xref: /freebsd/lib/libc/locale/big5.c (revision 40a8ac8f62b535d30349faf28cf47106b7041b83)
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  * Copyright (c) 2011 The FreeBSD Foundation
10  * All rights reserved.
11  * Portions of this software were developed by David Chisnall
12  * under sponsorship from the FreeBSD Foundation.
13  *
14  * Redistribution and use in source and binary forms, with or without
15  * modification, are permitted provided that the following conditions
16  * are met:
17  * 1. Redistributions of source code must retain the above copyright
18  *    notice, this list of conditions and the following disclaimer.
19  * 2. Redistributions in binary form must reproduce the above copyright
20  *    notice, this list of conditions and the following disclaimer in the
21  *    documentation and/or other materials provided with the distribution.
22  * 3. All advertising materials mentioning features or use of this software
23  *    must display the following acknowledgement:
24  *	This product includes software developed by the University of
25  *	California, Berkeley and its contributors.
26  * 4. Neither the name of the University nor the names of its contributors
27  *    may be used to endorse or promote products derived from this software
28  *    without specific prior written permission.
29  *
30  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
31  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
32  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
33  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
34  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
35  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
36  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
37  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
38  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
39  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
40  * SUCH DAMAGE.
41  */
42 
43 #if defined(LIBC_SCCS) && !defined(lint)
44 static char sccsid[] = "@(#)big5.c	8.1 (Berkeley) 6/4/93";
45 #endif /* LIBC_SCCS and not lint */
46 #include <sys/cdefs.h>
47 __FBSDID("$FreeBSD$");
48 
49 #include <sys/types.h>
50 #include <errno.h>
51 #include <runetype.h>
52 #include <stdlib.h>
53 #include <string.h>
54 #include <wchar.h>
55 #include "mblocal.h"
56 
57 extern int __mb_sb_limit;
58 
59 static size_t	_BIG5_mbrtowc(wchar_t * __restrict, const char * __restrict,
60 		    size_t, mbstate_t * __restrict);
61 static int	_BIG5_mbsinit(const mbstate_t *);
62 static size_t	_BIG5_wcrtomb(char * __restrict, wchar_t,
63 		    mbstate_t * __restrict);
64 
65 typedef struct {
66 	wchar_t	ch;
67 } _BIG5State;
68 
69 int
70 _BIG5_init(struct xlocale_ctype *l, _RuneLocale *rl)
71 {
72 
73 	l->__mbrtowc = _BIG5_mbrtowc;
74 	l->__wcrtomb = _BIG5_wcrtomb;
75 	l->__mbsinit = _BIG5_mbsinit;
76 	l->runes = rl;
77 	l->__mb_cur_max = 2;
78 	l->__mb_sb_limit = 128;
79 	return (0);
80 }
81 
82 static int
83 _BIG5_mbsinit(const mbstate_t *ps)
84 {
85 
86 	return (ps == NULL || ((const _BIG5State *)ps)->ch == 0);
87 }
88 
89 static __inline int
90 _big5_check(u_int c)
91 {
92 
93 	c &= 0xff;
94 	return ((c >= 0xa1 && c <= 0xfe) ? 2 : 1);
95 }
96 
97 static size_t
98 _BIG5_mbrtowc(wchar_t * __restrict pwc, const char * __restrict s, size_t n,
99     mbstate_t * __restrict ps)
100 {
101 	_BIG5State *bs;
102 	wchar_t wc;
103 	size_t len;
104 
105 	bs = (_BIG5State *)ps;
106 
107 	if ((bs->ch & ~0xFF) != 0) {
108 		/* Bad conversion state. */
109 		errno = EINVAL;
110 		return ((size_t)-1);
111 	}
112 
113 	if (s == NULL) {
114 		s = "";
115 		n = 1;
116 		pwc = NULL;
117 	}
118 
119 	if (n == 0)
120 		/* Incomplete multibyte sequence */
121 		return ((size_t)-2);
122 
123 	if (bs->ch != 0) {
124 		if (*s == '\0') {
125 			errno = EILSEQ;
126 			return ((size_t)-1);
127 		}
128 		wc = (bs->ch << 8) | (*s & 0xFF);
129 		if (pwc != NULL)
130 			*pwc = wc;
131 		bs->ch = 0;
132 		return (1);
133 	}
134 
135 	len = (size_t)_big5_check(*s);
136 	wc = *s++ & 0xff;
137 	if (len == 2) {
138 		if (n < 2) {
139 			/* Incomplete multibyte sequence */
140 			bs->ch = wc;
141 			return ((size_t)-2);
142 		}
143 		if (*s == '\0') {
144 			errno = EILSEQ;
145 			return ((size_t)-1);
146 		}
147 		wc = (wc << 8) | (*s++ & 0xff);
148 		if (pwc != NULL)
149 			*pwc = wc;
150                 return (2);
151 	} else {
152 		if (pwc != NULL)
153 			*pwc = wc;
154 		return (wc == L'\0' ? 0 : 1);
155 	}
156 }
157 
158 static size_t
159 _BIG5_wcrtomb(char * __restrict s, wchar_t wc, mbstate_t * __restrict ps)
160 {
161 	_BIG5State *bs;
162 
163 	bs = (_BIG5State *)ps;
164 
165 	if (bs->ch != 0) {
166 		errno = EINVAL;
167 		return ((size_t)-1);
168 	}
169 
170 	if (s == NULL)
171 		/* Reset to initial shift state (no-op) */
172 		return (1);
173 	if (wc & 0x8000) {
174 		*s++ = (wc >> 8) & 0xff;
175 		*s = wc & 0xff;
176 		return (2);
177 	}
178 	*s = wc & 0xff;
179 	return (1);
180 }
181