示例#1
0
  /**
   * given a DelayabilityAnalysis and the computations of each unit, calculates the latest
   * computation-point for each expression.<br>
   * the <code>equivRhsMap</code> could be calculated on the fly, but it is <b>very</b> likely that
   * it already exists (as similar maps are used for calculating Earliestness, Delayed,...<br>
   * the shared set allows more efficient set-operations, when they the computation is merged with
   * other analyses/computations.
   *
   * @param dg a ExceptionalUnitGraph
   * @param delayed the delayability-analysis of the same graph.
   * @param equivRhsMap all computations of the graph
   * @param set the shared flowSet
   */
  public LatestComputation(
      UnitGraph unitGraph, DelayabilityAnalysis delayed, Map equivRhsMap, BoundedFlowSet set) {
    unitToLatest = new HashMap<Unit, FlowSet>(unitGraph.size() + 1, 0.7f);

    Iterator unitIt = unitGraph.iterator();
    while (unitIt.hasNext()) {
      /* create a new Earliest-list for each unit */
      Unit currentUnit = (Unit) unitIt.next();

      /* basically the latest-set is:
       * (delayed) INTERSECT (comp UNION (UNION_successors ~Delayed)) =
       * (delayed) MINUS ((INTERSECTION_successors Delayed) MINUS comp).
       */

      FlowSet delaySet = (FlowSet) delayed.getFlowBefore(currentUnit);

      /* Calculate (INTERSECTION_successors Delayed) */
      FlowSet succCompSet = (FlowSet) set.topSet();
      List succList = unitGraph.getSuccsOf(currentUnit);
      Iterator succIt = succList.iterator();
      while (succIt.hasNext()) {
        Unit successor = (Unit) succIt.next();
        succCompSet.intersection((FlowSet) delayed.getFlowBefore(successor), succCompSet);
      }
      /* remove the computation of this set: succCompSet is then:
       * ((INTERSECTION_successors Delayed) MINUS comp) */
      if (equivRhsMap.get(currentUnit) != null) succCompSet.remove(equivRhsMap.get(currentUnit));

      /* make the difference: */
      FlowSet latest = (FlowSet) delaySet.emptySet();
      delaySet.difference(succCompSet, latest);

      unitToLatest.put(currentUnit, latest);
    }
  }
示例#2
0
  protected void flowThrough(Object inValue, Object unit, Object outValue) {
    FlowSet in = (FlowSet) inValue, out = (FlowSet) outValue;

    // Perform kill
    in.difference(unitToKillSet.get(unit), out);

    // Perform generation
    out.union(unitToGenerateSet.get(unit), out);
  }
示例#3
0
  /** Prints the given <code>JimpleBody</code> to the specified <code>PrintWriter</code>. */
  private void printLocalsInBody(Body body, UnitPrinter up) {
    // Print out local variables
    {
      Map typeToLocals = new DeterministicHashMap(body.getLocalCount() * 2 + 1, 0.7f);

      // Collect locals
      {
        Iterator localIt = body.getLocals().iterator();

        while (localIt.hasNext()) {
          Local local = (Local) localIt.next();

          List localList;

          Type t = local.getType();

          if (typeToLocals.containsKey(t)) localList = (List) typeToLocals.get(t);
          else {
            localList = new ArrayList();
            typeToLocals.put(t, localList);
          }

          localList.add(local);
        }
      }

      // Print locals
      {
        Iterator typeIt = typeToLocals.keySet().iterator();

        while (typeIt.hasNext()) {
          Type type = (Type) typeIt.next();

          List localList = (List) typeToLocals.get(type);
          Object[] locals = localList.toArray();
          up.type(type);
          up.literal(" ");

          for (int k = 0; k < locals.length; k++) {
            if (k != 0) up.literal(", ");

            up.local((Local) locals[k]);
          }

          up.literal(";");
          up.newline();
        }
      }

      if (!typeToLocals.isEmpty()) {
        up.newline();
      }
    }
  }
示例#4
0
  protected void internalTransform(Body b, String phaseName, Map<String, String> options) {
    initialize(options);
    SootMethod meth = b.getMethod();

    if ((methodsToPrint == null)
        || (meth.getDeclaringClass().getName() == methodsToPrint.get(meth.getName()))) {
      Body body = ir.getBody((JimpleBody) b);
      print_cfg(body);
    }
  }
示例#5
0
 public List getLiveLocalsBefore(Unit s) {
   return unitToLocalsBefore.get(s);
 }
示例#6
0
 public List getLiveLocalsAfter(Unit s) {
   return unitToLocalsAfter.get(s);
 }
示例#7
0
 /**
  * returns the set of expressions, that have their latest computation just before <code>node
  * </code>.
  *
  * @param node an Object of the flow-graph (in our case always a unit).
  * @return a FlowSet containing the expressions.
  */
 public Object getFlowBefore(Object node) {
   return unitToLatest.get(node);
 }
示例#8
0
  private static boolean internalAggregate(
      StmtBody body, Map<ValueBox, Zone> boxToZone, boolean onlyStackVars) {
    LocalUses localUses;
    LocalDefs localDefs;
    ExceptionalUnitGraph graph;
    boolean hadAggregation = false;
    Chain<Unit> units = body.getUnits();

    graph = new ExceptionalUnitGraph(body);
    localDefs = new SmartLocalDefs(graph, new SimpleLiveLocals(graph));
    localUses = new SimpleLocalUses(graph, localDefs);

    List<Unit> unitList = new PseudoTopologicalOrderer<Unit>().newList(graph, false);
    for (Unit u : unitList) {
      if (!(u instanceof AssignStmt)) continue;
      AssignStmt s = (AssignStmt) u;

