locale/setlocale.c

   1 /* Copyright (C) 1991, 1992, 1995, 1996 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
  16 not, 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 <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 const struct locale_data *_nl_current_##category;                      \
  39 extern const 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 const 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   };
  53
  54 /* Array indexed by category of pointers to _nl_C_CATEGORY slots.
  55    Elements are zero for categories whose data is never used.  */
  56 const struct locale_data *const _nl_C[] =
  57   {
  58 #define DEFINE_CATEGORY(category, category_name, items, a, b, c, d) \
  59     [category] = &_nl_C_##category,
  60 #include "categories.def"
  61 #undef  DEFINE_CATEGORY
  62   };
  63
  64
  65 /* Define an array of category names (also the environment variable names),
  66    indexed by integral category.  */
  67 const char *const _nl_category_names[] =
  68   {
  69 #define DEFINE_CATEGORY(category, category_name, items, a, b, c, d) \
  70     [category] = category_name,
  71 #include "categories.def"
  72 #undef  DEFINE_CATEGORY
  73     [LC_ALL] = "LC_ALL"
  74   };
  75 /* An array of their lengths, for convenience.  */
  76 const size_t _nl_category_name_sizes[] =
  77   {
  78 #define DEFINE_CATEGORY(category, category_name, items, a, b, c, d) \
  79     [category] = sizeof (category_name) - 1,
  80 #include "categories.def"
  81 #undef  DEFINE_CATEGORY
  82     [LC_ALL] = sizeof ("LC_ALL") - 1
  83   };
  84
  85
  86 /* Declare the postload functions used below.  */
  87 #undef  NO_POSTLOAD
  88 #define NO_POSTLOAD _nl_postload_ctype /* Harmless thing known to exist.  */
  89 #define DEFINE_CATEGORY(category, category_name, items, postload, b, c, d) \
  90 extern void postload (void);
  91 #include "categories.def"
  92 #undef  DEFINE_CATEGORY
  93 #undef  NO_POSTLOAD
  94
  95 /* Define an array indexed by category of postload functions to call after
  96    loading and installing that category's data.  */
  97 static void (*const _nl_category_postload[]) (void) =
  98   {
  99 #define DEFINE_CATEGORY(category, category_name, items, postload, b, c, d) \
 100     [category] = postload,
 101 #include "categories.def"
 102 #undef  DEFINE_CATEGORY
 103   };
 104
 105
 106 /* Name of current locale for each individual category.
 107    Each is malloc'd unless it is nl_C_name.  */
 108 static const char *_nl_current_names[] =
 109   {
 110 #define DEFINE_CATEGORY(category, category_name, items, a, b, c, d) \
 111     [category] = _nl_C_name,
 112 #include "categories.def"
 113 #undef  DEFINE_CATEGORY
 114     [LC_ALL] = _nl_C_name               /* For LC_ALL.  */
 115   };
 116
 117
 118 /* Lock for protecting global data.  */
 119 __libc_lock_define_initialized (, __libc_setlocale_lock)
 120
 121
 122 /* Use this when we come along an error.  */
 123 #define ERROR_RETURN                                                          \
 124   do {                                                                        \
 125     __set_errno (EINVAL);                                                     \
 126     return NULL;                                                              \
 127   } while (0)
 128
 129
 130 static inline char *
 131 clever_copy (const char *string)
 132 {
 133   size_t len;
 134   char *new;
 135
 136   if (strcmp (string, "C") == 0 || strcmp (string, "POSIX") == 0)
 137     /* This return is dangerous because the returned string might be
 138        placed in read-only memory.  But everything should be set up to
 139        handle this case.  */
 140     return (char *) _nl_C_name;
 141
 142   len = strlen (string) + 1;
 143   new = (char *) malloc (len);
 144   return new != NULL ? memcpy (new, string, len) : NULL;
 145 }
 146
 147
 148 /* Construct a new composite name.  */
 149 static inline char *
 150 new_composite_name (int category, char *newnames[LC_ALL])
 151 {
 152   size_t last_len;
 153   size_t cumlen = 0;
