/*

 * Copyright (c) 2015, 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.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * 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.

 */

/*

 * @test

 * @summary tests on constant folding of unsafe get operations

 * @library /testlibrary /test/lib

 * @run main/bootclasspath -XX:+UnlockDiagnosticVMOptions

 *                   -Xbatch -XX:-TieredCompilation

 *                   -XX:+FoldStableValues

 *                   -XX:+UseUnalignedAccesses

 *                   java.lang.invoke.UnsafeGetConstantField

 * @run main/bootclasspath -XX:+UnlockDiagnosticVMOptions

 *                   -Xbatch -XX:-TieredCompilation

 *                   -XX:+FoldStableValues

 *                   -XX:-UseUnalignedAccesses

 *                   java.lang.invoke.UnsafeGetConstantField

 */

package java.lang.invoke;

import jdk.internal.vm.annotation.DontInline;

import jdk.internal.vm.annotation.Stable;

import jdk.internal.misc.Unsafe;

import jdk.internal.org.objectweb.asm.ClassWriter;

import jdk.internal.org.objectweb.asm.FieldVisitor;

import jdk.internal.org.objectweb.asm.MethodVisitor;

import jdk.internal.org.objectweb.asm.Opcodes;

import jdk.internal.org.objectweb.asm.Type;

import jdk.test.lib.Asserts;

import static jdk.internal.org.objectweb.asm.Opcodes.*;

public class UnsafeGetConstantField {

    static final Class<?> THIS_CLASS = UnsafeGetConstantField.class;

    static final Unsafe U = Unsafe.getUnsafe();

    public static void main(String[] args) {

        testUnsafeGetAddress();

        testUnsafeGetField();

        testUnsafeGetFieldUnaligned();

        System.out.println("TEST PASSED");

    }

    static final long nativeAddr = U.allocateMemory(16);

    static void testUnsafeGetAddress() {

        long cookie = 0x12345678L;

        U.putAddress(nativeAddr, cookie);

        for (int i = 0; i < 20_000; i++) {

            Asserts.assertEquals(checkGetAddress(), cookie);

        }

    }

    @DontInline

    static long checkGetAddress() {

        return U.getAddress(nativeAddr);

    }

    static void testUnsafeGetField() {

        int[] testedFlags = new int[] { 0, ACC_STATIC, ACC_FINAL, (ACC_STATIC | ACC_FINAL) };

        boolean[] boolValues = new boolean[] { false, true };

        String[] modes = new String[] { "", "Volatile" };

        for (JavaType t : JavaType.values()) {

            for (int flags : testedFlags) {

                for (boolean stable : boolValues) {

                    for (boolean hasDefaultValue : boolValues) {

                        for (String suffix : modes) {

                            runTest(t, flags, stable, hasDefaultValue, suffix);

                        }

                    }

                }

            }

        }

    }

    static void testUnsafeGetFieldUnaligned() {

        JavaType[] types = new JavaType[] { JavaType.S, JavaType.C, JavaType.I, JavaType.J };

        int[] testedFlags = new int[] { 0, ACC_STATIC, ACC_FINAL, (ACC_STATIC | ACC_FINAL) };

        boolean[] boolValues = new boolean[] { false, true };

        for (JavaType t : types) {

            for (int flags : testedFlags) {

                for (boolean stable : boolValues) {

                    for (boolean hasDefaultValue : boolValues) {

                        runTest(t, flags, stable, hasDefaultValue, "Unaligned");

                    }

                }

            }

        }

    }

    static void runTest(JavaType t, int flags, boolean stable, boolean hasDefaultValue, String postfix) {

        Generator g = new Generator(t, flags, stable, hasDefaultValue, postfix);

        Test test = g.generate();

        System.out.printf("type=%s flags=%d stable=%b default=%b post=%s\n",

                          t.typeName, flags, stable, hasDefaultValue, postfix);

        // Trigger compilation

        for (int i = 0; i < 20_000; i++) {

            Asserts.assertEQ(test.testDirect(), test.testUnsafe());

        }

    }

    interface Test {

        Object testDirect();

        Object testUnsafe();

    }

    enum JavaType {

        Z("Boolean", true),

        B("Byte", new Byte((byte)-1)),

        S("Short", new Short((short)-1)),

        C("Char", Character.MAX_VALUE),

        I("Int", -1),

        J("Long", -1L),

        F("Float", -1F),

        D("Double", -1D),

        L("Object", new Object());

        String typeName;

