Examples with UnitMap soot.util.UnitMap used on opensource projects

Example 1 with UnitMap

use of soot.util.UnitMap in project soot by Sable.

the class BusyCodeMotion method internalTransform.

/**
 * performs the busy code motion.
 */
protected void internalTransform(Body b, String phaseName, Map<String, String> opts) {
    BCMOptions options = new BCMOptions(opts);
    HashMap<EquivalentValue, Local> expToHelper = new HashMap<EquivalentValue, Local>();
    Chain<Unit> unitChain = b.getUnits();
    if (Options.v().verbose())
        logger.debug("[" + b.getMethod().getName() + "]     performing Busy Code Motion...");
    CriticalEdgeRemover.v().transform(b, phaseName + ".cer");
    UnitGraph graph = new BriefUnitGraph(b);
    /* map each unit to its RHS. only take binary expressions */
    Map<Unit, EquivalentValue> unitToEquivRhs = new UnitMap<EquivalentValue>(b, graph.size() + 1, 0.7f) {

        protected EquivalentValue mapTo(Unit unit) {
            Value tmp = SootFilter.noInvokeRhs(unit);
            Value tmp2 = SootFilter.binop(tmp);
            if (tmp2 == null)
                tmp2 = SootFilter.concreteRef(tmp);
            return SootFilter.equiVal(tmp2);
        }
    };
    /* same as before, but without exception-throwing expressions */
    Map<Unit, EquivalentValue> unitToNoExceptionEquivRhs = new UnitMap<EquivalentValue>(b, graph.size() + 1, 0.7f) {

        protected EquivalentValue mapTo(Unit unit) {
            Value tmp = SootFilter.binopRhs(unit);
            tmp = SootFilter.noExceptionThrowing(tmp);
            return SootFilter.equiVal(tmp);
        }
    };
    /* if a more precise sideeffect-tester comes out, please change it here! */
    SideEffectTester sideEffect;
    if (Scene.v().hasCallGraph() && !options.naive_side_effect()) {
        sideEffect = new PASideEffectTester();
    } else {
        sideEffect = new NaiveSideEffectTester();
    }
    sideEffect.newMethod(b.getMethod());
    UpSafetyAnalysis upSafe = new UpSafetyAnalysis(graph, unitToEquivRhs, sideEffect);
    DownSafetyAnalysis downSafe = new DownSafetyAnalysis(graph, unitToNoExceptionEquivRhs, sideEffect);
    EarliestnessComputation earliest = new EarliestnessComputation(graph, upSafe, downSafe, sideEffect);
    LocalCreation localCreation = new LocalCreation(b.getLocals(), PREFIX);
    Iterator<Unit> unitIt = unitChain.snapshotIterator();
    {
        /* insert the computations at the earliest positions */
        while (unitIt.hasNext()) {
            Unit currentUnit = unitIt.next();
            for (EquivalentValue equiVal : earliest.getFlowBefore(currentUnit)) {
                // Value exp = equiVal.getValue();
                /* get the unic helper-name for this expression */
                Local helper = expToHelper.get(equiVal);
                // the beginning of the method
                if (currentUnit instanceof IdentityStmt)
                    currentUnit = getFirstNonIdentityStmt(b);
                if (helper == null) {
                    helper = localCreation.newLocal(equiVal.getType());
                    expToHelper.put(equiVal, helper);
                }
                /* insert a new Assignment-stmt before the currentUnit */
                Value insertValue = Jimple.cloneIfNecessary(equiVal.getValue());
                Unit firstComp = Jimple.v().newAssignStmt(helper, insertValue);
                unitChain.insertBefore(firstComp, currentUnit);
            }
        }
    }
    {
        /* replace old computations by the helper-vars */
        unitIt = unitChain.iterator();
        while (unitIt.hasNext()) {
            Unit currentUnit = unitIt.next();
            EquivalentValue rhs = unitToEquivRhs.get(currentUnit);
            if (rhs != null) {
                Local helper = expToHelper.get(rhs);
                if (helper != null)
                    ((AssignStmt) currentUnit).setRightOp(helper);
            }
        }
    }
    if (Options.v().verbose())
        logger.debug("[" + b.getMethod().getName() + "]     Busy Code Motion done!");
}