locale/setlocale.c

   1 /* Copyright (C) 1991, 92, 95, 96, 97, 98 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 #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 static struct locale_data * *const _nl_current[] =
  46   {
  47 #define DEFINE_CATEGORY(category, category_name, items, a, b, c, d) \
  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, b, c, d) \
  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, b, c, d) \
  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, b, c, d) \
  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, b, c, d) \
  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, b, c, d) \
 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, b, c, d) \
 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_ALL])
 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_ALL; ++i)
 143     {
 144       const char *name = (category == LC_ALL ? newnames[i] :
 145                           category == i ? newnames[0] :
 146                           _nl_current_names[i]);
 147       last_len = strlen (name);
 148       cumlen += _nl_category_name_sizes[i] + 1 + last_len + 1;
 149       if (i > 0 && same && strcmp (name, newnames[0]) != 0)
 150         same = 0;
 151     }
 152
 153   if (same)
 154     {
 155       /* All the categories use the same name.  */
 156       if (strcmp (newnames[0], _nl_C_name) == 0
 157           || strcmp (newnames[0], _nl_POSIX_name) == 0)
 158         return (char *) _nl_C_name;
 159
 160       new = malloc (last_len + 1);
 161
 162       return new == NULL ? NULL : memcpy (new, newnames[0], last_len + 1);
 163     }
 164
 165   new = malloc (cumlen);
 166   if (new == NULL)
 167     return NULL;
 168   p = new;
 169   for (i = 0; i < LC_ALL; ++i)
 170     {
 171       /* Add "CATEGORY=NAME;" to the string.  */
 172       const char *name = (category == LC_ALL ? newnames[i] :
 173                           category == i ? newnames[0] :
 174                           _nl_current_names[i]);
 175       p = __stpcpy (p, _nl_category_names[i]);
 176       *p++ = '=';
 177       p = __stpcpy (p, name);
 178       *p++ = ';';
 179     }
 180   p[-1] = '\0';         /* Clobber the last ';'.  */
 181   return new;
 182 }
 183
 184
 185 /* Put NAME in _nl_current_names.  */
 186 static inline void
 187 setname (int category, const char *name)
 188 {
 189   if (_nl_current_names[category] == name)
 190     return;
 191
 192   if (category == LC_ALL && _nl_current_names[category] != _nl_C_name)
 193     free ((char *) _nl_current_names[category]);
 194
 195   _nl_current_names[category] = name;
 196 }
 197
 198
 199 /* Put DATA in *_nl_current[CATEGORY].  */
 200 static inline void
 201 setdata (int category, struct locale_data *data)
 202 {
 203   if (_nl_current[category] != NULL)
 204     {
 205       *_nl_current[category] = data;
 206       if (_nl_category_postload[category])
 207         (*_nl_category_postload[category]) ();
 208     }
 209 }
 210
 211
 212 char *
 213 setlocale (int category, const char *locale)
 214 {
 215   char *locale_path;
 216   size_t locale_path_len;
 217   const char *locpath_var;
 218   char *composite;
 219
 220   /* Sanity check for CATEGORY argument.  */
 221   if (category < 0 || category > LC_ALL)
 222     ERROR_RETURN;
 223
 224   /* Does user want name of current locale?  */
 225   if (locale == NULL)
 226     return (char *) _nl_current_names[category];
 227
 228   if (strcmp (locale, _nl_current_names[category]) == 0)
 229     /* Changing to the same thing.  */
 230     return (char *) _nl_current_names[category];
 231
 232   /* We perhaps really have to load some data.  So we determine the
 233      path in which to look for the data now.  The environment variable
 234      `LOCPATH' must only be used when the binary has no SUID or SGID
 235      bit set.  */
 236   locale_path = NULL;
 237   locale_path_len = 0;
 238
 239   locpath_var = __secure_getenv ("LOCPATH");
 240   if (locpath_var != NULL && locpath_var[0] != '\0')
 241     if (__argz_create_sep (locpath_var, ':',
 242                            &locale_path, &locale_path_len) != 0)
 243       return NULL;
 244
 245   if (__argz_add_sep (&locale_path, &locale_path_len, LOCALE_PATH, ':') != 0)
 246     return NULL;
 247
 248   if (category == LC_ALL)
 249     {
 250       /* The user wants to set all categories.  The desired locales
 251          for the individual categories can be selected by using a
 252          composite locale name.  This is a semi-colon separated list
 253          of entries of the form `CATEGORY=VALUE'.  */
 254       const char *newnames[LC_ALL];
 255       struct locale_data *newdata[LC_ALL];
 256
 257       /* Set all name pointers to the argument name.  */
 258       for (category = 0; category < LC_ALL; ++category)
 259         newnames[category] = (char *) locale;
 260
