com.ibm.wala.dataflow.IFDS

Class BackwardsSupergraph<T,P>

java.lang.Object

com.ibm.wala.dataflow.IFDS.BackwardsSupergraph<T,P>

All Implemented Interfaces:

ISupergraph<T,P>, com.ibm.wala.util.graph.EdgeManager<T>, com.ibm.wala.util.graph.Graph<T>, com.ibm.wala.util.graph.NodeManager<T>, com.ibm.wala.util.graph.NumberedEdgeManager<T>, com.ibm.wala.util.graph.NumberedGraph<T>, com.ibm.wala.util.graph.NumberedNodeManager<T>, Iterable<T>

public class BackwardsSupergraph<T,P>
extends Object
implements ISupergraph<T,P>

A "reversed" supergraph for backwards analysis. In this view, a return is treated like a call, and vice-versa. All normal edges are reversed.

Field Summary

Fields inherited from interface com.ibm.wala.dataflow.IFDS.ISupergraph

CALL_EDGE, CALL_TO_RETURN_EDGE, OTHER, RETURN_EDGE

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	BackwardsSupergraph(ISupergraph<T,P> forwardGraph)

Method Summary

Methods

Modifier and Type	Method and Description
void	addEdge(Object src, Object dst)
void	addNode(Object n)
byte	classifyEdge(T src, T dest)
boolean	containsNode(T N)
Iterator<T>	getCalledNodes(T ret) get the "called" (sic) nodes for a return site; i.e., the exit nodes that flow directly to this return site.
Iterator<? extends T>	getCallSites(T r, P callee)
T[]	getEntriesForProcedure(P object)
T[]	getExitsForProcedure(P object)
T	getLocalBlock(P procedure, int i)
int	getLocalBlockNumber(T n)
int	getMaxNumber()
T	getNode(int number)
Iterator<T>	getNormalSuccessors(T ret) get the "normal" successors (sic) for a return site; i.e., the "normal" CFG predecessors that are not call nodes.
int	getNumber(T N)
int	getNumberOfBlocks(P procedure)
int	getNumberOfNodes()
int	getPredNodeCount(T N)
com.ibm.wala.util.intset.IntSet	getPredNodeNumbers(Object node)
Iterator<T>	getPredNodes(T N)
com.ibm.wala.util.graph.Graph<? extends P>	getProcedureGraph() TODO: for now, this is not inverted.
P	getProcOf(T n)
Iterator<? extends T>	getReturnSites(T c, P callee)
int	getSuccNodeCount(T N)
com.ibm.wala.util.intset.IntSet	getSuccNodeNumbers(T node)
Iterator<T>	getSuccNodes(T N)
boolean	hasEdge(T src, T dst)
boolean	isCall(T n)
boolean	isEntry(T n)
boolean	isExit(T n)
boolean	isReturn(T n)
Iterator<T>	iterateNodes(com.ibm.wala.util.intset.IntSet s)
Iterator<T>	iterator()
static <T,P> BackwardsSupergraph<T,P>	make(ISupergraph<T,P> forwardGraph)
void	removeAllIncidentEdges(Object node)
void	removeEdge(Object src, Object dst)
void	removeIncomingEdges(Object node)
void	removeNode(Object n)
void	removeNodeAndEdges(Object N)
void	removeOutgoingEdges(T node)
String	toString()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

BackwardsSupergraph

protected BackwardsSupergraph(ISupergraph<T,P> forwardGraph)

Parameters:

forwardGraph - the graph to ``reverse''

Method Detail

make

public static <T,P> BackwardsSupergraph<T,P> make(ISupergraph<T,P> forwardGraph)

getProcedureGraph

public com.ibm.wala.util.graph.Graph<? extends P> getProcedureGraph()

TODO: for now, this is not inverted.

Specified by:

getProcedureGraph in interface ISupergraph<T,P>

Returns:

the graph of procedures (e.g. a call graph) over which this supergraph is induced.

See Also:

ISupergraph.getProcedureGraph()

isCall

public boolean isCall(T n)

Specified by:

isCall in interface ISupergraph<T,P>

Parameters:

n - a node in this supergraph

Returns:

true iff this node includes a call.

getCalledNodes

public Iterator<T> getCalledNodes(T ret)

get the "called" (sic) nodes for a return site; i.e., the exit nodes that flow directly to this return site.

