lib/wcscoll-impl.h

   1 /* Compare two wide strings using the current locale.
   2    Copyright (C) 2011-2017 Free Software Foundation, Inc.
   3    Written by Bruno Haible <bruno@clisp.org>, 2011.
   4
   5    This program is free software: you can redistribute it and/or modify
   6    it under the terms of the GNU General Public License as published by
   7    the Free Software Foundation; either version 3 of the License, or
   8    (at your option) any later version.
   9
  10    This program is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13    GNU General Public License for more details.
  14
  15    You should have received a copy of the GNU General Public License
  16    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  17
  18 int
  19 wcscoll (const wchar_t *s1, const wchar_t *s2)
  20 {
  21   char mbbuf1[1024];
  22   char mbbuf2[1024];
  23   char *mbs1;
  24   char *mbs2;
  25
  26   {
  27     int saved_errno = errno;
  28
  29     /* Convert s1 to a multibyte string, trying to avoid malloc().  */
  30     {
  31       size_t ret;
  32
  33       ret = wcstombs (mbbuf1, s1, sizeof (mbbuf1));
  34       if (ret == (size_t)-1)
  35         goto failed1;
  36       if (ret < sizeof (mbbuf1))
  37         mbs1 = mbbuf1;
  38       else
  39         {
  40           size_t need = wcstombs (NULL, s1, 0);
  41           if (need == (size_t)-1)
  42             goto failed1;
  43           mbs1 = (char *) malloc (need + 1);
  44           if (mbs1 == NULL)
  45             goto out_of_memory1;
  46           ret = wcstombs (mbs1, s1, need + 1);
  47           if (ret != need)
  48             abort ();
  49         }
  50     }
  51
  52     /* Convert s2 to a multibyte string, trying to avoid malloc().  */
  53     {
  54       size_t ret;
  55
  56       ret = wcstombs (mbbuf2, s2, sizeof (mbbuf2));
  57       if (ret == (size_t)-1)
  58         goto failed2;
  59       if (ret < sizeof (mbbuf2))
  60         mbs2 = mbbuf2;
  61       else
  62         {
  63           size_t need = wcstombs (NULL, s2, 0);
  64           if (need == (size_t)-1)
  65             goto failed2;
  66           mbs2 = (char *) malloc (need + 1);
  67           if (mbs2 == NULL)
  68             goto out_of_memory2;
  69           ret = wcstombs (mbs2, s2, need + 1);
  70           if (ret != need)
  71             abort ();
  72         }
  73     }
  74
  75     /* No error so far.  */
  76     errno = saved_errno;
  77   }
  78
  79   /* Compare the two multibyte strings.  */
  80   {
  81     int result = strcoll (mbs1, mbs2);
  82
  83     if (mbs1 != mbbuf1)
  84       {
  85         int saved_errno = errno;
  86         free (mbs1);
  87         errno = saved_errno;
  88       }
  89     if (mbs2 != mbbuf2)
  90       {
  91         int saved_errno = errno;
  92         free (mbs2);
  93         errno = saved_errno;
  94       }
  95     return result;
  96   }
  97
  98  out_of_memory2:
  99   if (mbs1 != mbbuf1)
 100     free (mbs1);
 101  out_of_memory1:
 102   errno = ENOMEM;
 103   return 0;
 104
 105  failed2:
 106   if (mbs1 != mbbuf1)
 107     free (mbs1);
 108  failed1:
 109   errno = EILSEQ;
 110   return 0;
 111 }