xref: /freebsd/lib/libc/locale/gb2312.c (revision 8fc257994d0ce2396196d7a06d50d20c8015f4b7)
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  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  */
27 
28 #include <sys/param.h>
29 __FBSDID("$FreeBSD$");
30 
31 #include <errno.h>
32 #include <runetype.h>
33 #include <stdlib.h>
34 #include <string.h>
35 #include <wchar.h>
36 #include "mblocal.h"
37 
38 extern int __mb_sb_limit;
39 
40 static size_t	_GB2312_mbrtowc(wchar_t * __restrict, const char * __restrict,
41 		    size_t, mbstate_t * __restrict);
42 static int	_GB2312_mbsinit(const mbstate_t *);
43 static size_t	_GB2312_wcrtomb(char * __restrict, wchar_t,
44 		    mbstate_t * __restrict);
45 
46 typedef struct {
47 	int	count;
48 	u_char	bytes[2];
49 } _GB2312State;
50 
51 int
52 _GB2312_init(_RuneLocale *rl)
53 {
54 
55 	_CurrentRuneLocale = rl;
56 	__mbrtowc = _GB2312_mbrtowc;
57 	__wcrtomb = _GB2312_wcrtomb;
58 	__mbsinit = _GB2312_mbsinit;
59 	__mb_cur_max = 2;
60 	__mb_sb_limit = 128;
61 	return (0);
62 }
63 
64 static int
65 _GB2312_mbsinit(const mbstate_t *ps)
66 {
67 
68 	return (ps == NULL || ((const _GB2312State *)ps)->count == 0);
69 }
70 
71 static __inline int
72 _GB2312_check(const char *str, size_t n)
73 {
74 	const u_char *s = (const u_char *)str;
75 
76 	if (n == 0)
77 		/* Incomplete multibyte sequence */
78 		return (-2);
79 	if (s[0] >= 0xa1 && s[0] <= 0xfe) {
80 		if (n < 2)
81 			/* Incomplete multibyte sequence */
82 			return (-2);
83 		if (s[1] < 0xa1 || s[1] > 0xfe)
84 			/* Invalid multibyte sequence */
85 			return (-1);
86 		return (2);
87 	} else if (s[0] & 0x80) {
88 		/* Invalid multibyte sequence */
89 		return (-1);
90 	}
91 	return (1);
92 }
93 
94 static size_t
95 _GB2312_mbrtowc(wchar_t * __restrict pwc, const char * __restrict s, size_t n,
96     mbstate_t * __restrict ps)
97 {
98 	_GB2312State *gs;
99 	wchar_t wc;
100 	int i, len, ocount;
101 	size_t ncopy;
102 
103 	gs = (_GB2312State *)ps;
104 
105 	if (gs->count < 0 || gs->count > sizeof(gs->bytes)) {
106 		errno = EINVAL;
107 		return ((size_t)-1);
108 	}
109 
110 	if (s == NULL) {
111 		s = "";
112 		n = 1;
113 		pwc = NULL;
114 	}
115 
116 	ncopy = MIN(MIN(n, MB_CUR_MAX), sizeof(gs->bytes) - gs->count);
117 	memcpy(gs->bytes + gs->count, s, ncopy);
118 	ocount = gs->count;
119 	gs->count += ncopy;
120 	s = (char *)gs->bytes;
121 	n = gs->count;
122 
123 	if ((len = _GB2312_check(s, n)) < 0)
124 		return ((size_t)len);
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 	gs->count = 0;
132 	return (wc == L'\0' ? 0 : len - ocount);
133 }
134 
135 static size_t
136 _GB2312_wcrtomb(char * __restrict s, wchar_t wc, mbstate_t * __restrict ps)
137 {
138 	_GB2312State *gs;
139 
140 	gs = (_GB2312State *)ps;
141 
142 	if (gs->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