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 static inline char *
 134 clever_copy (const char *string)
 135 {
 136   size_t len;
 137   char *new;
 138
 139   if (strcmp (string, "C") == 0 || strcmp (string, "POSIX") == 0)
 140     /* This return is dangerous because the returned string might be
 141        placed in read-only memory.  But everything should be set up to
 142        handle this case.  */
 143     return (char *) _nl_C_name;
 144
 145   len = strlen (string) + 1;
 146   new = (char *) malloc (len);
 147   return new != NULL ? memcpy (new, string, len) : NULL;
 148 }
 149
 150
 151 /* Construct a new composite name.  */
 152 static inline char *
 153 new_composite_name (int category, const char *newnames[LC_ALL])
 154 {
 155   size_t last_len;
 156   size_t cumlen = 0;
 157   int i;
 158   char *new, *p;
 159   int same = 1;
 160
 161   for (i = 0; i < LC_ALL; ++i)
 162     {
 163       const char *name = (category == LC_ALL ? newnames[i] :
 164                           category == i ? newnames[0] :
 165                           _nl_current_names[i]);
 166       last_len = strlen (name);
 167       cumlen += _nl_category_name_sizes[i] + 1 + last_len + 1;
 168       if (i > 0 && same && strcmp (name, newnames[0]) != 0)
 169         same = 0;
 170     }
 171
 172   if (same)
 173     {
 174       /* All the categories use the same name.  */
 175       if (strcmp (newnames[0], "C") == 0 || strcmp (newnames[0], "POSIX") == 0)
 176         return (char *) _nl_C_name;
 177
 178       new = malloc (last_len + 1);
 179
 180       return new == NULL ? NULL : memcpy (new, newnames[0], last_len + 1);
 181     }
 182
 183   new = malloc (cumlen);
 184   if (new == NULL)
 185     return NULL;
 186   p = new;
 187   for (i = 0; i < LC_ALL; ++i)
 188     {
 189       /* Add "CATEGORY=NAME;" to the string.  */
 190       const char *name = (category == LC_ALL ? newnames[i] :
 191                           category == i ? newnames[0] :
 192                           _nl_current_names[i]);
 193       p = __stpcpy (p, _nl_category_names[i]);
 194       *p++ = '=';
 195       p = __stpcpy (p, name);
 196       *p++ = ';';
 197     }
 198   p[-1] = '\0';         /* Clobber the last ';'.  */
 199   return new;
 200 }
 201
 202
 203 /* Put NAME in _nl_current_names.  */
 204 static inline void
 205 setname (int category, const char *name)
 206 {
 207   if (_nl_current_names[category] != _nl_C_name)
 208     free ((void *) _nl_current_names[category]);
 209
 210   _nl_current_names[category] = name;
 211 }
 212
 213
 214 /* Put DATA in *_nl_current[CATEGORY].  */
 215 static inline void
 216 setdata (int category, struct locale_data *data)
 217 {
 218   if (_nl_current[category] != NULL)
 219     {
 220       *_nl_current[category] = data;
 221       if (_nl_category_postload[category])
 222         (*_nl_category_postload[category]) ();
 223     }
 224 }
 225
 226
 227 char *
 228 setlocale (int category, const char *locale)
 229 {
 230   char *locale_path;
 231   size_t locale_path_len;
 232   const char *locpath_var;
 233   char *composite;
 234
 235   /* Sanity check for CATEGORY argument.  */
 236   if (category < 0 || category > LC_ALL)
 237     ERROR_RETURN;
 238
 239   /* Does user want name of current locale?  */
 240   if (locale == NULL)
 241     return (char *) _nl_current_names[category];
 242
 243   if (strcmp (locale, _nl_current_names[category]) == 0)
 244     /* Changing to the same thing.  */
 245     return (char *) _nl_current_names[category];
 246
 247   /* We perhaps really have to load some data.  So we determine the
 248      path in which to look for the data now.  The environment variable
 249      `LOCPATH' must only be used when the binary has no SUID or SGID
 250      bit set.  */
 251   locale_path = NULL;
 252   locale_path_len = 0;
 253
 254   locpath_var = __secure_getenv ("LOCPATH");
 255   if (locpath_var != NULL && locpath_var[0] != '\0')
 256     if (__argz_create_sep (locpath_var, ':',
 257                            &locale_path, &locale_path_len) != 0)
 258       return NULL;
 259
 260   if (__argz_add_sep (&locale_path, &locale_path_len, LOCALE_PATH, ':') != 0)
 261     return NULL;
 262
 263   if (category == LC_ALL)
 264     {
 265       /* The user wants to set all categories.  The desired locales
 266          for the individual categories can be selected by using a
 267          composite locale name.  This is a semi-colon separated list
 268          of entries of the form `CATEGORY=VALUE'.  */
 269       const char *newnames[LC_ALL];
 270       struct locale_data *newdata[LC_ALL];
 271
 272       /* Set all name pointers to the argument name.  */
 273       for (category = 0; category < LC_ALL; ++category)
 274         newnames[category] = (char *) locale;
