xref: /openbsd-src/usr.bin/make/lst.lib/lstForEachFrom.c (revision 62a742911104f98b9185b2c6b6007d9b1c36396c)
1 /*	$OpenBSD: lstForEachFrom.c,v 1.4 1998/12/05 00:06:32 espie Exp $	*/
2 /*	$NetBSD: lstForEachFrom.c,v 1.5 1996/11/06 17:59:42 christos Exp $	*/
3 
4 /*
5  * Copyright (c) 1988, 1989, 1990, 1993
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * This code is derived from software contributed to Berkeley by
9  * Adam de Boor.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  * 3. All advertising materials mentioning features or use of this software
20  *    must display the following acknowledgement:
21  *	This product includes software developed by the University of
22  *	California, Berkeley and its contributors.
23  * 4. Neither the name of the University nor the names of its contributors
24  *    may be used to endorse or promote products derived from this software
25  *    without specific prior written permission.
26  *
27  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
28  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
29  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
30  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
31  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
32  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
33  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
34  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
35  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
36  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
37  * SUCH DAMAGE.
38  */
39 
40 #ifndef lint
41 #if 0
42 static char sccsid[] = "@(#)lstForEachFrom.c	8.1 (Berkeley) 6/6/93";
43 #else
44 static char rcsid[] = "$OpenBSD: lstForEachFrom.c,v 1.4 1998/12/05 00:06:32 espie Exp $";
45 #endif
46 #endif /* not lint */
47 
48 /*-
49  * lstForEachFrom.c --
50  *	Perform a given function on all elements of a list starting from
51  *	a given point.
52  */
53 
54 #include	"lstInt.h"
55 
56 /*-
57  *-----------------------------------------------------------------------
58  * Lst_ForEachFrom --
59  *	Apply the given function to each element of the given list. The
60  *	function should return 0 if traversal should continue and non-
61  *	zero if it should abort.
62  *
63  * Results:
64  *	None.
65  *
66  * Side Effects:
67  *	Only those created by the passed-in function.
68  *
69  *-----------------------------------------------------------------------
70  */
71 /*VARARGS2*/
72 void
73 Lst_ForEachFrom (l, ln, proc, d)
74     Lst	    	    	l;
75     LstNode    	  	ln;
76     register int	(*proc) __P((ClientData, ClientData));
77     register ClientData	d;
78 {
79     register ListNode	tln = (ListNode)ln;
80     register List 	list = (List)l;
81     register ListNode	next;
82     Boolean 	    	done;
83     int     	    	result;
84 
85     if (!LstValid (list) || LstIsEmpty (list)) {
86 	return;
87     }
88 
89     do {
90 	/*
91 	 * Take care of having the current element deleted out from under
92 	 * us.
93 	 */
94 
95 	next = tln->nextPtr;
96 
97 	(void) tln->useCount++;
98 	result = (*proc) (tln->datum, d);
99 	(void) tln->useCount--;
100 
101 	/*
102 	 * We're done with the traversal if
103 	 *  - nothing's been added after the current node and
104 	 *  - the next node to examine is the first in the queue or
105 	 *    doesn't exist.
106 	 */
107 	done = (next == tln->nextPtr &&
108 		(next == NilListNode || next == list->firstPtr));
109 
110 	next = tln->nextPtr;
111 
112 	if (tln->flags & LN_DELETED) {
113 	    free((char *)tln);
114 	}
115 	tln = next;
116     } while (!result && !LstIsEmpty(list) && !done);
117 
118 }
119 
120