src/locale/newlocale.c

   1 #include <stdlib.h>
   2 #include <string.h>
   3 #include <pthread.h>
   4 #include "locale_impl.h"
   5 #include "lock.h"
   6
   7 #define malloc __libc_malloc
   8 #define calloc undef
   9 #define realloc undef
  10 #define free undef
  11
  12 static int default_locale_init_done;
  13 static struct __locale_struct default_locale, default_ctype_locale;
  14
  15 int __loc_is_allocated(locale_t loc)
  16 {
  17         return loc && loc != C_LOCALE && loc != UTF8_LOCALE
  18                 && loc != &default_locale && loc != &default_ctype_locale;
  19 }
  20
  21 static locale_t do_newlocale(int mask, const char *name, locale_t loc)
  22 {
  23         struct __locale_struct tmp;
  24
  25         for (int i=0; i<LC_ALL; i++) {
  26                 tmp.cat[i] = (!(mask & (1<<i)) && loc) ? loc->cat[i] :
  27                         __get_locale(i, (mask & (1<<i)) ? name : "");
  28                 if (tmp.cat[i] == LOC_MAP_FAILED)
  29                         return 0;
  30         }
  31
  32         /* For locales with allocated storage, modify in-place. */
  33         if (__loc_is_allocated(loc)) {
  34                 *loc = tmp;
  35                 return loc;
  36         }
  37
  38         /* Otherwise, first see if we can use one of the builtin locales.
  39          * This makes the common usage case for newlocale, getting a C locale
  40          * with predictable behavior, very fast, and more importantly, fail-safe. */
  41         if (!memcmp(&tmp, C_LOCALE, sizeof tmp)) return C_LOCALE;
  42         if (!memcmp(&tmp, UTF8_LOCALE, sizeof tmp)) return UTF8_LOCALE;
  43
  44         /* And provide builtins for the initial default locale, and a
  45          * variant of the C locale honoring the default locale's encoding. */
  46         if (!default_locale_init_done) {
  47                 for (int i=0; i<LC_ALL; i++)
  48                         default_locale.cat[i] = __get_locale(i, "");
  49                 default_ctype_locale.cat[LC_CTYPE] = default_locale.cat[LC_CTYPE];
  50                 default_locale_init_done = 1;
  51         }
  52         if (!memcmp(&tmp, &default_locale, sizeof tmp)) return &default_locale;
  53         if (!memcmp(&tmp, &default_ctype_locale, sizeof tmp))
  54                 return &default_ctype_locale;
  55
  56         /* If no builtin locale matched, attempt to allocate and copy. */
  57         if ((loc = malloc(sizeof *loc))) *loc = tmp;
  58
  59         return loc;
  60 }
  61
  62 locale_t __newlocale(int mask, const char *name, locale_t loc)
  63 {
  64         LOCK(__locale_lock);
  65         loc = do_newlocale(mask, name, loc);
  66         UNLOCK(__locale_lock);
  67         return loc;
  68 }
  69
  70 weak_alias(__newlocale, newlocale);