WALA/com.ibm.wala.core/src/com/ibm/wala/ssa/SSASwitchInstruction.java

141 lines
3.5 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.ssa;
import com.ibm.wala.util.intset.IntIterator;
/**
* SSA instruction representing a switch statement.
*/
public class SSASwitchInstruction extends SSAInstruction {
private final int val;
private final int defaultLabel;
private final int[] casesAndLabels;
/**
* The labels in casesAndLabels represent <em>instruction indices</em> in the IR that each switch case branches to.
*/
public SSASwitchInstruction(int index, int val, int defaultLabel, int[] casesAndLabels) {
super(index);
this.val = val;
this.defaultLabel = defaultLabel;
this.casesAndLabels = casesAndLabels;
}
@Override
public SSAInstruction copyForSSA(SSAInstructionFactory insts, int[] defs, int[] uses) {
assert uses == null || uses.length == 1;
return insts.SwitchInstruction(iindex, uses == null ? val : uses[0], defaultLabel, casesAndLabels);
}
@Override
public String toString(SymbolTable symbolTable) {
StringBuffer result = new StringBuffer("switch ");
result.append(getValueString(symbolTable, val));
result.append(" [");
for (int i = 0; i < casesAndLabels.length - 1; i++) {
result.append(casesAndLabels[i]);
i++;
result.append("->");
result.append(casesAndLabels[i]);
if (i < casesAndLabels.length - 2) {
result.append(",");
}
}
result.append("]");
return result.toString();
}
/**
* @see com.ibm.wala.ssa.SSAInstruction#visit(IVisitor)
* @throws IllegalArgumentException if v is null
*/
@Override
public void visit(IVisitor v) {
if (v == null) {
throw new IllegalArgumentException("v is null");
}
v.visitSwitch(this);
}
/**
* @see com.ibm.wala.ssa.SSAInstruction#getNumberOfUses()
*/
@Override
public int getNumberOfUses() {
return 1;
}
/**
* @see com.ibm.wala.ssa.SSAInstruction#getUse(int)
*/
@Override
public int getUse(int j) {
assert j <= 1;
return val;
}
// public int[] getTargets() {
// // TODO Auto-generated method stub
// Assertions.UNREACHABLE();
// return null;
// }
public int getTarget(int caseValue) {
for (int i = 0; i < casesAndLabels.length; i += 2)
if (caseValue == casesAndLabels[i])
return casesAndLabels[i + 1];
return defaultLabel;
}
public int getDefault() {
return defaultLabel;
}
public int[] getCasesAndLabels() {
return casesAndLabels;
}
public IntIterator iterateLabels() {
return new IntIterator() {
private int i = 0;
public boolean hasNext() {
return i < casesAndLabels.length;
}
public int next() {
int v = casesAndLabels[i];
i += 2;
return v;
}
};
}
@Override
public int hashCode() {
return val * 1663 + 3499;
}
/*
* @see com.ibm.wala.ssa.Instruction#isFallThrough()
*/
@Override
public boolean isFallThrough() {
return false;
}
}