locale/setlocale.c

   1 /* Copyright (C) 1991, 1992, 1995, 1996, 1997 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, b, c, d) \
  38 extern struct locale_data *_nl_current_##category;                            \
  39 extern struct locale_data _nl_C_##category;                                   \
  40 weak_extern (_nl_current_##category) weak_extern (_nl_C_##category)
  41 #include "categories.def"
  42 #undef  DEFINE_CATEGORY
  43
  44 /* Array indexed by category of pointers to _nl_current_CATEGORY slots.
  45    Elements are zero for categories whose data is never used.  */
  46 static struct locale_data * *const _nl_current[] =
  47   {
  48 #define DEFINE_CATEGORY(category, category_name, items, a, b, c, d) \
  49     [category] = &_nl_current_##category,
  50 #include "categories.def"
  51 #undef  DEFINE_CATEGORY
  52     /* We need this additional element to simplify the code.  It must
  53        simply be != NULL.  */
  54     [LC_ALL] = (struct locale_data **) ~0ul
  55   };
  56
  57 /* Array indexed by category of pointers to _nl_C_CATEGORY slots.
  58    Elements are zero for categories whose data is never used.  */
  59 struct locale_data *const _nl_C[] =
  60   {
  61 #define DEFINE_CATEGORY(category, category_name, items, a, b, c, d) \
  62     [category] = &_nl_C_##category,
  63 #include "categories.def"
  64 #undef  DEFINE_CATEGORY
  65   };
  66
  67
  68 /* Define an array of category names (also the environment variable names),
  69    indexed by integral category.  */
  70 const char *const _nl_category_names[] =
  71   {
  72 #define DEFINE_CATEGORY(category, category_name, items, a, b, c, d) \
  73     [category] = category_name,
  74 #include "categories.def"
  75 #undef  DEFINE_CATEGORY
  76     [LC_ALL] = "LC_ALL"
  77   };
  78 /* An array of their lengths, for convenience.  */
  79 const size_t _nl_category_name_sizes[] =
  80   {
  81 #define DEFINE_CATEGORY(category, category_name, items, a, b, c, d) \
  82     [category] = sizeof (category_name) - 1,
  83 #include "categories.def"
  84 #undef  DEFINE_CATEGORY
  85     [LC_ALL] = sizeof ("LC_ALL") - 1
  86   };
  87
  88
  89 /* Declare the postload functions used below.  */
  90 #undef  NO_POSTLOAD
  91 #define NO_POSTLOAD _nl_postload_ctype /* Harmless thing known to exist.  */
  92 #define DEFINE_CATEGORY(category, category_name, items, postload, b, c, d) \
  93 extern void postload (void);
  94 #include "categories.def"
  95 #undef  DEFINE_CATEGORY
  96 #undef  NO_POSTLOAD
  97
  98 /* Define an array indexed by category of postload functions to call after
  99    loading and installing that category's data.  */
 100 static void (*const _nl_category_postload[]) (void) =
 101   {
 102 #define DEFINE_CATEGORY(category, category_name, items, postload, b, c, d) \
 103     [category] = postload,
 104 #include "categories.def"
 105 #undef  DEFINE_CATEGORY
 106   };
 107
 108
 109 /* Name of current locale for each individual category.
