xref: /freebsd/lib/libc/locale/xlocale_private.h (revision aa1a8ff2d6dbc51ef058f46f3db5a8bb77967145)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2011 The FreeBSD Foundation
5  *
6  * This software was developed by David Chisnall under sponsorship from
7  * the FreeBSD Foundation.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  */
30 
31 #ifndef _XLOCALE_PRIVATE__H_
32 #define _XLOCALE_PRIVATE__H_
33 
34 #include <xlocale.h>
35 #include <locale.h>
36 #include <stdlib.h>
37 #include <stdint.h>
38 #include <sys/types.h>
39 #include <machine/atomic.h>
40 #include "setlocale.h"
41 
42 /**
43  * The XLC_ values are indexes into the components array.  They are defined in
44  * the same order as the LC_ values in locale.h, but without the LC_ALL zero
45  * value.  Translating from LC_X to XLC_X is done by subtracting one.
46  *
47  * Any reordering of this enum should ensure that these invariants are not
48  * violated.
49  */
50 enum {
51 	XLC_COLLATE = 0,
52 	XLC_CTYPE,
53 	XLC_MONETARY,
54 	XLC_NUMERIC,
55 	XLC_TIME,
56 	XLC_MESSAGES,
57 	XLC_LAST
58 };
59 
60 _Static_assert(XLC_LAST - XLC_COLLATE == 6, "XLC values should be contiguous");
61 _Static_assert(XLC_COLLATE == LC_COLLATE - 1,
62                "XLC_COLLATE doesn't match the LC_COLLATE value.");
63 _Static_assert(XLC_CTYPE == LC_CTYPE - 1,
64                "XLC_CTYPE doesn't match the LC_CTYPE value.");
65 _Static_assert(XLC_MONETARY == LC_MONETARY - 1,
66                "XLC_MONETARY doesn't match the LC_MONETARY value.");
67 _Static_assert(XLC_NUMERIC == LC_NUMERIC - 1,
68                "XLC_NUMERIC doesn't match the LC_NUMERIC value.");
69 _Static_assert(XLC_TIME == LC_TIME - 1,
70                "XLC_TIME doesn't match the LC_TIME value.");
71 _Static_assert(XLC_MESSAGES == LC_MESSAGES - 1,
72                "XLC_MESSAGES doesn't match the LC_MESSAGES value.");
73 
74 /**
75  * Header used for objects that are reference counted.  Objects may optionally
76  * have a destructor associated, which is responsible for destroying the
77  * structure.  Global / static versions of the structure should have no
78  * destructor set - they can then have their reference counts manipulated as
79  * normal, but will not do anything with them.
80  *
81  * The header stores a retain count - objects are assumed to have a reference
82  * count of 1 when they are created, but the retain count is 0.  When the
83  * retain count is less than 0, they are freed.
84  */
85 struct xlocale_refcounted {
86 	/** Number of references to this component.  */
87 	long retain_count;
88 	/** Function used to destroy this component, if one is required*/
89 	void(*destructor)(void*);
90 };
91 
92 #define XLOCALE_DEF_VERSION_LEN 12
93 
94 /**
95  * Header for a locale component.  All locale components must begin with this
96  * header.
97  */
98 struct xlocale_component {
99 	struct xlocale_refcounted header;
100 	/** Name of the locale used for this component. */
101 	char locale[ENCODING_LEN+1];
102 	/** Version of the definition for this component. */
103 	char version[XLOCALE_DEF_VERSION_LEN];
104 };
105 
106 /**
107  * xlocale structure, stores per-thread locale information.
