Examples with PlainConstraint soot.jimple.spark.geom.dataRep.PlainConstraint used on opensource projects

Example 1 with PlainConstraint

use of soot.jimple.spark.geom.dataRep.PlainConstraint 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 PlainConstraint

use of soot.jimple.spark.geom.dataRep.PlainConstraint 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 3 with PlainConstraint

use of soot.jimple.spark.geom.dataRep.PlainConstraint in project soot by Sable.

the class GeomPointsTo method preprocess.

/**
 *	Read in the program facts generated by SPARK.
 *  We also construct our own call graph and pointer variables.
 */
private void preprocess() {
    int id;
    int s, t;
    // Build the call graph
    n_func = Scene.v().getReachableMethods().size() + 1;
    call_graph = new CgEdge[n_func];
    n_calls = 0;
    n_reach_spark_user_methods = 0;
    id = 1;
    QueueReader<MethodOrMethodContext> smList = Scene.v().getReachableMethods().listener();
    CallGraph soot_callgraph = Scene.v().getCallGraph();
    while (smList.hasNext()) {
        final SootMethod func = smList.next().method();
        func2int.put(func, id);
        int2func.put(id, func);
        /*
			 * We cannot identify all entry methods since some entry methods call themselves.
			 * In that case, the Soot CallGraph.isEntryMethod() function returns false.
			 */
        if (soot_callgraph.isEntryMethod(func) || func.isEntryMethod()) {
            CgEdge p = new CgEdge(Constants.SUPER_MAIN, id, null, call_graph[Constants.SUPER_MAIN]);
            call_graph[Constants.SUPER_MAIN] = p;
            n_calls++;
        }
        if (!func.isJavaLibraryMethod())
            ++n_reach_spark_user_methods;
        id++;
    }
    // Next, we scan all the call edges and rebuild the call graph in our own vocabulary
    QueueReader<Edge> edgeList = Scene.v().getCallGraph().listener();
    while (edgeList.hasNext()) {
        Edge edge = edgeList.next();
        if (edge.isClinit()) {
            continue;
        }
        SootMethod src_func = edge.src();
        SootMethod tgt_func = edge.tgt();
        s = func2int.get(src_func);
        t = func2int.get(tgt_func);
        // Create a new call edge in our own format
        CgEdge p = new CgEdge(s, t, edge, call_graph[s]);
        call_graph[s] = p;
        edgeMapping.put(edge, p);
        // We collect callsite information
        Stmt callsite = edge.srcStmt();
        if (edge.isThreadRunCall() || edge.kind().isExecutor() || edge.kind().isAsyncTask()) {
            // We don't modify the treatment to the thread run() calls
            thread_run_callsites.add(callsite);
        } else if (edge.isInstance() && !edge.isSpecial()) {
            // We try to refine the virtual callsites (virtual + interface) with multiple call targets
            InstanceInvokeExpr expr = (InstanceInvokeExpr) callsite.getInvokeExpr();
            if (expr.getMethodRef().getSignature().contains("<java.lang.Thread: void start()>")) {
                // It is a thread start function
                thread_run_callsites.add(callsite);
            } else {
                p.base_var = findLocalVarNode(expr.getBase());
                if (SootInfo.countCallEdgesForCallsite(callsite, true) > 1 && p.base_var != null) {
                    multiCallsites.add(callsite);
                }
            }
        }
        ++n_calls;
    }
    // We build the wrappers for all the pointers built by SPARK
    for (Iterator<VarNode> it = getVarNodeNumberer().iterator(); it.hasNext(); ) {
        VarNode vn = it.next();
        IVarAbstraction pn = makeInternalNode(vn);
        pointers.add(pn);
