Examples with LocalVarNode soot.jimple.spark.pag.LocalVarNode used on opensource projects

Example 1 with LocalVarNode

use of soot.jimple.spark.pag.LocalVarNode in project soot by Sable.

the class GeomPointsTo method finalizeInternalData.

/**
 * 1. Update the call graph;
 * 2. Eliminate the pointers, objects, and constraints related to the unreachable code.
 */
private void finalizeInternalData() {
    // Compute the set of reachable functions after the points-to analysis
    markReachableMethods();
    // Clean the unreachable objects
    for (Iterator<IVarAbstraction> it = allocations.iterator(); it.hasNext(); ) {
        IVarAbstraction po = it.next();
        AllocNode obj = (AllocNode) po.getWrappedNode();
        SootMethod sm = obj.getMethod();
        if (sm != null && func2int.containsKey(sm) == false)
            it.remove();
    }
    // Clean the unreachable pointers
    final Vector<AllocNode> removeSet = new Vector<AllocNode>();
    for (Iterator<IVarAbstraction> it = pointers.iterator(); it.hasNext(); ) {
        IVarAbstraction pn = it.next();
        // Is this pointer obsoleted?
        Node vn = pn.getWrappedNode();
        SootMethod sm = null;
        if (vn instanceof LocalVarNode) {
            sm = ((LocalVarNode) vn).getMethod();
        } else if (vn instanceof AllocDotField) {
            sm = ((AllocDotField) vn).getBase().getMethod();
        }
        if (sm != null) {
            if (func2int.containsKey(sm) == false) {
                pn.deleteAll();
                vn.discardP2Set();
                it.remove();
                continue;
            }
        }
        if (pn.getRepresentative() != pn)
            continue;
        removeSet.clear();
        if (pn.hasPTResult()) {
            // We remove the useless shapes or objects
            Set<AllocNode> objSet = pn.get_all_points_to_objects();
            for (Iterator<AllocNode> oit = objSet.iterator(); oit.hasNext(); ) {
                AllocNode obj = oit.next();
                IVarAbstraction po = consG.get(obj);
                if (!po.reachable() || pn.isDeadObject(obj)) {
                    removeSet.add(obj);
                }
            }
            for (AllocNode obj : removeSet) pn.remove_points_to(obj);
            pn.drop_duplicates();
        } else {
            // We also remove unreachable objects for SPARK nodes
            PointsToSetInternal pts = vn.getP2Set();
            pts.forall(new P2SetVisitor() {

                @Override
                public void visit(Node n) {
                    IVarAbstraction pan = findInternalNode(n);
                    // The removeSet is misused as a contains set
                    if (pan.reachable())
                        removeSet.add((AllocNode) n);
                }
            });
            pts = vn.makeP2Set();
            for (AllocNode an : removeSet) pts.add(an);
        }
    }
    // Clean the useless constraints
    for (Iterator<PlainConstraint> cIt = constraints.iterator(); cIt.hasNext(); ) {
        PlainConstraint cons = cIt.next();
        IVarAbstraction lhs = cons.getLHS();
        IVarAbstraction rhs = cons.getRHS();
        if (!lhs.reachable() || !rhs.reachable() || getMethodIDFromPtr(lhs) == Constants.UNKNOWN_FUNCTION || getMethodIDFromPtr(rhs) == Constants.UNKNOWN_FUNCTION) {
            cIt.remove();
        }
    }
    // We reassign the IDs to the pointers, objects and constraints
    pointers.reassign();
    allocations.reassign();
    constraints.reassign();
}

Example 2 with LocalVarNode

use of soot.jimple.spark.pag.LocalVarNode in project soot by Sable.

the class GeomPointsTo method reachingObjects.

@Override
public PointsToSet reachingObjects(Local l) {
    if (!hasExecuted)
        return super.reachingObjects(l);
    LocalVarNode vn = findLocalVarNode(l);
    if (vn == null)
        return EmptyPointsToSet.v();
    IVarAbstraction pn = consG.get(vn);
    // This is perhaps a bug
    if (pn == null)
        return vn.getP2Set();
    // Return the cached result
    if (hasTransformed || vn.getP2Set() != EmptyPointsToSet.v())
        return vn.getP2Set();
    // Compute and cache the result
    pn = pn.getRepresentative();
    PointsToSetInternal ptSet = vn.makeP2Set();
    for (AllocNode obj : pn.get_all_points_to_objects()) {
        ptSet.add(obj);
    }
    return ptSet;
}

Example 3 with LocalVarNode

use of soot.jimple.spark.pag.LocalVarNode in project soot by Sable.

the class GeomPointsTo method reachingObjects.

