1 /*
   2  * Copyright (c) 2014, 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.printer;
  24 
  25 import java.util.List;
  26 import java.util.Map;
  27 import java.util.concurrent.ConcurrentHashMap;
  28 
  29 import org.graalvm.compiler.debug.DebugVerifyHandler;
  30 import org.graalvm.compiler.debug.GraalError;
  31 import org.graalvm.compiler.graph.Node;
  32 import org.graalvm.compiler.nodes.StructuredGraph;
  33 import org.graalvm.compiler.options.Option;
  34 import org.graalvm.compiler.options.OptionType;
  35 import org.graalvm.compiler.options.OptionValue;
  36 import org.graalvm.compiler.phases.common.DeadCodeEliminationPhase;
  37 
  38 /**
  39  * Verifies that graphs have no dead code.
  40  */
  41 public class NoDeadCodeVerifyHandler implements DebugVerifyHandler {
  42 
  43     // The options below will be removed once all phases clean up their own dead code.
  44 
  45     private static final int OFF = 0;
  46     private static final int INFO = 1;
  47     private static final int VERBOSE = 2;
  48     private static final int FATAL = 3;
  49 
  50     static class Options {
  51         // @formatter:off
  52         @Option(help = "Run level for NoDeadCodeVerifyHandler (0 = off, 1 = info, 2 = verbose, 3 = fatal)", type = OptionType.Debug)
  53         public static final OptionValue<Integer> NDCV = new OptionValue<>(0);
  54         // @formatter:on
  55     }
  56 
  57     /**
  58      * Only the first instance of failure at any point is shown. This will also be removed once all
  59      * phases clean up their own dead code.
  60      */
  61     private static final Map<String, Boolean> discovered = new ConcurrentHashMap<>();
  62 
  63     @Override
  64     public void verify(Object object, String message) {
  65         if (Options.NDCV.getValue() != OFF && object instanceof StructuredGraph) {
  66             StructuredGraph graph = (StructuredGraph) object;
  67             List<Node> before = graph.getNodes().snapshot();
  68             new DeadCodeEliminationPhase().run(graph);
  69             List<Node> after = graph.getNodes().snapshot();
  70             assert after.size() <= before.size();
  71             if (before.size() != after.size()) {
  72                 if (discovered.put(message, Boolean.TRUE) == null) {
  73                     before.removeAll(after);
  74                     String prefix = message == null ? "" : message + ": ";
  75                     GraalError error = new GraalError("%sfound dead nodes in %s: %s", prefix, graph, before);
  76                     if (Options.NDCV.getValue() == INFO) {
  77                         System.out.println(error.getMessage());
  78                     } else if (Options.NDCV.getValue() == VERBOSE) {
  79                         error.printStackTrace(System.out);
  80                     } else {
  81                         assert Options.NDCV.getValue() == FATAL;
  82                         throw error;
  83                     }
  84                 }
  85             }
  86         }
  87     }
  88 }