locale/setlocale.c

   1 /* Copyright (C) 1991, 92, 95-99, 2000 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 Library General Public License as
   6    published by the Free Software Foundation; either version 2 of the
   7    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    Library General Public License for more details.
  13
  14    You should have received a copy of the GNU Library General Public
  15    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  16    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  17    Boston, MA 02111-1307, USA.  */
  18
  19 #include <alloca.h>
  20 #include <argz.h>
  21 #include <errno.h>
  22 #include <bits/libc-lock.h>
  23 #include <locale.h>
  24 #include <stdlib.h>
  25 #include <string.h>
  26 #include <unistd.h>
  27
  28 #include "localeinfo.h"
  29
  30 /* For each category declare two external variables (with weak references):
  31      extern const struct locale_data *_nl_current_CATEGORY;
  32    This points to the current locale's in-core data for CATEGORY.
  33      extern const struct locale_data _nl_C_CATEGORY;
  34    This contains the built-in "C"/"POSIX" locale's data for CATEGORY.
  35    Both are weak references; if &_nl_current_CATEGORY is zero,
  36    then nothing is using the locale data.  */
  37 #define DEFINE_CATEGORY(category, category_name, items, a) \
  38 extern struct locale_data *_nl_current_##category;                            \
  39 extern struct locale_data _nl_C_##category;
  40 #include "categories.def"
  41 #undef  DEFINE_CATEGORY
  42
  43 /* Array indexed by category of pointers to _nl_current_CATEGORY slots.
  44    Elements are zero for categories whose data is never used.  */
  45 struct locale_data * *const _nl_current[] =
  46   {
  47 #define DEFINE_CATEGORY(category, category_name, items, a) \
  48     [category] = &_nl_current_##category,
  49 #include "categories.def"
  50 #undef  DEFINE_CATEGORY
  51     /* We need this additional element to simplify the code.  It must
  52        simply be != NULL.  */
  53     [LC_ALL] = (struct locale_data **) ~0ul
  54   };
  55
  56 /* Array indexed by category of pointers to _nl_C_CATEGORY slots.
  57    Elements are zero for categories whose data is never used.  */
  58 struct locale_data *const _nl_C[] =
  59   {
  60 #define DEFINE_CATEGORY(category, category_name, items, a) \
  61     [category] = &_nl_C_##category,
  62 #include "categories.def"
  63 #undef  DEFINE_CATEGORY
  64   };
  65
  66
  67 /* Define an array of category names (also the environment variable names),
  68    indexed by integral category.  */
  69 const char *const _nl_category_names[] =
  70   {
  71 #define DEFINE_CATEGORY(category, category_name, items, a) \
  72     [category] = category_name,
  73 #include "categories.def"
  74 #undef  DEFINE_CATEGORY
  75     [LC_ALL] = "LC_ALL"
  76   };
  77 /* An array of their lengths, for convenience.  */
  78 const size_t _nl_category_name_sizes[] =
  79   {
  80 #define DEFINE_CATEGORY(category, category_name, items, a) \
  81     [category] = sizeof (category_name) - 1,
  82 #include "categories.def"
  83 #undef  DEFINE_CATEGORY
  84     [LC_ALL] = sizeof ("LC_ALL") - 1
  85   };
  86
  87
  88 /* Declare the postload functions used below.  */
  89 #undef  NO_POSTLOAD
  90 #define NO_POSTLOAD _nl_postload_ctype /* Harmless thing known to exist.  */
  91 #define DEFINE_CATEGORY(category, category_name, items, postload) \
  92 extern void postload (void);
  93 #include "categories.def"
  94 #undef  DEFINE_CATEGORY
  95 #undef  NO_POSTLOAD
  96
  97 /* Define an array indexed by category of postload functions to call after
  98    loading and installing that category's data.  */
  99 static void (*const _nl_category_postload[]) (void) =
 100   {
 101 #define DEFINE_CATEGORY(category, category_name, items, postload) \
 102     [category] = postload,
 103 #include "categories.def"
 104 #undef  DEFINE_CATEGORY
 105   };
 106
 107
 108 /* Name of current locale for each individual category.
