/*

 * Copyright (c) 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.core.test;

import java.util.List;

import org.graalvm.compiler.core.common.CompilationIdentifier;

import org.graalvm.compiler.graph.Node;

import org.graalvm.compiler.nodes.ConstantNode;

import org.graalvm.compiler.nodes.Invoke;

import org.graalvm.compiler.nodes.InvokeNode;

import org.graalvm.compiler.nodes.StructuredGraph;

import org.graalvm.compiler.nodes.StructuredGraph.AllowAssumptions;

import org.graalvm.compiler.nodes.ValueNode;

import org.graalvm.compiler.nodes.debug.OpaqueNode;

import org.graalvm.compiler.nodes.extended.LoadHubNode;

import org.graalvm.compiler.nodes.extended.LoadMethodNode;

import org.graalvm.compiler.nodes.graphbuilderconf.GraphBuilderContext;

import org.graalvm.compiler.nodes.graphbuilderconf.InvocationPlugin;

import org.graalvm.compiler.nodes.graphbuilderconf.InvocationPlugin.Receiver;

import org.graalvm.compiler.nodes.graphbuilderconf.InvocationPlugins;

import org.graalvm.compiler.nodes.graphbuilderconf.InvocationPlugins.Registration;

import org.graalvm.compiler.options.OptionValues;

import org.junit.Assert;

import org.junit.BeforeClass;

import org.junit.Test;

import jdk.vm.ci.meta.JavaKind;

import jdk.vm.ci.meta.ResolvedJavaMethod;

/**

 * Tests use of an intrinsic for virtual methods where the call site is indirect. A prime example is

 * an intrinsic for {@link Object#hashCode()}. The intrinsic can only be used if the call site would

 * actually dispatch to {@link Object#hashCode()} and not a method that overrides it.

 */

public class GuardedIntrinsicTest extends GraalCompilerTest {

    static class Super {

        int getAge() {

            return 11;

        }

    }

    public static class Person extends Super {

        int age;

        public Person(int age) {

            this.age = age;

        }

        @Override

        public int getAge() {

            return age;

        }

    }

    @BytecodeParserForceInline

    public static final Super createSuper() {

        return new Super();

    }

    @BytecodeParserNeverInline

    public static final Super createPerson() {

        return new Person(42);

    }

    public static int getSuperAge(Super s) {

        return s.getAge();

    }

    public static int getPersonAge(Person p) {

        return p.getAge();

    }

    public static int makeSuperAge() {

        return createSuper().getAge();

    }

    public static int makePersonAge() {

        return createPerson().getAge();

    }

    @BeforeClass

    public static void init() {

        // Ensure classes are initialized

        new Person(0).toString();

    }

    private StructuredGraph graph;

    private StructuredGraph parsedForCompile;

    @Override

    protected StructuredGraph parseForCompile(ResolvedJavaMethod method, CompilationIdentifier compilationId, OptionValues options) {

        graph = super.parseForCompile(method, compilationId, options);

        parsedForCompile = (StructuredGraph) graph.copy(graph.getDebug());

        return graph;

    }

    @Override

    protected void registerInvocationPlugins(InvocationPlugins invocationPlugins) {

        Registration r = new Registration(invocationPlugins, Super.class);

        r.register1("getAge", Receiver.class, new InvocationPlugin() {

            @Override

            public boolean apply(GraphBuilderContext b, ResolvedJavaMethod targetMethod, Receiver receiver) {

                ConstantNode res = b.add(ConstantNode.forInt(new Super().getAge()));

                b.add(new OpaqueNode(res));

                b.push(JavaKind.Int, res);

                return true;

            }

        });

        super.registerInvocationPlugins(invocationPlugins);

    }

    public static int referenceMakeSuperAge() {

        return 11;

    }

    public static int referenceMakePersonAge() {

        return 42;

    }

    @Test

    public void test01() {

        Super inheritsHC = new Super();

        Person overridesHC = new Person(0);

        test("getSuperAge", inheritsHC);

        test("getSuperAge", overridesHC);

        // Check that the virtual dispatch test exists after bytecode parsing

        Assert.assertEquals(1, parsedForCompile.getNodes().filter(LoadMethodNode.class).count());

        Assert.assertEquals(1, parsedForCompile.getNodes().filter(LoadHubNode.class).count());

        // Check for the marker node indicating the intrinsic was applied

        Assert.assertEquals(1, parsedForCompile.getNodes().filter(OpaqueNode.class).count());

        // Final graph should have a single invoke

        List<Node> invokes = graph.getNodes().filter(n -> n instanceof Invoke).snapshot();

        Assert.assertEquals(invokes.toString(), 1, invokes.size());

    }

    @Test

    public void test02() {

        test("getPersonAge", new Person(0));

        // Check that the virtual dispatch test does not exist after bytecode parsing

        Assert.assertEquals(0, parsedForCompile.getNodes().filter(LoadMethodNode.class).count());

        Assert.assertEquals(0, parsedForCompile.getNodes().filter(LoadHubNode.class).count());

        Assert.assertEquals(0, parsedForCompile.getNodes().filter(InvokeNode.class).count());

    }

    @Test

    public void test03() {

        test("makeSuperAge");

        // Check that the virtual dispatch test does not exist after bytecode parsing

        Assert.assertEquals(0, parsedForCompile.getNodes().filter(LoadMethodNode.class).count());

        Assert.assertEquals(0, parsedForCompile.getNodes().filter(LoadHubNode.class).count());

        StructuredGraph referenceGraph = parseEager("referenceMakeSuperAge", AllowAssumptions.NO);

        assertEquals(referenceGraph, graph, true, true);

    }

    @Test

    public void test04() {

        test("makePersonAge");

        // Check that the virtual dispatch test exists after bytecode parsing

        Assert.assertEquals(1, parsedForCompile.getNodes().filter(LoadMethodNode.class).count());

        Assert.assertEquals(1, parsedForCompile.getNodes().filter(LoadHubNode.class).count());

        StructuredGraph referenceGraph = parseEager("referenceMakePersonAge", AllowAssumptions.NO);

        assertEquals(referenceGraph, graph, true, true);

    }

    static final class ReadCacheEntry {

        public final Object identity;

        public final ValueNode object;

        ReadCacheEntry(Object identity, ValueNode object) {

            this.identity = identity;

            this.object = object;

        }

        @Override

        public int hashCode() {

            int result = ((identity == null) ? 0 : identity.hashCode());

            return result + System.identityHashCode(object);

        }

    }

    public static int getHashCode(ReadCacheEntry obj) {

        return obj.hashCode();

    }

    @Test

    public void test05() {

        ReadCacheEntry val1 = new ReadCacheEntry("identity", ConstantNode.forBoolean(false));

        ReadCacheEntry val2 = new ReadCacheEntry(Integer.valueOf(34), ConstantNode.forInt(42));

        for (int i = 0; i < 10000; i++) {

            getHashCode(val2);

        }

        test("getHashCode", val1);

    }

}