xref: /freebsd/lib/libc/locale/big5.c (revision 2357939bc239bd5334a169b62313806178dd8f30)
1 /*-
2  * Copyright (c) 2002-2004 Tim J. Robbins. All rights reserved.
3  * Copyright (c) 1993
4  *	The Regents of the University of California.  All rights reserved.
5  *
6  * This code is derived from software contributed to Berkeley by
7  * Paul Borman at Krystal Technologies.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  * 3. All advertising materials mentioning features or use of this software
18  *    must display the following acknowledgement:
19  *	This product includes software developed by the University of
20  *	California, Berkeley and its contributors.
21  * 4. Neither the name of the University nor the names of its contributors
22  *    may be used to endorse or promote products derived from this software
23  *    without specific prior written permission.
24  *
25  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
29  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35  * SUCH DAMAGE.
36  */
37 
38 #if defined(LIBC_SCCS) && !defined(lint)
39 static char sccsid[] = "@(#)big5.c	8.1 (Berkeley) 6/4/93";
40 #endif /* LIBC_SCCS and not lint */
41 #include <sys/param.h>
42 __FBSDID("$FreeBSD$");
43 
44 #include <errno.h>
45 #include <runetype.h>
46 #include <stdlib.h>
47 #include <string.h>
48 #include <wchar.h>
49 #include "mblocal.h"
50 
51 int	_BIG5_init(_RuneLocale *);
52 size_t	_BIG5_mbrtowc(wchar_t * __restrict, const char * __restrict, size_t,
53 	    mbstate_t * __restrict);
54 int	_BIG5_mbsinit(const mbstate_t *);
55 size_t	_BIG5_wcrtomb(char * __restrict, wchar_t, mbstate_t * __restrict);
56 
57 typedef struct {
58 	int	count;
59 	u_char	bytes[2];
60 } _BIG5State;
61 
62 int
63 _BIG5_init(_RuneLocale *rl)
64 {
65 
66 	__mbrtowc = _BIG5_mbrtowc;
67 	__wcrtomb = _BIG5_wcrtomb;
68 	__mbsinit = _BIG5_mbsinit;
69 	_CurrentRuneLocale = rl;
70 	__mb_cur_max = 2;
71 	return (0);
72 }
73 
74 int
75 _BIG5_mbsinit(const mbstate_t *ps)
76 {
77 
78 	return (ps == NULL || ((const _BIG5State *)ps)->count == 0);
79 }
80 
81 static __inline int
82 _big5_check(u_int c)
83 {
84 
85 	c &= 0xff;
86 	return ((c >= 0xa1 && c <= 0xfe) ? 2 : 1);
87 }
88 
89 size_t
90 _BIG5_mbrtowc(wchar_t * __restrict pwc, const char * __restrict s, size_t n,
91     mbstate_t * __restrict ps)
92 {
93 	_BIG5State *bs;
94 	wchar_t wc;
95 	int i, len, ocount;
96 	size_t ncopy;
97 
98 	bs = (_BIG5State *)ps;
99 
100 	if (bs->count < 0 || bs->count > sizeof(bs->bytes)) {
101 		errno = EINVAL;
102 		return ((size_t)-1);
103 	}
104 
105 	if (s == NULL) {
106 		s = "";
107 		n = 1;
108 		pwc = NULL;
109 	}
110 
111 	ncopy = MIN(MIN(n, MB_CUR_MAX), sizeof(bs->bytes) - bs->count);
112 	memcpy(bs->bytes + bs->count, s, ncopy);
113 	ocount = bs->count;
114 	bs->count += ncopy;
115 	s = (char *)bs->bytes;
116 	n = bs->count;
117 
118 	if (n == 0 || (size_t)(len = _big5_check(*s)) > n)
119 		/* Incomplete multibyte sequence */
120 		return ((size_t)-2);
121 	if (len == 2 && s[1] == '\0') {
122 		errno = EILSEQ;
123 		return ((size_t)-1);
124 	}
125 	wc = 0;
126 	i = len;
127 	while (i-- > 0)
128 		wc = (wc << 8) | (unsigned char)*s++;
129 	if (pwc != NULL)
130 		*pwc = wc;
131 	bs->count = 0;
132 	return (wc == L'\0' ? 0 : len - ocount);
133 }
134 
135 size_t
136 _BIG5_wcrtomb(char * __restrict s, wchar_t wc, mbstate_t * __restrict ps)
137 {
138 	_BIG5State *bs;
139 
140 	bs = (_BIG5State *)ps;
141 
142 	if (bs->count != 0) {
143 		errno = EINVAL;
144 		return ((size_t)-1);
145 	}
146 
147 	if (s == NULL)
148 		/* Reset to initial shift state (no-op) */
149 		return (1);
150 	if (wc & 0x8000) {
151 		*s++ = (wc >> 8) & 0xff;
152 		*s = wc & 0xff;
153 		return (2);
154 	}
155 	*s = wc & 0xff;
156 	return (1);
157 }
158