attributeusagemarker.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.obfuscate;

import proguard.classfile.*;
import proguard.classfile.attribute.*;
import proguard.classfile.attribute.annotation.*;
import proguard.classfile.attribute.preverification.*;
import proguard.classfile.attribute.visitor.AttributeVisitor;
import proguard.classfile.util.SimplifiedVisitor;
import proguard.classfile.visitor.*;
import proguard.util.*;

import java.util.List;


/**
 * This ClassVisitor marks all attributes that should be kept in the classes
 * it visits.
 *
 * @see AttributeShrinker
 *
 * @author Eric Lafortune
 */
public class AttributeUsageMarker
extends      SimplifiedVisitor
implements   ClassVisitor,
             MemberVisitor,
             AttributeVisitor
{
    // A visitor info flag to indicate the attribute is being used.
    private static final Object USED = new Object();


    // Flags to specify whether optional attributes should be kept anyway.
    private boolean       keepAllAttributes;
    private boolean       keepAllUnknownAttributes;
    private boolean       keepAllKnownAttributes;
    private StringMatcher keepAttributes;

    private boolean keepSourceFileAttribute;
    private boolean keepSourceDirAttribute;
    private boolean keepInnerClassesAttribute;
    private boolean keepEnclosingMethodAttribute;
    private boolean keepDeprecatedAttribute;
    private boolean keepSyntheticAttribute;
    private boolean keepSignatureAttribute;
    private boolean keepLineNumberTableAttribute;
    private boolean keepLocalVariableTableAttribute;
    private boolean keepLocalVariableTypeTableAttribute;
    private boolean keepRuntimeVisibleAnnotationsAttribute;
    private boolean keepRuntimeInvisibleAnnotationsAttribute;
    private boolean keepRuntimeVisibleParameterAnnotationsAttribute;
    private boolean keepRuntimeInvisibleParameterAnnotationsAttribute;
    private boolean keepAnnotationDefaultAttribute;


    /**
     * Specifies to keep all optional attributes.
     */
    public void setKeepAllAttributes()
    {
        keepAllAttributes = true;
    }

    /**
     * Specifies to keep all unknown attributes.
     */
    public void setKeepAllUnknownAttributes()
    {
        keepAllUnknownAttributes = true;
    }

    /**
     * Specifies to keep all known attributes.
     */
    public void setKeepAllKnownAttributes()
    {
        keepAllKnownAttributes = true;
    }


    /**
     * Specifies to keep optional attributes with the given names. The attribute
     * names may contain "*" or "?" wildcards, and they may be preceded by the
     * "!" negator.
     */
    public void setKeepAttributes(List attributeNames)
    {
        keepAttributes = new BasicListMatcher(attributeNames);

        // Precompute whether the list of attribute names matches the supported
        // attributes.
        keepSourceFileAttribute                           = keepAttributes.matches(ClassConstants.ATTR_SourceFile);
        keepSourceDirAttribute                            = keepAttributes.matches(ClassConstants.ATTR_SourceDir);
        keepInnerClassesAttribute                         = keepAttributes.matches(ClassConstants.ATTR_InnerClasses);
        keepEnclosingMethodAttribute                      = keepAttributes.matches(ClassConstants.ATTR_EnclosingMethod);
        keepDeprecatedAttribute                           = keepAttributes.matches(ClassConstants.ATTR_Deprecated);
        keepSyntheticAttribute                            = keepAttributes.matches(ClassConstants.ATTR_Synthetic);
        keepSignatureAttribute                            = keepAttributes.matches(ClassConstants.ATTR_Signature);
        keepLineNumberTableAttribute                      = keepAttributes.matches(ClassConstants.ATTR_LineNumberTable);
        keepLocalVariableTableAttribute                   = keepAttributes.matches(ClassConstants.ATTR_LocalVariableTable);
        keepLocalVariableTypeTableAttribute               = keepAttributes.matches(ClassConstants.ATTR_LocalVariableTypeTable);
        keepRuntimeVisibleAnnotationsAttribute            = keepAttributes.matches(ClassConstants.ATTR_RuntimeVisibleAnnotations);
        keepRuntimeInvisibleAnnotationsAttribute          = keepAttributes.matches(ClassConstants.ATTR_RuntimeInvisibleAnnotations);
        keepRuntimeVisibleParameterAnnotationsAttribute   = keepAttributes.matches(ClassConstants.ATTR_RuntimeVisibleParameterAnnotations);
        keepRuntimeInvisibleParameterAnnotationsAttribute = keepAttributes.matches(ClassConstants.ATTR_RuntimeInvisibleParameterAnnotations);
        keepAnnotationDefaultAttribute                    = keepAttributes.matches(ClassConstants.ATTR_AnnotationDefault);
    }


