xref: /freebsd/lib/libc/locale/xlocale.c (revision f5147e312f43a9050468de539aeafa072caa1a60)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2011 The FreeBSD Foundation
5  * All rights reserved.
6  *
7  * This software was developed by David Chisnall under sponsorship from
8  * the FreeBSD Foundation.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  *
31  * $FreeBSD$
32  */
33 
34 #include <pthread.h>
35 #include <stdio.h>
36 #include <string.h>
37 #include <runetype.h>
38 #include "libc_private.h"
39 #include "xlocale_private.h"
40 
41 /**
42  * Each locale loader declares a global component.  This is used by setlocale()
43  * and also by xlocale with LC_GLOBAL_LOCALE..
44  */
45 extern struct xlocale_component __xlocale_global_collate;
46 extern struct xlocale_component __xlocale_global_ctype;
47 extern struct xlocale_component __xlocale_global_monetary;
48 extern struct xlocale_component __xlocale_global_numeric;
49 extern struct xlocale_component __xlocale_global_time;
50 extern struct xlocale_component __xlocale_global_messages;
51 /*
52  * And another version for the statically-allocated C locale.  We only have
53  * components for the parts that are expected to be sensible.
54  */
55 extern struct xlocale_component __xlocale_C_collate;
56 extern struct xlocale_component __xlocale_C_ctype;
57 
58 #ifndef __NO_TLS
59 /*
60  * The locale for this thread.
61  */
62 _Thread_local locale_t __thread_locale;
63 #endif
64 /*
65  * Flag indicating that one or more per-thread locales exist.
66  */
67 int __has_thread_locale;
68 /*
69  * Private functions in setlocale.c.
70  */
71 const char *
72 __get_locale_env(int category);
73 int
74 __detect_path_locale(void);
75 
76 struct _xlocale __xlocale_global_locale = {
77 	{0},
78 	{
79 		&__xlocale_global_collate,
80 		&__xlocale_global_ctype,
81 		&__xlocale_global_monetary,
82 		&__xlocale_global_numeric,
83 		&__xlocale_global_time,
84 		&__xlocale_global_messages
85 	},
86 	1,
87 	0,
88 	1,
89 	0
90 };
91 
92 struct _xlocale __xlocale_C_locale = {
93 	{0},
94 	{
95 		&__xlocale_C_collate,
96 		&__xlocale_C_ctype,
97 		0, 0, 0, 0
98 	},
99 	1,
100 	0,
101 	1,
102 	0
103 };
104 
105 static void*(*constructors[])(const char*, locale_t) =
106 {
107 	__collate_load,
108 	__ctype_load,
109 	__monetary_load,
110 	__numeric_load,
111 	__time_load,
112 	__messages_load
113 };
114 
115 static pthread_key_t locale_info_key;
116 static int fake_tls;
117 static locale_t thread_local_locale;
118 
119 static void init_key(void)
120 {
121 
122 	pthread_key_create(&locale_info_key, xlocale_release);
123 	pthread_setspecific(locale_info_key, (void*)42);
124 	if (pthread_getspecific(locale_info_key) == (void*)42) {
125 		pthread_setspecific(locale_info_key, 0);
126 	} else {
127 		fake_tls = 1;
128 	}
129 	/* At least one per-thread locale has now been set. */
130 	__has_thread_locale = 1;
131 	__detect_path_locale();
132 }
133 
134 static pthread_once_t once_control = PTHREAD_ONCE_INIT;
135 
136 static locale_t
137 get_thread_locale(void)
138 {
139 
140 	_once(&once_control, init_key);
141 
142 	return (fake_tls ? thread_local_locale :
143 		pthread_getspecific(locale_info_key));
144 }
145 
146 #ifdef __NO_TLS
147 locale_t
148 __get_locale(void)
149 {
150 	locale_t l = get_thread_locale();
151 	return (l ? l : &__xlocale_global_locale);
152 
153 }
154 #endif
155 
156 static void
157 set_thread_locale(locale_t loc)
158 {
159 	locale_t l = (loc == LC_GLOBAL_LOCALE) ? 0 : loc;
160 
161 	_once(&once_control, init_key);
162 
163 	if (NULL != l) {
164 		xlocale_retain((struct xlocale_refcounted*)l);
165 	}
166 	locale_t old = pthread_getspecific(locale_info_key);
167 	if ((NULL != old) && (l != old)) {
168 		xlocale_release((struct xlocale_refcounted*)old);
169 	}
170 	if (fake_tls) {
171 		thread_local_locale = l;
172 	} else {
173 		pthread_setspecific(locale_info_key, l);
174 	}
175 #ifndef __NO_TLS
176 	__thread_locale = l;
177 	__set_thread_rune_locale(loc);
178 #endif
179 }
180 
181 /**
182  * Clean up a locale, once its reference count reaches zero.  This function is
183  * called by xlocale_release(), it should not be called directly.
184  */
185 static void
186 destruct_locale(void *l)
187 {
188 	locale_t loc = l;
189 
190 	for (int type=0 ; type<XLC_LAST ; type++) {
191 		if (loc->components[type]) {
192 			xlocale_release(loc->components[type]);
193 		}
194 	}
195 	if (loc->csym) {
196 		free(loc->csym);
197 	}
198 	free(l);
199 }
200 
201 /**
202  * Allocates a new, uninitialised, locale.
