1 /* Duplicate handle for selection of locales.
2    Copyright (C) 1997-2022 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.h>
20 #include <libc-lock.h>
21 #include <stdlib.h>
22 #include <string.h>
23 
24 #include <localeinfo.h>
25 
26 
27 /* Lock for protecting global data.  */
__libc_rwlock_define(extern,__libc_setlocale_lock attribute_hidden)28 __libc_rwlock_define (extern , __libc_setlocale_lock attribute_hidden)
29 
30 
31 locale_t
32 __duplocale (locale_t dataset)
33 {
34   /* This static object is returned for newlocale (LC_ALL_MASK, "C").  */
35   if (dataset == _nl_C_locobj_ptr)
36     return dataset;
37 
38   /* Handle a special value.  */
39   if (dataset == LC_GLOBAL_LOCALE)
40     dataset = &_nl_global_locale;
41 
42   locale_t result;
43   int cnt;
44   size_t names_len = 0;
45 
46   /* Calculate the total space we need to store all the names.  */
47   for (cnt = 0; cnt < __LC_LAST; ++cnt)
48     if (cnt != LC_ALL && dataset->__names[cnt] != _nl_C_name)
49       names_len += strlen (dataset->__names[cnt]) + 1;
50 
51   /* Get memory.  */
52   result = malloc (sizeof (struct __locale_struct) + names_len);
53 
54   if (result != NULL)
55     {
56       char *namep = (char *) (result + 1);
57 
58       /* We modify global data (the usage counts).  */
59       __libc_rwlock_wrlock (__libc_setlocale_lock);
60 
61       for (cnt = 0; cnt < __LC_LAST; ++cnt)
62 	if (cnt != LC_ALL)
63 	  {
64 	    result->__locales[cnt] = dataset->__locales[cnt];
65 	    if (result->__locales[cnt]->usage_count < MAX_USAGE_COUNT)
66 	      ++result->__locales[cnt]->usage_count;
67 
68 	    if (dataset->__names[cnt] == _nl_C_name)
69 	      result->__names[cnt] = _nl_C_name;
70 	    else
71 	      {
72 		result->__names[cnt] = namep;
73 		namep = __stpcpy (namep, dataset->__names[cnt]) + 1;
74 	      }
75 	  }
76 
77       /* Update the special members.  */
78       result->__ctype_b = dataset->__ctype_b;
79       result->__ctype_tolower = dataset->__ctype_tolower;
80       result->__ctype_toupper = dataset->__ctype_toupper;
81 
82       /* It's done.  */
83       __libc_rwlock_unlock (__libc_setlocale_lock);
84     }
85 
86   return result;
87 }
88 weak_alias (__duplocale, duplocale)
89