/*
 * Copyright (c) 2007, 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.  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.
 */

package com.sun.tools.classfile;

import java.io.DataOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Iterator;

See JVMS, section 4.5.
 
This is NOT part of any supported API.
 If you write code that depends on this, you do so at your own risk.
 This code and its internal interfaces are subject to change or
 deletion without notice.
/**
 * See JVMS, section 4.5.
 *
 *  <p><b>This is NOT part of any supported API.
 *  If you write code that depends on this, you do so at your own risk.
 *  This code and its internal interfaces are subject to change or
 *  deletion without notice.</b>
 */
public class ConstantPool {

    public static class InvalidIndex extends ConstantPoolException {
        private static final long serialVersionUID = -4350294289300939730L;
        InvalidIndex(int index) {
            super(index);
        }

        @Override
        public String getMessage() {
            // i18n
            return "invalid index #" + index;
        }
    }

    public static class UnexpectedEntry extends ConstantPoolException {
        private static final long serialVersionUID = 6986335935377933211L;
        UnexpectedEntry(int index, int expected_tag, int found_tag) {
            super(index);
            this.expected_tag = expected_tag;
            this.found_tag = found_tag;
        }

        @Override
        public String getMessage() {
            // i18n?
            return "unexpected entry at #" + index + " -- expected tag " + expected_tag + ", found " + found_tag;
        }

        public final int expected_tag;
        public final int found_tag;
    }

    public static class InvalidEntry extends ConstantPoolException {
        private static final long serialVersionUID = 1000087545585204447L;
        InvalidEntry(int index, int tag) {
            super(index);
            this.tag = tag;
        }

        @Override
        public String getMessage() {
            // i18n?
            return "unexpected tag at #" + index + ": " + tag;
        }

        public final int tag;
    }

    public static class EntryNotFound extends ConstantPoolException {
        private static final long serialVersionUID = 2885537606468581850L;
        EntryNotFound(Object value) {
            super(-1);
            this.value = value;
        }

        @Override
        public String getMessage() {
            // i18n?
            return "value not found: " + value;
        }

        public final Object value;
    }

    public static final int CONSTANT_Utf8 = 1;
    public static final int CONSTANT_Integer = 3;
    public static final int CONSTANT_Float = 4;
    public static final int CONSTANT_Long = 5;
    public static final int CONSTANT_Double = 6;
    public static final int CONSTANT_Class = 7;
    public static final int CONSTANT_String = 8;
    public static final int CONSTANT_Fieldref = 9;
    public static final int CONSTANT_Methodref = 10;
    public static final int CONSTANT_InterfaceMethodref = 11;
    public static final int CONSTANT_NameAndType = 12;
    public static final int CONSTANT_MethodHandle = 15;
    public static final int CONSTANT_MethodType = 16;
    public static final int CONSTANT_InvokeDynamic = 18;
    public static final int CONSTANT_Module = 19;
    public static final int CONSTANT_Package = 20;

    public static enum RefKind {
        REF_getField(1),
        REF_getStatic(2),
        REF_putField(3),
        REF_putStatic(4),
        REF_invokeVirtual(5),
        REF_invokeStatic(6),
        REF_invokeSpecial(7),
        REF_newInvokeSpecial(8),
        REF_invokeInterface(9);

        public final int tag;

        RefKind(int tag) {
            this.tag = tag;
        }

        static RefKind getRefkind(int tag) {
            switch(tag) {
                case 1:
                    return REF_getField;
                case 2:
                    return REF_getStatic;
                case 3:
                    return REF_putField;
                case 4:
                    return REF_putStatic;
                case 5:
                    return REF_invokeVirtual;
                case 6:
                    return REF_invokeStatic;
                case 7:
                    return REF_invokeSpecial;
                case 8:
                    return REF_newInvokeSpecial;
                case 9:
                    return REF_invokeInterface;
                default:
                    return null;
            }
        }
    }

