1 /**********************************************************************
2   big5.c -  Oniguruma (regular expression library)
3 **********************************************************************/
4 /*-
5  * Copyright (c) 2002-2020  K.Kosako
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #include "regenc.h"
31 
32 static const int EncLen_BIG5[] = {
33   1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
34   1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
35   1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
36   1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
37   1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
38   1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
39   1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
40   1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
41   1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
42   1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
43   1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
44   2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
45   2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
46   2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
47   2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
48   2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1
49 };
50 
51 static int
big5_mbc_enc_len(const UChar * p)52 big5_mbc_enc_len(const UChar* p)
53 {
54   return EncLen_BIG5[*p];
55 }
56 
57 static int
big5_code_to_mbclen(OnigCodePoint code)58 big5_code_to_mbclen(OnigCodePoint code)
59 {
60   if ((code & (~0xffff)) != 0) return ONIGERR_INVALID_CODE_POINT_VALUE;
61 
62   if ((code & 0xff00) != 0) {
63     if (EncLen_BIG5[(int )(code >> 8) & 0xff] == 2)
64       return 2;
65   }
66   else {
67     if (EncLen_BIG5[(int )(code & 0xff)] == 1)
68       return 1;
69   }
70 
71   return ONIGERR_INVALID_CODE_POINT_VALUE;
72 }
73 
74 static int
is_valid_mbc_string(const UChar * p,const UChar * end)75 is_valid_mbc_string(const UChar* p, const UChar* end)
76 {
77   while (p < end) {
78     if (*p < 0x80) {
79       p++;
80     }
81     else if (*p < 0xa1) {
82       return FALSE;
83     }
84     else if (*p < 0xff) {
85       p++;
86       if (p >= end)  return FALSE;
87       if (*p < 0x40) return FALSE;
88       if (*p > 0x7e && *p < 0xa1) return FALSE;
89       if (*p == 0xff) return FALSE;
90       p++;
91     }
92     else
93       return FALSE;
94   }
95 
96   return TRUE;
97 }
98 
99 static OnigCodePoint
big5_mbc_to_code(const UChar * p,const UChar * end)100 big5_mbc_to_code(const UChar* p, const UChar* end)
101 {
102   return onigenc_mbn_mbc_to_code(ONIG_ENCODING_BIG5, p, end);
103 }
104 
105 static int
big5_code_to_mbc(OnigCodePoint code,UChar * buf)106 big5_code_to_mbc(OnigCodePoint code, UChar *buf)
107 {
108   return onigenc_mb2_code_to_mbc(ONIG_ENCODING_BIG5, code, buf);
109 }
110 
111 static int
big5_mbc_case_fold(OnigCaseFoldType flag,const UChar ** pp,const UChar * end,UChar * lower)112 big5_mbc_case_fold(OnigCaseFoldType flag, const UChar** pp, const UChar* end,
113                    UChar* lower)
114 {
115   return onigenc_mbn_mbc_case_fold(ONIG_ENCODING_BIG5, flag,
116                                    pp, end, lower);
117 }
118 
119 static int
big5_is_code_ctype(OnigCodePoint code,unsigned int ctype)120 big5_is_code_ctype(OnigCodePoint code, unsigned int ctype)
121 {
122   return onigenc_mb2_is_code_ctype(ONIG_ENCODING_BIG5, code, ctype);
123 }
124 
125 static const char BIG5_CAN_BE_TRAIL_TABLE[256] = {
126   0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
127   0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
128   0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
129   0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
130   1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
131   1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
132   1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
133   1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0,
134   1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
135   1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
136   1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
137   1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
138   1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
139   1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
140   1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
141   1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0
142 };
143 
144 #define BIG5_ISMB_FIRST(byte)  (EncLen_BIG5[byte] > 1)
145 #define BIG5_ISMB_TRAIL(byte)  BIG5_CAN_BE_TRAIL_TABLE[(byte)]
146 
147 static UChar*
big5_left_adjust_char_head(const UChar * start,const UChar * s)148 big5_left_adjust_char_head(const UChar* start, const UChar* s)
149 {
150   const UChar *p;
151   int len;
152 
153   if (s <= start) return (UChar* )s;
154   p = s;
155 
156   if (BIG5_ISMB_TRAIL(*p)) {
157     while (p > start) {
158       if (! BIG5_ISMB_FIRST(*--p)) {
159         p++;
160         break;
161       }
162     }
163   }
164   len = enclen(ONIG_ENCODING_BIG5, p);
165   if (p + len > s) return (UChar* )p;
166   p += len;
167   return (UChar* )(p + ((s - p) & ~1));
168 }
169 
170 static int
big5_is_allowed_reverse_match(const UChar * s,const UChar * end ARG_UNUSED)171 big5_is_allowed_reverse_match(const UChar* s, const UChar* end ARG_UNUSED)
172 {
173   const UChar c = *s;
174 
175   return (BIG5_ISMB_TRAIL(c) ? FALSE : TRUE);
176 }
177 
178 OnigEncodingType OnigEncodingBIG5 = {
179   big5_mbc_enc_len,
180   "Big5",     /* name */
181   2,          /* max enc length */
182   1,          /* min enc length */
183   onigenc_is_mbc_newline_0x0a,
184   big5_mbc_to_code,
185   big5_code_to_mbclen,
186   big5_code_to_mbc,
187   big5_mbc_case_fold,
188   onigenc_ascii_apply_all_case_fold,
189   onigenc_ascii_get_case_fold_codes_by_str,
190   onigenc_minimum_property_name_to_ctype,
191   big5_is_code_ctype,
192   onigenc_not_support_get_ctype_code_range,
193   big5_left_adjust_char_head,
194   big5_is_allowed_reverse_match,
195   NULL, /* init */
196   NULL, /* is_initialized */
197   is_valid_mbc_string,
198   ENC_FLAG_ASCII_COMPATIBLE|ENC_FLAG_SKIP_OFFSET_1,
199   0, 0
200 };
201