/* * Copyright (c) 1989 The Regents of the University of California. * All rights reserved. * * This code is derived from software contributed to Berkeley by * Ozan Yigit. * * Redistribution and use in source and binary forms are permitted * provided that: (1) source distributions retain this entire copyright * notice and comment, and (2) distributions including binaries display * the following acknowledgement: ``This product includes software * developed by the University of California, Berkeley and its contributors'' * in the documentation or other materials provided with the distribution * and in all advertising materials mentioning features or use of this * software. Neither the name of the University nor the names of its * contributors may be used to endorse or promote products derived * from this software without specific prior written permission. * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. */ #ifndef lint static char sccsid[] = "@(#)look.c 5.2 (Berkeley) 6/1/90"; #endif /* not lint */ /* * look.c * Facility: m4 macro processor * by: oz */ #include "mdef.h" #include "extr.h" extern char *strsave(); /* * hash - compute hash value using the proverbial * hashing function. Taken from K&R. */ hash (name) register char *name; { register int h = 0; while (*name) h += *name++; return (h % HASHSIZE); } /* * lookup - find name in the hash table * */ ndptr lookup(name) char *name; { register ndptr p; for (p = hashtab[hash(name)]; p != nil; p = p->nxtptr) if (strcmp(name, p->name) == 0) break; return (p); } /* * addent - hash and create an entry in the hash * table. The new entry is added in front * of a hash bucket. */ ndptr addent(name) char *name; { register int h; ndptr p; h = hash(name); if ((p = (ndptr) malloc(sizeof(struct ndblock))) != NULL) { p->nxtptr = hashtab[h]; hashtab[h] = p; p->name = strsave(name); } else error("m4: no more memory."); return p; } /* * remhash - remove an entry from the hashtable * */ remhash(name, all) char *name; int all; { register int h; register ndptr xp, tp, mp; h = hash(name); mp = hashtab[h]; tp = nil; while (mp != nil) { if (strcmp(mp->name, name) == 0) { mp = mp->nxtptr; if (tp == nil) { freent(hashtab[h]); hashtab[h] = mp; } else { xp = tp->nxtptr; tp->nxtptr = mp; freent(xp); } if (!all) break; } else { tp = mp; mp = mp->nxtptr; } } } /* * freent - free a hashtable information block * */ freent(p) ndptr p; { if (!(p->type & STATIC)) { free(p->name); if (p->defn != null) free(p->defn); } free(p); }