    // Implementations for ClassVisitor.

    public void visitProgramClass(ProgramClass programClass)
    {
        // Mark the class member attributes that should be kept.
        programClass.fieldsAccept(this);
        programClass.methodsAccept(this);

        // Mark the class attributes that should be kept.
        programClass.attributesAccept(this);
    }


    // 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)
    {
        // Mark the class member attributes that should be kept.
        programMember.attributesAccept(programClass, this);
    }


    // Implementations for AttributeVisitor.

    public void visitUnknownAttribute(Clazz clazz, UnknownAttribute unknownAttribute)
    {
        if (keepAllAttributes        ||
            keepAllUnknownAttributes ||
            (keepAttributes != null &&
             keepAttributes.matches(unknownAttribute.getAttributeName(clazz))))
        {
            markAsUsed(unknownAttribute);
        }
    }


    public void visitSourceFileAttribute(Clazz clazz, SourceFileAttribute sourceFileAttribute)
    {
        if (keepAllAttributes      ||
            keepAllKnownAttributes ||
            keepSourceFileAttribute)
        {
            markAsUsed(sourceFileAttribute);
        }
    }


    public void visitSourceDirAttribute(Clazz clazz, SourceDirAttribute sourceDirAttribute)
    {
        if (keepAllAttributes      ||
            keepAllKnownAttributes ||
            keepSourceDirAttribute)
        {
            markAsUsed(sourceDirAttribute);
        }
    }


    public void visitInnerClassesAttribute(Clazz clazz, InnerClassesAttribute innerClassesAttribute)
    {
        if (keepAllAttributes      ||
            keepAllKnownAttributes ||
            keepInnerClassesAttribute)
        {
            markAsUsed(innerClassesAttribute);
        }
    }


    public void visitEnclosingMethodAttribute(Clazz clazz, EnclosingMethodAttribute enclosingMethodAttribute)
    {
        if (keepAllAttributes      ||
            keepAllKnownAttributes ||
            keepEnclosingMethodAttribute)
        {
            markAsUsed(enclosingMethodAttribute);
        }
    }


    public void visitDeprecatedAttribute(Clazz clazz, DeprecatedAttribute deprecatedAttribute)
    {
        if (keepAllAttributes      ||
            keepAllKnownAttributes ||
            keepDeprecatedAttribute)
        {
            markAsUsed(deprecatedAttribute);
        }
    }


    public void visitSyntheticAttribute(Clazz clazz, SyntheticAttribute syntheticAttribute)
    {
        if (keepAllAttributes      ||
            keepAllKnownAttributes ||
            keepSyntheticAttribute)
        {
            markAsUsed(syntheticAttribute);
        }
    }


    public void visitSignatureAttribute(Clazz clazz, SignatureAttribute signatureAttribute)
    {
        if (keepAllAttributes      ||
            keepAllKnownAttributes ||
            keepSignatureAttribute)
        {
            markAsUsed(signatureAttribute);
        }
    }


    public void visitConstantValueAttribute(Clazz clazz, Field field, ConstantValueAttribute constantValueAttribute)
    {
        markAsUsed(constantValueAttribute);
    }


    public void visitExceptionsAttribute(Clazz clazz, Method method, ExceptionsAttribute exceptionsAttribute)
    {
        markAsUsed(exceptionsAttribute);
    }


    public void visitCodeAttribute(Clazz clazz, Method method, CodeAttribute codeAttribute)
    {
        markAsUsed(codeAttribute);

