xref: /freebsd/lib/libc/string/strcoll.c (revision 97759ccc715c4b365432c16d763c50eecfcb1100)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright 2010 Nexenta Systems, Inc.  All rights reserved.
5  * Copyright (c) 1995 Alex Tatmanjants <alex@elvisti.kiev.ua>
6  *		at Electronni Visti IA, Kiev, Ukraine.
7  *			All rights reserved.
8  *
9  * Copyright (c) 2011 The FreeBSD Foundation
10  *
11  * Portions of this software were developed by David Chisnall
12  * under sponsorship from the FreeBSD Foundation.
13  *
14  * Redistribution and use in source and binary forms, with or without
15  * modification, are permitted provided that the following conditions
16  * are met:
17  * 1. Redistributions of source code must retain the above copyright
18  *    notice, this list of conditions and the following disclaimer.
19  * 2. Redistributions in binary form must reproduce the above copyright
20  *    notice, this list of conditions and the following disclaimer in the
21  *    documentation and/or other materials provided with the distribution.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 #include <stdlib.h>
37 #include <string.h>
38 #include <errno.h>
39 #include <wchar.h>
40 #include "collate.h"
41 
42 
43 /*
44  * In order to properly handle multibyte locales, its easiest to just
45  * convert to wide characters and then use wcscoll.  However if an
46  * error occurs, we gracefully fall back to simple strcmp.  Caller
47  * should check errno.
48  */
49 int
50 strcoll_l(const char *s, const char *s2, locale_t locale)
51 {
52 	int ret;
53 	wchar_t *t1 = NULL, *t2 = NULL;
54 	wchar_t *w1 = NULL, *w2 = NULL;
55 	const char *cs1, *cs2;
56 	mbstate_t mbs1;
57 	mbstate_t mbs2;
58 	size_t sz1, sz2;
59 
60 	memset(&mbs1, 0, sizeof (mbstate_t));
61 	memset(&mbs2, 0, sizeof (mbstate_t));
62 
63 	/*
64 	 * The mbsrtowcs_l function can set the src pointer to null upon
65 	 * failure, so it should act on a copy to avoid:
66 	 *   - sending null pointer to strcmp
67 	 *   - having strcoll/strcoll_l change *s or *s2 to null
68 	 */
69 	cs1 = s;
70 	cs2 = s2;
71 
72 	FIX_LOCALE(locale);
73 	struct xlocale_collate *table =
74 		(struct xlocale_collate*)locale->components[XLC_COLLATE];
75 
76 	if (table->__collate_load_error)
77 		goto error;
78 
79 	sz1 = strlen(s) + 1;
80 	sz2 = strlen(s2) + 1;
81 
82 	/*
83 	 * Simple assumption: conversion to wide format is strictly
84 	 * reducing, i.e. a single byte (or multibyte character)
85 	 * cannot result in multiple wide characters.
86 	 */
87 	if ((t1 = malloc(sz1 * sizeof (wchar_t))) == NULL)
88 		goto error;
89 	w1 = t1;
90 	if ((t2 = malloc(sz2 * sizeof (wchar_t))) == NULL)
91 		goto error;
92 	w2 = t2;
93 
94 	if ((mbsrtowcs_l(w1, &cs1, sz1, &mbs1, locale)) == (size_t)-1)
95 		goto error;
96 
97 	if ((mbsrtowcs_l(w2, &cs2, sz2, &mbs2, locale)) == (size_t)-1)
98 		goto error;
99 
100 	ret = wcscoll_l(w1, w2, locale);
101 	free(t1);
102 	free(t2);
103 
104 	return (ret);
105 
106 error:
107 	free(t1);
108 	free(t2);
109 	return (strcmp(s, s2));
110 }
111 
112 int
113 strcoll(const char *s, const char *s2)
114 {
115 	return strcoll_l(s, s2, __get_locale());
116 }
117 
118