minix/usr.bin/make/lst.lib/lstForEachFrom.c

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2010-02-04 17:52:54 +01:00
/* $NetBSD: lstForEachFrom.c,v 1.17 2009/01/23 21:26:30 dsl Exp $ */
/*
* Copyright (c) 1988, 1989, 1990, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Adam de Boor.
*
* 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. 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.
*/
#ifndef MAKE_NATIVE
static char rcsid[] = "$NetBSD: lstForEachFrom.c,v 1.17 2009/01/23 21:26:30 dsl Exp $";
#else
#include <sys/cdefs.h>
#ifndef lint
#if 0
static char sccsid[] = "@(#)lstForEachFrom.c 8.1 (Berkeley) 6/6/93";
#else
__RCSID("$NetBSD: lstForEachFrom.c,v 1.17 2009/01/23 21:26:30 dsl Exp $");
#endif
#endif /* not lint */
#endif
/*-
* lstForEachFrom.c --
* Perform a given function on all elements of a list starting from
* a given point.
*/
#include "lstInt.h"
/*-
*-----------------------------------------------------------------------
* Lst_ForEachFrom --
* Apply the given function to each element of the given list. The
* function should return 0 if traversal should continue and non-
* zero if it should abort.
*
* Results:
* None.
*
* Side Effects:
* Only those created by the passed-in function.
*
*-----------------------------------------------------------------------
*/
/*VARARGS2*/
int
Lst_ForEachFrom(Lst l, LstNode ln, int (*proc)(void *, void *),
void *d)
{
ListNode tln = ln;
List list = l;
ListNode next;
Boolean done;
int result;
if (!LstValid (list) || LstIsEmpty (list)) {
return 0;
}
do {
/*
* Take care of having the current element deleted out from under
* us.
*/
next = tln->nextPtr;
/*
* We're done with the traversal if
* - the next node to examine is the first in the queue or
* doesn't exist and
* - nothing's been added after the current node (check this
* after proc() has been called).
*/
done = (next == NULL || next == list->firstPtr);
(void) tln->useCount++;
result = (*proc) (tln->datum, d);
(void) tln->useCount--;
/*
* Now check whether a node has been added.
* Note: this doesn't work if this node was deleted before
* the new node was added.
*/
if (next != tln->nextPtr) {
next = tln->nextPtr;
done = 0;
}
if (tln->flags & LN_DELETED) {
free((char *)tln);
}
tln = next;
} while (!result && !LstIsEmpty(list) && !done);
return result;
}