WALA/com.ibm.wala.shrike/src/com/ibm/wala/shrikeBT/GotoInstruction.java

100 lines
2.4 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.shrikeBT;
/**
* This class represents goto and goto_w instructions.
*/
public final class GotoInstruction extends Instruction {
private int[] label;
protected GotoInstruction(int label) {
int[] l = { label };
this.label = l;
this.opcode = OP_goto;
}
private final static GotoInstruction[] preallocated = preallocate();
private static GotoInstruction[] preallocate() {
GotoInstruction[] r = new GotoInstruction[256];
for (int i = 0; i < r.length; i++) {
r[i] = new GotoInstruction(i);
}
return r;
}
public static GotoInstruction make(int label) {
if (0 <= label && label < preallocated.length) {
return preallocated[label];
} else {
return new GotoInstruction(label);
}
}
@Override
public boolean isFallThrough() {
return false;
}
@Override
public int[] getBranchTargets() {
return label;
}
public int getLabel() {
return label[0];
}
@Override
public Instruction redirectTargets(int[] targetMap) throws IllegalArgumentException {
if (targetMap == null) {
throw new IllegalArgumentException("targetMap is null");
}
try {
return make(targetMap[label[0]]);
} catch (ArrayIndexOutOfBoundsException e) {
throw new IllegalArgumentException("Illegal target map", e);
}
}
@Override
public boolean equals(Object o) {
if (o instanceof GotoInstruction) {
GotoInstruction i = (GotoInstruction) o;
return i.label == label;
} else {
return false;
}
}
@Override
public int hashCode() {
return label[0] * 1348091 + 18301;
}
@Override
public String toString() {
return "Goto(" + getLabel() + ")";
}
@Override
public void visit(Visitor v) throws IllegalArgumentException {
if (v == null) {
throw new IllegalArgumentException();
}
v.visitGoto(this);
}
public boolean isPEI() {
return false;
}
}