    ConstantPool(ClassReader cr) throws IOException, InvalidEntry {
        int count = cr.readUnsignedShort();
        pool = new CPInfo[count];
        for (int i = 1; i < count; i++) {
            int tag = cr.readUnsignedByte();
            switch (tag) {
            case CONSTANT_Class:
                pool[i] = new CONSTANT_Class_info(this, cr);
                break;

            case CONSTANT_Double:
                pool[i] = new CONSTANT_Double_info(cr);
                i++;
                break;

            case CONSTANT_Fieldref:
                pool[i] = new CONSTANT_Fieldref_info(this, cr);
                break;

            case CONSTANT_Float:
                pool[i] = new CONSTANT_Float_info(cr);
                break;

            case CONSTANT_Integer:
                pool[i] = new CONSTANT_Integer_info(cr);
                break;

            case CONSTANT_InterfaceMethodref:
                pool[i] = new CONSTANT_InterfaceMethodref_info(this, cr);
                break;

            case CONSTANT_InvokeDynamic:
                pool[i] = new CONSTANT_InvokeDynamic_info(this, cr);
                break;

            case CONSTANT_Long:
                pool[i] = new CONSTANT_Long_info(cr);
                i++;
                break;

            case CONSTANT_MethodHandle:
                pool[i] = new CONSTANT_MethodHandle_info(this, cr);
                break;

            case CONSTANT_MethodType:
                pool[i] = new CONSTANT_MethodType_info(this, cr);
                break;

            case CONSTANT_Methodref:
                pool[i] = new CONSTANT_Methodref_info(this, cr);
                break;

            case CONSTANT_Module:
                pool[i] = new CONSTANT_Module_info(this, cr);
                break;

            case CONSTANT_NameAndType:
                pool[i] = new CONSTANT_NameAndType_info(this, cr);
                break;

            case CONSTANT_Package:
                pool[i] = new CONSTANT_Package_info(this, cr);
                break;

            case CONSTANT_String:
                pool[i] = new CONSTANT_String_info(this, cr);
                break;

            case CONSTANT_Utf8:
                pool[i] = new CONSTANT_Utf8_info(cr);
                break;

            default:
                throw new InvalidEntry(i, tag);
            }
        }
    }

    public ConstantPool(CPInfo[] pool) {
        this.pool = pool;
    }

    public int size() {
        return pool.length;
    }

    public int byteLength() {
        int length = 2;
        for (int i = 1; i < size(); ) {
            CPInfo cpInfo = pool[i];
            length += cpInfo.byteLength();
            i += cpInfo.size();
        }
        return length;
    }

    public CPInfo get(int index) throws InvalidIndex {
        if (index <= 0 || index >= pool.length)
            throw new InvalidIndex(index);
        CPInfo info = pool[index];
        if (info == null) {
            // this occurs for indices referencing the "second half" of an
            // 8 byte constant, such as CONSTANT_Double or CONSTANT_Long
            throw new InvalidIndex(index);
        }
        return pool[index];
    }

    private CPInfo get(int index, int expected_type) throws InvalidIndex, UnexpectedEntry {
        CPInfo info = get(index);
        if (info.getTag() != expected_type)
            throw new UnexpectedEntry(index, expected_type, info.getTag());
        return info;
    }

    public CONSTANT_Utf8_info getUTF8Info(int index) throws InvalidIndex, UnexpectedEntry {
        return ((CONSTANT_Utf8_info) get(index, CONSTANT_Utf8));
    }

    public CONSTANT_Class_info getClassInfo(int index) throws InvalidIndex, UnexpectedEntry {
        return ((CONSTANT_Class_info) get(index, CONSTANT_Class));
    }

    public CONSTANT_Module_info getModuleInfo(int index) throws InvalidIndex, UnexpectedEntry {
        return ((CONSTANT_Module_info) get(index, CONSTANT_Module));
    }

    public CONSTANT_NameAndType_info getNameAndTypeInfo(int index) throws InvalidIndex, UnexpectedEntry {
        return ((CONSTANT_NameAndType_info) get(index, CONSTANT_NameAndType));
    }

    public CONSTANT_Package_info getPackageInfo(int index) throws InvalidIndex, UnexpectedEntry {
        return ((CONSTANT_Package_info) get(index, CONSTANT_Package));
    }

