xref: /titanic_41/usr/src/lib/libc/port/locale/towlower.c (revision 721df37ded2cce623b0249cc35a872c3ce291b9b)
1 /*
2  * Copyright 2010 Nexenta Systems, Inc.  All rights reserved.
3  * Copyright (c) 1989, 1993
4  *	The Regents of the University of California.  All rights reserved.
5  * (c) UNIX System Laboratories, Inc.
6  * All or some portions of this file are derived from material licensed
7  * to the University of California by American Telephone and Telegraph
8  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
9  * the permission of UNIX System Laboratories, Inc.
10  *
11  * This code is derived from software contributed to Berkeley by
12  * Paul Borman at Krystal Technologies.
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  * 4. Neither the name of the University nor the names of its contributors
23  *    may be used to endorse or promote products derived from this software
24  *    without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36  * SUCH DAMAGE.
37  */
38 
39 #include "lint.h"
40 #include <wctype.h>
41 #include <stdio.h>
42 #include "runetype.h"
43 
44 static wint_t
45 __change_case_ext(wint_t c, int lower)
46 {
47 	size_t lim;
48 	_RuneRange *rr;
49 	_RuneEntry *base, *re;
50 
51 	if (c < 0 || c == EOF)
52 		return (c);
53 
54 	rr = lower ?
55 	    &_CurrentRuneLocale->__maplower_ext :
56 	    &_CurrentRuneLocale->__mapupper_ext;
57 	/* Binary search -- see bsearch.c for explanation. */
58 	base = rr->__ranges;
59 	for (lim = rr->__nranges; lim != 0; lim >>= 1) {
60 		re = base + (lim >> 1);
61 		if (re->__min <= c && c <= re->__max) {
62 			return (re->__map + c - re->__min);
63 		} else if (c > re->__max) {
64 			base = re + 1;
65 			lim--;
66 		}
67 	}
68 
69 	return (c);
70 }
71 
72 #undef towlower
73 wint_t
74 towlower(wint_t wc)
75 {
76 	return ((wc < 0 || wc >= _CACHED_RUNES) ?
77 	    __change_case_ext(wc, 1) :
78 	    _CurrentRuneLocale->__maplower[wc]);
79 }
80 
81 #undef towupper
82 wint_t
83 towupper(wint_t wc)
84 {
85 	return ((wc < 0 || wc >= _CACHED_RUNES) ?
86 	    __change_case_ext(wc, 0) :
87 	    _CurrentRuneLocale->__mapupper[wc]);
88 }
89