 261       if (strchr (locale, ';') != NULL)
 262         {
 263           /* This is a composite name.  Make a copy and split it up.  */
 264           char *np = strdupa (locale);
 265           char *cp;
 266           int cnt;
 267
 268           while ((cp = strchr (np, '=')) != NULL)
 269             {
 270               for (cnt = 0; cnt < LC_ALL; ++cnt)
 271                 if ((size_t) (cp - np) == _nl_category_name_sizes[cnt]
 272                     && memcmp (np, _nl_category_names[cnt], cp - np) == 0)
 273                   break;
 274
 275               if (cnt == LC_ALL)
 276                 /* Bogus category name.  */
 277                 ERROR_RETURN;
 278
 279               /* Found the category this clause sets.  */
 280               newnames[cnt] = ++cp;
 281               cp = strchr (cp, ';');
 282               if (cp != NULL)
 283                 {
 284                   /* Examine the next clause.  */
 285                   *cp = '\0';
 286                   np = cp + 1;
 287                 }
 288               else
 289                 /* This was the last clause.  We are done.  */
 290                 break;
 291             }
 292
 293           for (cnt = 0; cnt < LC_ALL; ++cnt)
 294             if (newnames[cnt] == locale)
 295               /* The composite name did not specify all categories.  */
 296               ERROR_RETURN;
 297         }
 298
 299       /* Protect global data.  */
 300       __libc_lock_lock (__libc_setlocale_lock);
 301
 302       /* Load the new data for each category.  */
 303       while (category-- > 0)
 304         {
 305           newdata[category] = _nl_find_locale (locale_path, locale_path_len,
 306                                                category,
 307                                                &newnames[category]);
 308
 309           if (newdata[category] == NULL)
 310             break;
 311
 312           /* We must not simply free a global locale since we have no
 313              control over the usage.  So we mark it as un-deletable.  */
 314           if (newdata[category]->usage_count != UNDELETABLE)
 315             newdata[category]->usage_count = UNDELETABLE;
 316         }
 317
 318       /* Create new composite name.  */
 319       if (category >= 0
 320           || (composite = new_composite_name (LC_ALL, newnames)) == NULL)
 321         /* Loading this part of the locale failed.  Abort the
 322            composite load.  */
 323         composite = NULL;
 324       else
 325         {
 326           /* Now we have loaded all the new data.  Put it in place.  */
 327           for (category = 0; category < LC_ALL; ++category)
 328             {
 329               setdata (category, newdata[category]);
 330               setname (category, newnames[category]);
 331             }
 332           setname (LC_ALL, composite);
 333         }
 334
 335       /* Critical section left.  */
 336       __libc_lock_unlock (__libc_setlocale_lock);
 337
 338       /* Free the resources (the locale path variable.  */
 339       free (locale_path);
 340
 341       return composite;
 342     }
 343   else
 344     {
 345       struct locale_data *newdata = NULL;
 346       const char *newname[1] = { locale };
 347
 348       /* Protect global data.  */
 349       __libc_lock_lock (__libc_setlocale_lock);
 350
 351       if (_nl_current[category] != NULL)
 352         {
 353           /* Only actually load the data if anything will use it.  */
 354           newdata = _nl_find_locale (locale_path, locale_path_len, category,
 355                                      &newname[0]);
 356           if (newdata == NULL)
 357             goto abort_single;
 358
 359           /* We must not simply free a global locale since we have no
 360              control over the usage.  So we mark it as un-deletable.
 361
 362              Note: do not remove the `if', it's necessary to copy with
 363              the builtin locale data.  */
 364           if (newdata->usage_count != UNDELETABLE)
 365             newdata->usage_count = UNDELETABLE;
 366         }
 367
 368       /* Create new composite name.  */
 369       composite = new_composite_name (category, newname);
 370       if (composite == NULL)
 371         {
 372           /* Say that we don't have any data loaded.  */
 373         abort_single:
 374           newname[0] = NULL;
 375         }
 376       else
 377         {
 378           if (_nl_current[category] != NULL)
 379             setdata (category, newdata);
 380
 381           setname (category, newname[0]);
 382           setname (LC_ALL, composite);
 383         }
 384
 385       /* Critical section left.  */
 386       __libc_lock_unlock (__libc_setlocale_lock);
 387
 388       /* Free the resources (the locale path variable.  */
 389       free (locale_path);
 390
 391       return (char *) newname[0];
 392     }
 393 }