    public String getUTF8Value(int index) throws InvalidIndex, UnexpectedEntry {
        return getUTF8Info(index).value;
    }

    public int getUTF8Index(String value) throws EntryNotFound {
        for (int i = 1; i < pool.length; i++) {
            CPInfo info = pool[i];
            if (info instanceof CONSTANT_Utf8_info &&
                    ((CONSTANT_Utf8_info) info).value.equals(value))
                return i;
        }
        throw new EntryNotFound(value);
    }

    public Iterable<CPInfo> entries() {
        return () -> new Iterator<CPInfo>() {

            public boolean hasNext() {
                return next < pool.length;
            }

            public CPInfo next() {
                current = pool[next];
                switch (current.getTag()) {
                    case CONSTANT_Double:
                    case CONSTANT_Long:
                        next += 2;
                        break;
                    default:
                        next += 1;
                }
                return current;
            }

            public void remove() {
                throw new UnsupportedOperationException();
            }

            private CPInfo current;
            private int next = 1;

        };
    }

    private CPInfo[] pool;

    public interface Visitor<R,P> {
        R visitClass(CONSTANT_Class_info info, P p);
        R visitDouble(CONSTANT_Double_info info, P p);
        R visitFieldref(CONSTANT_Fieldref_info info, P p);
        R visitFloat(CONSTANT_Float_info info, P p);
        R visitInteger(CONSTANT_Integer_info info, P p);
        R visitInterfaceMethodref(CONSTANT_InterfaceMethodref_info info, P p);
        R visitInvokeDynamic(CONSTANT_InvokeDynamic_info info, P p);
        R visitLong(CONSTANT_Long_info info, P p);
        R visitMethodref(CONSTANT_Methodref_info info, P p);
        R visitMethodHandle(CONSTANT_MethodHandle_info info, P p);
        R visitMethodType(CONSTANT_MethodType_info info, P p);
        R visitModule(CONSTANT_Module_info info, P p);
        R visitNameAndType(CONSTANT_NameAndType_info info, P p);
        R visitPackage(CONSTANT_Package_info info, P p);
        R visitString(CONSTANT_String_info info, P p);
        R visitUtf8(CONSTANT_Utf8_info info, P p);
    }

    public static abstract class CPInfo {
        CPInfo() {
            this.cp = null;
        }

        CPInfo(ConstantPool cp) {
            this.cp = cp;
        }

        public abstract int getTag();

        
The number of slots in the constant pool used by this entry.
2 for CONSTANT_Double and CONSTANT_Long; 1 for everything else. /** The number of slots in the constant pool used by this entry.
         * 2 for CONSTANT_Double and CONSTANT_Long; 1 for everything else. */
        public int size() {
            return 1;
        }

        public abstract int byteLength();

        public abstract <R,D> R accept(Visitor<R,D> visitor, D data);

        protected final ConstantPool cp;
    }

    public static abstract class CPRefInfo extends CPInfo {
        protected CPRefInfo(ConstantPool cp, ClassReader cr, int tag) throws IOException {
            super(cp);
            this.tag = tag;
            class_index = cr.readUnsignedShort();
            name_and_type_index = cr.readUnsignedShort();
        }

        protected CPRefInfo(ConstantPool cp, int tag, int class_index, int name_and_type_index) {
            super(cp);
            this.tag = tag;
            this.class_index = class_index;
            this.name_and_type_index = name_and_type_index;
        }

        public int getTag() {
            return tag;
        }

        public int byteLength() {
            return 5;
        }

        public CONSTANT_Class_info getClassInfo() throws ConstantPoolException {
            return cp.getClassInfo(class_index);
        }

        public String getClassName() throws ConstantPoolException {
            return cp.getClassInfo(class_index).getName();
        }

        public CONSTANT_NameAndType_info getNameAndTypeInfo() throws ConstantPoolException {
            return cp.getNameAndTypeInfo(name_and_type_index);
        }

        public final int tag;
        public final int class_index;
        public final int name_and_type_index;
    }

