xref: /minix/usr.bin/make/lst.lib/lstIsEmpty.c (revision ebfedea0)
1 /*	$NetBSD: lstIsEmpty.c,v 1.11 2008/12/13 15:19:29 dsl Exp $	*/
2 
3 /*
4  * Copyright (c) 1988, 1989, 1990, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * This code is derived from software contributed to Berkeley by
8  * Adam de Boor.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. Neither the name of the University nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  */
34 
35 #ifndef MAKE_NATIVE
36 static char rcsid[] = "$NetBSD: lstIsEmpty.c,v 1.11 2008/12/13 15:19:29 dsl Exp $";
37 #else
38 #include <sys/cdefs.h>
39 #ifndef lint
40 #if 0
41 static char sccsid[] = "@(#)lstIsEmpty.c	8.1 (Berkeley) 6/6/93";
42 #else
43 __RCSID("$NetBSD: lstIsEmpty.c,v 1.11 2008/12/13 15:19:29 dsl Exp $");
44 #endif
45 #endif /* not lint */
46 #endif
47 
48 /*-
49  * LstIsEmpty.c --
50  *	A single function to decide if a list is empty
51  */
52 
53 #include	"lstInt.h"
54 
55 /*-
56  *-----------------------------------------------------------------------
57  * Lst_IsEmpty --
58  *	Return TRUE if the given list is empty.
59  *
60  * Results:
61  *	TRUE if the list is empty, FALSE otherwise.
62  *
63  * Side Effects:
64  *	None.
65  *
66  *	A list is considered empty if its firstPtr == NULL (or if
67  *	the list itself is NULL).
68  *-----------------------------------------------------------------------
69  */
70 Boolean
71 Lst_IsEmpty(Lst l)
72 {
73     return ( ! LstValid (l) || LstIsEmpty(l));
74 }
75 
76