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 * %sccs.include.redist.c% 9 */ 10 11 #ifndef lint 12 static char sccsid[] = "@(#)look.c 8.1 (Berkeley) 06/06/93"; 13 #endif /* not lint */ 14 15 /* 16 * look.c 17 * Facility: m4 macro processor 18 * by: oz 19 */ 20 21 #include <sys/types.h> 22 #include <stdio.h> 23 #include <stdlib.h> 24 #include <string.h> 25 #include "mdef.h" 26 #include "stdd.h" 27 #include "extern.h" 28 29 int 30 hash(name) 31 register char *name; 32 { 33 register unsigned long h = 0; 34 while (*name) 35 h = (h << 5) + h + *name++; 36 return (h % HASHSIZE); 37 } 38 39 /* 40 * find name in the hash table 41 */ 42 ndptr 43 lookup(name) 44 char *name; 45 { 46 register ndptr p; 47 48 for (p = hashtab[hash(name)]; p != nil; p = p->nxtptr) 49 if (STREQ(name, p->name)) 50 break; 51 return (p); 52 } 53 54 /* 55 * hash and create an entry in the hash table. 56 * The new entry is added in front of a hash bucket. 57 */ 58 ndptr 59 addent(name) 60 char *name; 61 { 62 register int h; 63 ndptr p; 64 65 h = hash(name); 66 p = (ndptr) xalloc(sizeof(struct ndblock)); 67 p->nxtptr = hashtab[h]; 68 hashtab[h] = p; 69 p->name = xstrdup(name); 70 return p; 71 } 72 73 static void 74 freent(p) 75 ndptr p; 76 { 77 if (!(p->type & STATIC)) { 78 free((char *) p->name); 79 if (p->defn != null) 80 free((char *) p->defn); 81 } 82 free((char *) p); 83 } 84 85 /* 86 * remove an entry from the hashtable 87 */ 88 void 89 remhash(name, all) 90 char *name; 91 int all; 92 { 93 register int h; 94 register ndptr xp, tp, mp; 95 96 h = hash(name); 97 mp = hashtab[h]; 98 tp = nil; 99 while (mp != nil) { 100 if (STREQ(mp->name, name)) { 101 mp = mp->nxtptr; 102 if (tp == nil) { 103 freent(hashtab[h]); 104 hashtab[h] = mp; 105 } 106 else { 107 xp = tp->nxtptr; 108 tp->nxtptr = mp; 109 freent(xp); 110 } 111 if (!all) 112 break; 113 } 114 else { 115 tp = mp; 116 mp = mp->nxtptr; 117 } 118 } 119 } 120