WALA/com.ibm.wala.util/src/com/ibm/wala/dataflow/graph/BitVectorMinusVector.java

72 lines
1.9 KiB
Java

/*******************************************************************************
* Copyright (c) 2002 - 2006 IBM Corporation.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* IBM Corporation - initial API and implementation
*******************************************************************************/
package com.ibm.wala.dataflow.graph;
import com.ibm.wala.fixpoint.BitVectorVariable;
import com.ibm.wala.fixpoint.UnaryOperator;
import com.ibm.wala.util.intset.BitVector;
import com.ibm.wala.util.intset.BitVectorIntSet;
/**
* Operator OUT = IN / v
*/
public class BitVectorMinusVector extends UnaryOperator<BitVectorVariable> {
private final BitVectorIntSet v;
public BitVectorMinusVector(BitVector v) {
this.v = new BitVectorIntSet(v);
}
@Override
public byte evaluate(BitVectorVariable lhs, BitVectorVariable rhs) throws IllegalArgumentException, IllegalArgumentException {
if (lhs == null) {
throw new IllegalArgumentException("lhs == null");
}
if (rhs == null) {
throw new IllegalArgumentException("rhs == null");
}
BitVectorVariable U = new BitVectorVariable();
BitVectorIntSet bv = new BitVectorIntSet();
bv.addAll(rhs.getValue());
bv.removeAll(v);
U.addAll(bv.getBitVector());
if (!lhs.sameValue(U)) {
lhs.copyState(U);
return CHANGED;
} else {
return NOT_CHANGED;
}
}
@Override
public String toString() {
return "U " + v;
}
@Override
public int hashCode() {
return 9901 * v.hashCode();
}
@Override
public boolean equals(Object o) {
if (o instanceof BitVectorMinusVector) {
BitVectorMinusVector other = (BitVectorMinusVector)o;
return v.sameValue(other.v);
} else {
return false;
}
}
}