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 <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     /* We need this additional element to simplify the code.  It must
  53        simply be != NULL.  */
  54     [LC_ALL] = (const 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 const 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, 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       char *name = (category == LC_ALL ? newnames[i] :
 164                     category == i ? newnames[0] :
 165                     (char *) _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       char *name = (category == LC_ALL ? newnames[i] :
 191                     category == i ? newnames[0] :
 192                     (char *) _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] == name)
 208     return;
 209
 210   if (category == LC_ALL && _nl_current_names[category] != _nl_C_name)
 211     free ((void *) _nl_current_names[category]);
 212
 213   _nl_current_names[category] = name;
 214 }
 215
 216
 217 /* Put DATA in *_nl_current[CATEGORY].  */
 218 static inline void
 219 setdata (int category, const struct locale_data *data)
 220 {
 221   if (_nl_current[category] != NULL)
 222     {
 223       *_nl_current[category] = data;
 224       if (_nl_category_postload[category])
 225         (*_nl_category_postload[category]) ();
 226     }
 227 }
 228
 229
 230 char *
 231 setlocale (int category, const char *locale)
 232 {
 233   char *locale_path;
 234   size_t locale_path_len;
 235   const char *locpath_var;
 236   char *composite;
 237
 238   /* Sanity check for CATEGORY argument.  */
 239   if (category < 0 || category > LC_ALL)
 240     ERROR_RETURN;
 241
 242   /* Does user want name of current locale?  */
 243   if (locale == NULL)
 244     return (char *) _nl_current_names[category];
 245
 246   if (strcmp (locale, _nl_current_names[category]) == 0)
 247     /* Changing to the same thing.  */
 248     return (char *) _nl_current_names[category];
 249
 250   /* We perhaps really have to load some data.  So we determine the
 251      path in which to look for the data now.  The environment variable
 252      `LOCPATH' must only be used when the binary has no SUID or SGID
 253      bit set.  */
 254   locale_path = NULL;
 255   locale_path_len = 0;
 256
 257   locpath_var = __secure_getenv ("LOCPATH");
 258   if (locpath_var != NULL && locpath_var[0] != '\0')
 259     if (__argz_create_sep (locpath_var, ':',
 260                            &locale_path, &locale_path_len) != 0)
 261       return NULL;
 262
 263   if (__argz_add_sep (&locale_path, &locale_path_len, LOCALE_PATH, ':') != 0)
 264     return NULL;
 265
 266   if (category == LC_ALL)
 267     {
 268       /* The user wants to set all categories.  The desired locales
 269          for the individual categories can be selected by using a
 270          composite locale name.  This is a semi-colon separated list
 271          of entries of the form `CATEGORY=VALUE'.  */
 272       char *newnames[LC_ALL];
 273       const struct locale_data *newdata[LC_ALL];
 274
 275       /* Set all name pointers to the argument name.  */
 276       for (category = 0; category < LC_ALL; ++category)
 277         newnames[category] = (char *) locale;
 278
 279       if (strchr (locale, ';') != NULL)
 280         {
 281           /* This is a composite name.  Make a copy and split it up.  */
 282           char *np = strdupa (locale);
 283           char *cp;
 284           int cnt;
 285
 286           while ((cp = strchr (np, '=')) != NULL)
 287             {
 288               for (cnt = 0; cnt < LC_ALL; ++cnt)
 289                 if ((size_t) (cp - np) == _nl_category_name_sizes[cnt]
 290                     && memcmp (np, _nl_category_names[cnt], cp - np) == 0)
 291                   break;
 292
 293               if (cnt == LC_ALL)
 294                 /* Bogus category name.  */
 295                 ERROR_RETURN;
 296
 297               /* Found the category this clause sets.  */
 298               newnames[cnt] = ++cp;
 299               cp = strchr (cp, ';');
 300               if (cp != NULL)
 301                 {
 302                   /* Examine the next clause.  */
 303                   *cp = '\0';
 304                   np = cp + 1;
 305                 }
 306               else
 307                 /* This was the last clause.  We are done.  */
 308                 break;
 309             }
 310
 311           for (cnt = 0; cnt < LC_ALL; ++cnt)
 312             if (newnames[cnt] == locale)
 313               /* The composite name did not specify all categories.  */
 314               ERROR_RETURN;
 315         }
 316
 317       /* Protect global data.  */
 318       __libc_lock_lock (__libc_setlocale_lock);
 319
 320       /* Load the new data for each category.  */
 321       while (category-- > 0)
 322         /* Only actually load the data if anything will use it.  */
 323         if (_nl_current[category] != NULL)
 324           {
 325             newdata[category] = _nl_find_locale (locale_path, locale_path_len,
 326                                                  category,
 327                                                  &newnames[category]);
 328
 329             if (newdata[category] == NULL)
 330               break;
 331           }
 332         else
 333           {
 334             /* The data is never used; just change the name.  */
 335             newnames[category] = clever_copy (newnames[category]);
 336             if (newnames[category] == NULL)
 337               break;
 338           }
 339
 340       /* Create new composite name.  */
 341       if (category >= 0
 342           || (composite = new_composite_name (LC_ALL, newnames)) == NULL)
 343         /* Loading this part of the locale failed.  Abort the
 344            composite load.  */
 345         composite = NULL;
 346       else
 347         {
 348           /* Now we have loaded all the new data.  Put it in place.  */
 349           for (category = 0; category < LC_ALL; ++category)
 350             {
 351               setdata (category, newdata[category]);
 352               setname (category, newnames[category]);
 353             }
 354           setname (LC_ALL, composite);
 355         }
 356
 357       /* Critical section left.  */
 358       __libc_lock_unlock (__libc_setlocale_lock);
 359
 360       /* Free the resources (the locale path variable.  */
 361       free (locale_path);
 362
 363       return composite;
 364     }
 365   else
 366     {
 367       const struct locale_data *newdata = NULL;
 368       char *newname = (char *) locale;
 369
 370       /* Protect global data.  */
 371       __libc_lock_lock (__libc_setlocale_lock);
 372
 373       if (_nl_current[category] != NULL)
 374         {
 375           /* Only actually load the data if anything will use it.  */
 376           newdata = _nl_find_locale (locale_path, locale_path_len, category,
 377                                      (char **) &newname);
 378           if (newdata == NULL)
 379             goto abort_single;
 380         }
 381
 382       /* Create new composite name.  */
 383       composite = new_composite_name (category, &newname);
 384       if (composite == NULL)
 385         {
 386           /* Say that we don't have any data loaded.  */
 387         abort_single:
 388           newname = NULL;
 389         }
 390       else
 391         {
 392           if (_nl_current[category] != NULL)
 393             setdata (category, newdata);
 394
 395           setname (category, newname);
 396           setname (LC_ALL, composite);
 397         }
 398
 399       /* Critical section left.  */
 400       __libc_lock_unlock (__libc_setlocale_lock);
 401
 402       /* Free the resources (the locale path variable.  */
 403       free (locale_path);
 404
 405       return newname;
 406     }
 407 }