108  */
109 struct _xlocale {
110 	struct xlocale_refcounted header;
111 	/** Components for the locale.  */
112 	struct xlocale_component *components[XLC_LAST];
113 	/** Flag indicating if components[XLC_MONETARY] has changed since the
114 	 * last call to localeconv_l() with this locale. */
115 	int monetary_locale_changed;
116 	/** Flag indicating whether this locale is actually using a locale for
117 	 * LC_MONETARY (1), or if it should use the C default instead (0). */
118 	int using_monetary_locale;
119 	/** Flag indicating if components[XLC_NUMERIC] has changed since the
120 	 * last call to localeconv_l() with this locale. */
121 	int numeric_locale_changed;
122 	/** Flag indicating whether this locale is actually using a locale for
123 	 * LC_NUMERIC (1), or if it should use the C default instead (0). */
124 	int using_numeric_locale;
125 	/** Flag indicating whether this locale is actually using a locale for
126 	 * LC_TIME (1), or if it should use the C default instead (0). */
127 	int using_time_locale;
128 	/** Flag indicating whether this locale is actually using a locale for
129 	 * LC_MESSAGES (1), or if it should use the C default instead (0). */
130 	int using_messages_locale;
131 	/** The structure to be returned from localeconv_l() for this locale. */
132 	struct lconv lconv;
133 	/** Buffer used by nl_langinfo_l() */
134 	char *csym;
135 };
136 
137 /**
138  * Increments the reference count of a reference-counted structure.
139  */
140 __attribute__((unused)) static void*
141 xlocale_retain(void *val)
142 {
143 	struct xlocale_refcounted *obj = val;
144 	atomic_add_long(&(obj->retain_count), 1);
145 	return (val);
146 }
147 /**
148  * Decrements the reference count of a reference-counted structure, freeing it
149  * if this is the last reference, calling its destructor if it has one.
150  */
151 __attribute__((unused)) static void
152 xlocale_release(void *val)
153 {
154 	struct xlocale_refcounted *obj = val;
155 	long count;
156 
157 	count = atomic_fetchadd_long(&(obj->retain_count), -1) - 1;
158 	if (count < 0 && obj->destructor != NULL)
159 		obj->destructor(obj);
160 }
161 
162 /**
163  * Load functions.  Each takes the name of a locale and a pointer to the data
164  * to be initialised as arguments.  Three special values are allowed for the
165  * name of the locale: C, POSIX, and C.UTF-8.  When these are used, we may
166  * use some statically defined tables rather than allocating memory for the
167  * locales' use.
168  */
169 extern void* __collate_load(const char*, locale_t);
170 extern void* __ctype_load(const char*, locale_t);
171 extern void* __messages_load(const char*, locale_t);
172 extern void* __monetary_load(const char*, locale_t);
173 extern void* __numeric_load(const char*, locale_t);
174 extern void* __time_load(const char*, locale_t);
175 
176 extern struct _xlocale __xlocale_global_locale;
177 extern struct _xlocale __xlocale_C_locale;
178 
179 /**
180  * Caches the rune table in TLS for fast access.
181  */
182 void __set_thread_rune_locale(locale_t loc);
183 /**
184  * Flag indicating whether a per-thread locale has been set.  If no per-thread
185  * locale has ever been set, then we always use the global locale.
186  */
187 extern int __has_thread_locale;
188 
189 /**
190  * The per-thread locale.  Avoids the need to use pthread lookup functions when
191  * getting the per-thread locale.
192  */
193 extern _Thread_local locale_t __thread_locale;
194 
195 /**
196  * Returns the current locale for this thread, or the global locale if none is
197  * set.  The caller does not have to free the locale.  The return value from
198  * this call is not guaranteed to remain valid after the locale changes.  As
199  * such, this should only be called within libc functions.
200  */
201 static inline locale_t __get_locale(void)
202 {
203 
204 	if (!__has_thread_locale) {
205 		return (&__xlocale_global_locale);
206 	}
207 	return (__thread_locale ? __thread_locale : &__xlocale_global_locale);
208 }
209 
210 /**
211  * Two magic values are allowed for locale_t objects.  NULL and -1.  This
212  * function maps those to the real locales that they represent.
213  */
214 static inline locale_t get_real_locale(locale_t locale)
215 {
216 	switch ((intptr_t)locale) {
217 		case 0: return (&__xlocale_C_locale);
218 		case -1: return (&__xlocale_global_locale);
219 		default: return (locale);
220 	}
221 }
222 
223 /**
224  * Replace a placeholder locale with the real global or thread-local locale_t.
225  */
226 #define FIX_LOCALE(l) (l = get_real_locale(l))
227 
228 #endif
229