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 #include <sys/cdefs.h> 40 __SCCSID("@(#)look.c 8.1 (Berkeley) 6/6/93"); 41 __RCSID_SOURCE("$OpenBSD: look.c,v 1.10 2002/04/26 16:15:16 espie Exp $"); 42 __FBSDID("$FreeBSD$"); 43 44 /* 45 * look.c 46 * Facility: m4 macro processor 47 * by: oz 48 */ 49 50 #include <sys/types.h> 51 #include <stdio.h> 52 #include <stdlib.h> 53 #include <stddef.h> 54 #include <string.h> 55 #include "mdef.h" 56 #include "stdd.h" 57 #include "extern.h" 58 59 static void freent(ndptr); 60 61 unsigned int 62 hash(const char *name) 63 { 64 unsigned int h = 0; 65 while (*name) 66 h = (h << 5) + h + *name++; 67 return (h); 68 } 69 70 /* 71 * find name in the hash table 72 */ 73 ndptr 74 lookup(const char *name) 75 { 76 ndptr p; 77 unsigned int h; 78 79 h = hash(name); 80 for (p = hashtab[h % HASHSIZE]; p != nil; p = p->nxtptr) 81 if (h == p->hv && STREQ(name, p->name)) 82 break; 83 return (p); 84 } 85 86 /* 87 * hash and create an entry in the hash table. 88 * The new entry is added in front of a hash bucket. 89 */ 90 ndptr 91 addent(const char *name) 92 { 93 unsigned int h; 94 ndptr p; 95 96 h = hash(name); 97 p = (ndptr) xalloc(sizeof(struct ndblock)); 98 p->nxtptr = hashtab[h % HASHSIZE]; 99 hashtab[h % HASHSIZE] = p; 100 p->name = xstrdup(name); 101 p->hv = h; 102 return p; 103 } 104 105 static void 106 freent(ndptr p) 107 { 108 free((char *) p->name); 109 if (p->defn != null) 110 free((char *) p->defn); 111 free((char *) p); 112 } 113 114 /* 115 * remove an entry from the hashtable 116 */ 117 void 118 remhash(const char *name, int all) 119 { 120 unsigned int h; 121 ndptr xp, tp, mp; 122 123 h = hash(name); 124 mp = hashtab[h % HASHSIZE]; 125 tp = nil; 126 while (mp != nil) { 127 if (mp->hv == h && STREQ(mp->name, name)) { 128 mp = mp->nxtptr; 129 if (tp == nil) { 130 freent(hashtab[h % HASHSIZE]); 131 hashtab[h % HASHSIZE] = mp; 132 } 133 else { 134 xp = tp->nxtptr; 135 tp->nxtptr = mp; 136 freent(xp); 137 } 138 if (!all) 139 break; 140 } 141 else { 142 tp = mp; 143 mp = mp->nxtptr; 144 } 145 } 146 } 147