    public static class CONSTANT_Class_info extends CPInfo {
        CONSTANT_Class_info(ConstantPool cp, ClassReader cr) throws IOException {
            super(cp);
            name_index = cr.readUnsignedShort();
        }

        public CONSTANT_Class_info(ConstantPool cp, int name_index) {
            super(cp);
            this.name_index = name_index;
        }

        public int getTag() {
            return CONSTANT_Class;
        }

        public int  byteLength() {
            return 3;
        }

        
Get the raw value of the class referenced by this constant pool entry.
This will either be the name of the class, in internal form, or a
descriptor for an array class.
Returns:
the raw value of the class/**
         * Get the raw value of the class referenced by this constant pool entry.
         * This will either be the name of the class, in internal form, or a
         * descriptor for an array class.
         * @return the raw value of the class
         */
        public String getName() throws ConstantPoolException {
            return cp.getUTF8Value(name_index);
        }

        
If this constant pool entry identifies either a class or interface type,
or a possibly multi-dimensional array of a class of interface type,
return the name of the class or interface in internal form. Otherwise,
(i.e. if this is a possibly multi-dimensional array of a primitive type),
return null.
Returns:
the base class or interface name/**
         * If this constant pool entry identifies either a class or interface type,
         * or a possibly multi-dimensional array of a class of interface type,
         * return the name of the class or interface in internal form. Otherwise,
         * (i.e. if this is a possibly multi-dimensional array of a primitive type),
         * return null.
         * @return the base class or interface name
         */
        public String getBaseName() throws ConstantPoolException {
            String name = getName();
            if (name.startsWith("[")) {
                int index = name.indexOf("[L");
                if (index == -1)
                    return null;
                return name.substring(index + 2, name.length() - 1);
            } else
                return name;
        }

        public int getDimensionCount() throws ConstantPoolException {
            String name = getName();
            int count = 0;
            while (name.charAt(count) == '[')
                count++;
            return count;
        }

        @Override
        public String toString() {
            return "CONSTANT_Class_info[name_index: " + name_index + "]";
        }

        public <R, D> R accept(Visitor<R, D> visitor, D data) {
            return visitor.visitClass(this, data);
        }

        public final int name_index;
    }

    public static class CONSTANT_Double_info extends CPInfo {
        CONSTANT_Double_info(ClassReader cr) throws IOException {
            value = cr.readDouble();
        }

        public CONSTANT_Double_info(double value) {
            this.value = value;
        }

        public int getTag() {
            return CONSTANT_Double;
        }

        public int  byteLength() {
            return 9;
        }

        @Override
        public int size() {
            return 2;
        }

        @Override
        public String toString() {
            return "CONSTANT_Double_info[value: " + value + "]";
        }

        public <R, D> R accept(Visitor<R, D> visitor, D data) {
            return visitor.visitDouble(this, data);
        }

        public final double value;
    }

    public static class CONSTANT_Fieldref_info extends CPRefInfo {
        CONSTANT_Fieldref_info(ConstantPool cp, ClassReader cr) throws IOException {
            super(cp, cr, CONSTANT_Fieldref);
        }

        public CONSTANT_Fieldref_info(ConstantPool cp, int class_index, int name_and_type_index) {
            super(cp, CONSTANT_Fieldref, class_index, name_and_type_index);
        }

        @Override
        public String toString() {
            return "CONSTANT_Fieldref_info[class_index: " + class_index + ", name_and_type_index: " + name_and_type_index + "]";
        }

        public <R, D> R accept(Visitor<R, D> visitor, D data) {
            return visitor.visitFieldref(this, data);
        }
    }

    public static class CONSTANT_Float_info extends CPInfo {
        CONSTANT_Float_info(ClassReader cr) throws IOException {
            value = cr.readFloat();
        }

        public CONSTANT_Float_info(float value) {
            this.value = value;
        }

        public int getTag() {
            return CONSTANT_Float;
        }

        public int byteLength() {
            return 5;
        }

        @Override
        public String toString() {
            return "CONSTANT_Float_info[value: " + value + "]";
        }