 109    Each is malloc'd unless it is nl_C_name.  */
 110 static const char *_nl_current_names[] =
 111   {
 112 #define DEFINE_CATEGORY(category, category_name, items, a) \
 113     [category] = _nl_C_name,
 114 #include "categories.def"
 115 #undef  DEFINE_CATEGORY
 116     [LC_ALL] = _nl_C_name               /* For LC_ALL.  */
 117   };
 118
 119
 120 /* Lock for protecting global data.  */
 121 __libc_lock_define_initialized (, __libc_setlocale_lock)
 122
 123
 124 /* Use this when we come along an error.  */
 125 #define ERROR_RETURN                                                          \
 126   do {                                                                        \
 127     __set_errno (EINVAL);                                                     \
 128     return NULL;                                                              \
 129   } while (0)
 130
 131
 132 /* Construct a new composite name.  */
 133 static inline char *
 134 new_composite_name (int category, const char *newnames[__LC_LAST])
 135 {
 136   size_t last_len = 0;
 137   size_t cumlen = 0;
 138   int i;
 139   char *new, *p;
 140   int same = 1;
 141
 142   for (i = 0; i < __LC_LAST; ++i)
 143     if (i != LC_ALL)
 144       {
 145         const char *name = (category == LC_ALL ? newnames[i] :
 146                             category == i ? newnames[0] :
 147                             _nl_current_names[i]);
 148         last_len = strlen (name);
 149         cumlen += _nl_category_name_sizes[i] + 1 + last_len + 1;
 150         if (i > 0 && same && strcmp (name, newnames[0]) != 0)
 151           same = 0;
 152       }
 153
 154   if (same)
 155     {
 156       /* All the categories use the same name.  */
 157       if (strcmp (newnames[0], _nl_C_name) == 0
 158           || strcmp (newnames[0], _nl_POSIX_name) == 0)
 159         return (char *) _nl_C_name;
 160
 161       new = malloc (last_len + 1);
 162
 163       return new == NULL ? NULL : memcpy (new, newnames[0], last_len + 1);
 164     }
 165
 166   new = malloc (cumlen);
 167   if (new == NULL)
 168     return NULL;
 169   p = new;
 170   for (i = 0; i < __LC_LAST; ++i)
 171     if (i != LC_ALL)
 172       {
 173         /* Add "CATEGORY=NAME;" to the string.  */
 174         const char *name = (category == LC_ALL ? newnames[i] :
 175                             category == i ? newnames[0] :
 176                             _nl_current_names[i]);
 177         p = __stpcpy (p, _nl_category_names[i]);
 178         *p++ = '=';
 179         p = __stpcpy (p, name);
 180         *p++ = ';';
 181       }
 182   p[-1] = '\0';         /* Clobber the last ';'.  */
 183   return new;
 184 }
 185
 186
 187 /* Put NAME in _nl_current_names.  */
 188 static inline void
 189 setname (int category, const char *name)
 190 {
 191   if (_nl_current_names[category] == name)
 192     return;
 193
 194   if (category == LC_ALL && _nl_current_names[category] != _nl_C_name)
 195     free ((char *) _nl_current_names[category]);
 196
 197   _nl_current_names[category] = name;
 198 }
 199
 200
 201 /* Put DATA in *_nl_current[CATEGORY].  */
 202 static inline void
 203 setdata (int category, struct locale_data *data)
 204 {
 205   if (_nl_current[category] != NULL)
 206     {
 207       *_nl_current[category] = data;
 208       if (_nl_category_postload[category])
 209         (*_nl_category_postload[category]) ();
 210     }
 211 }
 212
 213
 214 char *
 215 setlocale (int category, const char *locale)
 216 {
 217   char *locale_path;
 218   size_t locale_path_len;
 219   const char *locpath_var;
 220   char *composite;
 221
 222   /* Sanity check for CATEGORY argument.  */
 223   if (__builtin_expect (category, 0) < 0
 224       || __builtin_expect (category, 0) >= __LC_LAST)
 225     ERROR_RETURN;
 226
 227   /* Does user want name of current locale?  */
 228   if (locale == NULL)
 229     return (char *) _nl_current_names[category];
 230
 231   if (strcmp (locale, _nl_current_names[category]) == 0)
 232     /* Changing to the same thing.  */
 233     return (char *) _nl_current_names[category];
 234
 235   /* We perhaps really have to load some data.  So we determine the
 236      path in which to look for the data now.  The environment variable
 237      `LOCPATH' must only be used when the binary has no SUID or SGID
 238      bit set.  */
 239   locale_path = NULL;
 240   locale_path_len = 0;
 241
 242   locpath_var = __secure_getenv ("LOCPATH");
 243   if (locpath_var != NULL && locpath_var[0] != '\0')
 244     if (__argz_create_sep (locpath_var, ':',
 245                            &locale_path, &locale_path_len) != 0)
 246       return NULL;
 247
 248   if (__argz_add_sep (&locale_path, &locale_path_len, LOCALE_PATH, ':') != 0)
 249     return NULL;
 250
 251   if (category == LC_ALL)
 252     {
 253       /* The user wants to set all categories.  The desired locales
 254          for the individual categories can be selected by using a
 255          composite locale name.  This is a semi-colon separated list
 256          of entries of the form `CATEGORY=VALUE'.  */
 257       const char *newnames[__LC_LAST];
 258       struct locale_data *newdata[__LC_LAST];
 259
 260       /* Set all name pointers to the argument name.  */
 261       for (category = 0; category < __LC_LAST; ++category)
 262         if (category != LC_ALL)
 263           newnames[category] = (char *) locale;
 264
 265       if (__builtin_expect (strchr (locale, ';') != NULL, 0))
 266         {
 267           /* This is a composite name.  Make a copy and split it up.  */
 268           char *np = strdupa (locale);
