soot.AbstractUnit Maven / Gradle / Ivy

package soot;

/*-
 * #%L
 * Soot - a J*va Optimization Framework
 * %%
 * Copyright (C) 1997 - 1999 Raja Vallee-Rai
 * %%
 * 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 java.util.ArrayList;
import java.util.Collections;
import java.util.List;

import soot.tagkit.AbstractHost;
import soot.util.Switch;

/** Provides default implementations for the methods in Unit. */
@SuppressWarnings("serial")
public abstract class AbstractUnit extends AbstractHost implements Unit {

  /** Returns a deep clone of this object. */
  public abstract Object clone();

  /**
   * Returns a list of Boxes containing Values used in this Unit. The list of boxes is dynamically updated as the structure
   * changes. Note that they are returned in usual evaluation order. (this is important for aggregation)
   */
  @Override
  public List getUseBoxes() {
    return Collections.emptyList();
  }

  /**
   * Returns a list of Boxes containing Values defined in this Unit. The list of boxes is dynamically updated as the
   * structure changes.
   */
  @Override
  public List getDefBoxes() {
    return Collections.emptyList();
  }

  /**
   * Returns a list of Boxes containing Units defined in this Unit; typically branch targets. The list of boxes is
   * dynamically updated as the structure changes.
   */
  @Override
  public List getUnitBoxes() {
    return Collections.emptyList();
  }

  /** List of UnitBoxes pointing to this Unit. */
  protected List boxesPointingToThis = null;

  /** Returns a list of Boxes pointing to this Unit. */
  @Override
  public List getBoxesPointingToThis() {
    if (boxesPointingToThis == null) {
      return Collections.emptyList();
    }
    return Collections.unmodifiableList(boxesPointingToThis);
  }

  @Override
  public void addBoxPointingToThis(UnitBox b) {
    if (boxesPointingToThis == null) {
      boxesPointingToThis = new ArrayList();
    }
    boxesPointingToThis.add(b);
  }

  @Override
  public void removeBoxPointingToThis(UnitBox b) {
    if (boxesPointingToThis != null) {
      boxesPointingToThis.remove(b);
    }
  }

  @Override
  public void clearUnitBoxes() {
    for (UnitBox ub : getUnitBoxes()) {
      ub.setUnit(null);
    }
  }

  /** Returns a list of ValueBoxes, either used or defined in this Unit. */
  @Override
  public List getUseAndDefBoxes() {
    List useBoxes = getUseBoxes();
    List defBoxes = getDefBoxes();
    if (useBoxes.isEmpty()) {
      return defBoxes;
    } else {
      if (defBoxes.isEmpty()) {
        return useBoxes;
      } else {
        List valueBoxes = new ArrayList();
        valueBoxes.addAll(defBoxes);
        valueBoxes.addAll(useBoxes);
        return valueBoxes;
      }
    }
  }

  /** Used to implement the Switchable construct. */
  @Override
  public void apply(Switch sw) {
  }

  @Override
  public void redirectJumpsToThisTo(Unit newLocation) {
    List boxesPointing = getBoxesPointingToThis();

    UnitBox[] boxes = boxesPointing.toArray(new UnitBox[boxesPointing.size()]);
    // important to change this to an array to have a static copy

    for (UnitBox element : boxes) {
      UnitBox box = element;

      if (box.getUnit() != this) {
        throw new RuntimeException("Something weird's happening");
      }

      if (box.isBranchTarget()) {
        box.setUnit(newLocation);
      }
    }

  }
}