Specified by:

getCalledNodes in interface ISupergraph<T,P>

Parameters:

ret - a "call" node in the supergraph

Returns:

an Iterator of nodes that are targets of this call.

See Also:

ISupergraph.getCalledNodes(java.lang.Object)

getNormalSuccessors

public Iterator<T> getNormalSuccessors(T ret)

get the "normal" successors (sic) for a return site; i.e., the "normal" CFG predecessors that are not call nodes.

Specified by:

getNormalSuccessors in interface ISupergraph<T,P>

Parameters:

ret - a "call" node in the supergraph

Returns:

an Iterator of nodes that are normal (non-call) successors of this call. This should only apply to backwards problems, where we might have, say, a call and a goto flow into a return site.

See Also:

ISupergraph.getCalledNodes(java.lang.Object)

getReturnSites

public Iterator<? extends T> getReturnSites(T c,
                                   P callee)

Specified by:

getReturnSites in interface ISupergraph<T,P>

Parameters:

c - a "call" node in the supergraph

callee - a "called" "procedure" in the supergraph. if callee is null, answer return sites for which no callee was found.

Returns:

the corresponding return nodes. There may be many, because of exceptional control flow.

isExit

public boolean isExit(T n)

Specified by:

isExit in interface ISupergraph<T,P>

Parameters:

n - a node in the supergraph

Returns:

true iff this node is an exit node

getProcOf

public P getProcOf(T n)

Specified by:

getProcOf in interface ISupergraph<T,P>

Parameters:

n - a node in the supergraph

Returns:

an object which represents the procedure which contains n

removeNodeAndEdges

public void removeNodeAndEdges(Object N)
                        throws UnsupportedOperationException

Specified by:

removeNodeAndEdges in interface com.ibm.wala.util.graph.Graph<T>

Throws:

UnsupportedOperationException

iterator

public Iterator<T> iterator()

Specified by:

iterator in interface com.ibm.wala.util.graph.NodeManager<T>

Specified by:

iterator in interface Iterable<T>

getNumberOfNodes

public int getNumberOfNodes()

Specified by:

getNumberOfNodes in interface com.ibm.wala.util.graph.NodeManager<T>

addNode

public void addNode(Object n)
             throws UnsupportedOperationException

Specified by:

addNode in interface com.ibm.wala.util.graph.NodeManager<T>

Throws:

UnsupportedOperationException

removeNode

public void removeNode(Object n)
                throws UnsupportedOperationException

Specified by:

removeNode in interface com.ibm.wala.util.graph.NodeManager<T>

Throws:

UnsupportedOperationException

containsNode

public boolean containsNode(T N)

Specified by:

containsNode in interface com.ibm.wala.util.graph.NodeManager<T>

getPredNodes

public Iterator<T> getPredNodes(T N)

Specified by:

getPredNodes in interface com.ibm.wala.util.graph.EdgeManager<T>

getPredNodeCount

public int getPredNodeCount(T N)

Specified by:

getPredNodeCount in interface com.ibm.wala.util.graph.EdgeManager<T>

getSuccNodes

public Iterator<T> getSuccNodes(T N)

Specified by:

getSuccNodes in interface com.ibm.wala.util.graph.EdgeManager<T>

hasEdge

public boolean hasEdge(T src,
              T dst)

Specified by:

hasEdge in interface com.ibm.wala.util.graph.EdgeManager<T>

getSuccNodeCount

public int getSuccNodeCount(T N)

Specified by:

getSuccNodeCount in interface com.ibm.wala.util.graph.EdgeManager<T>

addEdge

public void addEdge(Object src,
           Object dst)
             throws UnsupportedOperationException

Specified by:

addEdge in interface com.ibm.wala.util.graph.EdgeManager<T>

Throws:

UnsupportedOperationException

removeEdge

public void removeEdge(Object src,
              Object dst)
                throws UnsupportedOperationException

Specified by:

removeEdge in interface com.ibm.wala.util.graph.EdgeManager<T>

Throws:

UnsupportedOperationException

removeAllIncidentEdges

public void removeAllIncidentEdges(Object node)
                            throws UnsupportedOperationException

Specified by:

removeAllIncidentEdges in interface com.ibm.wala.util.graph.EdgeManager<T>

Throws:

UnsupportedOperationException

getEntriesForProcedure

public T[] getEntriesForProcedure(P object)

Specified by:

getEntriesForProcedure in interface ISupergraph<T,P>

Returns:

the blocks in the supergraph that represents entry nodes for procedure p

getExitsForProcedure

public T[] getExitsForProcedure(P object)

Specified by:

getExitsForProcedure in interface ISupergraph<T,P>

Returns:

the blocks in the supergraph that represents exit nodes for procedure p

isReturn

public boolean isReturn(T n)
                 throws com.ibm.wala.util.debug.UnimplementedError

Specified by:

isReturn in interface ISupergraph<T,P>

Parameters:

n - a node in this supergraph

Returns:

true iff this node is a return site.

Throws:

com.ibm.wala.util.debug.UnimplementedError

getCallSites

public Iterator<? extends T> getCallSites(T r,
                                 P callee)

Specified by:

getCallSites in interface ISupergraph<T,P>

callee - a "called" "procedure" in the supergraph. if callee is null, answer return sites for which no callee was found.

Returns:

the corresponding call nodes. There may be many.

isEntry

public boolean isEntry(T n)

Specified by:

isEntry in interface ISupergraph<T,P>

Returns:

true iff this node is an entry node s_p for a procedure

classifyEdge

public byte classifyEdge(T src,
                T dest)

Specified by:

classifyEdge in interface ISupergraph<T,P>

Parameters:

src - node in the supergraph

dest - a successor of src in the supergraph

Returns:

one of CALL_EDGE, RETURN_EDGE, CALL_TO_RETURN_EDGE, or OTHER

toString

public String toString()

Overrides:

toString in class Object

removeIncomingEdges

public void removeIncomingEdges(Object node)
                         throws UnsupportedOperationException

Specified by:

removeIncomingEdges in interface com.ibm.wala.util.graph.EdgeManager<T>

Throws:

UnsupportedOperationException

removeOutgoingEdges

public void removeOutgoingEdges(T node)
                         throws UnsupportedOperationException

Specified by:

removeOutgoingEdges in interface com.ibm.wala.util.graph.EdgeManager<T>

Throws:

UnsupportedOperationException

getNumberOfBlocks

public int getNumberOfBlocks(P procedure)

Specified by:

getNumberOfBlocks in interface ISupergraph<T,P>

Parameters:

procedure - an object that represents a procedure

Returns:

the number of blocks from this procedure in this supergraph

getLocalBlockNumber

public int getLocalBlockNumber(T n)

Specified by:

getLocalBlockNumber in interface ISupergraph<T,P>

Parameters:

n - a node in the supergraph

Returns:

the "logical" basic block number of n in its procedure

getLocalBlock

public T getLocalBlock(P procedure,
              int i)

Specified by:

getLocalBlock in interface ISupergraph<T,P>

Parameters:

procedure - an object that represents a procedure

i - the "logical" basic block number of a node in the procedure

Returns:

the corresponding node in the supergraph

getNumber

public int getNumber(T N)

Specified by:

getNumber in interface com.ibm.wala.util.graph.NumberedNodeManager<T>

getNode

public T getNode(int number)

Specified by:

getNode in interface com.ibm.wala.util.graph.NumberedNodeManager<T>

getMaxNumber

public int getMaxNumber()

Specified by:

getMaxNumber in interface com.ibm.wala.util.graph.NumberedNodeManager<T>

iterateNodes

public Iterator<T> iterateNodes(com.ibm.wala.util.intset.IntSet s)
                         throws com.ibm.wala.util.debug.UnimplementedError

Specified by:

iterateNodes in interface com.ibm.wala.util.graph.NumberedNodeManager<T>

Throws:

com.ibm.wala.util.debug.UnimplementedError

getSuccNodeNumbers

public com.ibm.wala.util.intset.IntSet getSuccNodeNumbers(T node)

Specified by:

getSuccNodeNumbers in interface com.ibm.wala.util.graph.NumberedEdgeManager<T>

getPredNodeNumbers

public com.ibm.wala.util.intset.IntSet getPredNodeNumbers(Object node)
                                                   throws com.ibm.wala.util.debug.UnimplementedError

Specified by:

getPredNodeNumbers in interface com.ibm.wala.util.graph.NumberedEdgeManager<T>

Throws:

com.ibm.wala.util.debug.UnimplementedError