        // Mark the code attributes that should be kept.
        codeAttribute.attributesAccept(clazz, method, this);
    }


    public void visitStackMapAttribute(Clazz clazz, Method method, CodeAttribute codeAttribute, StackMapAttribute stackMapAttribute)
    {
        markAsUsed(stackMapAttribute);
    }


    public void visitStackMapTableAttribute(Clazz clazz, Method method, CodeAttribute codeAttribute, StackMapTableAttribute stackMapTableAttribute)
    {
        markAsUsed(stackMapTableAttribute);
    }


    public void visitLineNumberTableAttribute(Clazz clazz, Method method, CodeAttribute codeAttribute, LineNumberTableAttribute lineNumberTableAttribute)
    {
        if (keepAllAttributes      ||
            keepAllKnownAttributes ||
            keepLineNumberTableAttribute)
        {
            markAsUsed(lineNumberTableAttribute);
        }
    }


    public void visitLocalVariableTableAttribute(Clazz clazz, Method method, CodeAttribute codeAttribute, LocalVariableTableAttribute localVariableTableAttribute)
    {
        if (keepAllAttributes      ||
            keepAllKnownAttributes ||
            keepLocalVariableTableAttribute)
        {
            markAsUsed(localVariableTableAttribute);
        }
    }


    public void visitLocalVariableTypeTableAttribute(Clazz clazz, Method method, CodeAttribute codeAttribute, LocalVariableTypeTableAttribute localVariableTypeTableAttribute)
    {
        if (keepAllAttributes      ||
            keepAllKnownAttributes ||
            keepLocalVariableTypeTableAttribute)
        {
            markAsUsed(localVariableTypeTableAttribute);
        }
    }


    public void visitRuntimeVisibleAnnotationsAttribute(Clazz clazz, RuntimeVisibleAnnotationsAttribute runtimeVisibleAnnotationsAttribute)
    {
        if (keepAllAttributes      ||
            keepAllKnownAttributes ||
            keepRuntimeVisibleAnnotationsAttribute)
        {
            markAsUsed(runtimeVisibleAnnotationsAttribute);
        }
    }


    public void visitRuntimeInvisibleAnnotationsAttribute(Clazz clazz, RuntimeInvisibleAnnotationsAttribute runtimeInvisibleAnnotationsAttribute)
    {
        if (keepAllAttributes      ||
            keepAllKnownAttributes ||
            keepRuntimeInvisibleAnnotationsAttribute)
        {
            markAsUsed(runtimeInvisibleAnnotationsAttribute);
        }
    }


    public void visitRuntimeVisibleParameterAnnotationsAttribute(Clazz clazz, Method method, RuntimeVisibleParameterAnnotationsAttribute runtimeVisibleParameterAnnotationsAttribute)
    {
        if (keepAllAttributes      ||
            keepAllKnownAttributes ||
            keepRuntimeVisibleParameterAnnotationsAttribute)
        {
            markAsUsed(runtimeVisibleParameterAnnotationsAttribute);
        }
    }


    public void visitRuntimeInvisibleParameterAnnotationsAttribute(Clazz clazz, Method method, RuntimeInvisibleParameterAnnotationsAttribute runtimeInvisibleParameterAnnotationsAttribute)
    {
        if (keepAllAttributes      ||
            keepAllKnownAttributes ||
            keepRuntimeInvisibleParameterAnnotationsAttribute)
        {
            markAsUsed(runtimeInvisibleParameterAnnotationsAttribute);
        }
    }


    public void visitAnnotationDefaultAttribute(Clazz clazz, Method method, AnnotationDefaultAttribute annotationDefaultAttribute)
    {
        if (keepAllAttributes      ||
            keepAllKnownAttributes ||
            keepAnnotationDefaultAttribute)
        {
            markAsUsed(annotationDefaultAttribute);
        }
    }


    // Small utility methods.

    /**
     * Marks the given VisitorAccepter as being used (or useful).
     * In this context, the VisitorAccepter will be an Attribute object.
     */
    private static void markAsUsed(VisitorAccepter visitorAccepter)
    {
        visitorAccepter.setVisitorInfo(USED);
    }


    /**
     * Returns whether the given VisitorAccepter has been marked as being used.
     * In this context, the VisitorAccepter will be an Attribute object.
     */
    static boolean isUsed(VisitorAccepter visitorAccepter)
    {
        return visitorAccepter.getVisitorInfo() == USED;
    }
}