Class SSACFG.BasicBlock

java.lang.Object

com.ibm.wala.ssa.SSACFG.BasicBlock

All Implemented Interfaces:

IBasicBlock<SSAInstruction>, ISSABasicBlock, INodeWithNumber, Iterable<SSAInstruction>

Direct Known Subclasses:

SSACFG.ExceptionHandlerBasicBlock

Enclosing class:

SSACFG

public class SSACFG.BasicBlock
extends Object
implements ISSABasicBlock

A Basic Block in an SSA IR

Constructor Summary

Constructors

Constructor	Description
BasicBlock(int number)

Method Summary

Modifier and Type	Method	Description
void	addPhiForLocal(int n, SSAPhiInstruction phi)
void	addPhiForStackSlot(int slot, SSAPhiInstruction phi)
void	addPiForRefAndPath(int n, Object path, SSAPiInstruction pi)
boolean	equals(Object arg0)
List<SSAInstruction>	getAllInstructions()	TODO: make this more efficient if needed
Iterator<TypeReference>	getCaughtExceptionTypes()	The SSACFG.ExceptionHandlerBasicBlock subclass will override this.
int	getFirstInstructionIndex()	Method getFirstInstructionIndex.
int	getGraphNodeId()	A non-negative integer which serves as an identifier for this node in it's "dominant" graph.
SSAInstruction	getLastInstruction()
int	getLastInstructionIndex()	Get the index of the last instruction in the basic block.
IMethod	getMethod()
int	getNumber()	Each basic block should have a unique number in its cfg
SSAPhiInstruction	getPhiForLocal(int n)	This method is used during SSA construction.
SSAPhiInstruction	getPhiForStackSlot(int slot)	This method is used during SSA construction.
SSAPiInstruction	getPiForRefAndPath(int n, Object path)
int	hashCode()
boolean	hasPhi()
boolean	isCatchBlock()	Is this block marked as a catch block?
boolean	isEntryBlock()	Does this block represent the unique entry to a ControlFlowGraph
boolean	isExitBlock()	Does this block represent the unique exit from a ControlFlowGraph?
Iterator<SSAInstruction>	iterateNormalInstructions()
Iterator<SSAPhiInstruction>	iteratePhis()
Iterator<SSAPiInstruction>	iteratePis()
Iterator<SSAInstruction>	iterator()
void	removePhis(Set<SSAPhiInstruction> toRemove)	Remove any phis in the set.
void	setGraphNodeId(int number)
String	toString()

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Constructor Details

BasicBlock

public BasicBlock(int number)

Method Details

getNumber

public int getNumber()

Description copied from interface: IBasicBlock

Each basic block should have a unique number in its cfg

Specified by:

getNumber in interface IBasicBlock<SSAInstruction>

Returns:

the basic block's number

getFirstInstructionIndex

public int getFirstInstructionIndex()

Method getFirstInstructionIndex.

Specified by:

getFirstInstructionIndex in interface IBasicBlock<SSAInstruction>

Returns:

the instruction index for the first instruction in the basic block.

isCatchBlock

public boolean isCatchBlock()

Is this block marked as a catch block?

Specified by:

isCatchBlock in interface IBasicBlock<SSAInstruction>

Specified by:

isCatchBlock in interface ISSABasicBlock

Returns:

true if the basic block represents a catch block.

getLastInstructionIndex

public int getLastInstructionIndex()

Description copied from interface: IBasicBlock

Get the index of the last instruction in the basic block. The value is an index into the instruction array that contains all the instructions for the method.

If the result is < 0, the block has no instructions

Specified by:

getLastInstructionIndex in interface IBasicBlock<SSAInstruction>

Returns:

the instruction index for the last instruction in the basic block

iteratePhis

public Iterator<SSAPhiInstruction> iteratePhis()

Specified by:

iteratePhis in interface ISSABasicBlock

Returns:

the phi instructions incoming to this block

getPhiForStackSlot

public SSAPhiInstruction getPhiForStackSlot(int slot)

This method is used during SSA construction.

getPhiForLocal

public SSAPhiInstruction getPhiForLocal(int n)

This method is used during SSA construction.

addPhiForStackSlot

public void addPhiForStackSlot(int slot,
 SSAPhiInstruction phi)

addPhiForLocal

public void addPhiForLocal(int n,
 SSAPhiInstruction phi)

removePhis

public void removePhis(Set<SSAPhiInstruction> toRemove)

Remove any phis in the set.

getPiForRefAndPath

public SSAPiInstruction getPiForRefAndPath(int n,
 Object path)

addPiForRefAndPath

public void addPiForRefAndPath(int n,
 Object path,
 SSAPiInstruction pi)

Parameters:

n - can be the val in the pi instruction

path - can be the successor block in the pi instruction

iteratePis

public Iterator<SSAPiInstruction> iteratePis()

Specified by:

iteratePis in interface ISSABasicBlock

Returns:

the pi instructions incoming to this block

iterateNormalInstructions

public Iterator<SSAInstruction> iterateNormalInstructions()

getAllInstructions

public List<SSAInstruction> getAllInstructions()

TODO: make this more efficient if needed

iterator

public Iterator<SSAInstruction> iterator()

Specified by:

iterator in interface Iterable<SSAInstruction>

hasPhi

public boolean hasPhi()

Returns:

true iff this basic block has at least one phi

getGraphNodeId

public int getGraphNodeId()

Description copied from interface: INodeWithNumber

A non-negative integer which serves as an identifier for this node in it's "dominant" graph. Initially this number is -1; a NumberedGraph will set it to a non-negative value when this node is inserted into the graph

Specified by:

getGraphNodeId in interface INodeWithNumber

Returns:

the identifier

See Also:

• INodeWithNumber.getGraphNodeId()

setGraphNodeId

public void setGraphNodeId(int number)

Specified by:

setGraphNodeId in interface INodeWithNumber

See Also:

• INodeWithNumber.setGraphNodeId(int)

toString

public String toString()

Overrides:

toString in class Object

equals

public boolean equals(Object arg0)

Overrides:

equals in class Object

getMethod

public IMethod getMethod()

Specified by:

getMethod in interface IBasicBlock<SSAInstruction>

Returns:

governing method for this block

hashCode

public int hashCode()

Overrides:

hashCode in class Object

isExitBlock

public boolean isExitBlock()

Description copied from interface: ISSABasicBlock

Does this block represent the unique exit from a ControlFlowGraph?

Specified by:

isExitBlock in interface IBasicBlock<SSAInstruction>

Specified by:

isExitBlock in interface ISSABasicBlock

Returns:

true if the basic block represents the unique exit block.

See Also:

• IBasicBlock.isExitBlock()

isEntryBlock

public boolean isEntryBlock()

Description copied from interface: ISSABasicBlock

Does this block represent the unique entry to a ControlFlowGraph

Specified by:

isEntryBlock in interface IBasicBlock<SSAInstruction>

Specified by:

isEntryBlock in interface ISSABasicBlock

Returns:

true if the basic block represents the unique entry block.

See Also:

• IBasicBlock.isEntryBlock()

getLastInstruction

public SSAInstruction getLastInstruction()

Specified by:

getLastInstruction in interface ISSABasicBlock

Returns:

the last instruction in this block.

getCaughtExceptionTypes

public Iterator<TypeReference> getCaughtExceptionTypes()

The SSACFG.ExceptionHandlerBasicBlock subclass will override this.

Specified by:

getCaughtExceptionTypes in interface ISSABasicBlock

Returns:

the set of exception types this block may catch.