1 /* $OpenBSD: look.c,v 1.10 2002/04/26 16:15:16 espie Exp $ */ 2 3 /* 4 * Copyright (c) 1989, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * Ozan Yigit at York University. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 */ 38 39 #if 0 40 #ifndef lint 41 static char sccsid[] = "@(#)look.c 8.1 (Berkeley) 6/6/93"; 42 #endif /* not lint */ 43 #endif 44 45 #include <sys/cdefs.h> 46 __FBSDID("$FreeBSD$"); 47 48 /* 49 * look.c 50 * Facility: m4 macro processor 51 * by: oz 52 */ 53 54 #include <sys/types.h> 55 #include <stdio.h> 56 #include <stdlib.h> 57 #include <stddef.h> 58 #include <string.h> 59 #include "mdef.h" 60 #include "stdd.h" 61 #include "extern.h" 62 63 static void freent(ndptr); 64 65 unsigned int 66 hash(const char *name) 67 { 68 unsigned int h = 0; 69 while (*name) 70 h = (h << 5) + h + *name++; 71 return (h); 72 } 73 74 /* 75 * find name in the hash table 76 */ 77 ndptr 78 lookup(const char *name) 79 { 80 ndptr p; 81 unsigned int h; 82 83 h = hash(name); 84 for (p = hashtab[h % HASHSIZE]; p != nil; p = p->nxtptr) 85 if (h == p->hv && STREQ(name, p->name)) 86 break; 87 return (p); 88 } 89 90 /* 91 * hash and create an entry in the hash table. 92 * The new entry is added in front of a hash bucket. 93 */ 94 ndptr 95 addent(const char *name) 96 { 97 unsigned int h; 98 ndptr p; 99 100 h = hash(name); 101 p = (ndptr) xalloc(sizeof(struct ndblock)); 102 p->nxtptr = hashtab[h % HASHSIZE]; 103 hashtab[h % HASHSIZE] = p; 104 p->name = xstrdup(name); 105 p->hv = h; 106 return p; 107 } 108 109 static void 110 freent(ndptr p) 111 { 112 free((char *) p->name); 113 if (p->defn != null) 114 free((char *) p->defn); 115 free((char *) p); 116 } 117 118 /* 119 * remove an entry from the hashtable 120 */ 121 void 122 remhash(const char *name, int all) 123 { 124 unsigned int h; 125 ndptr xp, tp, mp; 126 127 h = hash(name); 128 mp = hashtab[h % HASHSIZE]; 129 tp = nil; 130 while (mp != nil) { 131 if (mp->hv == h && STREQ(mp->name, name)) { 132 mp = mp->nxtptr; 133 if (tp == nil) { 134 freent(hashtab[h % HASHSIZE]); 135 hashtab[h % HASHSIZE] = mp; 136 } 137 else { 138 xp = tp->nxtptr; 139 tp->nxtptr = mp; 140 freent(xp); 141 } 142 if (!all) 143 break; 144 } 145 else { 146 tp = mp; 147 mp = mp->nxtptr; 148 } 149 } 150 } 151