xref: /freebsd/lib/libc/locale/gb2312.c (revision b1f9167f94059fd55c630891d359bcff987bd7eb)
1 /*-
2  * Copyright (c) 2004 Tim J. Robbins. All rights reserved.
3  * Copyright (c) 2003 David Xu <davidxu@freebsd.org>
4  * All rights reserved.
5  *
6  * Copyright (c) 2011 The FreeBSD Foundation
7  * All rights reserved.
8  * Portions of this software were developed by David Chisnall
9  * under sponsorship from the FreeBSD Foundation.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 #include <sys/param.h>
34 __FBSDID("$FreeBSD$");
35 
36 #include <errno.h>
37 #include <runetype.h>
38 #include <stdlib.h>
39 #include <string.h>
40 #include <wchar.h>
41 #include "mblocal.h"
42 
43 static size_t	_GB2312_mbrtowc(wchar_t * __restrict, const char * __restrict,
44 		    size_t, mbstate_t * __restrict);
45 static int	_GB2312_mbsinit(const mbstate_t *);
46 static size_t	_GB2312_wcrtomb(char * __restrict, wchar_t,
47 		    mbstate_t * __restrict);
48 
49 typedef struct {
50 	int	count;
51 	u_char	bytes[2];
52 } _GB2312State;
53 
54 int
55 _GB2312_init(struct xlocale_ctype *l, _RuneLocale *rl)
56 {
57 
58 	l->runes = rl;
59 	l->__mbrtowc = _GB2312_mbrtowc;
60 	l->__wcrtomb = _GB2312_wcrtomb;
61 	l->__mbsinit = _GB2312_mbsinit;
62 	l->__mb_cur_max = 2;
63 	l->__mb_sb_limit = 128;
64 	return (0);
65 }
66 
67 static int
68 _GB2312_mbsinit(const mbstate_t *ps)
69 {
70 
71 	return (ps == NULL || ((const _GB2312State *)ps)->count == 0);
72 }
73 
74 static __inline int
75 _GB2312_check(const char *str, size_t n)
76 {
77 	const u_char *s = (const u_char *)str;
78 
79 	if (n == 0)
80 		/* Incomplete multibyte sequence */
81 		return (-2);
82 	if (s[0] >= 0xa1 && s[0] <= 0xfe) {
83 		if (n < 2)
84 			/* Incomplete multibyte sequence */
85 			return (-2);
86 		if (s[1] < 0xa1 || s[1] > 0xfe)
87 			/* Invalid multibyte sequence */
88 			return (-1);
89 		return (2);
90 	} else if (s[0] & 0x80) {
91 		/* Invalid multibyte sequence */
92 		return (-1);
93 	}
94 	return (1);
95 }
96 
97 static size_t
98 _GB2312_mbrtowc(wchar_t * __restrict pwc, const char * __restrict s, size_t n,
99     mbstate_t * __restrict ps)
100 {
101 	_GB2312State *gs;
102 	wchar_t wc;
103 	int i, len, ocount;
104 	size_t ncopy;
105 
106 	gs = (_GB2312State *)ps;
107 
108 	if (gs->count < 0 || gs->count > sizeof(gs->bytes)) {
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 	ncopy = MIN(MIN(n, MB_CUR_MAX), sizeof(gs->bytes) - gs->count);
120 	memcpy(gs->bytes + gs->count, s, ncopy);
121 	ocount = gs->count;
122 	gs->count += ncopy;
123 	s = (char *)gs->bytes;
124 	n = gs->count;
125 
126 	if ((len = _GB2312_check(s, n)) < 0)
127 		return ((size_t)len);
128 	wc = 0;
129 	i = len;
130 	while (i-- > 0)
131 		wc = (wc << 8) | (unsigned char)*s++;
132 	if (pwc != NULL)
133 		*pwc = wc;
134 	gs->count = 0;
135 	return (wc == L'\0' ? 0 : len - ocount);
136 }
137 
138 static size_t
139 _GB2312_wcrtomb(char * __restrict s, wchar_t wc, mbstate_t * __restrict ps)
140 {
141 	_GB2312State *gs;
142 
143 	gs = (_GB2312State *)ps;
144 
145 	if (gs->count != 0) {
146 		errno = EINVAL;
147 		return ((size_t)-1);
148 	}
149 
150 	if (s == NULL)
151 		/* Reset to initial shift state (no-op) */
152 		return (1);
153 	if (wc & 0x8000) {
154 		*s++ = (wc >> 8) & 0xff;
155 		*s = wc & 0xff;
156 		return (2);
157 	}
158 	*s = wc & 0xff;
159 	return (1);
160 }
161