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.DebugContext;
  30 import org.graalvm.compiler.debug.DebugVerifyHandler;
  31 import org.graalvm.compiler.debug.GraalError;
  32 import org.graalvm.compiler.graph.Node;
  33 import org.graalvm.compiler.nodes.StructuredGraph;
  34 import org.graalvm.compiler.options.Option;
  35 import org.graalvm.compiler.options.OptionKey;
  36 import org.graalvm.compiler.options.OptionType;
  37 import org.graalvm.compiler.options.OptionValues;
  38 import org.graalvm.compiler.phases.common.DeadCodeEliminationPhase;
  39 
  40 /**
  41  * Verifies that graphs have no dead code.
  42  */
  43 public class NoDeadCodeVerifyHandler implements DebugVerifyHandler {
  44 
  45     // The options below will be removed once all phases clean up their own dead code.
  46 
  47     private static final int OFF = 0;
  48     private static final int INFO = 1;
  49     private static final int VERBOSE = 2;
  50     private static final int FATAL = 3;
  51 
  52     static class Options {
  53         // @formatter:off
  54         @Option(help = "Run level for NoDeadCodeVerifyHandler (0 = off, 1 = info, 2 = verbose, 3 = fatal)", type = OptionType.Debug)
  55         public static final OptionKey<Integer> NDCV = new OptionKey<>(0);
  56         // @formatter:on
  57     }
  58 
  59     /**
  60      * Only the first instance of failure at any point is shown. This will also be removed once all
  61      * phases clean up their own dead code.
  62      */
  63     private static final Map<String, Boolean> discovered = new ConcurrentHashMap<>();
  64 
  65     @Override
  66     public void verify(DebugContext debug, Object object, String format, Object... args) {
  67         OptionValues options = debug.getOptions();
  68         if (Options.NDCV.getValue(options) != OFF && object instanceof StructuredGraph) {
  69             StructuredGraph graph = (StructuredGraph) object;
  70             List<Node> before = graph.getNodes().snapshot();
  71             new DeadCodeEliminationPhase().run(graph);
  72             List<Node> after = graph.getNodes().snapshot();
  73             assert after.size() <= before.size();
  74             if (before.size() != after.size()) {
  75                 if (discovered.put(format, Boolean.TRUE) == null) {
  76                     before.removeAll(after);
  77                     String prefix = format == null ? "" : format + ": ";
  78                     GraalError error = new GraalError("%sfound dead nodes in %s: %s", prefix, graph, before);
  79                     if (Options.NDCV.getValue(options) == INFO) {
  80                         System.out.println(error.getMessage());
  81                     } else if (Options.NDCV.getValue(options) == VERBOSE) {
  82                         error.printStackTrace(System.out);
  83                     } else {
  84                         assert Options.NDCV.getValue(options) == FATAL;
  85                         throw error;
  86                     }
  87                 }
  88             }
  89         }
  90     }
  91 }