xref: /illumos-gate/usr/src/lib/libc/port/locale/wcscoll.c (revision b6805bf78d2bbbeeaea8909a05623587b42d58b3)
1 /*
2  * Copyright 2010 Nexenta Systems, Inc.  All rights reserved.
3  * Copyright (c) 2002 Tim J. Robbins
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  */
27 
28 #include "lint.h"
29 #include <errno.h>
30 #include <stdlib.h>
31 #include <string.h>
32 #include <wchar.h>
33 #include <assert.h>
34 #include "collate.h"
35 
36 int
37 wcscoll(const wchar_t *ws1, const wchar_t *ws2)
38 {
39 	int len1, len2, pri1, pri2, ret;
40 	wchar_t *tr1 = NULL, *tr2 = NULL;
41 	int direc, pass;
42 
43 	collate_info_t *info = _collate_info;
44 
45 	if (_collate_load_error)
46 		/*
47 		 * Locale has no special collating order or could not be
48 		 * loaded, do a fast binary comparison.
49 		 */
50 		return (wcscmp(ws1, ws2));
51 
52 	ret = 0;
53 
54 	/*
55 	 * Once upon a time we had code to try to optimize this, but
56 	 * it turns out that you really can't make many assumptions
57 	 * safely.  You absolutely have to run this pass by pass,
58 	 * because some passes will be ignored for a given character,
59 	 * while others will not.  Simpler locales will benefit from
60 	 * having fewer passes, and most comparisions should resolve
61 	 * during the primary pass anyway.
62 	 *
63 	 * Note that we do one final extra pass at the end to pick
64 	 * up UNDEFINED elements.  There is special handling for them.
65 	 */
66 	for (pass = 0; pass <= info->directive_count; pass++) {
67 
68 		int32_t *st1 = NULL;
69 		int32_t *st2 = NULL;
70 		const wchar_t	*w1 = ws1;
71 		const wchar_t	*w2 = ws2;
72 
73 		/* special pass for UNDEFINED */
74 		if (pass == info->directive_count) {
75 			direc = DIRECTIVE_FORWARD | DIRECTIVE_UNDEFINED;
76 		} else {
77 			direc = info->directive[pass];
78 		}
79 
80 		if (direc & DIRECTIVE_BACKWARD) {
81 			wchar_t *bp, *fp, c;
82 			if ((tr1 = wcsdup(w1)) == NULL)
83 				goto fail;
84 			bp = tr1;
85 			fp = tr1 + wcslen(tr1) - 1;
86 			while (bp < fp) {
87 				c = *bp;
88 				*bp++ = *fp;
89 				*fp-- = c;
90 			}
91 			if ((tr2 = wcsdup(w2)) == NULL)
92 				goto fail;
93 			bp = tr2;
94 			fp = tr2 + wcslen(tr2) - 1;
95 			while (bp < fp) {
96 				c = *bp;
97 				*bp++ = *fp;
98 				*fp-- = c;
99 			}
100 			w1 = tr1;
101 			w2 = tr2;
102 		}
103 
104 		if (direc & DIRECTIVE_POSITION) {
105 			while ((*w1 || st1) && (*w2 || st2)) {
106 				pri1 = pri2 = 0;
107 				_collate_lookup(w1, &len1, &pri1, pass, &st1);
108 				if (pri1 <= 0) {
109 					if (pri1 < 0) {
110 						errno = EINVAL;
111 						goto fail;
112 					}
113 					pri1 = COLLATE_MAX_PRIORITY;
114 				}
115 				_collate_lookup(w2, &len2, &pri2, pass, &st2);
116 				if (pri2 <= 0) {
117 					if (pri2 < 0) {
118 						errno = EINVAL;
119 						goto fail;
120 					}
121 					pri2 = COLLATE_MAX_PRIORITY;
122 				}
123 				if (pri1 != pri2) {
124 					ret = pri1 - pri2;
125 					goto end;
126 				}
127 				w1 += len1;
128 				w2 += len2;
129 			}
130 		} else {
131 			while ((*w1 || st1) && (*w2 || st2)) {
132 				pri1 = pri2 = 0;
133 				while (*w1) {
134 					_collate_lookup(w1, &len1,
135 					    &pri1, pass, &st1);
136 					if (pri1 > 0)
137 						break;
138 					if (pri1 < 0) {
139 						errno = EINVAL;
140 						goto fail;
141 					}
142 					w1 += len1;
143 				}
144 				while (*w2) {
145 					_collate_lookup(w2, &len2,
146 					    &pri2, pass, &st2);
147 					if (pri2 > 0)
148 						break;
149 					if (pri2 < 0) {
150 						errno = EINVAL;
151 						goto fail;
152 					}
153 					w2 += len2;
154 				}
155 				if (!pri1 || !pri2)
156 					break;
157 				if (pri1 != pri2) {
158 					ret = pri1 - pri2;
159 					goto end;
160 				}
161 				w1 += len1;
162 				w2 += len2;
163 			}
164 		}
165 		if (!*w1) {
166 			if (*w2) {
167 				ret = -(int)*w2;
168 				goto end;
169 			}
170 		} else {
171 			ret = *w1;
172 			goto end;
173 		}
174 	}
175 	ret = 0;
176 
177 end:
178 	if (tr1)
179 		free(tr1);
180 	if (tr2)
181 		free(tr2);
182 
183 	return (ret);
184 
185 fail:
186 	ret = wcscmp(ws1, ws2);
187 	goto end;
188 }
189