xref: /csrg-svn/usr.bin/make/lst.lib/lstDestroy.c (revision 69094)

/*
 * 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.
 *
 * %sccs.include.redist.c%
 */

#ifndef lint
static char sccsid[] = "@(#)lstDestroy.c	8.2 (Berkeley) 04/28/95";
#endif /* not lint */

/*-
 * LstDestroy.c --
 *	Nuke a list and all its resources
 */

#include	"lstInt.h"

/*-
 *-----------------------------------------------------------------------
 * Lst_Destroy --
 *	Destroy a list and free all its resources. If the freeProc is
 *	given, it is called with the datum from each node in turn before
 *	the node is freed.
 *
 * Results:
 *	None.
 *
 * Side Effects:
 *	The given list is freed in its entirety.
 *
 *-----------------------------------------------------------------------
 */
void
Lst_Destroy (l, freeProc)
    Lst	    	  	l;
    register void	(*freeProc) __P((ClientData));
{
    register ListNode	ln;
    register ListNode	tln = NilListNode;
    register List 	list = (List)l;

    if (l == NILLST || ! l) {
	/*
	 * Note the check for l == (Lst)0 to catch uninitialized static Lst's.
	 * Gross, but useful.
	 */
	return;
    }

    /* To ease scanning */
    if (list->lastPtr != NilListNode)
	list->lastPtr->nextPtr = NilListNode;
    else {
	free ((Address)l);
	return;
    }

    if (freeProc) {
	for (ln = list->firstPtr; ln != NilListNode; ln = tln) {
	     tln = ln->nextPtr;
	     (*freeProc) (ln->datum);
	     free ((Address)ln);
	}
    } else {
	for (ln = list->firstPtr; ln != NilListNode; ln = tln) {
	     tln = ln->nextPtr;
	     free ((Address)ln);
	}
    }

    free ((Address)l);
}