edu.umd.cs.findbugs.ba

Class BasicBlock

java.lang.Object

edu.umd.cs.findbugs.graph.AbstractVertex<Edge,BasicBlock>

edu.umd.cs.findbugs.ba.BasicBlock

All Implemented Interfaces:

Debug, GraphVertex<BasicBlock>, java.lang.Comparable<BasicBlock>

public class BasicBlock
extends AbstractVertex<Edge,BasicBlock>
implements Debug

Simple basic block abstraction for BCEL.

Author:

David Hovemeyer

See Also:

CFG

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
class	BasicBlock.InstructionIterator A forward Iterator over the instructions of a basic block.

Field Summary

Fields inherited from interface edu.umd.cs.findbugs.ba.Debug

VERIFY_INTEGRITY

Constructor Summary

Constructors

Constructor and Description
BasicBlock() Constructor.

Method Summary

Methods

Modifier and Type	Method and Description
void	addInstruction(org.apache.bcel.generic.InstructionHandle handle) Add an InstructionHandle to the basic block.
boolean	containsInstruction(org.apache.bcel.generic.InstructionHandle handle) Return whether or not the basic block contains the given instruction.
boolean	containsInstructionWithOffset(int offset) Return whether or not the basic block contains the instruction with the given bytecode offset.
org.apache.bcel.generic.CodeExceptionGen	getExceptionGen() Get CodeExceptionGen object; returns null if this basic block is not the entry point of an exception handler.
org.apache.bcel.generic.InstructionHandle	getExceptionThrower() Get the instruction for which this block is an exception thrower.
org.apache.bcel.generic.InstructionHandle	getFirstInstruction() Get the first instruction in the basic block.
int	getId() Deprecated. call getLabel() instead
org.apache.bcel.generic.InstructionHandle	getLastInstruction() Get the last instruction in the basic block.
org.apache.bcel.generic.InstructionHandle	getPredecessorOf(org.apache.bcel.generic.InstructionHandle handle) Get the predecessor of given instruction within the basic block.
org.apache.bcel.generic.InstructionHandle	getSuccessorOf(org.apache.bcel.generic.InstructionHandle handle) Get the successor of given instruction within the basic block.
BasicBlock.InstructionIterator	instructionIterator() Get an Iterator over the instructions in the basic block.
java.util.Iterator<org.apache.bcel.generic.InstructionHandle>	instructionReverseIterator() Get an Iterator over the instructions in the basic block in reverse order.
boolean	isEmpty() Return true if there are no Instructions in this basic block.
boolean	isExceptionHandler() Is this block an exception handler?
boolean	isExceptionThrower() Return whether or not this block is an exception thrower.
boolean	isInJSRSubroutine()
boolean	isNullCheck() Return whether or not this block is a null check.
int	pos()
void	setExceptionGen(TypeMerger m, org.apache.bcel.generic.CodeExceptionGen exceptionGen) Set the CodeExceptionGen object.
void	setExceptionThrower(org.apache.bcel.generic.InstructionHandle exceptionThrower) Set the instruction for which this block is the ETB.
java.lang.String	toString()

Methods inherited from class edu.umd.cs.findbugs.graph.AbstractVertex

compareTo, equals, getLabel, hashCode, setLabel

Methods inherited from class java.lang.Object

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

Constructor Detail

BasicBlock

public BasicBlock()

Constructor.

Method Detail

isInJSRSubroutine

public boolean isInJSRSubroutine()

getId

@Deprecated
public int getId()

Deprecated. call getLabel() instead

Get the basic block's integer label.

Returns:

the BasicBlock's integer label

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

setExceptionThrower

public void setExceptionThrower(org.apache.bcel.generic.InstructionHandle exceptionThrower)

Set the instruction for which this block is the ETB.

Parameters:

exceptionThrower - the instruction

isExceptionThrower

public boolean isExceptionThrower()

Return whether or not this block is an exception thrower.

getExceptionThrower

public org.apache.bcel.generic.InstructionHandle getExceptionThrower()

Get the instruction for which this block is an exception thrower.

Returns:

the instruction, or null if this block is not an exception thrower

isNullCheck

public boolean isNullCheck()

Return whether or not this block is a null check.

getFirstInstruction

public org.apache.bcel.generic.InstructionHandle getFirstInstruction()

Get the first instruction in the basic block.

getLastInstruction

public org.apache.bcel.generic.InstructionHandle getLastInstruction()

Get the last instruction in the basic block.

getSuccessorOf

@CheckForNull
public org.apache.bcel.generic.InstructionHandle getSuccessorOf(org.apache.bcel.generic.InstructionHandle handle)

Get the successor of given instruction within the basic block.

Parameters:

handle - the instruction

Returns:

the instruction's successor, or null if the instruction is the last in the basic block

getPredecessorOf

public org.apache.bcel.generic.InstructionHandle getPredecessorOf(org.apache.bcel.generic.InstructionHandle handle)

Get the predecessor of given instruction within the basic block.

Parameters:

handle - the instruction

Returns:

the instruction's predecessor, or null if the instruction is the first in the basic block

addInstruction

public void addInstruction(org.apache.bcel.generic.InstructionHandle handle)

Add an InstructionHandle to the basic block.

Parameters:

handle - the InstructionHandle

instructionIterator

public BasicBlock.InstructionIterator instructionIterator()

Get an Iterator over the instructions in the basic block.

instructionReverseIterator

public java.util.Iterator<org.apache.bcel.generic.InstructionHandle> instructionReverseIterator()

Get an Iterator over the instructions in the basic block in reverse order. This is useful for backwards dataflow analyses.

isEmpty

public boolean isEmpty()

Return true if there are no Instructions in this basic block.

pos

public int pos()

isExceptionHandler

public boolean isExceptionHandler()

Is this block an exception handler?

getExceptionGen

public org.apache.bcel.generic.CodeExceptionGen getExceptionGen()

Get CodeExceptionGen object; returns null if this basic block is not the entry point of an exception handler.

Returns:

the CodeExceptionGen object, or null

setExceptionGen

public void setExceptionGen(@Nullable
                   TypeMerger m,
                   org.apache.bcel.generic.CodeExceptionGen exceptionGen)

Set the CodeExceptionGen object. Marks this basic block as the entry point of an exception handler.

Parameters:

exceptionGen - the CodeExceptionGen object for the block

containsInstruction

public boolean containsInstruction(org.apache.bcel.generic.InstructionHandle handle)

Return whether or not the basic block contains the given instruction.

Parameters:

handle - the instruction

Returns:

true if the block contains the instruction, false otherwise

containsInstructionWithOffset

public boolean containsInstructionWithOffset(int offset)

Return whether or not the basic block contains the instruction with the given bytecode offset.

Parameters:

offset - the bytecode offset

Returns:

true if the block contains an instruction with the given offset, false if it does not