        public <R, D> R accept(Visitor<R, D> visitor, D data) {
            return visitor.visitFloat(this, data);
        }

        public final float value;
    }

    public static class CONSTANT_Integer_info extends CPInfo {
        CONSTANT_Integer_info(ClassReader cr) throws IOException {
            value = cr.readInt();
        }

        public CONSTANT_Integer_info(int value) {
            this.value = value;
        }

        public int getTag() {
            return CONSTANT_Integer;
        }

        public int byteLength() {
            return 5;
        }

        @Override
        public String toString() {
            return "CONSTANT_Integer_info[value: " + value + "]";
        }

        public <R, D> R accept(Visitor<R, D> visitor, D data) {
            return visitor.visitInteger(this, data);
        }

        public final int value;
    }

    public static class CONSTANT_InterfaceMethodref_info extends CPRefInfo {
        CONSTANT_InterfaceMethodref_info(ConstantPool cp, ClassReader cr) throws IOException {
            super(cp, cr, CONSTANT_InterfaceMethodref);
        }

        public CONSTANT_InterfaceMethodref_info(ConstantPool cp, int class_index, int name_and_type_index) {
            super(cp, CONSTANT_InterfaceMethodref, class_index, name_and_type_index);
        }

        @Override
        public String toString() {
            return "CONSTANT_InterfaceMethodref_info[class_index: " + class_index + ", name_and_type_index: " + name_and_type_index + "]";
        }

        public <R, D> R accept(Visitor<R, D> visitor, D data) {
            return visitor.visitInterfaceMethodref(this, data);
        }
    }

    public static class CONSTANT_InvokeDynamic_info extends CPInfo {
        CONSTANT_InvokeDynamic_info(ConstantPool cp, ClassReader cr) throws IOException {
            super(cp);
            bootstrap_method_attr_index = cr.readUnsignedShort();
            name_and_type_index = cr.readUnsignedShort();
        }

        public CONSTANT_InvokeDynamic_info(ConstantPool cp, int bootstrap_method_index, int name_and_type_index) {
            super(cp);
            this.bootstrap_method_attr_index = bootstrap_method_index;
            this.name_and_type_index = name_and_type_index;
        }

        public int getTag() {
            return CONSTANT_InvokeDynamic;
        }

        public int byteLength() {
            return 5;
        }

        @Override
        public String toString() {
            return "CONSTANT_InvokeDynamic_info[bootstrap_method_index: " + bootstrap_method_attr_index + ", name_and_type_index: " + name_and_type_index + "]";
        }

        public <R, D> R accept(Visitor<R, D> visitor, D data) {
            return visitor.visitInvokeDynamic(this, data);
        }

        public CONSTANT_NameAndType_info getNameAndTypeInfo() throws ConstantPoolException {
            return cp.getNameAndTypeInfo(name_and_type_index);
        }

        public final int bootstrap_method_attr_index;
        public final int name_and_type_index;
    }

    public static class CONSTANT_Long_info extends CPInfo {
        CONSTANT_Long_info(ClassReader cr) throws IOException {
            value = cr.readLong();
        }

        public CONSTANT_Long_info(long value) {
            this.value = value;
        }

        public int getTag() {
            return CONSTANT_Long;
        }

        @Override
        public int size() {
            return 2;
        }

        public int byteLength() {
            return 9;
        }

        @Override
        public String toString() {
            return "CONSTANT_Long_info[value: " + value + "]";
        }

        public <R, D> R accept(Visitor<R, D> visitor, D data) {
            return visitor.visitLong(this, data);
        }

        public final long value;
    }

    public static class CONSTANT_MethodHandle_info extends CPInfo {
        CONSTANT_MethodHandle_info(ConstantPool cp, ClassReader cr) throws IOException {
            super(cp);
            reference_kind =  RefKind.getRefkind(cr.readUnsignedByte());
            reference_index = cr.readUnsignedShort();
        }

        public CONSTANT_MethodHandle_info(ConstantPool cp, RefKind ref_kind, int member_index) {
            super(cp);
            this.reference_kind = ref_kind;
            this.reference_index = member_index;
        }

