wcsmbs/wcsmbsload.c

   1 /* Copyright (C) 1998-2023 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, see
  16    <https://www.gnu.org/licenses/>.  */
  17
  18 #include <ctype.h>
  19 #include <langinfo.h>
  20 #include <limits.h>
  21 #include <stdlib.h>
  22 #include <stdio.h>
  23 #include <string.h>
  24
  25 #include <locale/localeinfo.h>
  26 #include <wcsmbsload.h>
  27 #include <libc-lock.h>
  28
  29
  30 /* These are the descriptions for the default conversion functions.  */
  31 static const struct __gconv_step to_wc =
  32 {
  33   .__shlib_handle = NULL,
  34   .__modname = NULL,
  35   .__counter = INT_MAX,
  36   .__from_name = (char *) "ANSI_X3.4-1968//TRANSLIT",
  37   .__to_name = (char *) "INTERNAL",
  38   .__fct = __gconv_transform_ascii_internal,
  39   .__btowc_fct = __gconv_btwoc_ascii,
  40   .__init_fct = NULL,
  41   .__end_fct = NULL,
  42   .__min_needed_from = 1,
  43   .__max_needed_from = 1,
  44   .__min_needed_to = 4,
  45   .__max_needed_to = 4,
  46   .__stateful = 0,
  47   .__data = NULL
  48 };
  49
  50 static const struct __gconv_step to_mb =
  51 {
  52   .__shlib_handle = NULL,
  53   .__modname = NULL,
  54   .__counter = INT_MAX,
  55   .__from_name = (char *) "INTERNAL",
  56   .__to_name = (char *) "ANSI_X3.4-1968//TRANSLIT",
  57   .__fct = __gconv_transform_internal_ascii,
  58   .__btowc_fct = NULL,
  59   .__init_fct = NULL,
  60   .__end_fct = NULL,
  61   .__min_needed_from = 4,
  62   .__max_needed_from = 4,
  63   .__min_needed_to = 1,
  64   .__max_needed_to = 1,
  65   .__stateful = 0,
  66   .__data = NULL
  67 };
  68
  69
  70 /* For the default locale we only have to handle ANSI_X3.4-1968.  */
  71 const struct gconv_fcts __wcsmbs_gconv_fcts_c =
  72 {
  73   .towc = (struct __gconv_step *) &to_wc,
  74   .towc_nsteps = 1,
  75   .tomb = (struct __gconv_step *) &to_mb,
  76   .tomb_nsteps = 1,
  77 };
  78
  79
  80 attribute_hidden
  81 struct __gconv_step *
  82 __wcsmbs_getfct (const char *to, const char *from, size_t *nstepsp)
  83 {
  84   size_t nsteps;
  85   struct __gconv_step *result;
  86 #if 0
  87   size_t nstateful;
  88   size_t cnt;
  89 #endif
  90
  91   if (__gconv_find_transform (to, from, &result, &nsteps, 0) != __GCONV_OK)
  92     /* Loading the conversion step is not possible.  */
  93     return NULL;
  94
  95   /* Maybe it is someday necessary to allow more than one step.
  96      Currently this is not the case since the conversions handled here
  97      are from and to INTERNAL and there always is a converted for
  98      that.  It the directly following code is enabled the libio
  99      functions will have to allocate appropriate __gconv_step_data
 100      elements instead of only one.  */
 101 #if 0
 102   /* Count the number of stateful conversions.  Since we will only
 103      have one 'mbstate_t' object available we can only deal with one
 104      stateful conversion.  */
 105   nstateful = 0;
 106   for (cnt = 0; cnt < nsteps; ++cnt)
 107     if (result[cnt].__stateful)
 108       ++nstateful;
 109   if (nstateful > 1)
 110 #else
 111   if (nsteps > 1)
 112 #endif
 113     {
 114       /* We cannot handle this case.  */
 115       __gconv_close_transform (result, nsteps);
 116       result = NULL;
 117     }
 118   else
 119     *nstepsp = nsteps;
 120
 121   return result;
 122 }
 123
 124
 125 /* Extract from the given locale name the character set portion.  Since
 126    only the XPG form of the name includes this information we don't have
 127    to take care for the CEN form.  */
 128 #define extract_charset_name(str) \
 129   ({                                                                          \
 130     const char *cp = str;                                                     \
 131     char *result = NULL;                                                      \
 132                                                                               \
 133     cp += strcspn (cp, "@.+,");                                               \
 134     if (*cp == '.')                                                           \
 135       {                                                                       \
 136         const char *endp = ++cp;                                              \
 137         while (*endp != '\0' && *endp != '@')                                 \
 138           ++endp;                                                             \
 139         if (endp != cp)                                                       \
 140           result = strndupa (cp, endp - cp);                                  \
 141       }                                                                       \
 142     result;                                                                   \
 143   })
 144
 145
 146 /* Some of the functions here must not be used while setlocale is called.  */
