/*
 * Copyright (c) 2013, 2016, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */
package org.graalvm.compiler.hotspot.test;

import java.util.List;
import java.util.Map;

import org.junit.Assert;
import org.junit.Test;

import org.graalvm.compiler.core.common.LocationIdentity;
import org.graalvm.compiler.debug.Debug;
import org.graalvm.compiler.debug.Debug.Scope;
import org.graalvm.compiler.debug.DebugConfig;
import org.graalvm.compiler.debug.DebugConfigScope;
import org.graalvm.compiler.debug.DebugDumpScope;
import org.graalvm.compiler.debug.internal.DebugScope;
import org.graalvm.compiler.hotspot.GraalHotSpotVMConfig;
import org.graalvm.compiler.hotspot.nodes.G1ArrayRangePostWriteBarrier;
import org.graalvm.compiler.hotspot.nodes.G1ArrayRangePreWriteBarrier;
import org.graalvm.compiler.hotspot.nodes.G1PostWriteBarrier;
import org.graalvm.compiler.hotspot.nodes.G1PreWriteBarrier;
import org.graalvm.compiler.hotspot.nodes.SerialArrayRangeWriteBarrier;
import org.graalvm.compiler.hotspot.nodes.SerialWriteBarrier;
import org.graalvm.compiler.hotspot.phases.WriteBarrierAdditionPhase;
import org.graalvm.compiler.hotspot.phases.WriteBarrierVerificationPhase;
import org.graalvm.compiler.hotspot.replacements.arraycopy.UnsafeArrayCopyNode;
import org.graalvm.compiler.nodes.AbstractBeginNode;
import org.graalvm.compiler.nodes.AbstractMergeNode;
import org.graalvm.compiler.nodes.FieldLocationIdentity;
import org.graalvm.compiler.nodes.FixedNode;
import org.graalvm.compiler.nodes.FixedWithNextNode;
import org.graalvm.compiler.nodes.LoopBeginNode;
import org.graalvm.compiler.nodes.LoopExitNode;
import org.graalvm.compiler.nodes.StructuredGraph;
import org.graalvm.compiler.nodes.StructuredGraph.AllowAssumptions;
import org.graalvm.compiler.nodes.memory.WriteNode;
import org.graalvm.compiler.nodes.spi.LoweringTool;
import org.graalvm.compiler.phases.OptimisticOptimizations;
import org.graalvm.compiler.phases.common.CanonicalizerPhase;
import org.graalvm.compiler.phases.common.GuardLoweringPhase;
import org.graalvm.compiler.phases.common.LoopSafepointInsertionPhase;
import org.graalvm.compiler.phases.common.LoweringPhase;
import org.graalvm.compiler.phases.common.inlining.InliningPhase;
import org.graalvm.compiler.phases.graph.ReentrantNodeIterator;
import org.graalvm.compiler.phases.graph.ReentrantNodeIterator.NodeIteratorClosure;
import org.graalvm.compiler.phases.tiers.HighTierContext;
import org.graalvm.compiler.phases.tiers.MidTierContext;

import jdk.vm.ci.meta.ResolvedJavaField;

The following tests validate the write barrier verification phase. For every tested snippet, an
array of write barrier indices and the total write barrier number are passed as parameters. The
indices denote the barriers that will be manually removed. The write barrier verification phase
runs after the write barrier removal and depending on the result an assertion might be generated.
The tests anticipate the presence or not of an assertion generated by the verification phase.
/**
 * The following tests validate the write barrier verification phase. For every tested snippet, an
 * array of write barrier indices and the total write barrier number are passed as parameters. The
 * indices denote the barriers that will be manually removed. The write barrier verification phase
 * runs after the write barrier removal and depending on the result an assertion might be generated.
 * The tests anticipate the presence or not of an assertion generated by the verification phase.
 */
public class WriteBarrierVerificationTest extends HotSpotGraalCompilerTest {

    public static int barrierIndex;

    private final GraalHotSpotVMConfig config = runtime().getVMConfig();

    public static class Container {

        public Container a;
        public Container b;
    }

    private static native void safepoint();

    public static void test1Snippet(Container main) {
        Container temp1 = new Container();
        Container temp2 = new Container();
        barrierIndex = 0;
        safepoint();
        barrierIndex = 1;
        main.a = temp1;
        safepoint();
        barrierIndex = 2;
        main.b = temp2;
        safepoint();
    }

    @Test(expected = AssertionError.class)
    public void test1() {
        test("test1Snippet", 2, new int[]{1});
    }

