xref: /titanic_50/usr/src/lib/libc/port/locale/wcscoll.c (revision 6ea3c0609e50782557505b88bb391b786bca32c9)
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 
27 /*
28  * Copyright 2010 Nexenta Systems, Inc.  All rights reserved.
29  * Use is subject to license terms.
30  */
31 
32 #include "lint.h"
33 #include <errno.h>
34 #include <stdlib.h>
35 #include <string.h>
36 #include <wchar.h>
37 #include "collate.h"
38 
39 static char *__mbsdup(const wchar_t *);
40 
41 /*
42  * Placeholder implementation of wcscoll(). Attempts to use the single-byte
43  * collation ordering where possible, and falls back on wcscmp() in locales
44  * with extended character sets.
45  */
46 int
47 wcscoll(const wchar_t *ws1, const wchar_t *ws2)
48 {
49 	char *mbs1, *mbs2;
50 	int diff, sverrno;
51 
52 	if (__collate_load_error || MB_CUR_MAX > 1)
53 		/*
54 		 * Locale has no special collating order, could not be
55 		 * loaded, or has an extended character set; do a fast binary
56 		 * comparison.
57 		 */
58 		return (wcscmp(ws1, ws2));
59 
60 	if ((mbs1 = __mbsdup(ws1)) == NULL || (mbs2 = __mbsdup(ws2)) == NULL) {
61 		/*
62 		 * Out of memory or illegal wide chars; fall back to wcscmp()
63 		 * but leave errno indicating the error. Callers that don't
64 		 * check for error will get a reasonable but often slightly
65 		 * incorrect result.
66 		 */
67 		sverrno = errno;
68 		free(mbs1);
69 		errno = sverrno;
70 		return (wcscmp(ws1, ws2));
71 	}
72 
73 	diff = strcoll(mbs1, mbs2);
74 	sverrno = errno;
75 	free(mbs1);
76 	free(mbs2);
77 	errno = sverrno;
78 
79 	return (diff);
80 }
81 
82 static char *
83 __mbsdup(const wchar_t *ws)
84 {
85 	static const mbstate_t initial = { 0 };
86 	mbstate_t st;
87 	const wchar_t *wcp;
88 	size_t len;
89 	char *mbs;
90 
91 	wcp = ws;
92 	st = initial;
93 	if ((len = wcsrtombs(NULL, &wcp, 0, &st)) == (size_t)-1)
94 		return (NULL);
95 	if ((mbs = malloc(len + 1)) == NULL)
96 		return (NULL);
97 	st = initial;
98 	(void) wcsrtombs(mbs, &ws, len + 1, &st);
99 
100 	return (mbs);
101 }
102