    }
    for (Iterator<AllocDotField> it = getAllocDotFieldNodeNumberer().iterator(); it.hasNext(); ) {
        AllocDotField adf = it.next();
        // Some allocdotfield is invalid, we check and remove them
        SparkField field = adf.getField();
        if (field instanceof SootField) {
            // This is an instance field of a class
            Type decType = ((SootField) field).getDeclaringClass().getType();
            Type baseType = adf.getBase().getType();
            // baseType must be a sub type of decType
            if (!castNeverFails(baseType, decType))
                continue;
        }
        IVarAbstraction pn = makeInternalNode(adf);
        pointers.add(pn);
    }
    for (Iterator<AllocNode> it = getAllocNodeNumberer().iterator(); it.hasNext(); ) {
        AllocNode obj = it.next();
        IVarAbstraction pn = makeInternalNode(obj);
        allocations.add(pn);
    }
    // The address constraints, new obj -> p
    for (Object object : allocSources()) {
        IVarAbstraction obj = makeInternalNode((AllocNode) object);
        Node[] succs = allocLookup((AllocNode) object);
        for (Node element0 : succs) {
            PlainConstraint cons = new PlainConstraint();
            IVarAbstraction p = makeInternalNode(element0);
            cons.expr.setPair(obj, p);
            cons.type = Constants.NEW_CONS;
            constraints.add(cons);
        }
    }
    // The assign constraints, p -> q
    Pair<Node, Node> intercall = new Pair<Node, Node>();
    for (Object object : simpleSources()) {
        IVarAbstraction p = makeInternalNode((VarNode) object);
        Node[] succs = simpleLookup((VarNode) object);
        for (Node element0 : succs) {
            PlainConstraint cons = new PlainConstraint();
            IVarAbstraction q = makeInternalNode(element0);
            cons.expr.setPair(p, q);
            cons.type = Constants.ASSIGN_CONS;
            intercall.setPair((VarNode) object, element0);
            cons.interCallEdges = lookupEdgesForAssignment(intercall);
            constraints.add(cons);
        }
    }
    intercall = null;
    assign2edges.clear();
    // The load constraints, p.f -> q
    for (Object object : loadSources()) {
        FieldRefNode frn = (FieldRefNode) object;
        IVarAbstraction p = makeInternalNode(frn.getBase());
        Node[] succs = loadLookup(frn);
        for (Node element0 : succs) {
            PlainConstraint cons = new PlainConstraint();
            IVarAbstraction q = makeInternalNode(element0);
            cons.f = frn.getField();
            cons.expr.setPair(p, q);
            cons.type = Constants.LOAD_CONS;
            constraints.add(cons);
        }
    }
    // The store constraints, p -> q.f
    for (Object object : storeSources()) {
        IVarAbstraction p = makeInternalNode((VarNode) object);
        Node[] succs = storeLookup((VarNode) object);
        for (Node element0 : succs) {
            PlainConstraint cons = new PlainConstraint();
            FieldRefNode frn = (FieldRefNode) element0;
            IVarAbstraction q = makeInternalNode(frn.getBase());
            cons.f = frn.getField();
            cons.expr.setPair(p, q);
            cons.type = Constants.STORE_CONS;
            constraints.add(cons);
        }
    }
    n_init_constraints = constraints.size();
    // Initialize other stuff
    low_cg = new int[n_func];
    vis_cg = new int[n_func];
    rep_cg = new int[n_func];
    indeg_cg = new int[n_func];
    scc_size = new int[n_func];
    block_num = new int[n_func];
    context_size = new long[n_func];
    max_context_size_block = new long[n_func];
}

