com.ibm.wala.ipa.cfg

Class PrunedCFG<I,T extends IBasicBlock<I>>

java.lang.Object

com.ibm.wala.util.graph.AbstractGraph<T>

com.ibm.wala.util.graph.AbstractNumberedGraph<T>

com.ibm.wala.ipa.cfg.PrunedCFG<I,T>

All Implemented Interfaces:

ControlFlowGraph<I,T>, MinimalCFG<T>, 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 PrunedCFG<I,T extends IBasicBlock<I>>
extends com.ibm.wala.util.graph.AbstractNumberedGraph<T>
implements ControlFlowGraph<I,T>

A pruned view of a ControlFlowGraph. Use this class along with an EdgeFilter to produce a custom view of a CFG.

For example, you can use this class to produce a CFG view that ignores certain types of exceptional edges.

Method Summary

Modifier and Type	Method and Description
T	entry() Return the entry basic block in the CFG
T	exit()
T	getBlockForInstruction(int index)
com.ibm.wala.util.intset.BitVector	getCatchBlocks()
protected com.ibm.wala.util.graph.NumberedEdgeManager<T>	getEdgeManager()
java.util.Collection<T>	getExceptionalPredecessors(T N) The order of blocks returned should be arbitrary but deterministic.
java.util.List<T>	getExceptionalSuccessors(T N) The order of blocks returned must indicate the exception-handling scope.
I[]	getInstructions()
IMethod	getMethod()
protected com.ibm.wala.util.graph.NumberedNodeManager<T>	getNodeManager()
java.util.Collection<T>	getNormalPredecessors(T N) The order of blocks returned should be arbitrary but deterministic.
java.util.Collection<T>	getNormalSuccessors(T N) The order of blocks returned should be arbitrary but deterministic.
com.ibm.wala.util.intset.IntSet	getPhiIndices(T bb)
int	getProgramCounter(int index) TODO: move this into IR?
static <I,T extends IBasicBlock<I>> PrunedCFG<I,T>	make(ControlFlowGraph<I,T> cfg, EdgeFilter<T> filter)

Methods inherited from class com.ibm.wala.util.graph.AbstractNumberedGraph

getMaxNumber, getNode, getNumber, getPredNodeNumbers, getSuccNodeNumbers, iterateNodes

Methods inherited from class com.ibm.wala.util.graph.AbstractGraph

addEdge, addNode, containsNode, edgeString, getNumberOfNodes, getPredNodeCount, getPredNodes, getSuccNodeCount, getSuccNodes, hasEdge, iterator, removeAllIncidentEdges, removeEdge, removeIncomingEdges, removeNode, removeNodeAndEdges, removeOutgoingEdges, stream, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.ibm.wala.util.graph.Graph

removeNodeAndEdges

Methods inherited from interface com.ibm.wala.util.graph.NumberedNodeManager

getMaxNumber, getNode, getNumber, iterateNodes

Methods inherited from interface com.ibm.wala.util.graph.NodeManager

addNode, containsNode, getNumberOfNodes, iterator, removeNode, stream

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Methods inherited from interface com.ibm.wala.util.graph.NumberedEdgeManager

getPredNodeNumbers, getSuccNodeNumbers

Methods inherited from interface com.ibm.wala.util.graph.EdgeManager

addEdge, getPredNodeCount, getPredNodes, getSuccNodeCount, getSuccNodes, hasEdge, removeAllIncidentEdges, removeEdge, removeIncomingEdges, removeOutgoingEdges

Method Detail

make

public static <I,T extends IBasicBlock<I>> PrunedCFG<I,T> make(ControlFlowGraph<I,T> cfg,
                                                               EdgeFilter<T> filter)

Parameters:

cfg - the original CFG that you want a view of

filter - an object that selectively filters edges in the original CFG

Returns:

a view of cfg that includes only edges accepted by the filter.

Throws:

java.lang.IllegalArgumentException - if cfg is null

getNodeManager

protected com.ibm.wala.util.graph.NumberedNodeManager<T> getNodeManager()

Overrides:

getNodeManager in class com.ibm.wala.util.graph.AbstractNumberedGraph<T extends IBasicBlock<I>>

getEdgeManager

protected com.ibm.wala.util.graph.NumberedEdgeManager<T> getEdgeManager()

Overrides:

getEdgeManager in class com.ibm.wala.util.graph.AbstractNumberedGraph<T extends IBasicBlock<I>>

getExceptionalSuccessors

public java.util.List<T> getExceptionalSuccessors(T N)

Description copied from interface: MinimalCFG

The order of blocks returned must indicate the exception-handling scope. So the first block is the first candidate catch block, and so on. With this invariant one can compute the exceptional control flow for a given exception type.

Specified by:

getExceptionalSuccessors in interface MinimalCFG<T extends IBasicBlock<I>>

Returns:

the basic blocks which may be reached from b via exceptional control flow

getNormalSuccessors

public java.util.Collection<T> getNormalSuccessors(T N)

Description copied from interface: MinimalCFG

The order of blocks returned should be arbitrary but deterministic.

Specified by:

getNormalSuccessors in interface MinimalCFG<T extends IBasicBlock<I>>

Returns:

the basic blocks which may be reached from b via normal control flow

getExceptionalPredecessors

public java.util.Collection<T> getExceptionalPredecessors(T N)

Description copied from interface: MinimalCFG

The order of blocks returned should be arbitrary but deterministic.

Specified by:

getExceptionalPredecessors in interface MinimalCFG<T extends IBasicBlock<I>>

Returns:

the basic blocks from which b may be reached via exceptional control flow

getNormalPredecessors

public java.util.Collection<T> getNormalPredecessors(T N)

Description copied from interface: MinimalCFG

The order of blocks returned should be arbitrary but deterministic.

Specified by:

getNormalPredecessors in interface MinimalCFG<T extends IBasicBlock<I>>

Returns:

the basic blocks from which b may be reached via normal control flow

entry

public T entry()

Description copied from interface: MinimalCFG

Return the entry basic block in the CFG

Specified by:

entry in interface MinimalCFG<T extends IBasicBlock<I>>

exit

public T exit()

Specified by:

exit in interface MinimalCFG<T extends IBasicBlock<I>>

Returns:

the synthetic exit block for the cfg

getBlockForInstruction

public T getBlockForInstruction(int index)

Specified by:

getBlockForInstruction in interface ControlFlowGraph<I,T extends IBasicBlock<I>>

Parameters:

index - an instruction index

Returns:

the basic block which contains this instruction.

getInstructions

public I[] getInstructions()

Specified by:

getInstructions in interface ControlFlowGraph<I,T extends IBasicBlock<I>>

Returns:

the instructions of this CFG, as an array.

getProgramCounter

public int getProgramCounter(int index)

Description copied from interface: ControlFlowGraph

TODO: move this into IR?

Specified by:

getProgramCounter in interface ControlFlowGraph<I,T extends IBasicBlock<I>>

Parameters:

index - an instruction index

Returns:

the program counter (bytecode index) corresponding to that instruction

getMethod

public IMethod getMethod()

Specified by:

getMethod in interface ControlFlowGraph<I,T extends IBasicBlock<I>>

Returns:

the Method this CFG represents

getCatchBlocks

public com.ibm.wala.util.intset.BitVector getCatchBlocks()

Specified by:

getCatchBlocks in interface ControlFlowGraph<I,T extends IBasicBlock<I>>

Returns:

the indices of the catch blocks, as a bit vector

getPhiIndices

public com.ibm.wala.util.intset.IntSet getPhiIndices(T bb)