t)idx;

        return (0);
}

static __inline int
/*ARGSUSED*/
_citrus_EUC_stdenc_get_state_desc_generic(_EUCEncodingInfo * __restrict ei __unused,
    _EUCState * __restrict psenc, int * __restrict rstate)
{

        *rstate = (psenc->chlen == 0) ? _STDENC_SDGEN_INITIAL :
            _STDENC_SDGEN_INCOMPLETE_CHAR;
        return (0);
}

static int
/*ARGSUSED*/
_citrus_EUC_encoding_module_init(_EUCEncodingInfo * __restrict ei,
    const void * __restrict var, size_t lenvar)
{

        return (_citrus_EUC_parse_variable(ei, var, lenvar));
}

static void
/*ARGSUSED*/
_citrus_EUC_encoding_module_uninit(_EUCEncodingInfo * __restrict ei __unused)
{

}

/* ----------------------------------------------------------------------
 * public interface for stdenc
 */

_CITRUS_STDENC_DECLS(EUC);
_CITRUS_STDENC_DEF_OPS(EUC);

#include "citrus_stdenc_template.h"