        Object value;

        String wrapper;

        JavaType(String name, Object value) {

            this.typeName = name;

            this.value = value;

            this.wrapper = internalName(value.getClass());

        }

        String desc() {

            if (this == JavaType.L) {

                return "Ljava/lang/Object;";

            } else {

                return toString();

            }

        }

    }

    static String internalName(Class cls) {

        return cls.getName().replace('.', '/');

    }

    static String descriptor(Class cls) {

        return String.format("L%s;", internalName(cls));

    }

    /**

     * Sample generated class:

     * static class T1 implements Test {

     *   final int f = -1;

     *   static final long FIELD_OFFSET;

     *   static final T1 t = new T1();

     *   static {

     *     FIELD_OFFSET = U.objectFieldOffset(T1.class.getDeclaredField("f"));

     *   }

     *   public Object testDirect()  { return t.f; }

     *   public Object testUnsafe()  { return U.getInt(t, FIELD_OFFSET); }

     * }

     */

    static class Generator {

        static final String FIELD_NAME = "f";

        static final String UNSAFE_NAME = internalName(Unsafe.class);

        static final String UNSAFE_DESC = descriptor(Unsafe.class);

        final JavaType type;

        final int flags;

        final boolean stable;

        final boolean hasDefaultValue;

        final String nameSuffix;

        final String className;

        final String classDesc;

        final String fieldDesc;

        Generator(JavaType t, int flags, boolean stable, boolean hasDefaultValue, String suffix) {

            this.type = t;

            this.flags = flags;

            this.stable = stable;

            this.hasDefaultValue = hasDefaultValue;

            this.nameSuffix = suffix;

            fieldDesc = type.desc();

            className = String.format("%s$Test%s%s__f=%d__s=%b__d=%b", internalName(THIS_CLASS), type.typeName,

                                      suffix, flags, stable, hasDefaultValue);

            classDesc = String.format("L%s;", className);

        }

        byte[] generateClassFile() {

            ClassWriter cw = new ClassWriter(ClassWriter.COMPUTE_MAXS | ClassWriter.COMPUTE_FRAMES);

            cw.visit(Opcodes.V1_8, Opcodes.ACC_PUBLIC | Opcodes.ACC_SUPER, className, null, "java/lang/Object",

                    new String[]{ internalName(Test.class) });

            // Declare fields

            cw.visitField(ACC_FINAL | ACC_STATIC, "t", classDesc, null, null).visitEnd();

            cw.visitField(ACC_FINAL | ACC_STATIC, "FIELD_OFFSET", "J", null, null).visitEnd();

            cw.visitField(ACC_FINAL | ACC_STATIC, "U", UNSAFE_DESC, null, null).visitEnd();

            if (isStatic()) {

                cw.visitField(ACC_FINAL | ACC_STATIC, "STATIC_BASE", "Ljava/lang/Object;", null, null).visitEnd();

            }

            FieldVisitor fv = cw.visitField(flags, FIELD_NAME, fieldDesc, null, null);

            if (stable) {

                fv.visitAnnotation(descriptor(Stable.class), true);

            }

            fv.visitEnd();

            // Methods

            {   // <init>

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

                mv.visitCode();

                mv.visitVarInsn(ALOAD, 0);

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

                if (!isStatic()) {

                    initField(mv);

                }

                mv.visitInsn(RETURN);

                mv.visitMaxs(0, 0);

                mv.visitEnd();

            }

            {   // public Object testDirect() { return t.f; }

                MethodVisitor mv = cw.visitMethod(ACC_PUBLIC, "testDirect", "()Ljava/lang/Object;", null, null);

                mv.visitCode();

                getFieldValue(mv);

                wrapResult(mv);

                mv.visitInsn(ARETURN);

                mv.visitMaxs(0, 0);

                mv.visitEnd();

            }

            {   // public Object testUnsafe() { return U.getInt(t, FIELD_OFFSET); }

                MethodVisitor mv = cw.visitMethod(ACC_PUBLIC, "testUnsafe", "()Ljava/lang/Object;", null, null);

                mv.visitCode();

                getFieldValueUnsafe(mv);

                wrapResult(mv);

                mv.visitInsn(ARETURN);

                mv.visitMaxs(0, 0);

                mv.visitEnd();

            }

            {   // <clinit>

                MethodVisitor mv = cw.visitMethod(ACC_STATIC, "<clinit>", "()V", null, null);

                mv.visitCode();

