xref: /freebsd/lib/libc/locale/big5.c (revision 7bd6fde3)
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/cdefs.h>
42 __FBSDID("$FreeBSD$");
43 
44 #include <sys/types.h>
45 #include <errno.h>
46 #include <runetype.h>
47 #include <stdlib.h>
48 #include <string.h>
49 #include <wchar.h>
50 #include "mblocal.h"
51 
52 static size_t	_BIG5_mbrtowc(wchar_t * __restrict, const char * __restrict,
53 		    size_t, mbstate_t * __restrict);
54 static int	_BIG5_mbsinit(const mbstate_t *);
55 static size_t	_BIG5_wcrtomb(char * __restrict, wchar_t,
56 		    mbstate_t * __restrict);
57 
58 typedef struct {
59 	wchar_t	ch;
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 static int
75 _BIG5_mbsinit(const mbstate_t *ps)
76 {
77 
78 	return (ps == NULL || ((const _BIG5State *)ps)->ch == 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 static 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 	size_t len;
96 
97 	bs = (_BIG5State *)ps;
98 
99 	if ((bs->ch & ~0xFF) != 0) {
100 		/* Bad conversion state. */
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 	if (n == 0)
112 		/* Incomplete multibyte sequence */
113 		return ((size_t)-2);
114 
115 	if (bs->ch != 0) {
116 		if (*s == '\0') {
117 			errno = EILSEQ;
118 			return ((size_t)-1);
119 		}
120 		wc = (bs->ch << 8) | (*s & 0xFF);
121 		if (pwc != NULL)
122 			*pwc = wc;
123 		bs->ch = 0;
124 		return (1);
125 	}
126 
127 	len = (size_t)_big5_check(*s);
128 	wc = *s++ & 0xff;
129 	if (len == 2) {
130 		if (n < 2) {
131 			/* Incomplete multibyte sequence */
132 			bs->ch = wc;
133 			return ((size_t)-2);
134 		}
135 		if (*s == '\0') {
136 			errno = EILSEQ;
137 			return ((size_t)-1);
138 		}
139 		wc = (wc << 8) | (*s++ & 0xff);
140 		if (pwc != NULL)
141 			*pwc = wc;
142                 return (2);
143 	} else {
144 		if (pwc != NULL)
145 			*pwc = wc;
146 		return (wc == L'\0' ? 0 : 1);
147 	}
148 }
149 
150 static size_t
151 _BIG5_wcrtomb(char * __restrict s, wchar_t wc, mbstate_t * __restrict ps)
152 {
153 	_BIG5State *bs;
154 
155 	bs = (_BIG5State *)ps;
156 
157 	if (bs->ch != 0) {
158 		errno = EINVAL;
159 		return ((size_t)-1);
160 	}
161 
162 	if (s == NULL)
163 		/* Reset to initial shift state (no-op) */
164 		return (1);
165 	if (wc & 0x8000) {
166 		*s++ = (wc >> 8) & 0xff;
167 		*s = wc & 0xff;
168 		return (2);
169 	}
170 	*s = wc & 0xff;
171 	return (1);
172 }
173