/*
	 * Currently, we only accept one call unit context (1CFA).
	 * For querying K-CFA (K >1), please see GeomQueries.contextsByCallChain
	 */
@Override
public PointsToSet reachingObjects(Context c, Local l) {
    if (!hasExecuted)
        return super.reachingObjects(c, l);
    if (hasTransformed || !(c instanceof Unit))
        return reachingObjects(l);
    LocalVarNode vn = findLocalVarNode(l);
    if (vn == null)
        return EmptyPointsToSet.v();
    // Lookup the context sensitive points-to information for this pointer
    IVarAbstraction pn = consG.get(vn);
    if (pn == null)
        return vn.getP2Set();
    pn = pn.getRepresentative();
    // Obtain the context sensitive points-to result
    SootMethod callee = vn.getMethod();
    Edge e = Scene.v().getCallGraph().findEdge((Unit) c, callee);
    if (e == null)
        return vn.getP2Set();
    // Compute the contexts interval
    CgEdge myEdge = getInternalEdgeFromSootEdge(e);
    if (myEdge == null)
        return vn.getP2Set();
    long low = myEdge.map_offset;
    long high = low + max_context_size_block[myEdge.s];
    // Lookup the cache
    ContextVarNode cvn = vn.context(c);
    if (cvn != null) {
        PointsToSetInternal ans = cvn.getP2Set();
        if (ans != EmptyPointsToSet.v())
            return ans;
    } else {
        // Create a new context sensitive variable
        // The points-to vector is set to empty at start
        cvn = makeContextVarNode(vn, c);
    }
    // Fill
    PointsToSetInternal ptset = cvn.makeP2Set();
    for (AllocNode an : pn.get_all_points_to_objects()) {
        if (pn.pointer_interval_points_to(low, high, an))
            ptset.add(an);
    }
    return ptset;
}

Example 4 with LocalVarNode

use of soot.jimple.spark.pag.LocalVarNode in project soot by Sable.

the class GeomPointsTo method mergeLocalVariables.

/**
 * As pointed out by the single entry graph contraction, temporary variables incur high redundancy in points-to relations.
 * Find and eliminate the redundancies as early as possible.
 *
 * Methodology:
 * If q has unique incoming edge p -> q, p and q are both local to the same function, and they have the same type, we merge them.
 */
private void mergeLocalVariables() {
    IVarAbstraction my_lhs, my_rhs;
    Node lhs, rhs;
    int[] count = new int[pointers.size()];
    // We count how many ways a local pointer can be assigned
    for (PlainConstraint cons : constraints) {
        my_lhs = cons.getLHS();
        my_rhs = cons.getRHS();
        switch(cons.type) {
            case Constants.NEW_CONS:
            case Constants.ASSIGN_CONS:
                count[my_rhs.id]++;
                break;
            case Constants.LOAD_CONS:
                lhs = my_lhs.getWrappedNode();
                count[my_rhs.id] += lhs.getP2Set().size();
                break;
        }
    }
    // Second time scan, we delete those constraints that only duplicate points-to information
    for (Iterator<PlainConstraint> cons_it = constraints.iterator(); cons_it.hasNext(); ) {
        PlainConstraint cons = cons_it.next();
        if (cons.type == Constants.ASSIGN_CONS) {
            my_lhs = cons.getLHS();
            my_rhs = cons.getRHS();
            lhs = my_lhs.getWrappedNode();
            rhs = my_rhs.getWrappedNode();
            if ((lhs instanceof LocalVarNode) && (rhs instanceof LocalVarNode)) {
                SootMethod sm1 = ((LocalVarNode) lhs).getMethod();
                SootMethod sm2 = ((LocalVarNode) rhs).getMethod();
                if (sm1 == sm2 && count[my_rhs.id] == 1 && lhs.getType() == rhs.getType()) {
                    // They are local to the same function and the receiver pointer has unique incoming edge
                    // More importantly, they have the same type.
                    my_rhs.merge(my_lhs);
                    cons_it.remove();
                }
            }
        }
    }
    // Third scan, update the constraints with the representatives
    for (PlainConstraint cons : constraints) {
        my_lhs = cons.getLHS();
        my_rhs = cons.getRHS();
        switch(cons.type) {
            case Constants.NEW_CONS:
                cons.setRHS(my_rhs.getRepresentative());
                break;
            case Constants.ASSIGN_CONS:
            case Constants.LOAD_CONS:
            case Constants.STORE_CONS:
                cons.setLHS(my_lhs.getRepresentative());
                cons.setRHS(my_rhs.getRepresentative());
                break;
        }
    }
}

Example 5 with LocalVarNode

use of soot.jimple.spark.pag.LocalVarNode in project soot by Sable.

the class OfflineProcessor method setAllUserCodeVariablesUseful.

/**
 * All the pointers that we need their points-to information are marked.
 * @param virtualBaseSet
 */
protected void setAllUserCodeVariablesUseful() {
    for (int i = 0; i < n_var; ++i) {
        IVarAbstraction pn = int2var.get(i);
        if (pn != pn.getRepresentative())
            continue;
        Node node = pn.getWrappedNode();
        int sm_id = geomPTA.getMethodIDFromPtr(pn);
        if (!geomPTA.isReachableMethod(sm_id))
            continue;
        if (node instanceof VarNode) {
            // flag == true if node is defined in the Java library
            boolean defined_in_lib = false;
            if (node instanceof LocalVarNode) {
                defined_in_lib = ((LocalVarNode) node).getMethod().isJavaLibraryMethod();
            } else if (node instanceof GlobalVarNode) {
                SootClass sc = ((GlobalVarNode) node).getDeclaringClass();
                if (sc != null)
                    defined_in_lib = sc.isJavaLibraryClass();
            }
            if (!defined_in_lib && !geomPTA.isExceptionPointer(node)) {
                // Defined in the user code
                pn.willUpdate = true;
            }
        }
    }
}