constantpoolremapper.java

ProGuard 是一个免费的 Java类文件的压缩

/*
 * ProGuard -- shrinking, optimization, obfuscation, and preverification
 *             of Java bytecode.
 *
 * Copyright (c) 2002-2007 Eric Lafortune ([e-mail])
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the Free
 * Software Foundation; either version 2 of the License, or (at your option)
 * any later version.
 *
 * This program 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 for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */
package proguard.classfile.editor;

import proguard.classfile.*;
import proguard.classfile.attribute.*;
import proguard.classfile.attribute.annotation.*;
import proguard.classfile.attribute.annotation.visitor.*;
import proguard.classfile.attribute.preverification.*;
import proguard.classfile.attribute.preverification.visitor.*;
import proguard.classfile.attribute.visitor.*;
import proguard.classfile.constant.*;
import proguard.classfile.constant.visitor.ConstantVisitor;
import proguard.classfile.instruction.*;
import proguard.classfile.instruction.visitor.InstructionVisitor;
import proguard.classfile.util.SimplifiedVisitor;
import proguard.classfile.visitor.*;

/**
 * This ClassVisitor remaps all possible references to constant pool entries
 * of the classes that it visits, based on a given index map. It is assumed that
 * the constant pool entries themselves have already been remapped.
 *
 * @author Eric Lafortune
 */
public class ConstantPoolRemapper
extends      SimplifiedVisitor
implements   ClassVisitor,
             ConstantVisitor,
             MemberVisitor,
             AttributeVisitor,
             InstructionVisitor,
             InnerClassesInfoVisitor,
             ExceptionInfoVisitor,
             StackMapFrameVisitor,
             VerificationTypeVisitor,
             LocalVariableInfoVisitor,
             LocalVariableTypeInfoVisitor,
             AnnotationVisitor,
             ElementValueVisitor
{
    private CodeAttributeEditor codeAttributeEditor = new CodeAttributeEditor();

    private int[] constantIndexMap;


    /**
     * Sets the given mapping of old constant pool entry indexes to their new
     * indexes.
     */
    public void setConstantIndexMap(int[] constantIndexMap)
    {
        this.constantIndexMap = constantIndexMap;
    }


    // Implementations for ClassVisitor.

    public void visitProgramClass(ProgramClass programClass)
    {
        // Remap the local constant pool references.
        programClass.u2thisClass  = remapConstantIndex(programClass.u2thisClass);
        programClass.u2superClass = remapConstantIndex(programClass.u2superClass);

        remapConstantIndexArray(programClass.u2interfaces,
                                programClass.u2interfacesCount);

        // Remap the references of the contant pool entries themselves.
        programClass.constantPoolEntriesAccept(this);

        // Remap the references in all fields, methods, and attributes.
        programClass.fieldsAccept(this);
        programClass.methodsAccept(this);
        programClass.attributesAccept(this);
    }


    public void visitLibraryClass(LibraryClass libraryClass)
    {
    }


    // Implementations for ConstantVisitor.

    public void visitClassConstant(Clazz clazz, ClassConstant classConstant)
    {
        classConstant.u2nameIndex =
            remapConstantIndex(classConstant.u2nameIndex);
    }


    public void visitDoubleConstant(Clazz clazz, DoubleConstant doubleConstant)
    {
        // Nothing to do.
    }


    public void visitFieldrefConstant(Clazz clazz, FieldrefConstant fieldrefConstant)
    {
        fieldrefConstant.u2classIndex =
            remapConstantIndex(fieldrefConstant.u2classIndex);
        fieldrefConstant.u2nameAndTypeIndex =
            remapConstantIndex(fieldrefConstant.u2nameAndTypeIndex);
    }


    public void visitFloatConstant(Clazz clazz, FloatConstant floatConstant)
    {
        // Nothing to do.
    }


    public void visitIntegerConstant(Clazz clazz, IntegerConstant integerConstant)
    {
        // Nothing to do.
    }


    public void visitInterfaceMethodrefConstant(Clazz clazz, InterfaceMethodrefConstant interfaceMethodrefConstant)
    {
        interfaceMethodrefConstant.u2classIndex =
            remapConstantIndex(interfaceMethodrefConstant.u2classIndex);
        interfaceMethodrefConstant.u2nameAndTypeIndex =
            remapConstantIndex(interfaceMethodrefConstant.u2nameAndTypeIndex);
    }


    public void visitLongConstant(Clazz clazz, LongConstant longConstant)
    {
        // Nothing to do.
    }


    public void visitMethodrefConstant(Clazz clazz, MethodrefConstant methodrefConstant)
    {
        methodrefConstant.u2classIndex =
            remapConstantIndex(methodrefConstant.u2classIndex);
        methodrefConstant.u2nameAndTypeIndex =
            remapConstantIndex(methodrefConstant.u2nameAndTypeIndex);
    }


    public void visitNameAndTypeConstant(Clazz clazz, NameAndTypeConstant nameAndTypeConstant)
    {
        nameAndTypeConstant.u2nameIndex =
            remapConstantIndex(nameAndTypeConstant.u2nameIndex);
        nameAndTypeConstant.u2descriptorIndex =
            remapConstantIndex(nameAndTypeConstant.u2descriptorIndex);
    }


    public void visitStringConstant(Clazz clazz, StringConstant stringConstant)
    {
        stringConstant.u2stringIndex =
            remapConstantIndex(stringConstant.u2stringIndex);
    }


    public void visitUtf8Constant(Clazz clazz, Utf8Constant utf8Constant)
    {
        // Nothing to do.
    }


