1 /* $NetBSD: hash.c,v 1.29 2023/12/03 18:17:41 rillig 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 #if HAVE_NBTOOL_CONFIG_H
35 #include "nbtool_config.h"
36 #endif
37
38 #include <sys/cdefs.h>
39 #if defined(__RCSID)
40 __RCSID("$NetBSD: hash.c,v 1.29 2023/12/03 18:17:41 rillig Exp $");
41 #endif
42
43 #include <limits.h>
44 #include <stddef.h>
45 #include <stdlib.h>
46 #include <string.h>
47
48 #include "lint2.h"
49
50 #define HTAB_BUCKETS 1009
51
52 static hte_t **htab;
53
54 hte_t **
htab_new(void)55 htab_new(void)
56 {
57 return xcalloc(HTAB_BUCKETS, sizeof(*htab_new()));
58 }
59
60 static unsigned int
hash(const char * s)61 hash(const char *s)
62 {
63 unsigned int v;
64 const char *p;
65
66 v = 0;
67 for (p = s; *p != '\0'; p++) {
68 v = (v << 4) + (unsigned char)*p;
69 v ^= v >> 28;
70 }
71 return v % HTAB_BUCKETS;
72 }
73
74 /*
75 * Look for a hash table entry. If no hash table entry for the
76 * given name exists and mknew is set, create a new one.
77 */
78 hte_t *
hash_search(hte_t ** table,const char * s,bool mknew)79 hash_search(hte_t **table, const char *s, bool mknew)
80 {
81 unsigned int h;
82 hte_t *hte;
83
84 if (table == NULL)
85 table = htab;
86
87 h = hash(s);
88 for (hte = table[h]; hte != NULL; hte = hte->h_link) {
89 if (strcmp(hte->h_name, s) == 0)
90 break;
91 }
92
93 if (hte != NULL || !mknew)
94 return hte;
95
96 /* create a new hte */
97 hte = xmalloc(sizeof(*hte));
98 hte->h_name = xstrdup(s);
99 hte->h_used = false;
100 hte->h_def = false;
101 hte->h_static = false;
102 hte->h_syms = NULL;
103 hte->h_lsym = &hte->h_syms;
104 hte->h_calls = NULL;
105 hte->h_lcall = &hte->h_calls;
106 hte->h_usyms = NULL;
107 hte->h_lusym = &hte->h_usyms;
108 hte->h_link = table[h];
109 hte->h_hte = NULL;
110 table[h] = hte;
111
112 return hte;
113 }
114
115 struct hte_list {
116 hte_t **items;
117 size_t len;
118 size_t cap;
119 };
120
121 static void
hte_list_add(struct hte_list * list,hte_t * item)122 hte_list_add(struct hte_list *list, hte_t *item)
123 {
124 if (list->len >= list->cap) {
125 list->cap = list->cap == 0 ? 1024 : 2 * list->cap;
126 list->items = xrealloc(list->items,
127 sizeof(list->items[0]) * list->cap);
128 }
129 list->items[list->len++] = item;
130 }
131
132 static int
hte_by_name(const void * va,const void * vb)133 hte_by_name(const void *va, const void *vb)
134 {
135 const hte_t *a = *((const hte_t *const *)va);
136 const hte_t *b = *((const hte_t *const *)vb);
137
138 return strcmp(a->h_name, b->h_name);
139 }
140
141 void
symtab_init(void)142 symtab_init(void)
143 {
144 htab = htab_new();
145 }
146
147 /*
148 * Call the action for each name in the hash table.
149 */
150 void
symtab_forall(void (* action)(hte_t *))151 symtab_forall(void (*action)(hte_t *))
152 {
153 int i;
154 hte_t *hte;
155 hte_t **table = htab;
156
157 for (i = 0; i < HTAB_BUCKETS; i++) {
158 for (hte = table[i]; hte != NULL; hte = hte->h_link)
159 action(hte);
160 }
161 }
162
163 /* Run the action for each name in the symbol table, in alphabetic order. */
164 void
symtab_forall_sorted(void (* action)(hte_t *))165 symtab_forall_sorted(void (*action)(hte_t *))
166 {
167 hte_t *hte;
168 struct hte_list sorted = { NULL, 0, 0 };
169 size_t i;
170 hte_t **table = htab;
171
172 for (i = 0; i < HTAB_BUCKETS; i++)
173 for (hte = table[i]; hte != NULL; hte = hte->h_link)
174 hte_list_add(&sorted, hte);
175
176 qsort(sorted.items, sorted.len, sizeof(sorted.items[0]), hte_by_name);
177
178 for (i = 0; i < sorted.len; i++)
179 action(sorted.items[i]);
180
181 free(sorted.items);
182 }
183
184 /*
185 * Free all contents of the hash table that this module allocated.
186 */
187 void
hash_free(hte_t ** table)188 hash_free(hte_t **table)
189 {
190 int i;
191 hte_t *hte, *nexthte;
192
193 for (i = 0; i < HTAB_BUCKETS; i++) {
194 for (hte = table[i]; hte != NULL; hte = nexthte) {
195 free(__UNCONST(hte->h_name));
196 nexthte = hte->h_link;
197 free(hte);
198 }
199 }
200 free(table);
201 }
202