locale/duplocale.c

   1 /* Duplicate handle for selection of locales.
   2    Copyright (C) 1997-2021 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4    Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, see
  18    <https://www.gnu.org/licenses/>.  */
  19
  20 #include <locale.h>
  21 #include <libc-lock.h>
  22 #include <stdlib.h>
  23 #include <string.h>
  24
  25 #include <localeinfo.h>
  26
  27
  28 /* Lock for protecting global data.  */
  29 __libc_rwlock_define (extern , __libc_setlocale_lock attribute_hidden)
  30
  31
  32 locale_t
  33 __duplocale (locale_t dataset)
  34 {
  35   /* This static object is returned for newlocale (LC_ALL_MASK, "C").  */
  36   if (dataset == _nl_C_locobj_ptr)
  37     return dataset;
  38
  39   /* Handle a special value.  */
  40   if (dataset == LC_GLOBAL_LOCALE)
  41     dataset = &_nl_global_locale;
  42
  43   locale_t result;
  44   int cnt;
  45   size_t names_len = 0;
  46
  47   /* Calculate the total space we need to store all the names.  */
  48   for (cnt = 0; cnt < __LC_LAST; ++cnt)
  49     if (cnt != LC_ALL && dataset->__names[cnt] != _nl_C_name)
  50       names_len += strlen (dataset->__names[cnt]) + 1;
  51
  52   /* Get memory.  */
  53   result = malloc (sizeof (struct __locale_struct) + names_len);
  54
  55   if (result != NULL)
  56     {
  57       char *namep = (char *) (result + 1);
  58
  59       /* We modify global data (the usage counts).  */
  60       __libc_rwlock_wrlock (__libc_setlocale_lock);
  61
  62       for (cnt = 0; cnt < __LC_LAST; ++cnt)
  63         if (cnt != LC_ALL)
  64           {
  65             result->__locales[cnt] = dataset->__locales[cnt];
  66             if (result->__locales[cnt]->usage_count < MAX_USAGE_COUNT)
  67               ++result->__locales[cnt]->usage_count;
  68
  69             if (dataset->__names[cnt] == _nl_C_name)
  70               result->__names[cnt] = _nl_C_name;
  71             else
  72               {
  73                 result->__names[cnt] = namep;
  74                 namep = __stpcpy (namep, dataset->__names[cnt]) + 1;
  75               }
  76           }
  77
  78       /* Update the special members.  */
  79       result->__ctype_b = dataset->__ctype_b;
  80       result->__ctype_tolower = dataset->__ctype_tolower;
  81       result->__ctype_toupper = dataset->__ctype_toupper;
  82
  83       /* It's done.  */
  84       __libc_rwlock_unlock (__libc_setlocale_lock);
  85     }
  86
  87   return result;
  88 }
  89 weak_alias (__duplocale, duplocale)