    @Test(expected = AssertionError.class)
    public void test2() {
        test("test1Snippet", 2, new int[]{2});
    }

    public static void test2Snippet(Container main) {
        Container temp1 = new Container();
        Container temp2 = new Container();
        barrierIndex = 0;
        safepoint();
        barrierIndex = 1;
        main.a = temp1;
        barrierIndex = 2;
        main.b = temp2;
        safepoint();
    }

    @Test(expected = AssertionError.class)
    public void test3() {
        test("test2Snippet", 2, new int[]{1});
    }

    @Test
    public void test4() {
        test("test2Snippet", 2, new int[]{2});
    }

    public static void test3Snippet(Container main, boolean test) {
        Container temp1 = new Container();
        Container temp2 = new Container();
        barrierIndex = 0;
        safepoint();
        for (int i = 0; i < 10; i++) {
            if (test) {
                barrierIndex = 1;
                main.a = temp1;
                barrierIndex = 2;
                main.b = temp2;
            } else {
                barrierIndex = 3;
                main.a = temp1;
                barrierIndex = 4;
                main.b = temp2;
            }
        }
    }

    @Test(expected = AssertionError.class)
    public void test5() {
        test("test3Snippet", 4, new int[]{1, 2});
    }

    @Test(expected = AssertionError.class)
    public void test6() {
        test("test3Snippet", 4, new int[]{3, 4});
    }

    @Test(expected = AssertionError.class)
    public void test7() {
        test("test3Snippet", 4, new int[]{1});
    }

    @Test
    public void test8() {
        test("test3Snippet", 4, new int[]{2});
    }

    @Test(expected = AssertionError.class)
    public void test9() {
        test("test3Snippet", 4, new int[]{3});
    }

    @Test
    public void test10() {
        test("test3Snippet", 4, new int[]{4});
    }

    public static void test4Snippet(Container main, boolean test) {
        Container temp1 = new Container();
        Container temp2 = new Container();
        safepoint();
        barrierIndex = 1;
        main.a = temp1;
        for (int i = 0; i < 10; i++) {
            if (test) {
                barrierIndex = 2;
                main.a = temp1;
                barrierIndex = 3;
                main.b = temp2;
            } else {
                barrierIndex = 4;
                main.a = temp2;
                barrierIndex = 5;
                main.b = temp1;
            }
        }
    }

    @Test(expected = AssertionError.class)
    public void test11() {
        test("test4Snippet", 5, new int[]{2, 3});
    }

    @Test(expected = AssertionError.class)
    public void test12() {
        test("test4Snippet", 5, new int[]{4, 5});
    }

    @Test(expected = AssertionError.class)
    public void test13() {
        test("test4Snippet", 5, new int[]{1});
    }

    public static void test5Snippet(Container main) {
        Container temp1 = new Container();
        Container temp2 = new Container();
        safepoint();
        barrierIndex = 1;
        main.a = temp1;
        if (main.a == main.b) {
            barrierIndex = 2;
            main.a = temp1;
            barrierIndex = 3;
            main.b = temp2;
        } else {
            barrierIndex = 4;
            main.a = temp2;
            barrierIndex = 5;
            main.b = temp1;
        }
        safepoint();
    }

    @Test(expected = AssertionError.class)
    public void test14() {
        test("test5Snippet", 5, new int[]{1});
    }

    @Test
    public void test15() {
        test("test5Snippet", 5, new int[]{2});
    }

    @Test
    public void test16() {
        test("test5Snippet", 5, new int[]{4});
    }

    @Test
    public void test17() {
        test("test5Snippet", 5, new int[]{3});
    }

    @Test
    public void test18() {
        test("test5Snippet", 5, new int[]{5});
    }

    @Test
    public void test19() {
        test("test5Snippet", 5, new int[]{2, 3});
    }

    @Test
    public void test20() {
        test("test5Snippet", 5, new int[]{4, 5});
    }

    public static void test6Snippet(Container main, boolean test) {
        Container temp1 = new Container();
        Container temp2 = new Container();
        safepoint();
        barrierIndex = 1;
        main.a = temp1;
        if (test) {
            barrierIndex = 2;
            main.a = temp1;
            barrierIndex = 3;
            main.b = temp1.a.a;
        } else {
            barrierIndex = 4;
            main.a = temp2;
            barrierIndex = 5;
            main.b = temp2.a.a;
        }
        safepoint();
    }