 154   int i;
 155   char *new, *p;
 156   int same = 1;
 157
 158   for (i = 0; i < LC_ALL; ++i)
 159     {
 160       char *name = (category == LC_ALL ? newnames[i] :
 161                     category == i ? newnames[0] :
 162                     (char *) _nl_current_names[i]);
 163       last_len = strlen (name);
 164       cumlen += _nl_category_name_sizes[i] + 1 + last_len + 1;
 165       if (i > 0 && same && strcmp (name, newnames[0]) != 0)
 166         same = 0;
 167     }
 168
 169   if (same)
 170     {
 171       /* All the categories use the same name.  */
 172       if (strcmp (newnames[0], "C") == 0 || strcmp (newnames[0], "POSIX") == 0)
 173         return (char *) _nl_C_name;
 174
 175       new = malloc (last_len + 1);
 176
 177       return new == NULL ? NULL : memcpy (new, newnames[0], last_len + 1);
 178     }
 179
 180   new = malloc (cumlen);
 181   if (new == NULL)
 182     return NULL;
 183   p = new;
 184   for (i = 0; i < LC_ALL; ++i)
 185     {
 186       /* Add "CATEGORY=NAME;" to the string.  */
 187       char *name = (category == LC_ALL ? newnames[i] :
 188                     category == i ? newnames[0] :
 189                     (char *) _nl_current_names[i]);
 190       p = __stpcpy (p, _nl_category_names[i]);
 191       *p++ = '=';
 192       p = __stpcpy (p, name);
 193       *p++ = ';';
 194     }
 195   p[-1] = '\0';         /* Clobber the last ';'.  */
 196   return new;
 197 }
 198
 199
 200 /* Put NAME in _nl_current_names.  */
 201 static inline void
 202 setname (int category, const char *name)
 203 {
 204   if (_nl_current[category] == NULL
 205       && _nl_current_names[category] != _nl_C_name)
 206     free ((void *) _nl_current_names[category]);
 207
 208   _nl_current_names[category] = name;
 209 }
 210
 211
 212 /* Put DATA in *_nl_current[CATEGORY].  */
 213 static inline void
 214 setdata (int category, const struct locale_data *data)
 215 {
 216   if (_nl_current[category] != NULL)
 217     {
 218       *_nl_current[category] = data;
 219       if (_nl_category_postload[category])
 220         (*_nl_category_postload[category]) ();
 221     }
 222 }
 223
 224
 225 char *
 226 setlocale (int category, const char *locale)
 227 {
 228   char *locale_path;
 229   size_t locale_path_len;
 230   const char *locpath_var;
 231   char *composite;
 232
 233   /* Sanity check for CATEGORY argument.  */
 234   if (category < 0 || category > LC_ALL)
 235     ERROR_RETURN;
 236
 237   /* Does user want name of current locale?  */
 238   if (locale == NULL)
 239     return (char *) _nl_current_names[category];
 240
 241   if (strcmp (locale, _nl_current_names[category]) == 0)
 242     /* Changing to the same thing.  */
 243     return (char *) _nl_current_names[category];
 244
 245   /* We perhaps really have to load some data.  So we determine the
 246      path in which to look for the data now.  The environment variable
 247      `LOCPATH' must only be used when the binary has no SUID or SGID
 248      bit set.  */
 249   locale_path = NULL;
 250   locale_path_len = 0;
 251
 252   locpath_var = __secure_getenv ("LOCPATH");
 253   if (locpath_var != NULL && locpath_var[0] != '\0')
 254     if (__argz_create_sep (locpath_var, ':',
 255                            &locale_path, &locale_path_len) != 0)
 256       return NULL;
 257
 258   if (__argz_add_sep (&locale_path, &locale_path_len, LOCALE_PATH, ':') != 0)
 259     return NULL;
 260
 261   if (category == LC_ALL)
 262     {
 263       /* The user wants to set all categories.  The desired locales
 264          for the individual categories can be selected by using a
 265          composite locale name.  This is a semi-colon separated list
 266          of entries of the form `CATEGORY=VALUE'.  */
 267       char *newnames[LC_ALL];
 268       const struct locale_data *newdata[LC_ALL];
 269
 270       /* Set all name pointers to the argument name.  */
 271       for (category = 0; category < LC_ALL; ++category)
 272         newnames[category] = (char *) locale;
 273
 274       if (strchr (locale, ';') != NULL)
 275         {
