1 /* 2 * Copyright (c) 1989, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * Ozan Yigit at York University. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)look.c 8.1 (Berkeley) 6/6/93 37 * $OpenBSD: look.c,v 1.10 2002/04/26 16:15:16 espie Exp $ 38 * $FreeBSD: src/usr.bin/m4/look.c,v 1.7 2002/07/15 02:15:12 jmallett Exp $ 39 * $DragonFly: src/usr.bin/m4/look.c,v 1.3 2006/12/27 21:29:02 pavalos Exp $ 40 */ 41 42 /* 43 * look.c 44 * Facility: m4 macro processor 45 * by: oz 46 */ 47 48 #include <sys/types.h> 49 #include <stdio.h> 50 #include <stdlib.h> 51 #include <stddef.h> 52 #include <string.h> 53 #include "mdef.h" 54 #include "stdd.h" 55 #include "extern.h" 56 57 static void freent(ndptr); 58 59 unsigned int 60 hash(const char *name) 61 { 62 unsigned int h = 0; 63 while (*name) 64 h = (h << 5) + h + *name++; 65 return (h); 66 } 67 68 /* 69 * find name in the hash table 70 */ 71 ndptr 72 lookup(const char *name) 73 { 74 ndptr p; 75 unsigned int h; 76 77 h = hash(name); 78 for (p = hashtab[h % HASHSIZE]; p != nil; p = p->nxtptr) 79 if (h == p->hv && STREQ(name, p->name)) 80 break; 81 return (p); 82 } 83 84 /* 85 * hash and create an entry in the hash table. 86 * The new entry is added in front of a hash bucket. 87 */ 88 ndptr 89 addent(const char *name) 90 { 91 unsigned int h; 92 ndptr p; 93 94 h = hash(name); 95 p = (ndptr) xalloc(sizeof(struct ndblock)); 96 p->nxtptr = hashtab[h % HASHSIZE]; 97 hashtab[h % HASHSIZE] = p; 98 p->name = xstrdup(name); 99 p->hv = h; 100 return p; 101 } 102 103 static void 104 freent(ndptr p) 105 { 106 free((char *) p->name); 107 if (p->defn != null) 108 free((char *) p->defn); 109 free((char *) p); 110 } 111 112 /* 113 * remove an entry from the hashtable 114 */ 115 void 116 remhash(const char *name, int all) 117 { 118 unsigned int h; 119 ndptr xp, tp, mp; 120 121 h = hash(name); 122 mp = hashtab[h % HASHSIZE]; 123 tp = nil; 124 while (mp != nil) { 125 if (mp->hv == h && STREQ(mp->name, name)) { 126 mp = mp->nxtptr; 127 if (tp == nil) { 128 freent(hashtab[h % HASHSIZE]); 129 hashtab[h % HASHSIZE] = mp; 130 } 131 else { 132 xp = tp->nxtptr; 133 tp->nxtptr = mp; 134 freent(xp); 135 } 136 if (!all) 137 break; 138 } 139 else { 140 tp = mp; 141 mp = mp->nxtptr; 142 } 143 } 144 } 145