Exemplo n.º 1
0
  /**
   * Traverse the statements in the given body, looking for aggregation possibilities; that is,
   * given a def d and a use u, d has no other uses, u has no other defs, collapse d and u.
   *
   * <p>option: only-stack-locals; if this is true, only aggregate variables starting with $
   */
  protected void internalTransform(Body b, String phaseName, Map<String, String> options) {
    StmtBody body = (StmtBody) b;
    boolean onlyStackVars = PhaseOptions.getBoolean(options, "only-stack-locals");

    int aggregateCount = 1;

    if (Options.v().time()) Timers.v().aggregationTimer.start();
    boolean changed = false;

    Map<ValueBox, Zone> boxToZone =
        new HashMap<ValueBox, Zone>(body.getUnits().size() * 2 + 1, 0.7f);

    // Determine the zone of every box
    {
      Zonation zonation = new Zonation(body);

      for (Unit u : body.getUnits()) {
        Zone zone = zonation.getZoneOf(u);

        for (ValueBox box : u.getUseBoxes()) {
          boxToZone.put(box, zone);
        }

        for (ValueBox box : u.getDefBoxes()) {
          boxToZone.put(box, zone);
        }
      }
    }

    do {
      if (Options.v().verbose())
        G.v()
            .out
            .println(
                "["
                    + body.getMethod().getName()
                    + "] Aggregating iteration "
                    + aggregateCount
                    + "...");

      // body.printTo(new java.io.PrintWriter(G.v().out, true));

      changed = internalAggregate(body, boxToZone, onlyStackVars);

      aggregateCount++;
    } while (changed);

    if (Options.v().time()) Timers.v().aggregationTimer.end();
  }
  public FaintVariableAnalysis(Body body) {

    Chain<Local> locals = body.getLocals();

    allVariables = new CollectionFlowUniverse<Local>(locals);

    universalSet = new ArrayPackedSet(allVariables);

    for (Local l : locals) universalSet.add(l);

    useSetMap = new HashMap<Unit, BoundedFlowSet>();
    defSetMap = new HashMap<Unit, BoundedFlowSet>();

    UnitGraph graph = new BriefUnitGraph(body);
    for (Unit u : graph) {

      BoundedFlowSet defSet = new ArrayPackedSet(allVariables);
      BoundedFlowSet useSet = new ArrayPackedSet(allVariables);

      for (ValueBox v : u.getDefBoxes()) {
        // Only do this for locals. We're not going to even try to handle anything
        // other than locals.
        if (v.getValue() instanceof Local) {
          defSet.add(v.getValue());
        }
      }
      for (ValueBox v : u.getUseBoxes()) {
        // Only do this for locals. We're not going to even try to handle anything
        // other than locals.
        if (v.getValue() instanceof Local) {
          useSet.add(v.getValue());
        }
      }

      defSetMap.put(u, defSet);
      useSetMap.put(u, useSet);
    }
  }
  /**
   * This method pushes all newExpr down to be the stmt directly before every invoke of the init
   * only if they are in the types list
   */
  public void internalTransform(Body b, String phaseName, Map options) {
    JimpleBody body = (JimpleBody) b;

    if (Options.v().verbose())
      G.v().out.println("[" + body.getMethod().getName() + "] Folding Jimple constructors...");

    Chain units = body.getUnits();
    List<Unit> stmtList = new ArrayList<Unit>();
    stmtList.addAll(units);

    Iterator<Unit> it = stmtList.iterator();
    Iterator<Unit> nextStmtIt = stmtList.iterator();
    // start ahead one
    nextStmtIt.next();

    SmartLocalDefs localDefs = SmartLocalDefsPool.v().getSmartLocalDefsFor(body);
    UnitGraph graph = localDefs.getGraph();
    LocalUses localUses = new SimpleLocalUses(graph, localDefs);

    /* fold in NewExpr's with specialinvoke's */
    while (it.hasNext()) {
      Stmt s = (Stmt) it.next();

      if (!(s instanceof AssignStmt)) continue;

      /* this should be generalized to ArrayRefs */
      // only deal with stmts that are an local = newExpr
      Value lhs = ((AssignStmt) s).getLeftOp();
      if (!(lhs instanceof Local)) continue;

      Value rhs = ((AssignStmt) s).getRightOp();
      if (!(rhs instanceof NewExpr)) continue;

      // check if very next statement is invoke -->
      // this indicates there is no control flow between
      // new and invoke and should do nothing
      if (nextStmtIt.hasNext()) {
        Stmt next = (Stmt) nextStmtIt.next();
        if (next instanceof InvokeStmt) {
          InvokeStmt invoke = (InvokeStmt) next;

          if (invoke.getInvokeExpr() instanceof SpecialInvokeExpr) {
            SpecialInvokeExpr invokeExpr = (SpecialInvokeExpr) invoke.getInvokeExpr();
            if (invokeExpr.getBase() == lhs) {
              break;
            }
          }
        }
      }

      // check if new is in the types list - only process these
      if (!types.contains(((NewExpr) rhs).getType())) continue;

      List lu = localUses.getUsesOf(s);
      Iterator luIter = lu.iterator();
      boolean MadeNewInvokeExpr = false;

      while (luIter.hasNext()) {
        Unit use = ((UnitValueBoxPair) (luIter.next())).unit;
        if (!(use instanceof InvokeStmt)) continue;
        InvokeStmt is = (InvokeStmt) use;
        if (!(is.getInvokeExpr() instanceof SpecialInvokeExpr)
            || lhs != ((SpecialInvokeExpr) is.getInvokeExpr()).getBase()) continue;

        // make a new one here
        AssignStmt constructStmt =
            Jimple.v()
                .newAssignStmt(((DefinitionStmt) s).getLeftOp(), ((DefinitionStmt) s).getRightOp());
        constructStmt.setRightOp(Jimple.v().newNewExpr(((NewExpr) rhs).getBaseType()));
        MadeNewInvokeExpr = true;

        // redirect jumps
        use.redirectJumpsToThisTo(constructStmt);
        // insert new one here
        units.insertBefore(constructStmt, use);

        constructStmt.addTag(s.getTag("SourceLnPosTag"));
      }
      if (MadeNewInvokeExpr) {
        units.remove(s);
      }
    }
  }