xref: /freebsd/lib/libc/locale/gb2312.c (revision f0adf7f5cdd241db2f2c817683191a6ef64a4e95)
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 int	_GB2312_init(_RuneLocale *);
39 size_t	_GB2312_mbrtowc(wchar_t * __restrict, const char * __restrict, size_t,
40 	    mbstate_t * __restrict);
41 int	_GB2312_mbsinit(const mbstate_t *);
42 size_t	_GB2312_wcrtomb(char * __restrict, wchar_t, mbstate_t * __restrict);
43 
44 typedef struct {
45 	int	count;
46 	u_char	bytes[2];
47 } _GB2312State;
48 
49 int
50 _GB2312_init(_RuneLocale *rl)
51 {
52 
53 	_CurrentRuneLocale = rl;
54 	__mbrtowc = _GB2312_mbrtowc;
55 	__wcrtomb = _GB2312_wcrtomb;
56 	__mbsinit = _GB2312_mbsinit;
57 	__mb_cur_max = 2;
58 	return (0);
59 }
60 
61 int
62 _GB2312_mbsinit(const mbstate_t *ps)
63 {
64 
65 	return (ps == NULL || ((const _GB2312State *)ps)->count == 0);
66 }
67 
68 static __inline int
69 _GB2312_check(const char *str, size_t n)
70 {
71 	const u_char *s = (const u_char *)str;
72 
73 	if (n == 0)
74 		/* Incomplete multibyte sequence */
75 		return (-2);
76 	if (s[0] >= 0xa1 && s[0] <= 0xfe) {
77 		if (n < 2)
78 			/* Incomplete multibyte sequence */
79 			return (-2);
80 		if (s[1] < 0xa1 || s[1] > 0xfe)
81 			/* Invalid multibyte sequence */
82 			return (-1);
83 		return (2);
84 	} else if (s[0] & 0x80) {
85 		/* Invalid multibyte sequence */
86 		return (-1);
87 	}
88 	return (1);
89 }
90 
91 size_t
92 _GB2312_mbrtowc(wchar_t * __restrict pwc, const char * __restrict s, size_t n,
93     mbstate_t * __restrict ps)
94 {
95 	_GB2312State *gs;
96 	wchar_t wc;
97 	int i, len, ocount;
98 	size_t ncopy;
99 
100 	gs = (_GB2312State *)ps;
101 
102 	if (gs->count < 0 || gs->count > sizeof(gs->bytes)) {
103 		errno = EINVAL;
104 		return ((size_t)-1);
105 	}
106 
107 	if (s == NULL) {
108 		s = "";
109 		n = 1;
110 		pwc = NULL;
111 	}
112 
113 	ncopy = MIN(MIN(n, MB_CUR_MAX), sizeof(gs->bytes) - gs->count);
114 	memcpy(gs->bytes + gs->count, s, ncopy);
115 	ocount = gs->count;
116 	gs->count += ncopy;
117 	s = (char *)gs->bytes;
118 	n = gs->count;
119 
120 	if ((len = _GB2312_check(s, n)) < 0)
121 		return ((size_t)len);
122 	wc = 0;
123 	i = len;
124 	while (i-- > 0)
125 		wc = (wc << 8) | (unsigned char)*s++;
126 	if (pwc != NULL)
127 		*pwc = wc;
128 	gs->count = 0;
129 	return (wc == L'\0' ? 0 : len - ocount);
130 }
131 
132 size_t
133 _GB2312_wcrtomb(char * __restrict s, wchar_t wc, mbstate_t * __restrict ps)
134 {
135 	_GB2312State *gs;
136 
137 	gs = (_GB2312State *)ps;
138 
139 	if (gs->count != 0) {
140 		errno = EINVAL;
141 		return ((size_t)-1);
142 	}
143 
144 	if (s == NULL)
145 		/* Reset to initial shift state (no-op) */
146 		return (1);
147 	if (wc & 0x8000) {
148 		*s++ = (wc >> 8) & 0xff;
149 		*s = wc & 0xff;
150 		return (2);
151 	}
152 	*s = wc & 0xff;
153 	return (1);
154 }
155