 147 __libc_rwlock_define (extern, __libc_setlocale_lock attribute_hidden)
 148
 149 /* Load conversion functions for the currently selected locale.  */
 150 void
 151 __wcsmbs_load_conv (struct __locale_data *new_category)
 152 {
 153   struct lc_ctype_data *data = new_category->private;
 154
 155   /* Acquire the lock.  */
 156   __libc_rwlock_wrlock (__libc_setlocale_lock);
 157
 158   /* We should repeat the test since while we waited some other thread
 159      might have run this function.  */
 160   if (__glibc_likely (data->fcts == NULL))
 161     {
 162       /* We must find the real functions.  */
 163       const char *charset_name;
 164       const char *complete_name;
 165       struct gconv_fcts *new_fcts;
 166       int use_translit;
 167
 168       /* Allocate the gconv_fcts structure.  */
 169       new_fcts = calloc (1, sizeof *new_fcts);
 170       if (new_fcts == NULL)
 171         goto failed;
 172
 173       /* Get name of charset of the locale.  */
 174       charset_name = new_category->values[_NL_ITEM_INDEX(CODESET)].string;
 175
 176       /* Does the user want transliteration?  */
 177       use_translit = new_category->use_translit;
 178
 179       /* Normalize the name and add the slashes necessary for a
 180          complete lookup.  */
 181       complete_name = norm_add_slashes (charset_name,
 182                                         use_translit ? "TRANSLIT" : "");
 183
 184       /* It is not necessary to use transliteration in this direction
 185          since the internal character set is supposed to be able to
 186          represent all others.  */
 187       new_fcts->towc = __wcsmbs_getfct ("INTERNAL", complete_name,
 188                                         &new_fcts->towc_nsteps);
 189       if (new_fcts->towc != NULL)
 190         new_fcts->tomb = __wcsmbs_getfct (complete_name, "INTERNAL",
 191                                           &new_fcts->tomb_nsteps);
 192
 193       /* If any of the conversion functions is not available we don't
 194          use any since this would mean we cannot convert back and
 195          forth.  NB: NEW_FCTS was allocated with calloc.  */
 196       if (new_fcts->tomb == NULL)
 197         {
 198           if (new_fcts->towc != NULL)
 199             __gconv_close_transform (new_fcts->towc, new_fcts->towc_nsteps);
 200
 201           free (new_fcts);
 202
 203         failed:
 204           data->fcts = (void *) &__wcsmbs_gconv_fcts_c;
 205         }
 206       else
 207         data->fcts = new_fcts;
 208     }
 209
 210   __libc_rwlock_unlock (__libc_setlocale_lock);
 211 }
 212
 213
 214 /* Clone the current conversion function set.  */
 215 void
 216 __wcsmbs_clone_conv (struct gconv_fcts *copy)
 217 {
 218   const struct gconv_fcts *orig;
 219
 220   orig = get_gconv_fcts (_NL_CURRENT_DATA (LC_CTYPE));
 221
 222   /* Copy the data.  */
 223   *copy = *orig;
 224
 225   /* Now increment the usage counters.  Note: This assumes
 226      copy->*_nsteps == 1.  The current locale holds a reference, so it
 227      is still there after acquiring the lock.  */
 228
 229   __libc_lock_lock (__gconv_lock);
 230
 231   bool overflow = false;
 232   if (copy->towc->__shlib_handle != NULL)
 233     overflow |= __builtin_add_overflow (copy->towc->__counter, 1,
 234                                         &copy->towc->__counter);
 235   if (copy->tomb->__shlib_handle != NULL)
 236     overflow |= __builtin_add_overflow (copy->tomb->__counter, 1,
 237                                         &copy->tomb->__counter);
 238
 239   __libc_lock_unlock (__gconv_lock);
 240
 241   if (overflow)
 242     __libc_fatal ("\
 243 Fatal glibc error: gconv module reference counter overflow\n");
 244 }
 245
 246
 247 /* Get converters for named charset.  */
 248 int
 249 __wcsmbs_named_conv (struct gconv_fcts *copy, const char *name)
 250 {
 251   copy->towc = __wcsmbs_getfct ("INTERNAL", name, &copy->towc_nsteps);
 252   if (copy->towc == NULL)
 253     return 1;
 254
 255   copy->tomb = __wcsmbs_getfct (name, "INTERNAL", &copy->tomb_nsteps);
 256   if (copy->tomb == NULL)
 257     {
 258       __gconv_close_transform (copy->towc, copy->towc_nsteps);
 259       return 1;
 260     }
 261
 262   return 0;
 263 }
 264
 265 void
 266 _nl_cleanup_ctype (struct __locale_data *locale)
 267 {
 268   struct lc_ctype_data *data = locale->private;
 269   if (data->fcts != NULL && data->fcts != &__wcsmbs_gconv_fcts_c)
 270     {
 271       /* Free the old conversions.  */
 272       __gconv_close_transform (data->fcts->tomb, data->fcts->tomb_nsteps);
 273       __gconv_close_transform (data->fcts->towc, data->fcts->towc_nsteps);
 274
 275       free ((void *) data->fcts);
 276       data->fcts = NULL;
 277       /* data itself is allocated within locale.  */
 278     }
 279 }