 269           char *cp;
 270           int cnt;
 271
 272           while ((cp = strchr (np, '=')) != NULL)
 273             {
 274               for (cnt = 0; cnt < __LC_LAST; ++cnt)
 275                 if (cnt != LC_ALL
 276                     && (size_t) (cp - np) == _nl_category_name_sizes[cnt]
 277                     && memcmp (np, _nl_category_names[cnt], cp - np) == 0)
 278                   break;
 279
 280               if (cnt == __LC_LAST)
 281                 /* Bogus category name.  */
 282                 ERROR_RETURN;
 283
 284               /* Found the category this clause sets.  */
 285               newnames[cnt] = ++cp;
 286               cp = strchr (cp, ';');
 287               if (cp != NULL)
 288                 {
 289                   /* Examine the next clause.  */
 290                   *cp = '\0';
 291                   np = cp + 1;
 292                 }
 293               else
 294                 /* This was the last clause.  We are done.  */
 295                 break;
 296             }
 297
 298           for (cnt = 0; cnt < __LC_LAST; ++cnt)
 299             if (cnt != LC_ALL && newnames[cnt] == locale)
 300               /* The composite name did not specify all categories.  */
 301               ERROR_RETURN;
 302         }
 303
 304       /* Protect global data.  */
 305       __libc_lock_lock (__libc_setlocale_lock);
 306
 307       /* Load the new data for each category.  */
 308       while (category-- > 0)
 309         if (category != LC_ALL)
 310           {
 311             newdata[category] = _nl_find_locale (locale_path, locale_path_len,
 312                                                  category,
 313                                                  &newnames[category]);
 314
 315             if (newdata[category] == NULL)
 316               break;
 317
 318             /* We must not simply free a global locale since we have no
 319                control over the usage.  So we mark it as un-deletable.  */
 320             if (newdata[category]->usage_count != UNDELETABLE)
 321               newdata[category]->usage_count = UNDELETABLE;
 322           }
 323
 324       /* Create new composite name.  */
 325       composite = (category >= 0
 326                    ? NULL : new_composite_name (LC_ALL, newnames));
 327       if (composite != NULL)
 328         {
 329           /* Now we have loaded all the new data.  Put it in place.  */
 330           for (category = 0; category < __LC_LAST; ++category)
 331             if (category != LC_ALL)
 332               {
 333                 setdata (category, newdata[category]);
 334                 setname (category, newnames[category]);
 335               }
 336           setname (LC_ALL, composite);
 337         }
 338
 339       /* Critical section left.  */
 340       __libc_lock_unlock (__libc_setlocale_lock);
 341
 342       /* Free the resources (the locale path variable.  */
 343       free (locale_path);
 344
 345       return composite;
 346     }
 347   else
 348     {
 349       struct locale_data *newdata = NULL;
 350       const char *newname[1] = { locale };
 351
 352       /* Protect global data.  */
 353       __libc_lock_lock (__libc_setlocale_lock);
 354
 355       if (_nl_current[category] != NULL)
 356         {
 357           /* Only actually load the data if anything will use it.  */
 358           newdata = _nl_find_locale (locale_path, locale_path_len, category,
 359                                      &newname[0]);
 360           if (newdata == NULL)
 361             goto abort_single;
 362
 363           /* We must not simply free a global locale since we have no
 364              control over the usage.  So we mark it as un-deletable.
 365
 366              Note: do not remove the `if', it's necessary to copy with
 367              the builtin locale data.  */
 368           if (newdata->usage_count != UNDELETABLE)
 369             newdata->usage_count = UNDELETABLE;
 370         }
 371
 372       /* Create new composite name.  */
 373       composite = new_composite_name (category, newname);
 374       if (composite == NULL)
 375         {
 376           /* Say that we don't have any data loaded.  */
 377         abort_single:
 378           newname[0] = NULL;
 379         }
 380       else
 381         {
 382           if (_nl_current[category] != NULL)
 383             setdata (category, newdata);
 384
 385           setname (category, newname[0]);
 386           setname (LC_ALL, composite);
 387         }
 388
 389       /* Critical section left.  */
 390       __libc_lock_unlock (__libc_setlocale_lock);
 391
 392       /* Free the resources (the locale path variable.  */
 393       free (locale_path);
 394
 395       return (char *) newname[0];
 396     }
 397 }
 398
 399
 400 static void __attribute__ ((unused))
 401 free_mem (void)
 402 {
 403   int category;
 404
 405   for (category = 0; category < __LC_LAST; ++category)
 406     if (category != LC_ALL)
 407       {
 408         struct locale_data *here = *_nl_current[category];
 409
 410         /* If this category is already "C" don't do anything.  */
 411         if (here == _nl_C[category])
 412           continue;
 413
 414         /* We have to be prepared that sometime later me still might
 415            need the locale information.  */
 416         setdata (category, _nl_C[category]);
 417         setname (category, _nl_C_name);
 418
 419         _nl_unload_locale (here);
 420       }
 421
 422   setname (LC_ALL, _nl_C_name);
 423 }
 424 text_set_element (__libc_subfreeres, free_mem);