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>, java.lang.Iterable<T>

public class BackwardsSupergraph<T,P>
extends java.lang.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

Modifier and Type	Method and Description
void	addEdge(java.lang.Object src, java.lang.Object dst)
void	addNode(java.lang.Object n)
byte	classifyEdge(T src, T dest)
boolean	containsNode(T N)
java.util.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.
java.util.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)
java.util.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(java.lang.Object node)
java.util.Iterator<T>	getPredNodes(T N)
com.ibm.wala.util.graph.Graph<P>	getProcedureGraph() TODO: for now, this is not inverted.
P	getProcOf(T n)
java.util.Iterator<? extends T>	getReturnSites(T c, P callee)
int	getSuccNodeCount(T N)
com.ibm.wala.util.intset.IntSet	getSuccNodeNumbers(T node)
java.util.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)
java.util.Iterator<T>	iterateNodes(com.ibm.wala.util.intset.IntSet s)
java.util.Iterator<T>	iterator()
static <T,P> BackwardsSupergraph<T,P>	make(ISupergraph<T,P> forwardGraph)
void	removeAllIncidentEdges(java.lang.Object node)
void	removeEdge(java.lang.Object src, java.lang.Object dst)
void	removeIncomingEdges(java.lang.Object node)
void	removeNode(java.lang.Object n)
void	removeNodeAndEdges(java.lang.Object N)
void	removeOutgoingEdges(T node)
java.util.stream.Stream<T>	stream()
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.lang.Iterable

forEach, spliterator

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<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.

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 java.util.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.

getNormalSuccessors

public java.util.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 java.util.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(java.lang.Object N)
                        throws java.lang.UnsupportedOperationException

Specified by:

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

Throws:

java.lang.UnsupportedOperationException

iterator

public java.util.Iterator<T> iterator()

Specified by:

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

Specified by:

iterator in interface java.lang.Iterable<T>

stream

public java.util.stream.Stream<T> stream()

Specified by:

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

getNumberOfNodes

public int getNumberOfNodes()

Specified by:

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

addNode

public void addNode(java.lang.Object n)
             throws java.lang.UnsupportedOperationException

Specified by:

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

Throws:

java.lang.UnsupportedOperationException

removeNode

public void removeNode(java.lang.Object n)
                throws java.lang.UnsupportedOperationException

Specified by:

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

Throws:

java.lang.UnsupportedOperationException

containsNode

public boolean containsNode(T N)

Specified by:

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

getPredNodes

public java.util.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 java.util.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(java.lang.Object src,
                    java.lang.Object dst)
             throws java.lang.UnsupportedOperationException

Specified by:

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

Throws:

java.lang.UnsupportedOperationException

removeEdge

public void removeEdge(java.lang.Object src,
                       java.lang.Object dst)
                throws java.lang.UnsupportedOperationException

Specified by:

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

Throws:

java.lang.UnsupportedOperationException

removeAllIncidentEdges

public void removeAllIncidentEdges(java.lang.Object node)
                            throws java.lang.UnsupportedOperationException

Specified by:

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

Throws:

java.lang.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 java.util.Iterator<? extends T> getCallSites(T r,
                                                    P callee)

Specified by:

getCallSites in interface ISupergraph<T,P>

Parameters:

r - a "return" 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 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 java.lang.String toString()

Overrides:

toString in class java.lang.Object

removeIncomingEdges

public void removeIncomingEdges(java.lang.Object node)
                         throws java.lang.UnsupportedOperationException

Specified by:

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

Throws:

java.lang.UnsupportedOperationException

removeOutgoingEdges

public void removeOutgoingEdges(T node)
                         throws java.lang.UnsupportedOperationException

Specified by:

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

Throws:

java.lang.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 java.util.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(java.lang.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