        public int getTag() {
            return CONSTANT_MethodHandle;
        }

        public int byteLength() {
            return 4;
        }

        @Override
        public String toString() {
            return "CONSTANT_MethodHandle_info[ref_kind: " + reference_kind + ", member_index: " + reference_index + "]";
        }

        public <R, D> R accept(Visitor<R, D> visitor, D data) {
            return visitor.visitMethodHandle(this, data);
        }

        public CPRefInfo getCPRefInfo() throws ConstantPoolException {
            int expected = CONSTANT_Methodref;
            int actual = cp.get(reference_index).getTag();
            // allow these tag types also:
            switch (actual) {
                case CONSTANT_Fieldref:
                case CONSTANT_InterfaceMethodref:
                    expected = actual;
            }
            return (CPRefInfo) cp.get(reference_index, expected);
        }

        public final RefKind reference_kind;
        public final int reference_index;
    }

    public static class CONSTANT_MethodType_info extends CPInfo {
        CONSTANT_MethodType_info(ConstantPool cp, ClassReader cr) throws IOException {
            super(cp);
            descriptor_index = cr.readUnsignedShort();
        }

        public CONSTANT_MethodType_info(ConstantPool cp, int signature_index) {
            super(cp);
            this.descriptor_index = signature_index;
        }

        public int getTag() {
            return CONSTANT_MethodType;
        }

        public int byteLength() {
            return 3;
        }

        @Override
        public String toString() {
            return "CONSTANT_MethodType_info[signature_index: " + descriptor_index + "]";
        }

        public <R, D> R accept(Visitor<R, D> visitor, D data) {
            return visitor.visitMethodType(this, data);
        }

        public String getType() throws ConstantPoolException {
            return cp.getUTF8Value(descriptor_index);
        }

        public final int descriptor_index;
    }

    public static class CONSTANT_Methodref_info extends CPRefInfo {
        CONSTANT_Methodref_info(ConstantPool cp, ClassReader cr) throws IOException {
            super(cp, cr, CONSTANT_Methodref);
        }

        public CONSTANT_Methodref_info(ConstantPool cp, int class_index, int name_and_type_index) {
            super(cp, CONSTANT_Methodref, class_index, name_and_type_index);
        }

        @Override
        public String toString() {
            return "CONSTANT_Methodref_info[class_index: " + class_index + ", name_and_type_index: " + name_and_type_index + "]";
        }

        public <R, D> R accept(Visitor<R, D> visitor, D data) {
            return visitor.visitMethodref(this, data);
        }
    }

    public static class CONSTANT_Module_info extends CPInfo {
        CONSTANT_Module_info(ConstantPool cp, ClassReader cr) throws IOException {
            super(cp);
            name_index = cr.readUnsignedShort();
        }

        public CONSTANT_Module_info(ConstantPool cp, int name_index) {
            super(cp);
            this.name_index = name_index;
        }

        public int getTag() {
            return CONSTANT_Module;
        }

        public int  byteLength() {
            return 3;
        }

        
Get the raw value of the module name referenced by this constant pool entry.
This will be the name of the module.
Returns:
the raw value of the module name/**
         * Get the raw value of the module name referenced by this constant pool entry.
         * This will be the name of the module.
         * @return the raw value of the module name
         */
        public String getName() throws ConstantPoolException {
            return cp.getUTF8Value(name_index);
        }

        @Override
        public String toString() {
            return "CONSTANT_Module_info[name_index: " + name_index + "]";
        }

        public <R, D> R accept(Visitor<R, D> visitor, D data) {
            return visitor.visitModule(this, data);
        }

        public final int name_index;
    }

    public static class CONSTANT_NameAndType_info extends CPInfo {
        CONSTANT_NameAndType_info(ConstantPool cp, ClassReader cr) throws IOException {
            super(cp);
            name_index = cr.readUnsignedShort();
            type_index = cr.readUnsignedShort();
        }

        public CONSTANT_NameAndType_info(ConstantPool cp, int name_index, int type_index) {
            super(cp);
            this.name_index = name_index;
            this.type_index = type_index;
        }

        public int getTag() {
            return CONSTANT_NameAndType;
        }

        public int byteLength() {
            return 5;
        }

        public String getName() throws ConstantPoolException {
            return cp.getUTF8Value(name_index);
        }

        public String getType() throws ConstantPoolException {
            return cp.getUTF8Value(type_index);
        }

        public <R, D> R accept(Visitor<R, D> visitor, D data) {
            return visitor.visitNameAndType(this, data);
        }

