soot.jimple.spark.geom.geomPA.IVarAbstraction Maven / Gradle / Ivy

package soot.jimple.spark.geom.geomPA;

/*-
 * #%L
 * Soot - a J*va Optimization Framework
 * %%
 * Copyright (C) 2011 Richard Xiao
 * %%
 * 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.io.PrintStream;
import java.util.Set;

import soot.SootMethod;
import soot.Type;
import soot.jimple.spark.geom.dataMgr.Obj_full_extractor;
import soot.jimple.spark.geom.dataMgr.PtSensVisitor;
import soot.jimple.spark.geom.dataRep.PlainConstraint;
import soot.jimple.spark.geom.dataRep.RectangleNode;
import soot.jimple.spark.pag.AllocNode;
import soot.jimple.spark.pag.LocalVarNode;
import soot.jimple.spark.pag.Node;
import soot.util.Numberable;

/**
 * Pointer/object representation in geomPTA. This interface defines the operations needed for manipulating a pointer/object.
 *
 * @author xiao
 *
 */
public abstract class IVarAbstraction implements Numberable {
  // A shape manager that has only one all map to all member, representing the context insensitive points-to info
  protected static IFigureManager stubManager = null;
  // This is used to indicate the corresponding object should be removed
  protected static IFigureManager deadManager = null;
  // A temporary rectangle holds the candidate figure
  protected static RectangleNode pres = null;

  // Corresponding SPARK node
  public Node me;
  // The integer mapping for this node
  public int id = -1;
  // Position in the queue
  public int Qpos = 0;
  // Will we update the points-to information for this node in the geometric analysis?
  // Because of constraints distillation, not all the pointers will be updated.
  public boolean willUpdate = false;
  // top_value: the topological value for this node on the symbolic assignment graph
  // lrf_value: the number of processing times for this pointer
  // top_value will be modified in the offlineProcessor and every pointer has a different value
  public int top_value = 1, lrf_value = 0;
  // union-find tree link
  protected IVarAbstraction parent;

  public IVarAbstraction() {
    parent = this;
  }

  /**
   * Used by ordering the nodes in priority worklist.
   */
  public boolean lessThan(IVarAbstraction other) {
    if (lrf_value != other.lrf_value) {
      return lrf_value < other.lrf_value;
    }

    return top_value < other.top_value;
  }

  public IVarAbstraction getRepresentative() {
    return parent == this ? this : (parent = parent.getRepresentative());
  }

  /**
   * Make the variable other be the parent of this variable.
   *
   * @param other
   * @return
   */
  public IVarAbstraction merge(IVarAbstraction other) {
    getRepresentative();
    parent = other.getRepresentative();
    return parent;
  }

  @Override
  public void setNumber(int number) {
    id = number;
  }

  @Override
  public int getNumber() {
    return id;
  }

  @Override
  public String toString() {
    if (me != null) {
      return me.toString();
    }
    return super.toString();
  }

  /**
   * This pointer/object is reachable if its enclosing method is reachable. Pleas always call this method to check the status
   * before querying points-to information.
   */
  public boolean reachable() {
    return id != -1;
  }

  /**
   * Test if this pointer currently has points-to result. The result can be computed in the last iteration of geomPTA,
   * although its willUpdate = false this round.
   */
  public boolean hasPTResult() {
    return num_of_diff_objs() != -1;
  }

  /**
   * Processing the wrapped SPARK node.
   */
  public Node getWrappedNode() {
    return me;
  }

  public Type getType() {
    return me.getType();
  }

  public boolean isLocalPointer() {
    return me instanceof LocalVarNode;
  }

  public SootMethod enclosingMethod() {
    if (me instanceof LocalVarNode) {
      return ((LocalVarNode) me).getMethod();
    }
    return null;
  }

  // Initiation
  public abstract boolean add_points_to_3(AllocNode obj, long I1, long I2, long L);

  public abstract boolean add_points_to_4(AllocNode obj, long I1, long I2, long L1, long L2);

  public abstract boolean add_simple_constraint_3(IVarAbstraction qv, long I1, long I2, long L);

  public abstract boolean add_simple_constraint_4(IVarAbstraction qv, long I1, long I2, long L1, long L2);

  public abstract void put_complex_constraint(PlainConstraint cons);

  public abstract void reconstruct();

  // Points-to facts propagation
  public abstract void do_before_propagation();

  public abstract void do_after_propagation();

  public abstract void propagate(GeomPointsTo ptAnalyzer, IWorklist worklist);

  // Manipulate points-to results
  public abstract void drop_duplicates();

  public abstract void remove_points_to(AllocNode obj);

  public abstract void deleteAll();

  public abstract void keepPointsToOnly();

  public abstract void injectPts();

  // Obtaining points-to information statistics
  /**
   * Return -1 if this pointer does not have points-to information. This function can be used for testing if the pointer has
   * been processed by geomPTA.
   */
  public abstract int num_of_diff_objs();

  public abstract int num_of_diff_edges();

  public abstract int count_pts_intervals(AllocNode obj);

  public abstract int count_new_pts_intervals();

  public abstract int count_flow_intervals(IVarAbstraction qv);

  // Querying procedures
  /**
   * Perform context sensitive alias checking with qv.
   *
   * @param qv
   * @return
   */
  public abstract boolean heap_sensitive_intersection(IVarAbstraction qv);

  /**
   * Test if the pointer in the context range [l, R) points to object obj.
   *
   * @param l
   * @param r
   * @param obj
   * @return
   */
  public abstract boolean pointer_interval_points_to(long l, long r, AllocNode obj);

  /**
   * Test if the particular object has been obsoleted. It's mainly for points-to developer use.
   *
   * @param obj
   * @return
   */
  public abstract boolean isDeadObject(AllocNode obj);

  /**
   * Obtain context insensitive points-to result (by removing contexts).
   *
   * @return
   */
  public abstract Set get_all_points_to_objects();

  /**
   * Given the pointers falling in the context range [l, r), we compute the set of context sensitive objects pointed to by
   * those pointers. This function is designed in visitor pattern.
   *
   * @see Obj_1cfa_extractor
   * @see Obj_full_extractor
   */
  public abstract void get_all_context_sensitive_objects(long l, long r, PtSensVisitor visitor);

  // Debugging facilities
  public abstract void print_context_sensitive_points_to(PrintStream outPrintStream);
}