    @Test(expected = AssertionError.class)
    public void test21() {
        test("test6Snippet", 5, new int[]{1});
    }

    @Test(expected = AssertionError.class)
    public void test22() {
        test("test6Snippet", 5, new int[]{1, 2});
    }

    @Test(expected = AssertionError.class)
    public void test23() {
        test("test6Snippet", 5, new int[]{3});
    }

    @Test
    public void test24() {
        test("test6Snippet", 5, new int[]{4});
    }

    public static void test7Snippet(Container main, boolean test) {
        Container temp1 = new Container();
        Container temp2 = new Container();
        safepoint();
        barrierIndex = 1;
        main.a = temp1;
        if (test) {
            barrierIndex = 2;
            main.a = temp1;
        }
        barrierIndex = 3;
        main.b = temp2;
        safepoint();
    }

    @Test
    public void test25() {
        test("test7Snippet", 3, new int[]{2});
    }

    @Test
    public void test26() {
        test("test7Snippet", 3, new int[]{3});
    }

    @Test
    public void test27() {
        test("test7Snippet", 3, new int[]{2, 3});
    }

    @Test(expected = AssertionError.class)
    public void test28() {
        test("test7Snippet", 3, new int[]{1});
    }

    public static void test8Snippet(Container main, boolean test) {
        Container temp1 = new Container();
        Container temp2 = new Container();
        safepoint();
        if (test) {
            barrierIndex = 1;
            main.a = temp1;
        }
        barrierIndex = 2;
        main.b = temp2;
        safepoint();
    }

    @Test(expected = AssertionError.class)
    public void test29() {
        test("test8Snippet", 2, new int[]{1});
    }

    @Test(expected = AssertionError.class)
    public void test30() {
        test("test8Snippet", 2, new int[]{2});
    }

    @Test(expected = AssertionError.class)
    public void test31() {
        test("test8Snippet", 2, new int[]{1, 2});
    }

    public static void test9Snippet(Container main1, Container main2, boolean test) {
        Container temp1 = new Container();
        Container temp2 = new Container();
        safepoint();
        if (test) {
            barrierIndex = 1;
            main1.a = temp1;
        } else {
            barrierIndex = 2;
            main2.a = temp1;
        }
        barrierIndex = 3;
        main1.b = temp2;
        barrierIndex = 4;
        main2.b = temp2;
        safepoint();
    }

    @Test(expected = AssertionError.class)
    public void test32() {
        test("test9Snippet", 4, new int[]{1});
    }

    @Test(expected = AssertionError.class)
    public void test33() {
        test("test9Snippet", 4, new int[]{2});
    }

    @Test(expected = AssertionError.class)
    public void test34() {
        test("test9Snippet", 4, new int[]{3});
    }

    @Test(expected = AssertionError.class)
    public void test35() {
        test("test9Snippet", 4, new int[]{4});
    }

    @Test(expected = AssertionError.class)
    public void test36() {
        test("test9Snippet", 4, new int[]{1, 2});
    }

    @Test(expected = AssertionError.class)
    public void test37() {
        test("test9Snippet", 4, new int[]{3, 4});
    }

    public static void test10Snippet(Container main1, Container main2, boolean test) {
        Container temp1 = new Container();
        Container temp2 = new Container();
        safepoint();
        if (test) {
            barrierIndex = 1;
            main1.a = temp1;
            barrierIndex = 2;
            main2.a = temp2;
        } else {
            barrierIndex = 3;
            main2.a = temp1;
        }
        barrierIndex = 4;
        main1.b = temp2;
        barrierIndex = 5;
        main2.b = temp2;
        safepoint();
    }

    @Test(expected = AssertionError.class)
    public void test38() {
        test("test10Snippet", 5, new int[]{1});
    }

    @Test(expected = AssertionError.class)
    public void test39() {
        test("test10Snippet", 5, new int[]{2});
    }

    @Test(expected = AssertionError.class)
    public void test40() {
        test("test10Snippet", 5, new int[]{3});
    }

    @Test(expected = AssertionError.class)
    public void test41() {
        test("test10Snippet", 5, new int[]{4});
    }

    @Test
    public void test42() {
        test("test10Snippet", 5, new int[]{5});
    }

    @Test(expected = AssertionError.class)
    public void test43() {
        test("test10Snippet", 5, new int[]{1, 2});
    }

    @Test(expected = AssertionError.class)
    public void test44() {
        test("test10Snippet", 5, new int[]{1, 2, 3});
    }