 110    Each is malloc'd unless it is nl_C_name.  */
 111 static const char *_nl_current_names[] =
 112   {
 113 #define DEFINE_CATEGORY(category, category_name, items, a, b, c, d) \
 114     [category] = _nl_C_name,
 115 #include "categories.def"
 116 #undef  DEFINE_CATEGORY
 117     [LC_ALL] = _nl_C_name               /* For LC_ALL.  */
 118   };
 119
 120
 121 /* Lock for protecting global data.  */
 122 __libc_lock_define_initialized (, __libc_setlocale_lock)
 123
 124
 125 /* Use this when we come along an error.  */
 126 #define ERROR_RETURN                                                          \
 127   do {                                                                        \
 128     __set_errno (EINVAL);                                                     \
 129     return NULL;                                                              \
 130   } while (0)
 131
 132
 133 /* Construct a new composite name.  */
 134 static inline char *
 135 new_composite_name (int category, const char *newnames[LC_ALL])
 136 {
 137   size_t last_len;
 138   size_t cumlen = 0;
 139   int i;
 140   char *new, *p;
 141   int same = 1;
 142
 143   for (i = 0; i < LC_ALL; ++i)
 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_ALL; ++i)
 171     {
 172       /* Add "CATEGORY=NAME;" to the string.  */
 173       const char *name = (category == LC_ALL ? newnames[i] :
 174                           category == i ? newnames[0] :
 175                           _nl_current_names[i]);
 176       p = __stpcpy (p, _nl_category_names[i]);
 177       *p++ = '=';
 178       p = __stpcpy (p, name);
 179       *p++ = ';';
 180     }
 181   p[-1] = '\0';         /* Clobber the last ';'.  */
 182   return new;
 183 }
 184
 185
 186 /* Put NAME in _nl_current_names.  */
 187 static inline void
 188 setname (int category, const char *name)
 189 {
 190   if (_nl_current_names[category] == name)
 191     return;
 192
 193   if (category == LC_ALL && _nl_current_names[category] != _nl_C_name)
 194     free ((char *) _nl_current_names[category]);
 195
 196   _nl_current_names[category] = name;
 197 }
 198
 199
 200 /* Put DATA in *_nl_current[CATEGORY].  */
 201 static inline void
 202 setdata (int category, struct locale_data *data)
 203 {
 204   if (_nl_current[category] != NULL)
 205     {
 206       *_nl_current[category] = data;
 207       if (_nl_category_postload[category])
 208         (*_nl_category_postload[category]) ();
 209     }
 210 }
 211
 212
 213 char *
 214 setlocale (int category, const char *locale)
 215 {
 216   char *locale_path;
 217   size_t locale_path_len;
 218   const char *locpath_var;
 219   char *composite;
 220
 221   /* Sanity check for CATEGORY argument.  */
 222   if (category < 0 || category > LC_ALL)
 223     ERROR_RETURN;
 224
 225   /* Does user want name of current locale?  */
 226   if (locale == NULL)
 227     return (char *) _nl_current_names[category];
 228
 229   if (strcmp (locale, _nl_current_names[category]) == 0)
 230     /* Changing to the same thing.  */
 231     return (char *) _nl_current_names[category];
 232
 233   /* We perhaps really have to load some data.  So we determine the
 234      path in which to look for the data now.  The environment variable
 235      `LOCPATH' must only be used when the binary has no SUID or SGID
 236      bit set.  */
 237   locale_path = NULL;
 238   locale_path_len = 0;
 239
 240   locpath_var = __secure_getenv ("LOCPATH");
 241   if (locpath_var != NULL && locpath_var[0] != '\0')
 242     if (__argz_create_sep (locpath_var, ':',
 243                            &locale_path, &locale_path_len) != 0)
 244       return NULL;
 245
 246   if (__argz_add_sep (&locale_path, &locale_path_len, LOCALE_PATH, ':') != 0)
 247     return NULL;
 248
 249   if (category == LC_ALL)
 250     {
 251       /* The user wants to set all categories.  The desired locales
 252          for the individual categories can be selected by using a
 253          composite locale name.  This is a semi-colon separated list
 254          of entries of the form `CATEGORY=VALUE'.  */
 255       const char *newnames[LC_ALL];
 256       struct locale_data *newdata[LC_ALL];
 257
 258       /* Set all name pointers to the argument name.  */
 259       for (category = 0; category < LC_ALL; ++category)
 260         newnames[category] = (char *) locale;
 261
 262       if (strchr (locale, ';') != NULL)
 263         {
 264           /* This is a composite name.  Make a copy and split it up.  */
 265           char *np = strdupa (locale);
 266           char *cp;
 267           int cnt;
 268
 269           while ((cp = strchr (np, '=')) != NULL)
