lib/libc/string/wcscoll.c

   1 /*-
   2  * Copyright (c) 2002 Tim J. Robbins
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  *
  14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  24  * SUCH DAMAGE.
  25  *
  26  * $FreeBSD: src/lib/libc/string/wcscoll.c,v 1.3 2004/04/07 09:47:56 tjr Exp $
  27  */
  28
  29 #include <errno.h>
  30 #include <stdlib.h>
  31 #include <string.h>
  32 #include <wchar.h>
  33 #include "collate.h"
  34
  35 static char *__mbsdup(const wchar_t *);
  36
  37 /*
  38  * Placeholder implementation of wcscoll(). Attempts to use the single-byte
  39  * collation ordering where possible, and falls back on wcscmp() in locales
  40  * with extended character sets.
  41  */
  42 int
  43 wcscoll(const wchar_t *ws1, const wchar_t *ws2)
  44 {
  45         char *mbs1, *mbs2;
  46         int diff, sverrno;
  47
  48         if (__collate_load_error || MB_CUR_MAX > 1)
  49                 /*
  50                  * Locale has no special collating order, could not be
  51                  * loaded, or has an extended character set; do a fast binary
  52                  * comparison.
  53                  */
  54                 return (wcscmp(ws1, ws2));
  55
  56         if ((mbs1 = __mbsdup(ws1)) == NULL || (mbs2 = __mbsdup(ws2)) == NULL) {
  57                 /*
  58                  * Out of memory or illegal wide chars; fall back to wcscmp()
  59                  * but leave errno indicating the error. Callers that don't
  60                  * check for error will get a reasonable but often slightly
  61                  * incorrect result.
  62                  */
  63                 sverrno = errno;
  64                 free(mbs1);
  65                 errno = sverrno;
  66                 return (wcscmp(ws1, ws2));
  67         }
  68
  69         diff = strcoll(mbs1, mbs2);
  70         sverrno = errno;
  71         free(mbs1);
  72         free(mbs2);
  73         errno = sverrno;
  74
  75         return (diff);
  76 }
  77
  78 static char *
  79 __mbsdup(const wchar_t *ws)
  80 {
  81         static const mbstate_t initial;
  82         mbstate_t st;
  83         const wchar_t *wcp;
  84         size_t len;
  85         char *mbs;
  86
  87         wcp = ws;
  88         st = initial;
  89         if ((len = wcsrtombs(NULL, &wcp, 0, &st)) == (size_t)-1)
  90                 return (NULL);
  91         if ((mbs = malloc(len + 1)) == NULL)
  92                 return (NULL);
  93         st = initial;
  94         wcsrtombs(mbs, &ws, len + 1, &st);
  95
  96         return (mbs);
  97 }