freebsd-dev/usr.bin/m4/look.c

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/* $OpenBSD: look.c,v 1.10 2002/04/26 16:15:16 espie Exp $ */
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/*
* Copyright (c) 1989, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Ozan Yigit at York University.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. 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 BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#if 0
#ifndef lint
static char sccsid[] = "@(#)look.c 8.1 (Berkeley) 6/6/93";
#endif /* not lint */
#endif
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
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/*
* look.c
* Facility: m4 macro processor
* by: oz
*/
#include <sys/types.h>
#include <stdio.h>
#include <stdlib.h>
#include <stddef.h>
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#include <string.h>
#include "mdef.h"
#include "stdd.h"
#include "extern.h"
static void freent(ndptr);
unsigned int
hash(const char *name)
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{
unsigned int h = 0;
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while (*name)
h = (h << 5) + h + *name++;
return (h);
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}
/*
* find name in the hash table
*/
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ndptr
lookup(const char *name)
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{
ndptr p;
unsigned int h;
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h = hash(name);
for (p = hashtab[h % HASHSIZE]; p != nil; p = p->nxtptr)
if (h == p->hv && STREQ(name, p->name))
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break;
return (p);
}
/*
* hash and create an entry in the hash table.
* The new entry is added in front of a hash bucket.
*/
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ndptr
addent(const char *name)
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{
unsigned int h;
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ndptr p;
h = hash(name);
p = (ndptr) xalloc(sizeof(struct ndblock));
p->nxtptr = hashtab[h % HASHSIZE];
hashtab[h % HASHSIZE] = p;
p->name = xstrdup(name);
p->hv = h;
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return p;
}
static void
freent(ndptr p)
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{
free((char *) p->name);
if (p->defn != null)
free((char *) p->defn);
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free((char *) p);
}
/*
* remove an entry from the hashtable
*/
void
remhash(const char *name, int all)
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{
unsigned int h;
ndptr xp, tp, mp;
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h = hash(name);
mp = hashtab[h % HASHSIZE];
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tp = nil;
while (mp != nil) {
if (mp->hv == h && STREQ(mp->name, name)) {
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mp = mp->nxtptr;
if (tp == nil) {
freent(hashtab[h % HASHSIZE]);
hashtab[h % HASHSIZE] = mp;
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}
else {
xp = tp->nxtptr;
tp->nxtptr = mp;
freent(xp);
}
if (!all)
break;
}
else {
tp = mp;
mp = mp->nxtptr;
}
}
}