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 * Copyright (c) 2014, 2019, 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.

 *

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package org.graalvm.compiler.core.test;

import jdk.vm.ci.meta.Assumptions.AssumptionResult;

import jdk.vm.ci.meta.ResolvedJavaMethod;

import jdk.vm.ci.meta.ResolvedJavaType;

import org.junit.Assert;

import org.junit.Test;

public class FindUniqueConcreteMethodBugTest extends GraalCompilerTest {

    // To cause a C1 or C2 crash: -DFindUniqueConcreteMethodBugTest.ITERATIONS=10000

    private static final int ITERATIONS = Integer.getInteger("FindUniqueConcreteMethodBugTest.ITERATIONS", 100);

    /**

     * Executing {@link ResolvedJavaType#findUniqueConcreteMethod(ResolvedJavaMethod)} for the

     * method {@link Person#getName()} on the type {@link AbstractPerson} should return null as both

     * {@link PersonImpl} and {@link TenantImpl} provide implementations (namely

     * {@link PersonImpl#getName()} and {@link Tenant#getName()}).

     */

    @Test

    public void test() throws NoSuchMethodException {

        ResolvedJavaMethod ifaceMethod = getMetaAccess().lookupJavaMethod(Person.class.getDeclaredMethod("getName"));

        PersonImpl person = new PersonImpl("maya");

        TenantImpl tenant = new TenantImpl(0xdeadbeef);

        // Ensure the relevant methods are linked

        person.getName();

        tenant.getName();

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

            getLabelLength(person);

            getLabelLength(tenant);

        }

        // Until HotSpotResolvedObjectTypeImpl.findUniqueConcreteMethod is fixed,

        // this causes a VM crash as getLabelLength() directly invokes PersonImpl.getName().

        test("getLabelLength", tenant);

        AssumptionResult<ResolvedJavaMethod> actual = getMetaAccess().lookupJavaType(AbstractPerson.class).findUniqueConcreteMethod(ifaceMethod);

        Assert.assertNull(String.valueOf(actual), actual);

    }

    public int getLabelLength(AbstractPerson person) {

        return person.getName().length();

    }

    interface Person {

        String getName();

        default int getId() {

            return -1;

        }

    }

    interface Tenant extends Person {

        @Override

        default String getName() {

            return getAddress();

        }

        String getAddress();

    }

    abstract static class AbstractPerson implements Person {

    }

    static class PersonImpl extends AbstractPerson {

        public String name;

        PersonImpl(String name) {

            this.name = name;

        }

        @Override

        public String getName() {

            return name;

        }

    }

    static class TenantImpl extends AbstractPerson implements Tenant {

        public int id;

        TenantImpl(int id) {

            this.id = id;

        }

        @Override

        public String getAddress() {

            return String.valueOf(id);

        }

    }

}