File: [local] / src / usr.bin / make / lst.lib / Attic / lstNext.c (download)
Revision 1.8, Thu Sep 14 13:32:10 2000 UTC (23 years, 9 months ago) by espie
Branch: MAIN
CVS Tags: OPENBSD_2_9_BASE, OPENBSD_2_9, OPENBSD_2_8_BASE, OPENBSD_2_8 Changes since 1.7: +10 -9 lines
Some systematic clean-up.
- UNUSED macro that expands to __attribute__((unused)) for gcc
- move rcsid around so that they can be tagged UNUSED.
- activate -Wunused.
- use UNUSED instead of kludgy junk for function arguments.
- add extern to all extern prototypes.
- update comments in lst.h.
- clean up var.c a little bit, constifying arguments, updating comments...
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/* $OpenBSD: lstNext.c,v 1.8 2000/09/14 13:32:10 espie Exp $ */
/* $NetBSD: lstNext.c,v 1.5 1996/11/06 17:59:49 christos 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. 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.
*/
/*-
* LstNext.c --
* Return the next node for a list.
* The sequential functions access the list in a slightly different way.
* CurPtr points to their idea of the current node in the list and they
* access the list based on it. Because the list is circular, Lst_Next
* and Lst_Prev will go around the list forever. Lst_IsAtEnd must be
* used to determine when to stop.
*/
#include "lstInt.h"
#ifndef lint
#if 0
static char sccsid[] = "@(#)lstNext.c 8.1 (Berkeley) 6/6/93";
#else
UNUSED
static char rcsid[] = "$OpenBSD: lstNext.c,v 1.8 2000/09/14 13:32:10 espie Exp $";
#endif
#endif /* not lint */
/*-
*-----------------------------------------------------------------------
* Lst_Next --
* Return the next node for the given list.
*
* Results:
* The next node or NULL if the list has yet to be opened. Also
* if the list is non-circular and the end has been reached, NULL
* is returned.
*
* Side Effects:
* the curPtr field is updated.
*
*-----------------------------------------------------------------------
*/
LstNode
Lst_Next(l)
Lst l;
{
LstNode tln;
if (l->isOpen == FALSE)
return NULL;
l->prevPtr = l->curPtr;
if (l->curPtr == NULL) {
if (l->atEnd == Unknown) {
/*
* If we're just starting out, atEnd will be Unknown.
* Then we want to start this thing off in the right
* direction -- at the start with atEnd being Middle.
*/
l->curPtr = tln = l->firstPtr;
l->atEnd = Middle;
} else {
tln = NULL;
l->atEnd = Tail;
}
} else {
tln = l->curPtr->nextPtr;
l->curPtr = tln;
if (tln == l->firstPtr || tln == NULL)
/*
* If back at the front, then we've hit the end...
*/
l->atEnd = Tail;
else
/*
* Reset to Middle if gone past first.
*/
l->atEnd = Middle;
}
return tln;
}