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/*
* ProGuard -- shrinking, optimization, obfuscation, and preverification
* of Java bytecode.
*
* Copyright (c) 2002-2014 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.classfile.editor;
import proguard.classfile.*;
import proguard.classfile.attribute.*;
import proguard.classfile.attribute.visitor.AttributeVisitor;
import proguard.classfile.instruction.*;
import proguard.classfile.instruction.visitor.InstructionVisitor;
import proguard.classfile.util.*;
/**
* This AttributeVisitor computes and updates the maximum local variable frame
* size of the code attributes that it visits. It also cleans up the local
* variable tables.
*
* @author Eric Lafortune
*/
public class VariableSizeUpdater
extends SimplifiedVisitor
implements AttributeVisitor,
InstructionVisitor
{
//*
private static final boolean DEBUG = false;
/*/
private static boolean DEBUG = true;
//*/
private VariableCleaner variableCleaner = new VariableCleaner();
// Implementations for AttributeVisitor.
public void visitAnyAttribute(Clazz clazz, Attribute attribute) {}
public void visitCodeAttribute(Clazz clazz, Method method, CodeAttribute codeAttribute)
{
// DEBUG =
// clazz.getName().equals("abc/Def") &&
// method.getName(clazz).equals("abc");
// The minimum variable size is determined by the arguments.
codeAttribute.u2maxLocals =
ClassUtil.internalMethodParameterSize(method.getDescriptor(clazz),
method.getAccessFlags());
if (DEBUG)
{
System.out.println("VariableSizeUpdater: "+clazz.getName()+"."+method.getName(clazz)+method.getDescriptor(clazz));
System.out.println(" Max locals: "+codeAttribute.u2maxLocals+" <- parameters");
}
// Go over all instructions.
codeAttribute.instructionsAccept(clazz, method, this);
// Remove the unused variables of the attributes.
variableCleaner.visitCodeAttribute(clazz, method, codeAttribute);
}
// Implementations for InstructionVisitor.
public void visitAnyInstruction(Clazz clazz, Method method, CodeAttribute codeAttribute, int offset, Instruction instruction) {}
public void visitVariableInstruction(Clazz clazz, Method method, CodeAttribute codeAttribute, int offset, VariableInstruction variableInstruction)
{
int variableSize = variableInstruction.variableIndex + 1;
if (variableInstruction.isCategory2())
{
variableSize++;
}
if (codeAttribute.u2maxLocals < variableSize)
{
codeAttribute.u2maxLocals = variableSize;
if (DEBUG)
{
System.out.println(" Max locals: "+codeAttribute.u2maxLocals+" <- "+variableInstruction.toString(offset));
}
}
}
}
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