      Value lhs = s.getLeftOp();
      if (!(lhs instanceof Local)) continue;
      Local lhsLocal = (Local) lhs;

      if (onlyStackVars && !lhsLocal.getName().startsWith("$")) continue;

      List<UnitValueBoxPair> lu = localUses.getUsesOf(s);
      if (lu.size() != 1) continue;

      UnitValueBoxPair usepair = lu.get(0);
      Unit use = usepair.unit;
      ValueBox useBox = usepair.valueBox;

      List<Unit> ld = localDefs.getDefsOfAt(lhsLocal, use);
      if (ld.size() != 1) continue;

      // Check to make sure aggregation pair in the same zone
      if (boxToZone.get(s.getRightOpBox()) != boxToZone.get(usepair.valueBox)) {
        continue;
      }

      /* we need to check the path between def and use */
      /* to see if there are any intervening re-defs of RHS */
      /* in fact, we should check that this path is unique. */
      /* if the RHS uses only locals, then we know what
      to do; if RHS has a method invocation f(a, b,
      c) or field access, we must ban field writes, other method
      calls and (as usual) writes to a, b, c. */

      boolean cantAggr = false;
      boolean propagatingInvokeExpr = false;
      boolean propagatingFieldRef = false;
      boolean propagatingArrayRef = false;
      ArrayList<FieldRef> fieldRefList = new ArrayList<FieldRef>();

      LinkedList<Value> localsUsed = new LinkedList<Value>();
      for (ValueBox vb : s.getUseBoxes()) {
        Value v = vb.getValue();
        if (v instanceof Local) localsUsed.add(v);
        else if (v instanceof InvokeExpr) propagatingInvokeExpr = true;
        else if (v instanceof ArrayRef) propagatingArrayRef = true;
        else if (v instanceof FieldRef) {
          propagatingFieldRef = true;
          fieldRefList.add((FieldRef) v);
        }
      }

      // look for a path from s to use in graph.
      // only look in an extended basic block, though.

      List<Unit> path = graph.getExtendedBasicBlockPathBetween(s, use);

      if (path == null) continue;

      Iterator<Unit> pathIt = path.iterator();

      // skip s.
      if (pathIt.hasNext()) pathIt.next();

      while (pathIt.hasNext() && !cantAggr) {
        Stmt between = (Stmt) (pathIt.next());

        if (between != use) {
          // Check for killing definitions

          for (ValueBox vb : between.getDefBoxes()) {
            Value v = vb.getValue();
            if (localsUsed.contains(v)) {
              cantAggr = true;
              break;
            }

            if (propagatingInvokeExpr || propagatingFieldRef || propagatingArrayRef) {
              if (v instanceof FieldRef) {
                if (propagatingInvokeExpr) {
                  cantAggr = true;
                  break;
                } else if (propagatingFieldRef) {
                  // Can't aggregate a field access if passing a definition of a field
                  // with the same name, because they might be aliased
                  for (FieldRef fieldRef : fieldRefList) {
                    if (((FieldRef) v).getField() == fieldRef.getField()) {
                      cantAggr = true;
                      break;
                    }
                  }
                }
              } else if (v instanceof ArrayRef) {
                if (propagatingInvokeExpr) {
                  // Cannot aggregate an invoke expr past an array write
                  cantAggr = true;
                  break;
                } else if (propagatingArrayRef) {
                  // cannot aggregate an array read past a write
                  // this is somewhat conservative
                  // (if types differ they may not be aliased)

                  cantAggr = true;
                  break;
                }
              }
            }
          }

          // Make sure not propagating past a {enter,exit}Monitor
          if (propagatingInvokeExpr && between instanceof MonitorStmt) cantAggr = true;
        }

        // Check for intervening side effects due to method calls
        if (propagatingInvokeExpr || propagatingFieldRef || propagatingArrayRef) {
          for (final ValueBox box : between.getUseBoxes()) {
            if (between == use && box == useBox) {
              // Reached use point, stop looking for
              // side effects
              break;
            }

            Value v = box.getValue();

            if (v instanceof InvokeExpr
                || (propagatingInvokeExpr && (v instanceof FieldRef || v instanceof ArrayRef))) {
              cantAggr = true;
              break;
            }
          }
        }
      }

      // we give up: can't aggregate.
      if (cantAggr) {
        continue;
      }
      /* assuming that the d-u chains are correct, */
      /* we need not check the actual contents of ld */

      Value aggregatee = s.getRightOp();

      if (usepair.valueBox.canContainValue(aggregatee)) {
        boolean wasSimpleCopy = isSimpleCopy(usepair.unit);
        usepair.valueBox.setValue(aggregatee);
        units.remove(s);
        hadAggregation = true;
        // clean up the tags. If s was not a simple copy, the new statement should get
        // the tags of s.
        // OK, this fix was wrong. The condition should not be
        // "If s was not a simple copy", but rather "If usepair.unit
        // was a simple copy". This way, when there's a load of a constant
        // followed by an invoke, the invoke gets the tags.
        if (wasSimpleCopy) {
          // usepair.unit.removeAllTags();
          usepair.unit.addAllTagsOf(s);
        }
      } else {
        /*
        if(Options.v().verbose())
        {
            G.v().out.println("[debug] failed aggregation");
              G.v().out.println("[debug] tried to put "+aggregatee+
                             " into "+usepair.stmt +
                             ": in particular, "+usepair.valueBox);
              G.v().out.println("[debug] aggregatee instanceof Expr: "
                             +(aggregatee instanceof Expr));
        }*/
      }
    }
    return hadAggregation;
  }