/*
* ProGuard -- shrinking, optimization, obfuscation, and preverification
* of Java bytecode.
*
* Copyright (c) 2002-2011 Eric Lafortune (eric@graphics.cornell.edu)
*
* 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.optimize;
import proguard.classfile.*;
import proguard.classfile.util.*;
import proguard.classfile.visitor.MemberVisitor;
import proguard.evaluation.value.Value;
import proguard.optimize.evaluation.StoringInvocationUnit;
import proguard.optimize.info.ParameterUsageMarker;
/**
* This <code>MemberVisitor</code> delegates its visits to program methods
* to another given <code>MemberVisitor</code>, for each method parameter
* that has been marked as constant.
*
* @see StoringInvocationUnit
* @author Eric Lafortune
*/
public class ConstantParameterFilter
extends SimplifiedVisitor
implements MemberVisitor
{
private final MemberVisitor constantParameterVisitor;
/**
* Creates a new ConstantParameterFilter.
* @param constantParameterVisitor the <code>MemberVisitor</code> to which
* visits will be delegated.
*/
public ConstantParameterFilter(MemberVisitor constantParameterVisitor)
{
this.constantParameterVisitor = constantParameterVisitor;
}
// Implementations for MemberVisitor.
public void visitProgramMethod(ProgramClass programClass, ProgramMethod programMethod)
{
// All parameters of non-static methods are shifted by one in the local
// variable frame.
int firstParameterIndex =
(programMethod.getAccessFlags() & ClassConstants.INTERNAL_ACC_STATIC) != 0 ?
0 : 1;
int parameterCount =
ClassUtil.internalMethodParameterCount(programMethod.getDescriptor(programClass));
for (int index = firstParameterIndex; index < parameterCount; index++)
{
Value value = StoringInvocationUnit.getMethodParameterValue(programMethod, index);
if (value != null &&
value.isParticular())
{
constantParameterVisitor.visitProgramMethod(programClass, programMethod);
}
}
}
}