 276           /* This is a composite name.  Make a copy and split it up.  */
 277           char *np = strdupa (locale);
 278           char *cp;
 279           int cnt;
 280
 281           while ((cp = strchr (np, '=')) != NULL)
 282             {
 283               for (cnt = 0; cnt < LC_ALL; ++cnt)
 284                 if ((size_t) (cp - np) == _nl_category_name_sizes[cnt]
 285                     && memcmp (np, _nl_category_names[cnt], cp - np) == 0)
 286                   break;
 287
 288               if (cnt == LC_ALL)
 289                 /* Bogus category name.  */
 290                 ERROR_RETURN;
 291
 292               /* Found the category this clause sets.  */
 293               newnames[cnt] = ++cp;
 294               cp = strchr (cp, ';');
 295               if (cp != NULL)
 296                 {
 297                   /* Examine the next clause.  */
 298                   *cp = '\0';
 299                   np = cp + 1;
 300                 }
 301               else
 302                 /* This was the last clause.  We are done.  */
 303                 break;
 304             }
 305
 306           for (cnt = 0; cnt < LC_ALL; ++cnt)
 307             if (newnames[cnt] == locale)
 308               /* The composite name did not specify all categories.  */
 309               ERROR_RETURN;
 310         }
 311
 312       /* Protect global data.  */
 313       __libc_lock_lock (__libc_setlocale_lock);
 314
 315       /* Load the new data for each category.  */
 316       while (category-- > 0)
 317         /* Only actually load the data if anything will use it.  */
 318         if (_nl_current[category] != NULL)
 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         else
 328           {
 329             /* The data is never used; just change the name.  */
 330             newnames[category] = clever_copy (newnames[category]);
 331             if (newnames[category] == NULL)
 332               break;
 333           }
 334
 335       /* Create new composite name.  */
 336       if (category >= 0
 337           || (composite = new_composite_name (LC_ALL, newnames)) == NULL)
 338         /* Loading this part of the locale failed.  Abort the
 339            composite load.  */
 340         composite = NULL;
 341       else
 342         {
 343           /* Now we have loaded all the new data.  Put it in place.  */
 344           for (category = 0; category < LC_ALL; ++category)
 345             {
 346               setdata (category, newdata[category]);
 347               setname (category, newnames[category]);
 348             }
 349           setname (LC_ALL, composite);
 350         }
 351
 352       /* Critical section left.  */
 353       __libc_lock_unlock (__libc_setlocale_lock);
 354
 355       return composite;
 356     }
 357   else
 358     {
 359       const struct locale_data *newdata = NULL;
 360       char *newname = (char *) locale;
 361
 362       /* Protect global data.  */
 363       __libc_lock_lock (__libc_setlocale_lock);
 364
 365       if (_nl_current[category] != NULL)
 366         {
 367           /* Only actually load the data if anything will use it.  */
 368           newdata = _nl_find_locale (locale_path, locale_path_len, category,
 369                                      (char **) &newname);
 370           if (newdata == NULL)
 371             goto abort_single;
 372         }
 373
 374       /* Create new composite name.  */
 375       composite = new_composite_name (category, &newname);
 376       if (composite == NULL)
 377         {
 378           /* Say that we don't have any data loaded.  */
 379         abort_single:
 380           newname = NULL;
 381         }
 382       else
 383         {
 384           if (_nl_current[category] != NULL)
 385             setdata (category, newdata);
 386
 387           setname (category, newname);
 388           setname (LC_ALL, composite);
 389         }
 390
 391       /* Critical section left.  */
 392       __libc_lock_unlock (__libc_setlocale_lock);
 393
 394       return newname;
 395     }
 396 }