    // Implementations for MemberVisitor.

    public void visitProgramField(ProgramClass programClass, ProgramField programField)
    {
        visitMember(programClass, programField);
    }


    public void visitProgramMethod(ProgramClass programClass, ProgramMethod programMethod)
    {
        visitMember(programClass, programMethod);
    }


    private void visitMember(ProgramClass programClass, ProgramMember programMember)
    {
        // Remap the local constant pool references.
        programMember.u2nameIndex =
            remapConstantIndex(programMember.u2nameIndex);
        programMember.u2descriptorIndex =
            remapConstantIndex(programMember.u2descriptorIndex);

        // Remap the constant pool references of the remaining attributes.
        programMember.attributesAccept(programClass, this);
    }


    public void visitLibraryField(LibraryClass libraryClass, LibraryField libraryField)
    {
        // Library classes are left unchanged.
    }


    public void visitLibraryMethod(LibraryClass libraryClass, LibraryMethod libraryMethod)
    {
        // Library classes are left unchanged.
    }


    // Implementations for AttributeVisitor.

    public void visitUnknownAttribute(Clazz clazz, UnknownAttribute unknownAttribute)
    {
        unknownAttribute.u2attributeNameIndex =
            remapConstantIndex(unknownAttribute.u2attributeNameIndex);

        // There's not much else we can do with unknown attributes.
    }


    public void visitSourceFileAttribute(Clazz clazz, SourceFileAttribute sourceFileAttribute)
    {
        sourceFileAttribute.u2attributeNameIndex =
            remapConstantIndex(sourceFileAttribute.u2attributeNameIndex);
        sourceFileAttribute.u2sourceFileIndex =
            remapConstantIndex(sourceFileAttribute.u2sourceFileIndex);
    }


    public void visitSourceDirAttribute(Clazz clazz, SourceDirAttribute sourceDirAttribute)
    {
        sourceDirAttribute.u2attributeNameIndex =
            remapConstantIndex(sourceDirAttribute.u2attributeNameIndex);
        sourceDirAttribute.u2sourceDirIndex       =
            remapConstantIndex(sourceDirAttribute.u2sourceDirIndex);
    }


    public void visitInnerClassesAttribute(Clazz clazz, InnerClassesAttribute innerClassesAttribute)
    {
        innerClassesAttribute.u2attributeNameIndex =
            remapConstantIndex(innerClassesAttribute.u2attributeNameIndex);

        // Remap the constant pool references of the inner classes.
        innerClassesAttribute.innerClassEntriesAccept(clazz, this);
    }


    public void visitEnclosingMethodAttribute(Clazz clazz, EnclosingMethodAttribute enclosingMethodAttribute)
    {
        enclosingMethodAttribute.u2attributeNameIndex =
            remapConstantIndex(enclosingMethodAttribute.u2attributeNameIndex);
        enclosingMethodAttribute.u2classIndex =
            remapConstantIndex(enclosingMethodAttribute.u2classIndex);
        enclosingMethodAttribute.u2nameAndTypeIndex =
            remapConstantIndex(enclosingMethodAttribute.u2nameAndTypeIndex);
    }


    public void visitDeprecatedAttribute(Clazz clazz, DeprecatedAttribute deprecatedAttribute)
    {
        deprecatedAttribute.u2attributeNameIndex =
            remapConstantIndex(deprecatedAttribute.u2attributeNameIndex);
    }


    public void visitSyntheticAttribute(Clazz clazz, SyntheticAttribute syntheticAttribute)
    {
        syntheticAttribute.u2attributeNameIndex =
            remapConstantIndex(syntheticAttribute.u2attributeNameIndex);
    }


    public void visitSignatureAttribute(Clazz clazz, SignatureAttribute signatureAttribute)
    {
        signatureAttribute.u2attributeNameIndex =
            remapConstantIndex(signatureAttribute.u2attributeNameIndex);
        signatureAttribute.u2signatureIndex       =
            remapConstantIndex(signatureAttribute.u2signatureIndex);
    }


    public void visitConstantValueAttribute(Clazz clazz, Field field, ConstantValueAttribute constantValueAttribute)
    {
        constantValueAttribute.u2attributeNameIndex =
            remapConstantIndex(constantValueAttribute.u2attributeNameIndex);
        constantValueAttribute.u2constantValueIndex =
            remapConstantIndex(constantValueAttribute.u2constantValueIndex);
    }


    public void visitExceptionsAttribute(Clazz clazz, Method method, ExceptionsAttribute exceptionsAttribute)
    {
        exceptionsAttribute.u2attributeNameIndex =
            remapConstantIndex(exceptionsAttribute.u2attributeNameIndex);

        // Remap the constant pool references of the exceptions.