                // Cache Unsafe instance

                mv.visitMethodInsn(INVOKESTATIC, UNSAFE_NAME, "getUnsafe", "()"+UNSAFE_DESC, false);

                mv.visitFieldInsn(PUTSTATIC, className, "U", UNSAFE_DESC);

                // Create test object instance

                mv.visitTypeInsn(NEW, className);

                mv.visitInsn(DUP);

                mv.visitMethodInsn(INVOKESPECIAL, className, "<init>", "()V", false);

                mv.visitFieldInsn(PUTSTATIC, className, "t", classDesc);

                // Compute field offset

                getUnsafe(mv);

                getField(mv);

                mv.visitMethodInsn(INVOKEVIRTUAL, UNSAFE_NAME, (isStatic() ? "staticFieldOffset" : "objectFieldOffset"),

                        "(Ljava/lang/reflect/Field;)J", false);

                mv.visitFieldInsn(PUTSTATIC, className, "FIELD_OFFSET", "J");

                // Compute base offset for static field

                if (isStatic()) {

                    getUnsafe(mv);

                    getField(mv);

                    mv.visitMethodInsn(INVOKEVIRTUAL, UNSAFE_NAME, "staticFieldBase", "(Ljava/lang/reflect/Field;)Ljava/lang/Object;", false);

                    mv.visitFieldInsn(PUTSTATIC, className, "STATIC_BASE", "Ljava/lang/Object;");

                    initField(mv);

                }

                mv.visitInsn(RETURN);

                mv.visitMaxs(0, 0);

                mv.visitEnd();

            }

            return cw.toByteArray();

        }

        Test generate() {

            byte[] classFile = generateClassFile();

            Class<?> c = U.defineClass(className, classFile, 0, classFile.length, THIS_CLASS.getClassLoader(), null);

            try {

                return (Test) c.newInstance();

            } catch(Exception e) {

                throw new Error(e);

            }

        }

        boolean isStatic() {

            return (flags & ACC_STATIC) > 0;

        }

        boolean isFinal() {

            return (flags & ACC_FINAL) > 0;

        }

        void getUnsafe(MethodVisitor mv) {

            mv.visitFieldInsn(GETSTATIC, className, "U", UNSAFE_DESC);

        }

        void getField(MethodVisitor mv) {

            mv.visitLdcInsn(Type.getType(classDesc));

            mv.visitLdcInsn(FIELD_NAME);

            mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/Class", "getDeclaredField", "(Ljava/lang/String;)Ljava/lang/reflect/Field;", false);

        }

        void getFieldValue(MethodVisitor mv) {

            if (isStatic()) {

                mv.visitFieldInsn(GETSTATIC, className, FIELD_NAME, fieldDesc);

            } else {

                mv.visitFieldInsn(GETSTATIC, className, "t", classDesc);

                mv.visitFieldInsn(GETFIELD, className, FIELD_NAME, fieldDesc);

            }

        }

        void getFieldValueUnsafe(MethodVisitor mv) {

            getUnsafe(mv);

            if (isStatic()) {

                mv.visitFieldInsn(GETSTATIC, className, "STATIC_BASE", "Ljava/lang/Object;");

            } else {

                mv.visitFieldInsn(GETSTATIC, className, "t", classDesc);

            }

            mv.visitFieldInsn(GETSTATIC, className, "FIELD_OFFSET", "J");

            String name = "get" + type.typeName + nameSuffix;

            mv.visitMethodInsn(INVOKEVIRTUAL, UNSAFE_NAME, name, "(Ljava/lang/Object;J)" + type.desc(), false);

        }

        void wrapResult(MethodVisitor mv) {

            if (type != JavaType.L) {

                String desc = String.format("(%s)L%s;", type.desc(), type.wrapper);

                mv.visitMethodInsn(INVOKESTATIC, type.wrapper, "valueOf", desc, false);

            }

        }

        void initField(MethodVisitor mv) {

            if (hasDefaultValue) {

                return; // Nothing to do

            }

            if (!isStatic()) {

                mv.visitVarInsn(ALOAD, 0);

            }

            switch (type) {

                case L: {

                    mv.visitTypeInsn(NEW, "java/lang/Object");

                    mv.visitInsn(DUP);

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

                    break;

                }

                default: {

                    mv.visitLdcInsn(type.value);

                    break;

                }

            }

            mv.visitFieldInsn((isStatic() ? PUTSTATIC : PUTFIELD), className, FIELD_NAME, fieldDesc);

        }

    }

}