xref: /illumos-gate/usr/src/lib/libc/port/locale/wcscoll.c (revision 3ba944265c4ae1fcf23ef758537c2e4f4feec16e)
1 /*
2  * Copyright 2013 Garrett D'Amore <garrett@damore.org>
3  * Copyright 2010 Nexenta Systems, Inc.  All rights reserved.
4  * Copyright (c) 2002 Tim J. Robbins
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include "lint.h"
30 #include <errno.h>
31 #include <stdlib.h>
32 #include <string.h>
33 #include <wchar.h>
34 #include <assert.h>
35 #include "collate.h"
36 #include "localeimpl.h"
37 
38 int
39 wcscoll_l(const wchar_t *ws1, const wchar_t *ws2, locale_t loc)
40 {
41 	int len1, len2, pri1, pri2, ret;
42 	wchar_t *tr1 = NULL, *tr2 = NULL;
43 	int direc, pass;
44 	const struct lc_collate *lcc = loc->collate;
45 
46 	if (lcc->lc_is_posix)
47 		/*
48 		 * Locale has no special collating order or could not be
49 		 * loaded, do a fast binary comparison.
50 		 */
51 		return (wcscmp(ws1, ws2));
52 
53 	ret = 0;
54 
55 	/*
56 	 * Once upon a time we had code to try to optimize this, but
57 	 * it turns out that you really can't make many assumptions
58 	 * safely.  You absolutely have to run this pass by pass,
59 	 * because some passes will be ignored for a given character,
60 	 * while others will not.  Simpler locales will benefit from
61 	 * having fewer passes, and most comparisions should resolve
62 	 * during the primary pass anyway.
63 	 *
64 	 * Note that we do one final extra pass at the end to pick
65 	 * up UNDEFINED elements.  There is special handling for them.
66 	 */
67 	for (pass = 0; pass <= lcc->lc_directive_count; pass++) {
68 
69 		const int32_t *st1 = NULL;
70 		const int32_t *st2 = NULL;
71 		const wchar_t	*w1 = ws1;
72 		const wchar_t	*w2 = ws2;
73 
74 		/* special pass for UNDEFINED */
75 		if (pass == lcc->lc_directive_count) {
76 			direc = DIRECTIVE_FORWARD | DIRECTIVE_UNDEFINED;
77 		} else {
78 			direc = lcc->lc_directive[pass];
79 		}
80 
81 		if (direc & DIRECTIVE_BACKWARD) {
82 			wchar_t *bp, *fp, c;
83 			if ((tr1 = wcsdup(w1)) == NULL)
84 				goto fail;
85 			bp = tr1;
86 			fp = tr1 + wcslen(tr1) - 1;
87 			while (bp < fp) {
88 				c = *bp;
89 				*bp++ = *fp;
90 				*fp-- = c;
91 			}
92 			if ((tr2 = wcsdup(w2)) == NULL)
93 				goto fail;
94 			bp = tr2;
95 			fp = tr2 + wcslen(tr2) - 1;
96 			while (bp < fp) {
97 				c = *bp;
98 				*bp++ = *fp;
99 				*fp-- = c;
100 			}
101 			w1 = tr1;
102 			w2 = tr2;
103 		}
104 
105 		if (direc & DIRECTIVE_POSITION) {
106 			while ((*w1 || st1) && (*w2 || st2)) {
107 				pri1 = pri2 = 0;
108 				_collate_lookup(lcc, w1, &len1, &pri1, pass,
109 				    &st1);
110 				if (pri1 <= 0) {
111 					if (pri1 < 0) {
112 						errno = EINVAL;
113 						goto fail;
114 					}
115 					pri1 = COLLATE_MAX_PRIORITY;
116 				}
117 				_collate_lookup(lcc, w2, &len2, &pri2, pass,
118 				    &st2);
119 				if (pri2 <= 0) {
120 					if (pri2 < 0) {
121 						errno = EINVAL;
122 						goto fail;
123 					}
124 					pri2 = COLLATE_MAX_PRIORITY;
125 				}
126 				if (pri1 != pri2) {
127 					ret = pri1 - pri2;
128 					goto end;
129 				}
130 				w1 += len1;
131 				w2 += len2;
132 			}
133 		} else {
134 			while ((*w1 || st1) && (*w2 || st2)) {
135 				pri1 = pri2 = 0;
136 				while (*w1) {
137 					_collate_lookup(lcc, w1, &len1,
138 					    &pri1, pass, &st1);
139 					if (pri1 > 0)
140 						break;
141 					if (pri1 < 0) {
142 						errno = EINVAL;
143 						goto fail;
144 					}
145 					w1 += len1;
146 				}
147 				while (*w2) {
148 					_collate_lookup(lcc, w2, &len2,
149 					    &pri2, pass, &st2);
150 					if (pri2 > 0)
151 						break;
152 					if (pri2 < 0) {
153 						errno = EINVAL;
154 						goto fail;
155 					}
156 					w2 += len2;
157 				}
158 				if (!pri1 || !pri2)
159 					break;
160 				if (pri1 != pri2) {
161 					ret = pri1 - pri2;
162 					goto end;
163 				}
164 				w1 += len1;
165 				w2 += len2;
166 			}
167 		}
168 		if (!*w1) {
169 			if (*w2) {
170 				ret = -(int)*w2;
171 				goto end;
172 			}
173 		} else {
174 			ret = *w1;
175 			goto end;
176 		}
177 	}
178 	ret = 0;
179 
180 end:
181 	if (tr1)
182 		free(tr1);
183 	if (tr2)
184 		free(tr2);
185 
186 	return (ret);
187 
188 fail:
189 	ret = wcscmp(ws1, ws2);
190 	goto end;
191 }
192 
193 
194 int
195 wcscoll(const wchar_t *ws1, const wchar_t *ws2)
196 {
197 	return (wcscoll_l(ws1, ws2, uselocale(NULL)));
198 }
199