xref: /titanic_51/usr/src/lib/libc/port/locale/towlower.c (revision eb8f03cde11ee9fc86ee179ef61fc5861756b1c6)
1 /*
2  * Copyright (c) 1989, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  * (c) UNIX System Laboratories, Inc.
5  * All or some portions of this file are derived from material licensed
6  * to the University of California by American Telephone and Telegraph
7  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
8  * the permission of UNIX System Laboratories, Inc.
9  *
10  * This code is derived from software contributed to Berkeley by
11  * Paul Borman at Krystal Technologies.
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 /*
39  * Copyright 2010 Nexenta Systems, Inc.  All rights reserved.
40  * Use is subject to license terms.
41  */
42 
43 #include "lint.h"
44 #include <wctype.h>
45 #include <stdio.h>
46 #include "runetype.h"
47 
48 static wint_t
49 __change_case_ext(wint_t c, int lower)
50 {
51 	size_t lim;
52 	_RuneRange *rr;
53 	_RuneEntry *base, *re;
54 
55 	if (c < 0 || c == EOF)
56 		return (c);
57 
58 	rr = lower ?
59 	    &_CurrentRuneLocale->__maplower_ext :
60 	    &_CurrentRuneLocale->__mapupper_ext;
61 	/* Binary search -- see bsearch.c for explanation. */
62 	base = rr->__ranges;
63 	for (lim = rr->__nranges; lim != 0; lim >>= 1) {
64 		re = base + (lim >> 1);
65 		if (re->__min <= c && c <= re->__max) {
66 			return (re->__map + c - re->__min);
67 		} else if (c > re->__max) {
68 			base = re + 1;
69 			lim--;
70 		}
71 	}
72 
73 	return (c);
74 }
75 
76 #undef towlower
77 wint_t
78 towlower(wint_t wc)
79 {
80 	return ((wc < 0 || wc >= _CACHED_RUNES) ?
81 	    __change_case_ext(wc, 1) :
82 	    _CurrentRuneLocale->__maplower[wc]);
83 }
84 
85 #undef towupper
86 wint_t
87 towupper(wint_t wc)
88 {
89 	return ((wc < 0 || wc >= _CACHED_RUNES) ?
90 	    __change_case_ext(wc, 0) :
91 	    _CurrentRuneLocale->__mapupper[wc]);
92 }
93