xref: /freebsd/lib/libc/locale/tolower.c (revision 59e2ff550c448126b988150ce800cdf73bb5103e)
1 /*-
2  * Copyright (c) 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * This code is derived from software contributed to Berkeley by
6  * Paul Borman at Krystal Technologies.
7  *
8  * Copyright (c) 2011 The FreeBSD Foundation
9  * All rights reserved.
10  * Portions of this software were developed by David Chisnall
11  * under sponsorship from the FreeBSD Foundation.
12  *
13  * Redistribution and use in source and binary forms, with or without
14  * modification, are permitted provided that the following conditions
15  * are met:
16  * 1. Redistributions of source code must retain the above copyright
17  *    notice, this list of conditions and the following disclaimer.
18  * 2. Redistributions in binary form must reproduce the above copyright
19  *    notice, this list of conditions and the following disclaimer in the
20  *    documentation and/or other materials provided with the distribution.
21  * 4. Neither the name of the University nor the names of its contributors
22  *    may be used to endorse or promote products derived from this software
23  *    without specific prior written permission.
24  *
25  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
29  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35  * SUCH DAMAGE.
36  */
37 
38 #include <sys/cdefs.h>
39 __FBSDID("$FreeBSD$");
40 
41 #include <ctype.h>
42 #include <stdio.h>
43 #include <runetype.h>
44 #include <wchar.h>
45 #include "mblocal.h"
46 
47 __ct_rune_t
48 ___tolower_l(__ct_rune_t c, locale_t l)
49 {
50 	size_t lim;
51 	FIX_LOCALE(l);
52 	_RuneRange *rr = &XLOCALE_CTYPE(l)->runes->__maplower_ext;
53 	_RuneEntry *base, *re;
54 
55 	if (c < 0 || c == EOF)
56 		return(c);
57 
58 	/* Binary search -- see bsearch.c for explanation. */
59 	base = rr->__ranges;
60 	for (lim = rr->__nranges; lim != 0; lim >>= 1) {
61 		re = base + (lim >> 1);
62 		if (re->__min <= c && c <= re->__max)
63 			return (re->__map + c - re->__min);
64 		else if (c > re->__max) {
65 			base = re + 1;
66 			lim--;
67 		}
68 	}
69 
70 	return(c);
71 }
72 __ct_rune_t
73 ___tolower(__ct_rune_t c)
74 {
75 	return ___tolower_l(c, __get_locale());
76 }
77