jdk-24/jdk/test/java/lang/Class/GetModuleTest.java

/**
 * Copyright (c) 2014, 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
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 *
 * 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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/*
 * @test
 * @summary Exercise Class#getModule
 * @modules java.base/jdk.internal.org.objectweb.asm
 *          java.base/jdk.internal.misc
 *          java.desktop
 * @run testng GetModuleTest
 */

import java.awt.Component;
import java.lang.reflect.Field;
import java.lang.reflect.Module;

import jdk.internal.org.objectweb.asm.ClassWriter;
import static jdk.internal.org.objectweb.asm.Opcodes.*;
import jdk.internal.misc.Unsafe;

import org.testng.annotations.DataProvider;
import org.testng.annotations.Test;
import static org.testng.Assert.*;

public class GetModuleTest {

    static final Unsafe U;
    static {
        try {
            Field theUnsafe = Unsafe.class.getDeclaredField("theUnsafe");
            theUnsafe.setAccessible(true);
            U = (Unsafe) theUnsafe.get(null);
        } catch (Exception e) {
            throw new AssertionError(e);
        }
    }

    private static final Module TEST_MODULE = GetModuleTest.class.getModule();


    @DataProvider(name = "testclasses")
    public Object[][] testClasses() {
        return new Object[][] {

            // unnamed module

            { GetModuleTest.class,      null },
            { GetModuleTest[].class,    null },
            { GetModuleTest[][].class,  null },

            // should return named module

            { int.class,            "java.base" },
            { int[].class,          "java.base" },
            { int[][].class,        "java.base" },
            { void.class,           "java.base" },

            { Object.class,         "java.base" },
            { Object[].class,       "java.base" },
            { Object[][].class,     "java.base" },
            { Component.class,      "java.desktop" },
            { Component[].class,    "java.desktop" },
            { Component[][].class,  "java.desktop" },
        };
    }

    @Test(dataProvider = "testclasses")
    public void testGetModule(Class<?> type, String expected) {
        Module m = type.getModule();
        assertNotNull(m);
        if (expected == null) {
            assertTrue(m == TEST_MODULE);
        } else {
            assertEquals(m.getName(), expected);
        }
    }


    @DataProvider(name = "hostclasses")
    public Object[][] hostClasses() {
        return new Object[][] {

            { GetModuleTest.class,      null },
            { GetModuleTest[].class,    null },
            { Object.class,             null },
            { Object[].class,           null },
            { Component.class,          null },
            { Component[].class,        null },

        };
    }

    /**
     * Exercise Class::getModule on VM anonymous classes
     */
    @Test(dataProvider = "hostclasses")
    public void testGetModuleOnVMAnonymousClass(Class<?> hostClass, String ignore) {

        // choose a class name in the same package as the host class
        String prefix = packageName(hostClass);
        if (prefix.length() > 0)
            prefix = prefix.replace('.', '/') + "/";
        String className = prefix + "Anon";

        // create the class
        String superName = "java/lang/Object";
        ClassWriter cw = new ClassWriter(ClassWriter.COMPUTE_MAXS
                                         + ClassWriter.COMPUTE_FRAMES);
        cw.visit(V1_8, ACC_PUBLIC + ACC_FINAL + ACC_SUPER,
                 className, null, superName, null);
        byte[] classBytes = cw.toByteArray();
        int cpPoolSize = constantPoolSize(classBytes);
        Class<?> anonClass
            = U.defineAnonymousClass(hostClass, classBytes, new Object[cpPoolSize]);

        assertTrue(anonClass.getModule() == hostClass.getModule());
    }

    private static String packageName(Class<?> c) {
        if (c.isArray()) {
            return packageName(c.getComponentType());
        } else {
            String name = c.getName();
            int dot = name.lastIndexOf('.');
            if (dot == -1) return "";
            return name.substring(0, dot);
        }
    }

    private static int constantPoolSize(byte[] classFile) {
        return ((classFile[8] & 0xFF) << 8) | (classFile[9] & 0xFF);
    }

}