001/*
002 * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
003 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
004 *
005 * This code is free software; you can redistribute it and/or modify it
006 * under the terms of the GNU General Public License version 2 only, as
007 * published by the Free Software Foundation.
008 *
009 * This code is distributed in the hope that it will be useful, but WITHOUT
010 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
011 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
012 * version 2 for more details (a copy is included in the LICENSE file that
013 * accompanied this code).
014 *
015 * You should have received a copy of the GNU General Public License version
016 * 2 along with this work; if not, write to the Free Software Foundation,
017 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
018 *
019 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
020 * or visit www.oracle.com if you need additional information or have any
021 * questions.
022 */
023package com.oracle.graal.printer;
024
025import static com.oracle.graal.printer.NoDeadCodeVerifyHandler.Options.*;
026
027import java.util.*;
028import java.util.concurrent.*;
029
030import jdk.internal.jvmci.common.*;
031import com.oracle.graal.debug.*;
032import jdk.internal.jvmci.options.*;
033
034import com.oracle.graal.graph.*;
035import com.oracle.graal.nodes.*;
036import com.oracle.graal.phases.common.*;
037
038/**
039 * Verifies that graphs have no dead code.
040 */
041public class NoDeadCodeVerifyHandler implements DebugVerifyHandler {
042
043    // The options below will be removed once all phases clean up their own dead code.
044
045    private static final int OFF = 0;
046    private static final int INFO = 1;
047    private static final int VERBOSE = 2;
048    private static final int FATAL = 3;
049
050    static class Options {
051        // @formatter:off
052        @Option(help = "Run level for NoDeadCodeVerifyHandler (0 = off, 1 = info, 2 = verbose, 3 = fatal)", type = OptionType.Debug)
053        public static final OptionValue<Integer> NDCV = new OptionValue<>(0);
054        // @formatter:on
055    }
056
057    /**
058     * Only the first instance of failure at any point is shown. This will also be removed once all
059     * phases clean up their own dead code.
060     */
061    private static final Map<String, Boolean> discovered = new ConcurrentHashMap<>();
062
063    public void verify(Object object, String message) {
064        if (NDCV.getValue() != OFF && object instanceof StructuredGraph) {
065            StructuredGraph graph = (StructuredGraph) object;
066            List<Node> before = graph.getNodes().snapshot();
067            new DeadCodeEliminationPhase().run(graph);
068            List<Node> after = graph.getNodes().snapshot();
069            assert after.size() <= before.size();
070            if (before.size() != after.size()) {
071                if (discovered.put(message, Boolean.TRUE) == null) {
072                    before.removeAll(after);
073                    String prefix = message == null ? "" : message + ": ";
074                    JVMCIError error = new JVMCIError("%sfound dead nodes in %s: %s", prefix, graph, before);
075                    if (NDCV.getValue() == INFO) {
076                        System.out.println(error.getMessage());
077                    } else if (NDCV.getValue() == VERBOSE) {
078                        error.printStackTrace(System.out);
079                    } else {
080                        assert NDCV.getValue() == FATAL;
081                        throw error;
082                    }
083                }
084            }
085        }
086    }
087}