/*
* ProGuard -- shrinking, optimization, obfuscation, and preverification
* of Java bytecode.
*
* Copyright (c) 2002-2013 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.evaluation;
import proguard.classfile.Clazz;
import proguard.classfile.attribute.CodeAttribute;
import proguard.evaluation.value.InstructionOffsetValue;
/**
* This BranchUnit remembers the branch unit commands that are invoked on it.
* I doesn't consider conditions when branching.
*
* @author Eric Lafortune
*/
public class BasicBranchUnit
implements BranchUnit
{
private boolean wasCalled;
private InstructionOffsetValue traceBranchTargets;
/**
* Resets the flag that tells whether any of the branch unit commands was
* called.
*/
public void resetCalled()
{
wasCalled = false;
}
/**
* Sets the flag that tells whether any of the branch unit commands was
* called.
*/
protected void setCalled()
{
wasCalled = true;
}
/**
* Returns whether any of the branch unit commands was called.
*/
public boolean wasCalled()
{
return wasCalled;
}
/**
* Sets the initial branch targets, which will be updated as the branch
* methods of the branch unit are called.
*/
public void setTraceBranchTargets(InstructionOffsetValue branchTargets)
{
this.traceBranchTargets = branchTargets;
}
public InstructionOffsetValue getTraceBranchTargets()
{
return traceBranchTargets;
}
// Implementations for BranchUnit.
public void branch(Clazz clazz,
CodeAttribute codeAttribute,
int offset,
int branchTarget)
{
// Override the branch targets.
traceBranchTargets = new InstructionOffsetValue(branchTarget);
wasCalled = true;
}
public void branchConditionally(Clazz clazz,
CodeAttribute codeAttribute,
int offset,
int branchTarget,
int conditional)
{
// Accumulate the branch targets.
traceBranchTargets =
traceBranchTargets.generalize(new InstructionOffsetValue(branchTarget)).instructionOffsetValue();
wasCalled = true;
}
public void returnFromMethod()
{
// Stop processing this block.
traceBranchTargets = InstructionOffsetValue.EMPTY_VALUE;
wasCalled = true;
}
public void throwException()
{
// Stop processing this block.
traceBranchTargets = InstructionOffsetValue.EMPTY_VALUE;
wasCalled = true;
}
}