wcsmbs/wcsmbsload.c

   1 /* Copyright (C) 1998 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Ulrich Drepper <drepper@cygnus.com>, 1998.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Library General Public License as
   7    published by the Free Software Foundation; either version 2 of the
   8    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    Library General Public License for more details.
  14
  15    You should have received a copy of the GNU Library General Public
  16    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  17    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  18    Boston, MA 02111-1307, USA.  */
  19
  20 #include <langinfo.h>
  21 #include <limits.h>
  22 #include <stdlib.h>
  23 #include <string.h>
  24
  25 #include <locale/localeinfo.h>
  26 #include <wcsmbsload.h>
  27 #include <bits/libc-lock.h>
  28 #include <iconv/gconv_int.h>
  29
  30
  31 /* Last loaded locale for LC_CTYPE.  We initialize for the C locale
  32    which is enabled at startup.  */
  33 extern const struct locale_data _nl_C_LC_CTYPE;
  34 const struct locale_data *__wcsmbs_last_locale = &_nl_C_LC_CTYPE;
  35
  36
  37 /* These are the descriptions for the default conversion functions.  */
  38 static struct gconv_step to_wc =
  39 {
  40   shlib_handle: NULL,
  41   modname: NULL,
  42   counter: INT_MAX,
  43   from_name: "ANSI_X3.4-1968//",
  44   to_name: "INTERNAL",
  45   fct: __gconv_transform_ascii_internal,
  46   init_fct: NULL,
  47   end_fct: NULL,
  48   data: NULL
  49 };
  50
  51 static struct gconv_step to_mb =
  52 {
  53   shlib_handle: NULL,
  54   modname: NULL,
  55   counter: INT_MAX,
  56   from_name: "INTERNAL",
  57   to_name: "ANSI_X3.4-1968//",
  58   fct: __gconv_transform_internal_ascii,
  59   init_fct: NULL,
  60   end_fct: NULL,
  61   data: NULL
  62 };
  63
  64
  65 /* For the default locale we only have to handle ANSI_X3.4-1968.  */
  66 struct gconv_fcts __wcsmbs_gconv_fcts =
  67 {
  68   towc: &to_wc,
  69   tomb: &to_mb
  70 };
  71
  72
  73 static inline struct gconv_step *
  74 getfct (const char *to, const char *from)
  75 {
  76   size_t nsteps;
  77   struct gconv_step *result;
  78
  79   if (__gconv_find_transform (to, from, &result, &nsteps) != GCONV_OK)
  80     /* Loading the conversion step is not possible.  */
  81     return NULL;
  82
  83   /* We must only have one step in this conversion.  */
  84   if (nsteps != 1)
  85     return NULL;
  86
  87   return result;
  88 }
  89
  90
  91 /* Extract from the given locale name the character set portion.  Since
  92    only the XPG form of the name includes this information we don't have
  93    to take care for the CEN form.  */
  94 #define extract_charset_name(str) \
  95   ({                                                                          \
  96     const char *cp = str;                                                     \
  97     char *result = NULL;                                                      \
  98                                                                               \
  99     cp += strcspn (cp, "@.+,");                                               \
 100     if (*cp == '.')                                                           \
 101       {                                                                       \
 102         const char *endp = ++cp;                                              \
 103         while (*endp != '\0' && *endp != '@')                                 \
 104           ++endp;                                                             \
 105         if (endp != cp)                                                       \
 106           result = strndupa (cp, endp - cp);                                  \
 107       }                                                                       \
 108     result;                                                                   \
 109   })
 110
 111
 112 /* The gconv functions expects the name to be complete, including the
 113    trailing shashes if necessary.  */
 114 #define add_slashes(str) \
 115   ({                                                                          \
 116     const char *cp = str;                                                     \
 117     char *result;                                                             \
 118     char *tmp;                                                                \
 119     size_t cnt = 0;                                                           \
 120                                                                               \
 121     while (*cp != '\0')                                                       \
 122       if (*cp++ == '/')                                                       \
 123         ++cnt;                                                                \
 124                                                                               \
 125     result = alloca (cp - str + 3);                                           \
 126     tmp = __mempcpy (result, str, cp - str);                                  \
 127     if (cnt < 2)                                                              \
 128       {                                                                       \
 129         *tmp++ = '/';                                                         \
 130         if (cnt < 1)                                                          \
 131           *tmp++ = '/';                                                       \
 132       }                                                                       \
 133     *tmp = '\0';                                                              \
 134     result;                                                                   \
 135   })
 136
 137
 138 /* Load conversion functions for the currently selected locale.  */
 139 void
 140 internal_function
 141 __wcsmbs_load_conv (const struct locale_data *new_category)
 142 {
 143   /* We must modify global data.  */
 144   __libc_lock_define_initialized (static, lock)
 145
 146   /* Acquire the lock.  */
 147   __libc_lock_lock (lock);
 148
 149   /* We should repest the test since while we waited some other thread
 150      might have run this function.  */
 151   if (__wcsmbs_last_locale != new_category)
 152     {
 153       if (new_category->name == _nl_C_name)     /* Yes, pointer comparison.  */
 154         {
 155         failed:
 156           __wcsmbs_gconv_fcts.towc = &to_wc;
 157           __wcsmbs_gconv_fcts.tomb = &to_mb;
 158         }
 159       else
 160         {
 161           /* We must find the real functions.  */
 162           const char *charset_name;
 163           const char *complete_name;
 164
 165           /* Get name of charset of the locale.  We first examine
 166              whether we have a character set mentioned in the locale
 167              name.  If this isn't the case we use the information from
 168              the locale files.  */
 169           charset_name = extract_charset_name (setlocale (LC_CTYPE, NULL));
 170           if (charset_name == NULL)
 171             charset_name =
 172               new_category->values[_NL_ITEM_INDEX(CODESET)].string;
 173
 174           /* Add the slashes necessary for a complete lookup.  */
 175           complete_name = add_slashes (charset_name);
 176
 177           __wcsmbs_gconv_fcts.tomb = getfct (complete_name, "INTERNAL");
 178           __wcsmbs_gconv_fcts.towc = getfct ("INTERNAL", complete_name);
 179
 180           /* If any of the conversion functions is not available we don't
 181              use any since this would mean we cannot convert back and
 182              forth.*/
 183           if (__wcsmbs_gconv_fcts.towc == NULL
 184               || __wcsmbs_gconv_fcts.tomb == NULL)
 185             goto failed;
 186         }
 187
 188       /* Set last-used variable for current locale.  */
 189       __wcsmbs_last_locale = new_category;
 190     }
 191
 192   __libc_lock_unlock (lock);
 193 }