 275
 276       if (strchr (locale, ';') != NULL)
 277         {
 278           /* This is a composite name.  Make a copy and split it up.  */
 279           char *np = strdupa (locale);
 280           char *cp;
 281           int cnt;
 282
 283           while ((cp = strchr (np, '=')) != NULL)
 284             {
 285               for (cnt = 0; cnt < LC_ALL; ++cnt)
 286                 if ((size_t) (cp - np) == _nl_category_name_sizes[cnt]
 287                     && memcmp (np, _nl_category_names[cnt], cp - np) == 0)
 288                   break;
 289
 290               if (cnt == LC_ALL)
 291                 /* Bogus category name.  */
 292                 ERROR_RETURN;
 293
 294               /* Found the category this clause sets.  */
 295               newnames[cnt] = ++cp;
 296               cp = strchr (cp, ';');
 297               if (cp != NULL)
 298                 {
 299                   /* Examine the next clause.  */
 300                   *cp = '\0';
 301                   np = cp + 1;
 302                 }
 303               else
 304                 /* This was the last clause.  We are done.  */
 305                 break;
 306             }
 307
 308           for (cnt = 0; cnt < LC_ALL; ++cnt)
 309             if (newnames[cnt] == locale)
 310               /* The composite name did not specify all categories.  */
 311               ERROR_RETURN;
 312         }
 313
 314       /* Protect global data.  */
 315       __libc_lock_lock (__libc_setlocale_lock);
 316
 317       /* Load the new data for each category.  */
 318       while (category-- > 0)
 319         {
 320           newdata[category] = _nl_find_locale (locale_path, locale_path_len,
 321                                                category,
 322                                                &newnames[category]);
 323
 324           if (newdata[category] == NULL)
 325             break;
 326
 327           /* We must not simply free a global locale since we have no
 328              control over the usage.  So we mark it as un-deletable.  */
 329           if (newdata[category]->usage_count != MAX_USAGE_COUNT)
 330             newdata[category]->usage_count = MAX_USAGE_COUNT;
 331         }
 332
 333       /* Create new composite name.  */
 334       if (category >= 0
 335           || (composite = new_composite_name (LC_ALL, newnames)) == NULL)
 336         /* Loading this part of the locale failed.  Abort the
 337            composite load.  */
 338         composite = NULL;
 339       else
 340         {
 341           /* Now we have loaded all the new data.  Put it in place.  */
 342           for (category = 0; category < LC_ALL; ++category)
 343             {
 344               setdata (category, newdata[category]);
 345               setname (category, newnames[category]);
 346             }
 347           setname (LC_ALL, composite);
 348         }
 349
 350       /* Critical section left.  */
 351       __libc_lock_unlock (__libc_setlocale_lock);
 352
 353       /* Free the resources (the locale path variable.  */
 354       free (locale_path);
 355
 356       return composite;
 357     }
 358   else
 359     {
 360       struct locale_data *newdata = NULL;
 361       const char *newname = locale;
 362
 363       /* Protect global data.  */
 364       __libc_lock_lock (__libc_setlocale_lock);
 365
 366       if (_nl_current[category] != NULL)
 367         {
 368           /* Only actually load the data if anything will use it.  */
 369           newdata = _nl_find_locale (locale_path, locale_path_len, category,
 370                                      &newname);
 371           if (newdata == NULL)
 372             goto abort_single;
 373
 374           /* We must not simply free a global locale since we have no
 375              control over the usage.  So we mark it as un-deletable.  */
 376           if (newdata->usage_count != MAX_USAGE_COUNT)
 377             newdata->usage_count = MAX_USAGE_COUNT;
 378         }
 379
 380       /* Create new composite name.  */
 381       composite = new_composite_name (category, &newname);
 382       if (composite == NULL)
 383         {
 384           /* Say that we don't have any data loaded.  */
 385         abort_single:
 386           newname = NULL;
 387         }
 388       else
 389         {
 390           if (_nl_current[category] != NULL)
 391             setdata (category, newdata);
 392
 393           setname (category, newname);
 394           setname (LC_ALL, composite);
 395         }
 396
 397       /* Critical section left.  */
 398       __libc_lock_unlock (__libc_setlocale_lock);
 399
 400       /* Free the resources (the locale path variable.  */
 401       free (locale_path);
 402
 403       return (char *) newname;
 404     }
 405 }