203  */
204 static locale_t
205 alloc_locale(void)
206 {
207 	locale_t new = calloc(sizeof(struct _xlocale), 1);
208 
209 	new->header.destructor = destruct_locale;
210 	new->monetary_locale_changed = 1;
211 	new->numeric_locale_changed = 1;
212 	return (new);
213 }
214 static void
215 copyflags(locale_t new, locale_t old)
216 {
217 	new->using_monetary_locale = old->using_monetary_locale;
218 	new->using_numeric_locale = old->using_numeric_locale;
219 	new->using_time_locale = old->using_time_locale;
220 	new->using_messages_locale = old->using_messages_locale;
221 }
222 
223 static int dupcomponent(int type, locale_t base, locale_t new)
224 {
225 	/* Always copy from the global locale, since it has mutable components.
226 	 */
227 	struct xlocale_component *src = base->components[type];
228 
229 	if (&__xlocale_global_locale == base) {
230 		new->components[type] = constructors[type](src->locale, new);
231 		if (new->components[type]) {
232 			strncpy(new->components[type]->locale, src->locale,
233 			    ENCODING_LEN);
234 		}
235 	} else if (base->components[type]) {
236 		new->components[type] = xlocale_retain(base->components[type]);
237 	} else {
238 		/* If the component was NULL, return success - if base is a
239 		 * valid locale then the flag indicating that this isn't
240 		 * present should be set.  If it isn't a valid locale, then
241 		 * we're stuck anyway. */
242 		return 1;
243 	}
244 	return (0 != new->components[type]);
245 }
246 
247 /*
248  * Public interfaces.  These are the five public functions described by the
249  * xlocale interface.
250  */
251 
252 locale_t newlocale(int mask, const char *locale, locale_t base)
253 {
254 	int type;
255 	const char *realLocale = locale;
256 	int useenv = 0;
257 	int success = 1;
258 
259 	_once(&once_control, init_key);
260 
261 	locale_t new = alloc_locale();
262 	if (NULL == new) {
263 		return (NULL);
264 	}
265 
266 	FIX_LOCALE(base);
267 	copyflags(new, base);
268 
269 	if (NULL == locale) {
270 		realLocale = "C";
271 	} else if ('\0' == locale[0]) {
272 		useenv = 1;
273 	}
274 
275 	for (type=0 ; type<XLC_LAST ; type++) {
276 		if (mask & 1) {
277 			if (useenv) {
278 				realLocale = __get_locale_env(type + 1);
279 			}
280 			new->components[type] =
281 			     constructors[type](realLocale, new);
282 			if (new->components[type]) {
283 				strncpy(new->components[type]->locale,
284 				     realLocale, ENCODING_LEN);
285 			} else {
286 				success = 0;
287 				break;
288 			}
289 		} else {
290 			if (!dupcomponent(type, base, new)) {
291 				success = 0;
292 				break;
293 			}
294 		}
295 		mask >>= 1;
296 	}
297 	if (0 == success) {
298 		xlocale_release(new);
299 		new = NULL;
300 	}
301 
302 	return (new);
303 }
304 
305 locale_t duplocale(locale_t base)
306 {
307 	locale_t new = alloc_locale();
308 	int type;
309 
310 	_once(&once_control, init_key);
311 
312 	if (NULL == new) {
313 		return (NULL);
314 	}
315 
316 	FIX_LOCALE(base);
317 	copyflags(new, base);
318 
319 	for (type=0 ; type<XLC_LAST ; type++) {
320 		dupcomponent(type, base, new);
321 	}
322 
323 	return (new);
324 }
325 
326 /*
327  * Free a locale_t.  This is quite a poorly named function.  It actually
328  * disclaims a reference to a locale_t, rather than freeing it.
329  */
330 void
331 freelocale(locale_t loc)
332 {
333 
334 	/*
335 	 * Fail if we're passed something that isn't a locale. If we're
336 	 * passed the global locale, pretend that we freed it but don't
337 	 * actually do anything.
338 	 */
339 	if (loc != NULL && loc != LC_GLOBAL_LOCALE &&
340 	    loc != &__xlocale_global_locale)
341 		xlocale_release(loc);
342 }
343 
344 /*
345  * Returns the name of the locale for a particular component of a locale_t.
346  */
347 const char *querylocale(int mask, locale_t loc)
348 {
349 	int type = ffs(mask) - 1;
350 	FIX_LOCALE(loc);
351 	if (type >= XLC_LAST)
352 		return (NULL);
353 	if (loc->components[type])
354 		return (loc->components[type]->locale);
355 	return ("C");
356 }
357 
358 /*
359  * Installs the specified locale_t as this thread's locale.
360  */
361 locale_t uselocale(locale_t loc)
362 {
363 	locale_t old = get_thread_locale();
364 	if (NULL != loc) {
365 		set_thread_locale(loc);
366 	}
367 	return (old ? old : LC_GLOBAL_LOCALE);
368 }
369 
370