        @Override
        public String toString() {
            return "CONSTANT_NameAndType_info[name_index: " + name_index + ", type_index: " + type_index + "]";
        }

        public final int name_index;
        public final int type_index;
    }

    public static class CONSTANT_Package_info extends CPInfo {
        CONSTANT_Package_info(ConstantPool cp, ClassReader cr) throws IOException {
            super(cp);
            name_index = cr.readUnsignedShort();
        }

        public CONSTANT_Package_info(ConstantPool cp, int name_index) {
            super(cp);
            this.name_index = name_index;
        }

        public int getTag() {
            return CONSTANT_Package;
        }

        public int  byteLength() {
            return 3;
        }

        
Get the raw value of the package name referenced by this constant pool entry.
This will be the name of the package, in internal form.
Returns:
the raw value of the module name/**
         * Get the raw value of the package name referenced by this constant pool entry.
         * This will be the name of the package, in internal form.
         * @return the raw value of the module name
         */
        public String getName() throws ConstantPoolException {
            return cp.getUTF8Value(name_index);
        }

        @Override
        public String toString() {
            return "CONSTANT_Package_info[name_index: " + name_index + "]";
        }

        public <R, D> R accept(Visitor<R, D> visitor, D data) {
            return visitor.visitPackage(this, data);
        }

        public final int name_index;
    }

    public static class CONSTANT_String_info extends CPInfo {
        CONSTANT_String_info(ConstantPool cp, ClassReader cr) throws IOException {
            super(cp);
            string_index = cr.readUnsignedShort();
        }

        public CONSTANT_String_info(ConstantPool cp, int string_index) {
            super(cp);
            this.string_index = string_index;
        }

        public int getTag() {
            return CONSTANT_String;
        }

        public int byteLength() {
            return 3;
        }

        public String getString() throws ConstantPoolException {
            return cp.getUTF8Value(string_index);
        }

        public <R, D> R accept(Visitor<R, D> visitor, D data) {
            return visitor.visitString(this, data);
        }

        @Override
        public String toString() {
            return "CONSTANT_String_info[class_index: " + string_index + "]";
        }

        public final int string_index;
    }

    public static class CONSTANT_Utf8_info extends CPInfo {
        CONSTANT_Utf8_info(ClassReader cr) throws IOException {
            value = cr.readUTF();
        }

        public CONSTANT_Utf8_info(String value) {
            this.value = value;
        }

        public int getTag() {
            return CONSTANT_Utf8;
        }

        public int byteLength() {
            class SizeOutputStream extends OutputStream {
                @Override
                public void write(int b) {
                    size++;
                }
                int size;
            }
            SizeOutputStream sizeOut = new SizeOutputStream();
            DataOutputStream out = new DataOutputStream(sizeOut);
            try { out.writeUTF(value); } catch (IOException ignore) { }
            return 1 + sizeOut.size;
        }

        @Override
        public String toString() {
            if (value.length() < 32 && isPrintableAscii(value))
                return "CONSTANT_Utf8_info[value: \"" + value + "\"]";
            else
                return "CONSTANT_Utf8_info[value: (" + value.length() + " chars)]";
        }

        static boolean isPrintableAscii(String s) {
            for (int i = 0; i < s.length(); i++) {
                char c = s.charAt(i);
                if (c < 32 || c >= 127)
                    return false;
            }
            return true;
        }

        public <R, D> R accept(Visitor<R, D> visitor, D data) {
            return visitor.visitUtf8(this, data);
        }

        public final String value;
    }

}