1 /*
   2  * Copyright (c) 2011, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  */
  23 package org.graalvm.compiler.nodes;
  24 
  25 import static org.graalvm.compiler.nodeinfo.NodeCycles.CYCLES_0;
  26 import static org.graalvm.compiler.nodeinfo.NodeSize.SIZE_0;
  27 
  28 import java.util.Arrays;
  29 import java.util.Collections;
  30 
  31 import org.graalvm.compiler.core.common.type.StampFactory;
  32 import org.graalvm.compiler.graph.Node;
  33 import org.graalvm.compiler.graph.NodeClass;
  34 import org.graalvm.compiler.nodeinfo.NodeInfo;
  35 import org.graalvm.compiler.nodes.spi.LIRLowerable;
  36 import org.graalvm.compiler.nodes.spi.NodeLIRBuilderTool;
  37 
  38 @NodeInfo(cycles = CYCLES_0, size = SIZE_0)
  39 public abstract class AbstractEndNode extends FixedNode implements LIRLowerable {
  40 
  41     public static final NodeClass<AbstractEndNode> TYPE = NodeClass.create(AbstractEndNode.class);
  42 
  43     protected AbstractEndNode(NodeClass<? extends AbstractEndNode> c) {
  44         super(c, StampFactory.forVoid());
  45     }
  46 
  47     @Override
  48     public void generate(NodeLIRBuilderTool gen) {
  49         gen.visitEndNode(this);
  50     }
  51 
  52     public AbstractMergeNode merge() {
  53         return (AbstractMergeNode) usages().first();
  54     }
  55 
  56     @Override
  57     public boolean verify() {
  58         assertTrue(getUsageCount() <= 1, "at most one usage");
  59         return super.verify();
  60     }
  61 
  62     @Override
  63     public Iterable<? extends Node> cfgSuccessors() {
  64         AbstractMergeNode merge = merge();
  65         if (merge != null) {
  66             return Arrays.asList(merge);
  67         }
  68         return Collections.emptyList();
  69     }
  70 }