Example 4 with PlainConstraint

use of soot.jimple.spark.geom.dataRep.PlainConstraint in project soot by Sable.

the class OfflineProcessor method buildDependenceGraph.

/**
 * The dependence graph reverses the assignment relations. E.g., p = q  =>  p -> q
 * Note that, the assignments that are eliminated by local variable merging should be used here.
 * Otherwise, the graph would be erroneously disconnected.
 */
protected void buildDependenceGraph() {
    for (PlainConstraint cons : geomPTA.constraints) {
        // In our constraint representation, lhs -> rhs means rhs = lhs.
        final IVarAbstraction lhs = cons.getLHS();
        final IVarAbstraction rhs = cons.getRHS();
        final SparkField field = cons.f;
        IVarAbstraction rep;
        // Now we use this constraint for graph construction
        switch(cons.type) {
            // rhs = lhs
            case Constants.ASSIGN_CONS:
                add_graph_edge(rhs.id, lhs.id);
                break;
            // rhs = lhs.f
            case Constants.LOAD_CONS:
                {
                    rep = lhs.getRepresentative();
                    if (rep.hasPTResult() == false) {
                        lhs.getWrappedNode().getP2Set().forall(new P2SetVisitor() {

                            @Override
                            public void visit(Node n) {
                                IVarAbstraction padf = geomPTA.findInstanceField((AllocNode) n, field);
                                if (padf == null || padf.reachable() == false)
                                    return;
                                off_graph_edge e = add_graph_edge(rhs.id, padf.id);
                                e.base_var = lhs;
                            }
                        });
                    } else {
                        // Use geom
                        for (AllocNode o : rep.get_all_points_to_objects()) {
                            IVarAbstraction padf = geomPTA.findInstanceField((AllocNode) o, field);
                            if (padf == null || padf.reachable() == false)
                                continue;
                            off_graph_edge e = add_graph_edge(rhs.id, padf.id);
                            e.base_var = lhs;
                        }
                    }
                }
                break;
            // rhs.f = lhs
            case Constants.STORE_CONS:
                {
                    rep = rhs.getRepresentative();
                    if (rep.hasPTResult() == false) {
                        rhs.getWrappedNode().getP2Set().forall(new P2SetVisitor() {

                            @Override
                            public void visit(Node n) {
                                IVarAbstraction padf = geomPTA.findInstanceField((AllocNode) n, field);
                                if (padf == null || padf.reachable() == false)
                                    return;
                                off_graph_edge e = add_graph_edge(padf.id, lhs.id);
                                e.base_var = rhs;
                            }
                        });
                    } else {
                        // use geom
                        for (AllocNode o : rep.get_all_points_to_objects()) {
                            IVarAbstraction padf = geomPTA.findInstanceField((AllocNode) o, field);
                            if (padf == null || padf.reachable() == false)
                                continue;
                            off_graph_edge e = add_graph_edge(padf.id, lhs.id);
                            e.base_var = rhs;
                        }
                    }
                }
                break;
        }
    }
}

Example 5 with PlainConstraint

use of soot.jimple.spark.geom.dataRep.PlainConstraint in project soot by Sable.

the class OfflineProcessor method distillConstraints.

/**
 * Eliminate the constraints that do not contribute points-to information to the seed pointers.
 * Prerequisite: dependence graph
 */
protected void distillConstraints() {
    IVarAbstraction pn;
    // Mark the pointers
    computeReachablePts();
    // Mark the constraints
    for (PlainConstraint cons : geomPTA.constraints) {
        // We only look at the receiver pointers
        pn = cons.getRHS();
        final SparkField field = cons.f;
        visitedFlag = false;
        switch(cons.type) {
            case Constants.NEW_CONS:
            case Constants.ASSIGN_CONS:
            case Constants.LOAD_CONS:
                visitedFlag = pn.willUpdate;
                break;
            case Constants.STORE_CONS:
                /**
                 * Interesting point in store constraint p.f = q:
                 * For example, pts(p) = { o1, o2 };
                 * If any of the o1.f and the o2.f (e.g. o1.f) will be updated, this constraint should be kept.
                 * However, in the points-to analysis, we only assign to o1.f.
                 */
                pn = pn.getRepresentative();
                if (pn.hasPTResult() == false) {
                    pn.getWrappedNode().getP2Set().forall(new P2SetVisitor() {

                        @Override
                        public void visit(Node n) {
                            if (visitedFlag)
                                return;
                            IVarAbstraction padf = geomPTA.findInstanceField((AllocNode) n, field);
                            if (padf == null || padf.reachable() == false)
                                return;
                            visitedFlag |= padf.willUpdate;
                        }
                    });
                } else {
                    // Use the geometric points-to result
                    for (AllocNode o : pn.get_all_points_to_objects()) {
                        IVarAbstraction padf = geomPTA.findInstanceField((AllocNode) o, field);
                        if (padf == null || padf.reachable() == false)
                            continue;
                        visitedFlag |= padf.willUpdate;
                        if (visitedFlag)
                            break;
                    }
                }
                break;
        }
        cons.isActive = visitedFlag;
    }
}