    @Test(expected = AssertionError.class)
    public void test45() {
        test("test10Snippet", 5, new int[]{3, 4});
    }

    public static void test11Snippet(Container main1, Container main2, Container main3, boolean test) {
        Container temp1 = new Container();
        Container temp2 = new Container();
        safepoint();
        if (test) {
            barrierIndex = 1;
            main1.a = temp1;
            barrierIndex = 2;
            main3.a = temp1;
            if (!test) {
                barrierIndex = 3;
                main2.a = temp2;
            } else {
                barrierIndex = 4;
                main1.a = temp2;
                barrierIndex = 5;
                main3.a = temp2;
            }
        } else {
            barrierIndex = 6;
            main1.b = temp2;
            for (int i = 0; i < 10; i++) {
                barrierIndex = 7;
                main3.a = temp1;
            }
            barrierIndex = 8;
            main3.b = temp2;
        }
        barrierIndex = 9;
        main1.b = temp2;
        barrierIndex = 10;
        main2.b = temp2;
        barrierIndex = 11;
        main3.b = temp2;
        safepoint();
    }

    @Test(expected = AssertionError.class)
    public void test46() {
        test("test11Snippet", 11, new int[]{1});
    }

    @Test(expected = AssertionError.class)
    public void test47() {
        test("test11Snippet", 11, new int[]{2});
    }

    @Test(expected = AssertionError.class)
    public void test48() {
        test("test11Snippet", 11, new int[]{3});
    }

    @Test(expected = AssertionError.class)
    public void test49() {
        test("test11Snippet", 11, new int[]{6});
    }

    @Test(expected = AssertionError.class)
    public void test50() {
        test("test11Snippet", 11, new int[]{7});
    }

    @Test(expected = AssertionError.class)
    public void test51() {
        test("test11Snippet", 11, new int[]{8});
    }

    @Test(expected = AssertionError.class)
    public void test52() {
        test("test11Snippet", 11, new int[]{9});
    }

    @Test(expected = AssertionError.class)
    public void test53() {
        test("test11Snippet", 11, new int[]{10});
    }

    @Test
    public void test54() {
        test("test11Snippet", 11, new int[]{4});
    }

    @Test
    public void test55() {
        test("test11Snippet", 11, new int[]{5});
    }

    @Test
    public void test56() {
        test("test11Snippet", 11, new int[]{11});
    }

    public static void test12Snippet(Container main, Container main1, boolean test) {
        Container temp1 = new Container();
        Container temp2 = new Container();
        barrierIndex = 0;
        safepoint();
        barrierIndex = 7;
        main1.a = temp1;
        for (int i = 0; i < 10; i++) {
            if (test) {
                barrierIndex = 1;
                main.a = temp1;
                barrierIndex = 2;
                main.b = temp2;
            } else {
                barrierIndex = 3;
                main.a = temp1;
                barrierIndex = 4;
                main.b = temp2;
            }
        }
        barrierIndex = 5;
        main.a = temp1;
        barrierIndex = 6;
        main.b = temp1;
        barrierIndex = 8;
        main1.b = temp1;
        safepoint();
    }

    @Test(expected = AssertionError.class)
    public void test57() {
        test("test12Snippet", 8, new int[]{5});
    }

    @Test
    public void test58() {
        test("test12Snippet", 8, new int[]{6});
    }

    @Test(expected = AssertionError.class)
    public void test59() {
        test("test12Snippet", 8, new int[]{7});
    }

    @Test(expected = AssertionError.class)
    public void test60() {
        test("test12Snippet", 8, new int[]{8});
    }

    public static void test13Snippet(Object[] a, Object[] b) {
        System.arraycopy(a, 0, b, 0, a.length);
    }

    @Test
    public void test61() {
        GraphPredicate checkForUnsafeArrayCopy = graph -> graph.getNodes().filter(UnsafeArrayCopyNode.class).count() > 0 ? 1 : 0;
        testPredicate("test13Snippet", checkForUnsafeArrayCopy, new int[]{});
    }

    private interface GraphPredicate {
        int apply(StructuredGraph graph);
    }

    private void test(final String snippet, final int expectedBarriers, final int... removedBarrierIndices) {
        GraphPredicate noCheck = noArg -> expectedBarriers;
        testPredicate(snippet, noCheck, removedBarrierIndices);
    }

