1 /* $NetBSD: hash.c,v 1.7 2002/01/21 19:49:52 tv Exp $ */
2
3 /*
4 * Copyright (c) 1994, 1995 Jochen Pohl
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 * 3. All advertising materials mentioning features or use of this software
16 * must display the following acknowledgement:
17 * This product includes software developed by Jochen Pohl for
18 * The NetBSD Project.
19 * 4. The name of the author may not be used to endorse or promote products
20 * derived from this software without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
23 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
24 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
25 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
26 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
27 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
28 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
29 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
31 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32 */
33
34 #include <sys/cdefs.h>
35 #if defined(__RCSID) && !defined(lint)
36 __RCSID("$NetBSD: hash.c,v 1.7 2002/01/21 19:49:52 tv Exp $");
37 #endif
38 __FBSDID("$FreeBSD$");
39
40 /*
41 * XXX Really need a generalized hash table package
42 */
43
44 #include <err.h>
45 #include <limits.h>
46 #include <stddef.h>
47 #include <stdlib.h>
48 #include <string.h>
49
50 #include "lint2.h"
51
52 /* pointer to hash table, initialized in inithash() */
53 static hte_t **htab;
54
55 static int hash(const char *);
56
57 /*
58 * Initialize hash table.
59 */
60 void
_inithash(hte_t *** tablep)61 _inithash(hte_t ***tablep)
62 {
63
64 if (tablep == NULL)
65 tablep = &htab;
66
67 *tablep = xcalloc(HSHSIZ2, sizeof (hte_t *));
68 }
69
70 /*
71 * Compute hash value from a string.
72 */
73 static int
hash(const char * s)74 hash(const char *s)
75 {
76 u_int v;
77 const u_char *us;
78
79 v = 0;
80 for (us = (const u_char *)s; *us != '\0'; us++) {
81 v = (v << sizeof (v)) + *us;
82 v ^= v >> (sizeof (v) * CHAR_BIT - sizeof (v));
83 }
84 return (v % HSHSIZ2);
85 }
86
87 /*
88 * Look for a hash table entry. If no hash table entry for the
89 * given name exists and mknew is set, create a new one.
90 */
91 hte_t *
_hsearch(hte_t ** table,const char * s,int mknew)92 _hsearch(hte_t **table, const char *s, int mknew)
93 {
94 int h;
95 hte_t *hte;
96
97 if (table == NULL)
98 table = htab;
99
100 h = hash(s);
101 for (hte = table[h]; hte != NULL; hte = hte->h_link) {
102 if (strcmp(hte->h_name, s) == 0)
103 break;
104 }
105
106 if (hte != NULL || !mknew)
107 return (hte);
108
109 /* create a new hte */
110 hte = xmalloc(sizeof (hte_t));
111 hte->h_name = xstrdup(s);
112 hte->h_used = 0;
113 hte->h_def = 0;
114 hte->h_static = 0;
115 hte->h_syms = NULL;
116 hte->h_lsym = &hte->h_syms;
117 hte->h_calls = NULL;
118 hte->h_lcall = &hte->h_calls;
119 hte->h_usyms = NULL;
120 hte->h_lusym = &hte->h_usyms;
121 hte->h_link = table[h];
122 hte->h_hte = NULL;
123 table[h] = hte;
124
125 return (hte);
126 }
127
128 /*
129 * Call function f for each name in the hash table.
130 */
131 void
_forall(hte_t ** table,void (* f)(hte_t *))132 _forall(hte_t **table, void (*f)(hte_t *))
133 {
134 int i;
135 hte_t *hte;
136
137 if (table == NULL)
138 table = htab;
139
140 for (i = 0; i < HSHSIZ2; i++) {
141 for (hte = table[i]; hte != NULL; hte = hte->h_link)
142 (*f)(hte);
143 }
144 }
145
146 /*
147 * Free all contents of the hash table that this module allocated.
148 */
149 void
_destroyhash(hte_t ** table)150 _destroyhash(hte_t **table)
151 {
152 int i;
153 hte_t *hte, *nexthte;
154
155 if (table == NULL)
156 err(1, "_destroyhash called on main hash table");
157
158 for (i = 0; i < HSHSIZ2; i++) {
159 for (hte = table[i]; hte != NULL; hte = nexthte) {
160 free((void *)hte->h_name);
161 nexthte = hte->h_link;
162 free(hte);
163 }
164 }
165 free(table);
166 }
167