soot.util.LocalBitSetPacker Maven / Gradle / Ivy
package soot.util;
/*-
* #%L
* Soot - a J*va Optimization Framework
* %%
* Copyright (C) 1997 - 2018 Raja Vallée-Rai and others
* %%
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation, either version 2.1 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 Lesser Public License for more details.
*
* You should have received a copy of the GNU General Lesser Public
* License along with this program. If not, see
* .
* #L%
*/
import soot.Body;
import soot.Local;
/**
* Class for packing local numbers such that bit sets can easily be used to reference locals in bodies
*
* @author Steven Arzt
*
*/
public class LocalBitSetPacker {
private final Body body;
private Local[] locals;
private int[] oldNumbers;
public LocalBitSetPacker(Body body) {
this.body = body;
}
/**
* Reassigns the local numbers such that a dense bit set can be created over them
*/
public void pack() {
int n = body.getLocalCount();
locals = new Local[n];
oldNumbers = new int[n];
n = 0;
for (Local local : body.getLocals()) {
locals[n] = local;
oldNumbers[n] = local.getNumber();
local.setNumber(n++);
}
}
/**
* Restores the original local numbering
*/
public void unpack() {
for (int i = 0; i < locals.length; i++) {
locals[i].setNumber(oldNumbers[i]);
}
locals = null;
oldNumbers = null;
}
public int getLocalCount() {
return locals == null ? 0 : locals.length;
}
}