1 /**********************************************************************
2   euc_tw.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_EUCTW[] = {
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, 4, 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
euctw_mbc_enc_len(const UChar * p)52 euctw_mbc_enc_len(const UChar* p)
53 {
54   return EncLen_EUCTW[*p];
55 }
56 
57 static int
euctw_code_to_mbclen(OnigCodePoint code)58 euctw_code_to_mbclen(OnigCodePoint code)
59 {
60   if ((code & 0xff000000) != 0) {
61     if (EncLen_EUCTW[(int )(code >> 24) & 0xff] == 4)
62       return 4;
63   }
64   else if ((code & 0xff0000) != 0)
65     return ONIGERR_INVALID_CODE_POINT_VALUE;
66   else if ((code & 0xff00) != 0) {
67     if (EncLen_EUCTW[(int )(code >> 8) & 0xff] == 2)
68       return 2;
69   }
70   else {
71     if (EncLen_EUCTW[(int )(code & 0xff)] == 1)
72       return 1;
73   }
74 
75   return ONIGERR_INVALID_CODE_POINT_VALUE;
76 }
77 
78 static int
is_valid_mbc_string(const UChar * p,const UChar * end)79 is_valid_mbc_string(const UChar* p, const UChar* end)
80 {
81   while (p < end) {
82     if (*p < 0x80) {
83       p++;
84     }
85     else if (*p < 0xa1) {
86       if (*p == 0x8e) {
87         p++;
88         if (p >= end) return FALSE;
89         if (*p < 0xa1 || *p > 0xb0) return FALSE;
90         p++;
91         if (p >= end) return FALSE;
92         if (*p < 0xa1 || *p == 0xff)
93           return FALSE;
94         p++;
95         if (p >= end) return FALSE;
96         if (*p < 0xa1 || *p == 0xff)
97           return FALSE;
98         p++;
99       }
100       else
101         return FALSE;
102     }
103     else if (*p < 0xff) {
104       p++;
105       if (p >= end) return FALSE;
106       if (*p < 0xa1 || *p == 0xff)
107         return FALSE;
108       p++;
109     }
110     else
111       return FALSE;
112   }
113 
114   return TRUE;
115 }
116 
117 static OnigCodePoint
euctw_mbc_to_code(const UChar * p,const UChar * end)118 euctw_mbc_to_code(const UChar* p, const UChar* end)
119 {
120   return onigenc_mbn_mbc_to_code(ONIG_ENCODING_EUC_TW, p, end);
121 }
122 
123 static int
euctw_code_to_mbc(OnigCodePoint code,UChar * buf)124 euctw_code_to_mbc(OnigCodePoint code, UChar *buf)
125 {
126   return onigenc_mb4_code_to_mbc(ONIG_ENCODING_EUC_TW, code, buf);
127 }
128 
129 static int
euctw_mbc_case_fold(OnigCaseFoldType flag,const UChar ** pp,const UChar * end,UChar * lower)130 euctw_mbc_case_fold(OnigCaseFoldType flag, const UChar** pp, const UChar* end,
131                     UChar* lower)
132 {
133   return onigenc_mbn_mbc_case_fold(ONIG_ENCODING_EUC_TW, flag,
134                                    pp, end, lower);
135 }
136 
137 static int
euctw_is_code_ctype(OnigCodePoint code,unsigned int ctype)138 euctw_is_code_ctype(OnigCodePoint code, unsigned int ctype)
139 {
140   return onigenc_mb4_is_code_ctype(ONIG_ENCODING_EUC_TW, code, ctype);
141 }
142 
143 #define euctw_islead(c)    ((UChar )((c) - 0xa1) > 0xfe - 0xa1)
144 
145 static UChar*
euctw_left_adjust_char_head(const UChar * start,const UChar * s)146 euctw_left_adjust_char_head(const UChar* start, const UChar* s)
147 {
148   /* Assumed in this encoding,
149      mb-trail bytes don't mix with single bytes.
150   */
151   const UChar *p;
152   int len;
153 
154   if (s <= start) return (UChar* )s;
155   p = s;
156 
157   while (!euctw_islead(*p) && p > start) p--;
158   len = enclen(ONIG_ENCODING_EUC_TW, p);
159   if (p + len > s) return (UChar* )p;
160   p += len;
161   return (UChar* )(p + ((s - p) & ~1));
162 }
163 
164 static int
euctw_is_allowed_reverse_match(const UChar * s,const UChar * end ARG_UNUSED)165 euctw_is_allowed_reverse_match(const UChar* s, const UChar* end ARG_UNUSED)
166 {
167   const UChar c = *s;
168   if (c <= 0x7e) return TRUE;
169   else           return FALSE;
170 }
171 
172 OnigEncodingType OnigEncodingEUC_TW = {
173   euctw_mbc_enc_len,
174   "EUC-TW",   /* name */
175   4,          /* max enc length */
176   1,          /* min enc length */
177   onigenc_is_mbc_newline_0x0a,
178   euctw_mbc_to_code,
179   euctw_code_to_mbclen,
180   euctw_code_to_mbc,
181   euctw_mbc_case_fold,
182   onigenc_ascii_apply_all_case_fold,
183   onigenc_ascii_get_case_fold_codes_by_str,
184   onigenc_minimum_property_name_to_ctype,
185   euctw_is_code_ctype,
186   onigenc_not_support_get_ctype_code_range,
187   euctw_left_adjust_char_head,
188   euctw_is_allowed_reverse_match,
189   NULL, /* init */
190   NULL, /* is_initialized */
191   is_valid_mbc_string,
192   ENC_FLAG_ASCII_COMPATIBLE|ENC_FLAG_SKIP_OFFSET_1,
193   0, 0
194 };
195