1 /* Helper functions used by strftime/strptime to handle locale-specific "eras".
2 Copyright (C) 1995-2021 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. */
__libc_rwlock_define(extern,__libc_setlocale_lock attribute_hidden)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_WORD(item) (current->values[_NL_ITEM_INDEX (item)].word)
31
32 #define ERA_DATE_CMP(a, b) \
33 (a[0] < b[0] || (a[0] == b[0] && (a[1] < b[1] \
34 || (a[1] == b[1] && a[2] <= b[2]))))
35
36 /* Look up the era information in CURRENT's locale strings and
37 cache it in CURRENT->private. */
38 static void
39 _nl_init_era_entries (struct __locale_data *current)
40 {
41 size_t cnt;
42 struct lc_time_data *data;
43
44 /* Avoid touching CURRENT if there is no data at all, for _nl_C_LC_TIME. */
45 if (CURRENT_WORD (_NL_TIME_ERA_NUM_ENTRIES) == 0)
46 return;
47
48 __libc_rwlock_wrlock (__libc_setlocale_lock);
49
50 if (current->private.time == NULL)
51 {
52 current->private.time = malloc (sizeof *current->private.time);
53 if (current->private.time == NULL)
54 goto out;
55 memset (current->private.time, 0, sizeof *current->private.time);
56 current->private.cleanup = &_nl_cleanup_time;
57 }
58 data = current->private.time;
59
60 if (! data->era_initialized)
61 {
62 size_t new_num_eras = CURRENT_WORD (_NL_TIME_ERA_NUM_ENTRIES);
63 if (new_num_eras == 0)
64 {
65 if (data->eras != NULL)
66 {
67 free (data->eras);
68 data->eras = NULL;
69 }
70 }
71 else
72 {
73 struct era_entry *new_eras = data->eras;
74
75 if (data->num_eras != new_num_eras)
76 new_eras =
77 (struct era_entry *) realloc (data->eras,
78 new_num_eras
79 * sizeof (struct era_entry));
80 if (new_eras == NULL)
81 {
82 free (data->eras);
83 data->num_eras = 0;
84 data->eras = NULL;
85 }
86 else
87 {
88 const char *ptr = CURRENT (_NL_TIME_ERA_ENTRIES);
89 data->num_eras = new_num_eras;
90 data->eras = new_eras;
91
92 for (cnt = 0; cnt < new_num_eras; ++cnt)
93 {
94 const char *base_ptr = ptr;
95 memcpy ((void *) (new_eras + cnt), (const void *) ptr,
96 sizeof (uint32_t) * 8);
97
98 if (ERA_DATE_CMP(new_eras[cnt].start_date,
99 new_eras[cnt].stop_date))
100 if (new_eras[cnt].direction == (uint32_t) '+')
101 new_eras[cnt].absolute_direction = 1;
102 else
103 new_eras[cnt].absolute_direction = -1;
104 else
105 if (new_eras[cnt].direction == (uint32_t) '+')
106 new_eras[cnt].absolute_direction = -1;
107 else
108 new_eras[cnt].absolute_direction = 1;
109
110 /* Skip numeric values. */
111 ptr += sizeof (uint32_t) * 8;
112
113 /* Set and skip era name. */
114 new_eras[cnt].era_name = ptr;
115 ptr = strchr (ptr, '\0') + 1;
116
117 /* Set and skip era format. */
118 new_eras[cnt].era_format = ptr;
119 ptr = strchr (ptr, '\0') + 1;
120
121 ptr += 3 - (((ptr - (const char *) base_ptr) + 3) & 3);
122
123 /* Set and skip wide era name. */
124 new_eras[cnt].era_wname = (wchar_t *) ptr;
125 ptr = (char *) (__wcschr ((wchar_t *) ptr, L'\0') + 1);
126
127 /* Set and skip wide era format. */
128 new_eras[cnt].era_wformat = (wchar_t *) ptr;
129 ptr = (char *) (__wcschr ((wchar_t *) ptr, L'\0') + 1);
130 }
131 }
132 }
133
134 data->era_initialized = 1;
135 }
136
137 out:
138 __libc_rwlock_unlock (__libc_setlocale_lock);
139 }
140
141 struct era_entry *
_nl_get_era_entry(const struct tm * tp,struct __locale_data * current)142 _nl_get_era_entry (const struct tm *tp, struct __locale_data *current)
143 {
144 if (current->private.time == NULL || !current->private.time->era_initialized)
145 _nl_init_era_entries (current);
146
147 if (current->private.time != NULL)
148 {
149 /* Now compare date with the available eras. */
150 const int32_t tdate[3] = { tp->tm_year, tp->tm_mon, tp->tm_mday };
151 size_t cnt;
152 for (cnt = 0; cnt < current->private.time->num_eras; ++cnt)
153 if ((ERA_DATE_CMP (current->private.time->eras[cnt].start_date, tdate)
154 && ERA_DATE_CMP (tdate,
155 current->private.time->eras[cnt].stop_date))
156 || (ERA_DATE_CMP (current->private.time->eras[cnt].stop_date,
157 tdate)
158 && ERA_DATE_CMP (tdate,
159 current->private.time->eras[cnt].start_date)))
160 return ¤t->private.time->eras[cnt];
161 }
162
163 return NULL;
164 }
165
166
167 struct era_entry *
_nl_select_era_entry(int cnt,struct __locale_data * current)168 _nl_select_era_entry (int cnt, struct __locale_data *current)
169 {
170 if (current->private.time == NULL || !current->private.time->era_initialized)
171 _nl_init_era_entries (current);
172
173 return (current->private.time == NULL
174 ? NULL : ¤t->private.time->eras[cnt]);
175 }
176