proguard.classfile.editor.AccessFixer Maven / Gradle / Ivy
/*
* ProGuard -- shrinking, optimization, obfuscation, and preverification
* of Java bytecode.
*
* Copyright (c) 2002-2018 GuardSquare NV
*
* 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.constant.*;
import proguard.classfile.constant.visitor.ConstantVisitor;
import proguard.classfile.util.*;
import proguard.classfile.visitor.*;
/**
* This ClassVisitor fixes the access modifiers of all classes and class
* members that are referenced by the classes that it visits.
*
* @author Eric Lafortune
*/
public class AccessFixer
extends ReferencedClassVisitor
implements ClassVisitor
{
private final ConstantVisitor referencedClassStorer = new MyReferencedClassStorer();
/**
* Creates a new AccessFixer.
*/
public AccessFixer()
{
// Unfortunately, the inner class must be static to be passed to the
// super constructor. We therefore can't let it refer to this class;
// we'll let this class refer to the inner class instead.
super(new MyAccessFixer());
}
// Overridden methods for ClassVisitor.
public void visitProgramClass(ProgramClass programClass)
{
// Remember the referencing class.
((MyAccessFixer)classVisitor).referencingClass = programClass;
// Start visiting and fixing the referenced classes and class members.
super.visitProgramClass(programClass);
}
public void visitLibraryClass(LibraryClass libraryClass)
{
// Remember the referencing class.
((MyAccessFixer)classVisitor).referencingClass = libraryClass;
// Start visiting and fixing the referenced classes and class members.
super.visitLibraryClass(libraryClass);
}
// Overridden methods for MemberVisitor.
public void visitProgramMethod(ProgramClass programClass, ProgramMethod programMethod)
{
// Fix the referenced classes and class members.
super.visitProgramMember(programClass, programMethod);
// Fix overridden or implemented methods higher up the hierarchy.
// We can ignore private and static methods and initializers.
if ((programMethod.getAccessFlags() & (ClassConstants.ACC_PRIVATE |
ClassConstants.ACC_STATIC)) == 0 &&
!ClassUtil.isInitializer(programMethod.getName(programClass)))
{
programClass.hierarchyAccept(false, true, false, false,
new NamedMethodVisitor(programMethod.getName(programClass),
programMethod.getDescriptor(programClass),
new MemberAccessFilter(0, ClassConstants.ACC_PRIVATE |
ClassConstants.ACC_STATIC,
(MemberVisitor)classVisitor)));
}
}
public void visitLibraryMethod(LibraryClass libraryClass, LibraryMethod libraryMethod)
{
// Fix the referenced classes and class members.
super.visitLibraryMember(libraryClass, libraryMethod);
// Fix overridden or implemented methods higher up the hierarchy.
// We can ignore private and static methods and initializers.
if ((libraryMethod.getAccessFlags() & (ClassConstants.ACC_PRIVATE |
ClassConstants.ACC_STATIC)) == 0 &&
!ClassUtil.isInitializer(libraryMethod.getName(libraryClass)))
{
libraryClass.hierarchyAccept(false, true, false, false,
new NamedMethodVisitor(libraryMethod.getName(libraryClass),
libraryMethod.getDescriptor(libraryClass),
new MemberAccessFilter(0, ClassConstants.ACC_PRIVATE |
ClassConstants.ACC_STATIC,
(MemberVisitor)classVisitor)));
}
}
// Overridden methods for ConstantVisitor.
public void visitStringConstant(Clazz clazz, StringConstant stringConstant)
{
// Fix the access flags of the referenced class, if any.
super.visitStringConstant(clazz, stringConstant);
// Fix the access flags of the referenced class member, if any.
stringConstant.referencedMemberAccept((MemberVisitor)classVisitor);
}
public void visitAnyRefConstant(Clazz clazz, RefConstant refConstant)
{
// Remember the referenced class. Note that we're interested in the
// class of the invocation, not in the class in which the member was
// actually found, unless it is an array type.
if (ClassUtil.isInternalArrayType(refConstant.getClassName(clazz)))
{
// For an array type, the class will be java.lang.Object.
((MyAccessFixer)classVisitor).referencedClass =
refConstant.referencedClass;
}
else
{
// Remember the referenced class.
clazz.constantPoolEntryAccept(refConstant.u2classIndex,
referencedClassStorer);
}
// Fix the access flags of the class of the referenced class member.
super.visitAnyRefConstant(clazz, refConstant);
// Fix the access flags of the referenced class member.
refConstant.referencedMemberAccept((MemberVisitor)classVisitor);
}
/**
* This ConstantVisitor stores the classes referenced by the class
* constants that it visits.
*/
private class MyReferencedClassStorer
extends SimplifiedVisitor
implements ConstantVisitor
{
// Implementations for ConstantVisitor.
public void visitClassConstant(Clazz clazz, ClassConstant classConstant)
{
// Remember the referenced class.
((MyAccessFixer)classVisitor).referencedClass =
classConstant.referencedClass;
}
}
/**
* This ClassVisitor and MemberVisitor fixes the access flags of the
* classes and class members that it visits, relative to the referencing
* class.
*
* This class must be static so it can be passed to the super constructor
* of the outer class.
*/
private static class MyAccessFixer
extends SimplifiedVisitor
implements ClassVisitor,
MemberVisitor
{
private Clazz referencingClass;
private Clazz referencedClass;
// Implementations for ClassVisitor.
public void visitLibraryClass(LibraryClass libraryClass) {}
public void visitProgramClass(ProgramClass programClass)
{
int currentAccessFlags = programClass.getAccessFlags();
int currentAccessLevel = AccessUtil.accessLevel(currentAccessFlags);
// Compute the required access level.
int requiredAccessLevel =
inSamePackage(programClass, referencingClass) ?
AccessUtil.PACKAGE_VISIBLE :
AccessUtil.PUBLIC;
// Fix the class access flags if necessary.
if (currentAccessLevel < requiredAccessLevel)
{
programClass.u2accessFlags =
AccessUtil.replaceAccessFlags(currentAccessFlags,
AccessUtil.accessFlags(requiredAccessLevel));
}
}
// Implementations for MemberVisitor.
public void visitLibraryMember(LibraryClass libraryClass, LibraryMember libraryMember) {}
public void visitProgramMember(ProgramClass programClass, ProgramMember programMember)
{
int currentAccessFlags = programMember.getAccessFlags();
int currentAccessLevel = AccessUtil.accessLevel(currentAccessFlags);
// Compute the required access level.
// For protected access, we're taking into account the class in the
// invocation and the class that actually contains the member.
int requiredAccessLevel =
programClass.equals(referencingClass) ? AccessUtil.PRIVATE :
inSamePackage(programClass, referencingClass) ? AccessUtil.PACKAGE_VISIBLE :
referencedClass != null &&
referencingClass.extends_(referencedClass) &&
referencingClass.extends_(programClass) ? AccessUtil.PROTECTED :
AccessUtil.PUBLIC;
// Fix the class member access flags if necessary.
if (currentAccessLevel < requiredAccessLevel)
{
programMember.u2accessFlags =
AccessUtil.replaceAccessFlags(currentAccessFlags,
AccessUtil.accessFlags(requiredAccessLevel));
}
}
// Small utility methods.
/**
* Returns whether the two given classes are in the same package.
*/
private boolean inSamePackage(Clazz class1, Clazz class2)
{
return ClassUtil.internalPackageName(class1.getName()).equals(
ClassUtil.internalPackageName(class2.getName()));
}
}
}
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