1 /*
   2  * Copyright (c) 2015, 2018, 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 
  24 
  25 package org.graalvm.compiler.core.phases;
  26 
  27 import jdk.internal.vm.compiler.collections.EconomicSet;
  28 import jdk.internal.vm.compiler.collections.Equivalence;
  29 import org.graalvm.compiler.debug.DebugContext;
  30 import org.graalvm.compiler.graph.Graph.NodeEvent;
  31 import org.graalvm.compiler.graph.Graph.NodeEventScope;
  32 import org.graalvm.compiler.graph.Node;
  33 import org.graalvm.compiler.nodes.LogicConstantNode;
  34 import org.graalvm.compiler.nodes.StructuredGraph;
  35 import org.graalvm.compiler.phases.BasePhase;
  36 import org.graalvm.compiler.phases.PhaseSuite;
  37 import org.graalvm.compiler.phases.common.util.EconomicSetNodeEventListener;
  38 import org.graalvm.compiler.phases.tiers.PhaseContext;
  39 
  40 /**
  41  * A utility phase for detecting when a phase would change the graph and reporting extra information
  42  * about the effects. The phase is first run on a copy of the graph and if a change in that graph is
  43  * detected then it's rerun on the original graph inside a new debug scope under
  44  * GraphChangeMonitoringPhase. The message argument can be used to distinguish between the same
  45  * phase run at different points.
  46  *
  47  * @param <C>
  48  */
  49 public class GraphChangeMonitoringPhase<C extends PhaseContext> extends PhaseSuite<C> {
  50 
  51     private final String message;
  52 
  53     public GraphChangeMonitoringPhase(String message, BasePhase<C> phase) {
  54         super();
  55         this.message = message;
  56         appendPhase(phase);
  57     }
  58 
  59     public GraphChangeMonitoringPhase(String message) {
  60         super();
  61         this.message = message;
  62     }
  63 
  64     @Override
  65     @SuppressWarnings("try")
  66     protected void run(StructuredGraph graph, C context) {
  67         /*
  68          * Phase may add nodes but not end up using them so ignore additions. Nodes going dead and
  69          * having their inputs change are the main interesting differences.
  70          */
  71         EconomicSetNodeEventListener listener = new EconomicSetNodeEventListener().exclude(NodeEvent.NODE_ADDED);
  72         StructuredGraph graphCopy = (StructuredGraph) graph.copy(graph.getDebug());
  73         DebugContext debug = graph.getDebug();
  74         try (NodeEventScope s = graphCopy.trackNodeEvents(listener)) {
  75             try (DebugContext.Scope s2 = debug.sandbox("WithoutMonitoring", null)) {
  76                 super.run(graphCopy, context);
  77             } catch (Throwable t) {
  78                 debug.handle(t);
  79             }
  80         }
  81 
  82         EconomicSet<Node> filteredNodes = EconomicSet.create(Equivalence.IDENTITY);
  83         for (Node n : listener.getNodes()) {
  84             if (n instanceof LogicConstantNode) {
  85                 // Ignore LogicConstantNode since those are sometimes created and deleted as part of
  86                 // running a phase.
  87             } else {
  88                 filteredNodes.add(n);
  89             }
  90         }
  91         if (!filteredNodes.isEmpty()) {
  92             /* rerun it on the real graph in a new Debug scope so Dump and Log can find it. */
  93             listener = new EconomicSetNodeEventListener();
  94             try (NodeEventScope s = graph.trackNodeEvents(listener)) {
  95                 try (DebugContext.Scope s2 = debug.scope("WithGraphChangeMonitoring")) {
  96                     if (debug.isDumpEnabled(DebugContext.DETAILED_LEVEL)) {
  97                         debug.dump(DebugContext.DETAILED_LEVEL, graph, "*** Before phase %s", getName());
  98                     }
  99                     super.run(graph, context);
 100                     if (debug.isDumpEnabled(DebugContext.DETAILED_LEVEL)) {
 101                         debug.dump(DebugContext.DETAILED_LEVEL, graph, "*** After phase %s %s", getName(), filteredNodes);
 102                     }
 103                     debug.log("*** %s %s %s\n", message, graph, filteredNodes);
 104                 }
 105             }
 106         } else {
 107             // Go ahead and run it normally even though it should have no effect
 108             super.run(graph, context);
 109         }
 110     }
 111 }