Needed to allow complete dynamic list removal.

1 files changed, 107 insertions, 0 deletions

diff --git a/usr.bin/make/lst.lib/lstConcatDestroy.c b/usr.bin/make/lst.lib/lstConcatDestroy.c
new file mode 100644
index 00000000000..5f53abd51d1
--- /dev/null
+++ b/usr.bin/make/lst.lib/lstConcatDestroy.c
@@ -0,0 +1,107 @@
+/*	$OpenBSD: lstConcatDestroy.c,v 1.1 2000/06/17 14:44:26 espie Exp $	*/
+/*	$NetBSD: lstConcat.c,v 1.6 1996/11/06 17:59:34 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.
+ */
+
+#ifndef lint
+#if 0
+static char sccsid[] = "@(#)lstConcat.c	8.1 (Berkeley) 6/6/93";
+#else
+static char rcsid[] = "$OpenBSD: lstConcatDestroy.c,v 1.1 2000/06/17 14:44:26 espie Exp $";
+#endif
+#endif /* not lint */
+
+/*-
+ * listConcatDestroy.c --
+ *	Function to concatentate two lists.
+ */
+
+#include    "lstInt.h"
+
+/*-
+ *-----------------------------------------------------------------------
+ * Lst_ConcatDestroy --
+ *	Concatenate two lists. The elements of the second list are
+ *	destructively added to the first list.  If the elements should 
+ *	be duplicated to avoid confusion with another list, the 
+ *	Lst_Duplicate function should be called first.
+ *
+ * Results:
+ *	SUCCESS if all went well. FAILURE otherwise.
+ *
+ * Side Effects:
+ *	The second list is destroyed
+ *-----------------------------------------------------------------------
+ */
+void
+Lst_ConcatDestroy(l1, l2)
+    Lst    	  	l1; 	/* The list to which l2 is to be appended */
+    Lst    	  	l2; 	/* The list to append to l1 */
+{
+    LstNode  	ln;     	/* original LstNode */
+    LstNode  	nln;    	/* new LstNode */
+    LstNode  	last;   	/* the last element in the list. Keeps
+				 * bookkeeping until the end */
+
+    if (l2->firstPtr != NULL) {
+	/*
+	 * We set the nextPtr of the
+	 * last element of list two to be NULL to make the loop easier and
+	 * so we don't need an extra case should the first list turn
+	 * out to be non-circular -- the final element will already point
+	 * to NULL space and the first element will be untouched if it
+	 * existed before and will also point to NULL space if it didn't.
+	 */
+	l2->lastPtr->nextPtr = NULL;
+	/*
+	 * So long as the second list isn't empty, we just link the
+	 * first element of the second list to the last element of the
+	 * first list. If the first list isn't empty, we then link the
+	 * last element of the list to the first element of the second list
+	 * The last element of the second list, if it exists, then becomes
+	 * the last element of the first list.
+	 */
+	l2->firstPtr->prevPtr = l1->lastPtr;
+	if (l1->lastPtr != NULL) {
+	    l1->lastPtr->nextPtr = l2->firstPtr;
+	} else {
+	    l1->firstPtr = l2->firstPtr;
+	}
+	l1->lastPtr = l2->lastPtr;
+    }
+}
+