    @SuppressWarnings("try")
    private void testPredicate(final String snippet, final GraphPredicate expectedBarriers, final int... removedBarrierIndices) {
        try (Scope d = Debug.scope("WriteBarrierVerificationTest", new DebugDumpScope(snippet))) {
            final StructuredGraph graph = parseEager(snippet, AllowAssumptions.YES);
            HighTierContext highTierContext = getDefaultHighTierContext();
            new InliningPhase(new CanonicalizerPhase()).apply(graph, highTierContext);

            MidTierContext midTierContext = new MidTierContext(getProviders(), getTargetProvider(), OptimisticOptimizations.ALL, graph.getProfilingInfo());

            new LoweringPhase(new CanonicalizerPhase(), LoweringTool.StandardLoweringStage.HIGH_TIER).apply(graph, highTierContext);
            new GuardLoweringPhase().apply(graph, midTierContext);
            new LoopSafepointInsertionPhase().apply(graph);
            new LoweringPhase(new CanonicalizerPhase(), LoweringTool.StandardLoweringStage.MID_TIER).apply(graph, highTierContext);

            new WriteBarrierAdditionPhase(config).apply(graph);

            int barriers = 0;
            // First, the total number of expected barriers is checked.
            if (config.useG1GC) {
                barriers = graph.getNodes().filter(G1PreWriteBarrier.class).count() + graph.getNodes().filter(G1PostWriteBarrier.class).count() +
                                graph.getNodes().filter(G1ArrayRangePreWriteBarrier.class).count() + graph.getNodes().filter(G1ArrayRangePostWriteBarrier.class).count();
                Assert.assertTrue(expectedBarriers.apply(graph) * 2 == barriers);
            } else {
                barriers = graph.getNodes().filter(SerialWriteBarrier.class).count() + graph.getNodes().filter(SerialArrayRangeWriteBarrier.class).count();
                Assert.assertTrue(expectedBarriers.apply(graph) == barriers);
            }
            ResolvedJavaField barrierIndexField = getMetaAccess().lookupJavaField(WriteBarrierVerificationTest.class.getDeclaredField("barrierIndex"));
            LocationIdentity barrierIdentity = new FieldLocationIdentity(barrierIndexField);
            // Iterate over all write nodes and remove barriers according to input indices.
            NodeIteratorClosure<Boolean> closure = new NodeIteratorClosure<Boolean>() {

                @Override
                protected Boolean processNode(FixedNode node, Boolean currentState) {
                    if (node instanceof WriteNode) {
                        WriteNode write = (WriteNode) node;
                        LocationIdentity obj = write.getLocationIdentity();
                        if (obj.equals(barrierIdentity)) {
                            /*
                             * A "barrierIndex" variable was found and is checked against the input
                             * barrier array.
                             */
                            if (eliminateBarrier(write.value().asJavaConstant().asInt(), removedBarrierIndices)) {
                                return true;
                            }
                        }
                    } else if (node instanceof SerialWriteBarrier || node instanceof G1PostWriteBarrier) {
                        // Remove flagged write barriers.
                        if (currentState) {
                            graph.removeFixed(((FixedWithNextNode) node));
                            return false;
                        }
                    }
                    return currentState;
                }

                private boolean eliminateBarrier(int index, int[] map) {
                    for (int i = 0; i < map.length; i++) {
                        if (map[i] == index) {
                            return true;
                        }
                    }
                    return false;
                }

                @Override
                protected Map<LoopExitNode, Boolean> processLoop(LoopBeginNode loop, Boolean initialState) {
                    return ReentrantNodeIterator.processLoop(this, loop, initialState).exitStates;
                }

                @Override
                protected Boolean merge(AbstractMergeNode merge, List<Boolean> states) {
                    return false;
                }

                @Override
                protected Boolean afterSplit(AbstractBeginNode node, Boolean oldState) {
                    return false;
                }
            };

            DebugConfig debugConfig = DebugScope.getConfig();
            DebugConfig fixedConfig = debugConfig == null ? null
                            : Debug.fixedConfig(0, 0, false, false, false, false, false, debugConfig.dumpHandlers(), debugConfig.verifyHandlers(), debugConfig.output());
            try (DebugConfigScope s = Debug.setConfig(fixedConfig)) {
                ReentrantNodeIterator.apply(closure, graph.start(), false);
                new WriteBarrierVerificationPhase(config).apply(graph);
            } catch (AssertionError error) {
                /*
                 * Catch assertion, test for expected one and re-throw in order to validate unit
                 * test.
                 */
                Assert.assertTrue(error.getMessage().contains("Write barrier must be present"));
                throw error;
            }
        } catch (Throwable e) {
            throw Debug.handle(e);
        }
    }
}