/*

 * Copyright (c) 2015, 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.

 *

 * 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.lang.reflect.Method;

import org.graalvm.compiler.core.test.GraalCompilerTest;

import org.graalvm.compiler.debug.DebugContext;

import org.graalvm.compiler.graph.Node;

import org.graalvm.compiler.nodes.Invoke;

import org.graalvm.compiler.nodes.StructuredGraph;

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

import org.graalvm.compiler.serviceprovider.JavaVersionUtil;

import org.graalvm.compiler.test.ModuleSupport;

import org.junit.BeforeClass;

import org.junit.Test;

import org.objectweb.asm.ClassWriter;

import org.objectweb.asm.MethodVisitor;

import org.objectweb.asm.Opcodes;

import jdk.vm.ci.meta.ResolvedJavaMethod;

public class ConstantPoolSubstitutionsTests extends GraalCompilerTest {

    public ConstantPoolSubstitutionsTests() {

        exportPackage(JAVA_BASE, "jdk.internal.org.objectweb.asm");

    }

    @SuppressWarnings("try")

    protected StructuredGraph test(final String snippet) {

        ResolvedJavaMethod method = getMetaAccess().lookupJavaMethod(getMethod(snippet));

        DebugContext debug = getDebugContext();

        try (DebugContext.Scope s = debug.scope("ConstantPoolSubstitutionsTests", method)) {

            StructuredGraph graph = parseEager(snippet, AllowAssumptions.YES);

            compile(graph.method(), graph);

            assertNotInGraph(graph, Invoke.class);

            debug.dump(DebugContext.BASIC_LEVEL, graph, snippet);

            return graph;

        } catch (Throwable e) {

            throw debug.handle(e);

        }

    }

    protected static StructuredGraph assertNotInGraph(StructuredGraph graph, Class<?> clazz) {

        for (Node node : graph.getNodes()) {

            if (clazz.isInstance(node)) {

                fail(node.toString());

            }

        }

        return graph;

    }

    private static String getMiscPackage() {

        if (JavaVersionUtil.JAVA_SPEC <= 8) {

            return "sun.misc";

        }

        try {

            String miscPackage = "jdk.internal.access";

            Class.forName(miscPackage + ".SharedSecrets");

            return miscPackage;

        } catch (ClassNotFoundException e) {

            try {

                String miscPackage = "jdk.internal.misc";

                Class.forName(miscPackage + ".SharedSecrets");

                return miscPackage;

            } catch (ClassNotFoundException ex) {

            }

            throw new AssertionError(e);

        }

    }

    private static Object getConstantPoolForObject() {

        String miscPackage = getMiscPackage();

        try {

            Class<?> sharedSecretsClass = Class.forName(miscPackage + ".SharedSecrets");

            Class<?> javaLangAccessClass = Class.forName(miscPackage + ".JavaLangAccess");

            Object jla = sharedSecretsClass.getDeclaredMethod("getJavaLangAccess").invoke(null);

            return javaLangAccessClass.getDeclaredMethod("getConstantPool", Class.class).invoke(jla, Object.class);

        } catch (Exception e) {

            throw new AssertionError(e);

        }

    }

    /**

     * Get the test methods from the generated class.

     */

    @Override

    protected Method getMethod(String methodName) {

        Class<?> cl;

        try {

            cl = LOADER.findClass(AsmLoader.NAME);

            addExports(cl);

        } catch (ClassNotFoundException e) {

            throw new AssertionError(e);

        }

        return getMethod(cl, methodName);

    }

    @BeforeClass

    public static void beforeClass() {

        addExports(AsmLoader.class);

    }

    /**

     * This test uses some non-public API.

     */

    private static void addExports(Class<?> c) {

        ModuleSupport.exportPackageTo(String.class, getMiscPackage(), c);

        ModuleSupport.exportPackageTo(String.class, "jdk.internal.reflect", c);

    }

    @Test

    public void testGetSize() {

        Object cp = getConstantPoolForObject();

        test("getSize", cp);

    }

    @Test

    public void testGetIntAt() {

        test("getIntAt");

    }

    @Test

    public void testGetLongAt() {

        test("getLongAt");

    }

    @Test

    public void testGetFloatAt() {

        test("getFloatAt");

    }

    @Test

    public void testGetDoubleAt() {

        test("getDoubleAt");

    }

    private static final String PACKAGE_NAME = ConstantPoolSubstitutionsTests.class.getPackage().getName();

    private static final String PACKAGE_NAME_INTERNAL = PACKAGE_NAME.replace('.', '/');

    private static AsmLoader LOADER = new AsmLoader(ConstantPoolSubstitutionsTests.class.getClassLoader());

    public static class AsmLoader extends ClassLoader {

        Class<?> loaded;

        static final String NAME = PACKAGE_NAME + ".ConstantPoolTest";

        public AsmLoader(ClassLoader parent) {

            super(parent);

        }

        @Override

        protected Class<?> findClass(String name) throws ClassNotFoundException {

            if (name.equals(NAME)) {

                if (loaded != null) {

                    return loaded;

                }

                byte[] bytes = Gen.generateClass();

                return (loaded = defineClass(name, bytes, 0, bytes.length));

            } else {

                return super.findClass(name);

            }

        }

    }

    static class Gen implements Opcodes {

        // @formatter:off

        /*

        static class ConstantPoolTest {

            public static int getSize(Object o) {

                ConstantPool cp = (ConstantPool) o;

                return cp.getSize();

            }

            public static int getIntAt(Object o) {

                ConstantPool cp = (ConstantPool) o;

                return cp.getIntAt(0);

            }

            public static long getLongAt(Object o) {

                ConstantPool cp = (ConstantPool) o;

                return cp.getLongAt(0);

