xref: /freebsd/lib/libc/locale/big5.c (revision 1669d8afc64812c8d2d1d147ae1fd42ff441e1b1)
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 extern int __mb_sb_limit;
53 
54 static size_t	_BIG5_mbrtowc(wchar_t * __restrict, const char * __restrict,
55 		    size_t, mbstate_t * __restrict);
56 static int	_BIG5_mbsinit(const mbstate_t *);
57 static size_t	_BIG5_wcrtomb(char * __restrict, wchar_t,
58 		    mbstate_t * __restrict);
59 
60 typedef struct {
61 	wchar_t	ch;
62 } _BIG5State;
63 
64 int
65 _BIG5_init(_RuneLocale *rl)
66 {
67 
68 	__mbrtowc = _BIG5_mbrtowc;
69 	__wcrtomb = _BIG5_wcrtomb;
70 	__mbsinit = _BIG5_mbsinit;
71 	_CurrentRuneLocale = rl;
72 	__mb_cur_max = 2;
73 	__mb_sb_limit = 128;
74 	return (0);
75 }
76 
77 static int
78 _BIG5_mbsinit(const mbstate_t *ps)
79 {
80 
81 	return (ps == NULL || ((const _BIG5State *)ps)->ch == 0);
82 }
83 
84 static __inline int
85 _big5_check(u_int c)
86 {
87 
88 	c &= 0xff;
89 	return ((c >= 0xa1 && c <= 0xfe) ? 2 : 1);
90 }
91 
92 static size_t
93 _BIG5_mbrtowc(wchar_t * __restrict pwc, const char * __restrict s, size_t n,
94     mbstate_t * __restrict ps)
95 {
96 	_BIG5State *bs;
97 	wchar_t wc;
98 	size_t len;
99 
100 	bs = (_BIG5State *)ps;
101 
102 	if ((bs->ch & ~0xFF) != 0) {
103 		/* Bad conversion state. */
104 		errno = EINVAL;
105 		return ((size_t)-1);
106 	}
107 
108 	if (s == NULL) {
109 		s = "";
110 		n = 1;
111 		pwc = NULL;
112 	}
113 
114 	if (n == 0)
115 		/* Incomplete multibyte sequence */
116 		return ((size_t)-2);
117 
118 	if (bs->ch != 0) {
119 		if (*s == '\0') {
120 			errno = EILSEQ;
121 			return ((size_t)-1);
122 		}
123 		wc = (bs->ch << 8) | (*s & 0xFF);
124 		if (pwc != NULL)
125 			*pwc = wc;
126 		bs->ch = 0;
127 		return (1);
128 	}
129 
130 	len = (size_t)_big5_check(*s);
131 	wc = *s++ & 0xff;
132 	if (len == 2) {
133 		if (n < 2) {
134 			/* Incomplete multibyte sequence */
135 			bs->ch = wc;
136 			return ((size_t)-2);
137 		}
138 		if (*s == '\0') {
139 			errno = EILSEQ;
140 			return ((size_t)-1);
141 		}
142 		wc = (wc << 8) | (*s++ & 0xff);
143 		if (pwc != NULL)
144 			*pwc = wc;
145                 return (2);
146 	} else {
147 		if (pwc != NULL)
148 			*pwc = wc;
149 		return (wc == L'\0' ? 0 : 1);
150 	}
151 }
152 
153 static size_t
154 _BIG5_wcrtomb(char * __restrict s, wchar_t wc, mbstate_t * __restrict ps)
155 {
156 	_BIG5State *bs;
157 
158 	bs = (_BIG5State *)ps;
159 
160 	if (bs->ch != 0) {
161 		errno = EINVAL;
162 		return ((size_t)-1);
163 	}
164 
165 	if (s == NULL)
166 		/* Reset to initial shift state (no-op) */
167 		return (1);
168 	if (wc & 0x8000) {
169 		*s++ = (wc >> 8) & 0xff;
170 		*s = wc & 0xff;
171 		return (2);
172 	}
173 	*s = wc & 0xff;
174 	return (1);
175 }
176