1 /* Helper functions used by strftime/strptime to handle alternate digits.
2 Copyright (C) 1995-2023 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
18
19 #include "../locale/localeinfo.h"
20 #include <libc-lock.h>
21 #include <stdlib.h>
22 #include <wchar.h>
23 #include <string.h>
24 #include <stdint.h>
25
26 /* Some of the functions here must not be used while setlocale is called. */
27 __libc_rwlock_define (extern, __libc_setlocale_lock attribute_hidden)
28
29 #define CURRENT(item) (current->values[_NL_ITEM_INDEX (item)].string)
30 #define CURRENT_WSTR(item) \
31 ((wchar_t *) current->values[_NL_ITEM_INDEX (item)].wstr)
32
33 static struct lc_time_data *
34 _nl_init_alt_digit (struct __locale_data *current)
35 {
36 struct lc_time_data *data = current->private;
37
38 if (data == NULL)
39 {
40 data = calloc (sizeof *data, 1);
41 if (data == NULL)
42 return NULL;
43 current->private = data;
44 }
45
46 if (! data->alt_digits_initialized)
47 {
48 const char *ptr = CURRENT (ALT_DIGITS);
49 size_t cnt;
50
51 data->alt_digits_initialized = 1;
52
53 if (ptr != NULL)
54 {
55 data->alt_digits = malloc (100 * sizeof (const char *));
56 if (data->alt_digits != NULL)
57 for (cnt = 0; cnt < 100; ++cnt)
58 {
59 data->alt_digits[cnt] = ptr;
60
61 /* Skip digit format. */
62 ptr = strchr (ptr, '\0') + 1;
63 }
64 }
65 }
66
67 return data;
68 }
69
70 const char *
71 _nl_get_alt_digit (unsigned int number, struct __locale_data *current)
72 {
73 const char *result;
74
75 if (number >= 100 || CURRENT (ALT_DIGITS)[0] == '\0')
76 return NULL;
77
78 __libc_rwlock_wrlock (__libc_setlocale_lock);
79
80 struct lc_time_data *data = _nl_init_alt_digit (current);
81
82 result = ((data != NULL
83 && data->alt_digits != NULL)
84 ? data->alt_digits[number]
85 : NULL);
86
87 __libc_rwlock_unlock (__libc_setlocale_lock);
88
89 return result;
90 }
91
92
93 const wchar_t *
94 _nl_get_walt_digit (unsigned int number, struct __locale_data *current)
95 {
96 const wchar_t *result = NULL;
97
98 if (number >= 100 || CURRENT_WSTR (_NL_WALT_DIGITS)[0] == L'\0')
99 return NULL;
100
101 __libc_rwlock_wrlock (__libc_setlocale_lock);
102
103 struct lc_time_data *data = current->private;
104 if (data == NULL)
105 {
106 data = calloc (sizeof *data, 1);
107 if (data == NULL)
108 goto out;
109 current->private = data;
110 }
111
112 if (! data->walt_digits_initialized)
113 {
114 const wchar_t *ptr = CURRENT_WSTR (_NL_WALT_DIGITS);
115 size_t cnt;
116
117 data->walt_digits_initialized = 1;
118
119 if (ptr != NULL)
120 {
121 data->walt_digits = malloc (100 * sizeof (const uint32_t *));
122 if (data->walt_digits != NULL)
123 for (cnt = 0; cnt < 100; ++cnt)
124 {
125 data->walt_digits[cnt] = ptr;
126
127 /* Skip digit format. */
128 ptr = __wcschr (ptr, L'\0') + 1;
129 }
130 }
131 }
132
133 if (data->walt_digits != NULL)
134 result = data->walt_digits[number];
135
136 out:
137 __libc_rwlock_unlock (__libc_setlocale_lock);
138
139 return (wchar_t *) result;
140 }
141
142
143 int
144 _nl_parse_alt_digit (const char **strp, struct __locale_data *current)
145 {
146 const char *str = *strp;
147 int result = -1;
148 size_t cnt;
149 size_t maxlen = 0;
150
151 if (CURRENT_WSTR (_NL_WALT_DIGITS)[0] == L'\0')
152 return result;
153
154 __libc_rwlock_wrlock (__libc_setlocale_lock);
155
156 struct lc_time_data *data = _nl_init_alt_digit (current);
157 if (data != NULL && data->alt_digits != NULL)
158 /* Matching is not unambiguous. The alternative digits could be like
159 I, II, III, ... and the first one is a substring of the second
160 and third. Therefore we must keep on searching until we found
161 the longest possible match. Note that this is not specified in
162 the standard. */
163 for (cnt = 0; cnt < 100; ++cnt)
164 {
165 const char *const dig = data->alt_digits[cnt];
166 size_t len = strlen (dig);
167
168 if (len > maxlen && strncmp (dig, str, len) == 0)
169 {
170 maxlen = len;
171 result = (int) cnt;
172 }
173 }
174
175 __libc_rwlock_unlock (__libc_setlocale_lock);
176
177 if (result != -1)
178 *strp += maxlen;
179
180 return result;
181 }