 270             {
 271               for (cnt = 0; cnt < LC_ALL; ++cnt)
 272                 if ((size_t) (cp - np) == _nl_category_name_sizes[cnt]
 273                     && memcmp (np, _nl_category_names[cnt], cp - np) == 0)
 274                   break;
 275
 276               if (cnt == LC_ALL)
 277                 /* Bogus category name.  */
 278                 ERROR_RETURN;
 279
 280               /* Found the category this clause sets.  */
 281               newnames[cnt] = ++cp;
 282               cp = strchr (cp, ';');
 283               if (cp != NULL)
 284                 {
 285                   /* Examine the next clause.  */
 286                   *cp = '\0';
 287                   np = cp + 1;
 288                 }
 289               else
 290                 /* This was the last clause.  We are done.  */
 291                 break;
 292             }
 293
 294           for (cnt = 0; cnt < LC_ALL; ++cnt)
 295             if (newnames[cnt] == locale)
 296               /* The composite name did not specify all categories.  */
 297               ERROR_RETURN;
 298         }
 299
 300       /* Protect global data.  */
 301       __libc_lock_lock (__libc_setlocale_lock);
 302
 303       /* Load the new data for each category.  */
 304       while (category-- > 0)
 305         {
 306           newdata[category] = _nl_find_locale (locale_path, locale_path_len,
 307                                                category,
 308                                                &newnames[category]);
 309
 310           if (newdata[category] == NULL)
 311             break;
 312
 313           /* We must not simply free a global locale since we have no
 314              control over the usage.  So we mark it as un-deletable.  */
 315           if (newdata[category]->usage_count != UNDELETABLE)
 316             newdata[category]->usage_count = UNDELETABLE;
 317         }
 318
 319       /* Create new composite name.  */
 320       if (category >= 0
 321           || (composite = new_composite_name (LC_ALL, newnames)) == NULL)
 322         /* Loading this part of the locale failed.  Abort the
 323            composite load.  */
 324         composite = NULL;
 325       else
 326         {
 327           /* Now we have loaded all the new data.  Put it in place.  */
 328           for (category = 0; category < LC_ALL; ++category)
 329             {
 330               setdata (category, newdata[category]);
 331               setname (category, newnames[category]);
 332             }
 333           setname (LC_ALL, composite);
 334         }
 335
 336       /* Critical section left.  */
 337       __libc_lock_unlock (__libc_setlocale_lock);
 338
 339       /* Free the resources (the locale path variable.  */
 340       free (locale_path);
 341
 342       return composite;
 343     }
 344   else
 345     {
 346       struct locale_data *newdata = NULL;
 347       const char *newname[1] = { locale };
 348
 349       /* Protect global data.  */
 350       __libc_lock_lock (__libc_setlocale_lock);
 351
 352       if (_nl_current[category] != NULL)
 353         {
 354           /* Only actually load the data if anything will use it.  */
 355           newdata = _nl_find_locale (locale_path, locale_path_len, category,
 356                                      &newname[0]);
 357           if (newdata == NULL)
 358             goto abort_single;
 359
 360           /* We must not simply free a global locale since we have no
 361              control over the usage.  So we mark it as un-deletable.
 362
 363              Note: do ont remove the `if', it's necessary to copy with
 364              the builtin locale data.  */
 365           if (newdata->usage_count != UNDELETABLE)
 366             newdata->usage_count = UNDELETABLE;
 367         }
 368
 369       /* Create new composite name.  */
 370       composite = new_composite_name (category, newname);
 371       if (composite == NULL)
 372         {
 373           /* Say that we don't have any data loaded.  */
 374         abort_single:
 375           newname[0] = NULL;
 376         }
 377       else
 378         {
 379           if (_nl_current[category] != NULL)
 380             setdata (category, newdata);
 381
 382           setname (category, newname[0]);
 383           setname (LC_ALL, composite);
 384         }
 385
 386       /* Critical section left.  */
 387       __libc_lock_unlock (__libc_setlocale_lock);
 388
 389       /* Free the resources (the locale path variable.  */
 390       free (locale_path);
 391
 392       return (char *) newname[0];
 393     }
 394 }