xref: /openbsd/usr.bin/make/lst.lib/lstAddNew.c (revision 09467b48)
1 /*	$OpenBSD: lstAddNew.c,v 1.8 2010/07/19 19:46:44 espie Exp $	*/
2 /* ex:ts=8 sw=4:
3  */
4 
5 /*
6  * Copyright (c) 1999 Marc Espie.
7  *
8  * Code written for the OpenBSD project.
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  *
19  * THIS SOFTWARE IS PROVIDED BY THE OPENBSD PROJECT AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
21  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
22  * A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OPENBSD
23  * PROJECT OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
24  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
25  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
26  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
27  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
28  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
29  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 #include	"lstInt.h"
33 #include	<stddef.h>
34 
35 /* Add datum to the end of a list only if it wasn't there already.
36  * Returns false if datum was already there.
37  */
38 bool
39 Lst_AddNew(Lst l, void *d)
40 {
41 	if (Lst_Member(l, d) != NULL)
42 		return false;
43 	else {
44 		Lst_AtEnd(l, d);
45 		return true;
46 	}
47 }
48 
49