1 /* $NetBSD: hash.c,v 1.6 2001/05/28 12:40:38 lukem 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 #ifndef lint 36 __RCSID("$NetBSD: hash.c,v 1.6 2001/05/28 12:40:38 lukem Exp $"); 37 #endif 38 39 /* 40 * XXX Really need a generalized hash table package 41 */ 42 43 #include <stddef.h> 44 #include <stdlib.h> 45 #include <string.h> 46 #include <limits.h> 47 #include <err.h> 48 49 #include "lint2.h" 50 51 /* pointer to hash table, initialized in inithash() */ 52 static hte_t **htab; 53 54 static int hash(const char *); 55 56 /* 57 * Initialize hash table. 58 */ 59 void 60 _inithash(hte_t ***tablep) 61 { 62 63 if (tablep == NULL) 64 tablep = &htab; 65 66 *tablep = xcalloc(HSHSIZ2, sizeof (hte_t *)); 67 } 68 69 /* 70 * Compute hash value from a string. 71 */ 72 static int 73 hash(const char *s) 74 { 75 u_int v; 76 const u_char *us; 77 78 v = 0; 79 for (us = (const u_char *)s; *us != '\0'; us++) { 80 v = (v << sizeof (v)) + *us; 81 v ^= v >> (sizeof (v) * CHAR_BIT - sizeof (v)); 82 } 83 return (v % HSHSIZ2); 84 } 85 86 /* 87 * Look for a hash table entry. If no hash table entry for the 88 * given name exists and mknew is set, create a new one. 89 */ 90 hte_t * 91 _hsearch(hte_t **table, const char *s, int mknew) 92 { 93 int h; 94 hte_t *hte; 95 96 if (table == NULL) 97 table = htab; 98 99 h = hash(s); 100 for (hte = table[h]; hte != NULL; hte = hte->h_link) { 101 if (strcmp(hte->h_name, s) == 0) 102 break; 103 } 104 105 if (hte != NULL || !mknew) 106 return (hte); 107 108 /* create a new hte */ 109 hte = xmalloc(sizeof (hte_t)); 110 hte->h_name = xstrdup(s); 111 hte->h_used = 0; 112 hte->h_def = 0; 113 hte->h_static = 0; 114 hte->h_syms = NULL; 115 hte->h_lsym = &hte->h_syms; 116 hte->h_calls = NULL; 117 hte->h_lcall = &hte->h_calls; 118 hte->h_usyms = NULL; 119 hte->h_lusym = &hte->h_usyms; 120 hte->h_link = table[h]; 121 hte->h_hte = NULL; 122 table[h] = hte; 123 124 return (hte); 125 } 126 127 /* 128 * Call function f for each name in the hash table. 129 */ 130 void 131 _forall(hte_t **table, void (*f)(hte_t *)) 132 { 133 int i; 134 hte_t *hte; 135 136 if (table == NULL) 137 table = htab; 138 139 for (i = 0; i < HSHSIZ2; i++) { 140 for (hte = table[i]; hte != NULL; hte = hte->h_link) 141 (*f)(hte); 142 } 143 } 144 145 /* 146 * Free all contents of the hash table that this module allocated. 147 */ 148 void 149 _destroyhash(hte_t **table) 150 { 151 int i; 152 hte_t *hte, *nexthte; 153 154 if (table == NULL) 155 err(1, "_destroyhash called on main hash table"); 156 157 for (i = 0; i < HSHSIZ2; i++) { 158 for (hte = table[i]; hte != NULL; hte = nexthte) { 159 free((void *)hte->h_name); 160 nexthte = hte->h_link; 161 free(hte); 162 } 163 } 164 free(table); 165 } 166