            }

            public static float getFloatAt(Object o) {

                ConstantPool cp = (ConstantPool) o;

                return cp.getFloatAt(0);

            }

            public static double getDoubleAt(Object o) {

                ConstantPool cp = (ConstantPool) o;

                return cp.getDoubleAt(0);

            }

            public static String getUTF8At(Object o) {

                ConstantPool cp = (ConstantPool) o;

                return cp.getUTF8At(0);

            }

        }

        */

        // @formatter:on

        static byte[] generateClass() {

            ClassWriter cw = new ClassWriter(0);

            MethodVisitor mv;

            cw.visit(52, ACC_SUPER, PACKAGE_NAME_INTERNAL + "/ConstantPoolTest", null, "java/lang/Object", null);

            cw.visitInnerClass(PACKAGE_NAME_INTERNAL + "/ConstantPoolTest", PACKAGE_NAME_INTERNAL + "/ConstantPoolSubstitutionsTests", "ConstantPoolTest",

                            ACC_STATIC);

            String constantPool = JavaVersionUtil.JAVA_SPEC <= 8 ? "sun/reflect/ConstantPool" : "jdk/internal/reflect/ConstantPool";

            mv = cw.visitMethod(0, "<init>", "()V", null, null);

            mv.visitCode();

            mv.visitVarInsn(ALOAD, 0);

            mv.visitMethodInsn(INVOKESPECIAL, "java/lang/Object", "<init>", "()V", false);

            mv.visitInsn(RETURN);

            mv.visitMaxs(1, 1);

            mv.visitEnd();

            mv = cw.visitMethod(ACC_PUBLIC | ACC_STATIC, "getSize", "(Ljava/lang/Object;)I", null, null);

            mv.visitCode();

            mv.visitVarInsn(ALOAD, 0);

            mv.visitTypeInsn(CHECKCAST, constantPool);

            mv.visitVarInsn(ASTORE, 1);

            mv.visitVarInsn(ALOAD, 1);

            mv.visitMethodInsn(INVOKEVIRTUAL, constantPool, "getSize", "()I", false);

            mv.visitInsn(IRETURN);

            mv.visitMaxs(1, 3);

            mv.visitEnd();

            mv = cw.visitMethod(ACC_PUBLIC | ACC_STATIC, "getIntAt", "(Ljava/lang/Object;)I", null, null);

            mv.visitCode();

            mv.visitVarInsn(ALOAD, 0);

            mv.visitTypeInsn(CHECKCAST, constantPool);

            mv.visitVarInsn(ASTORE, 1);

            mv.visitVarInsn(ALOAD, 1);

            mv.visitInsn(ICONST_0);

            mv.visitMethodInsn(INVOKEVIRTUAL, constantPool, "getIntAt", "(I)I", false);

            mv.visitInsn(IRETURN);

            mv.visitMaxs(2, 3);

            mv.visitEnd();

            mv = cw.visitMethod(ACC_PUBLIC | ACC_STATIC, "getLongAt", "(Ljava/lang/Object;)J", null, null);

            mv.visitCode();

            mv.visitVarInsn(ALOAD, 0);

            mv.visitTypeInsn(CHECKCAST, constantPool);

            mv.visitVarInsn(ASTORE, 1);

            mv.visitVarInsn(ALOAD, 1);

            mv.visitInsn(ICONST_0);

            mv.visitMethodInsn(INVOKEVIRTUAL, constantPool, "getLongAt", "(I)J", false);

            mv.visitInsn(LRETURN);

            mv.visitMaxs(2, 3);

            mv.visitEnd();

            mv = cw.visitMethod(ACC_PUBLIC | ACC_STATIC, "getFloatAt", "(Ljava/lang/Object;)F", null, null);

            mv.visitCode();

            mv.visitVarInsn(ALOAD, 0);

            mv.visitTypeInsn(CHECKCAST, constantPool);

            mv.visitVarInsn(ASTORE, 1);

            mv.visitVarInsn(ALOAD, 1);

            mv.visitInsn(ICONST_0);

            mv.visitMethodInsn(INVOKEVIRTUAL, constantPool, "getFloatAt", "(I)F", false);

            mv.visitInsn(FRETURN);

            mv.visitMaxs(2, 3);

            mv.visitEnd();

            mv = cw.visitMethod(ACC_PUBLIC | ACC_STATIC, "getDoubleAt", "(Ljava/lang/Object;)D", null, null);

            mv.visitCode();

            mv.visitVarInsn(ALOAD, 0);

            mv.visitTypeInsn(CHECKCAST, constantPool);

            mv.visitVarInsn(ASTORE, 1);

            mv.visitVarInsn(ALOAD, 1);

            mv.visitInsn(ICONST_0);

            mv.visitMethodInsn(INVOKEVIRTUAL, constantPool, "getDoubleAt", "(I)D", false);

            mv.visitInsn(DRETURN);

            mv.visitMaxs(2, 3);

            mv.visitEnd();

            mv = cw.visitMethod(ACC_PUBLIC | ACC_STATIC, "getUTF8At", "(Ljava/lang/Object;)Ljava/lang/String;", null, null);

            mv.visitCode();

            mv.visitVarInsn(ALOAD, 0);

            mv.visitTypeInsn(CHECKCAST, constantPool);

            mv.visitVarInsn(ASTORE, 1);

            mv.visitVarInsn(ALOAD, 1);

            mv.visitInsn(ICONST_0);

            mv.visitMethodInsn(INVOKEVIRTUAL, constantPool, "getUTF8At", "(I)Ljava/lang/String;", false);

            mv.visitInsn(ARETURN);

            mv.visitMaxs(2, 3);

            mv.visitEnd();

            cw.visitEnd();

            return cw.toByteArray();

        }

    }

}