org.apache.bcel.generic
Class Select

java.lang.Object
  org.apache.bcel.generic.Instruction
      org.apache.bcel.generic.BranchInstruction
          org.apache.bcel.generic.Select

All Implemented Interfaces:

java.io.Serializable, java.lang.Cloneable, InstructionTargeter, StackProducer, VariableLengthInstruction

Direct Known Subclasses:

LOOKUPSWITCH, TABLESWITCH

public abstract class Select
extends BranchInstruction
implements VariableLengthInstruction, StackProducer

Select - Abstract super class for LOOKUPSWITCH and TABLESWITCH instructions.

We use our super's target property as the default target.

Version:

$Id: Select.java 386056 2006-03-15 11:31:56Z tcurdt $

Author:

M. Dahm

See Also:

LOOKUPSWITCH, TABLESWITCH, InstructionList, Serialized Form

Field Summary

protected int	fixed_length
protected int[]	indices
protected int[]	match
protected int	match_length
protected int	padding
protected InstructionHandle[]	targets

Fields inherited from class org.apache.bcel.generic.BranchInstruction

index, position, target

Fields inherited from class org.apache.bcel.generic.Instruction

length, opcode

Constructor Summary

Select()
Empty constructor needed for the Class.newInstance() statement in Instruction.readInstruction().

Select(short opcode, int[] match, InstructionHandle[] targets, InstructionHandle defaultTarget)
(Match, target) pairs for switch.

Method Summary

protected java.lang.Object	clone()
boolean	containsTarget(InstructionHandle ih)
(package private) void	dispose() Inform targets that they're not targeted anymore.
void	dump(java.io.DataOutputStream out) Dump instruction as byte code to stream out.
int[]	getIndices()
int[]	getMatchs()
InstructionHandle[]	getTargets()
protected void	initFromFile(ByteSequence bytes, boolean wide) Read needed data (e.g.
void	setTarget(int i, InstructionHandle target) Set branch target for `i'th case
java.lang.String	toString(boolean verbose) Long output format: <position in byte code> <name of opcode> "["<opcode number>"]" "("<length of instruction>")" "<"<target instruction>">" "@"<branch target offset>
protected int	updatePosition(int offset, int max_offset) Since this is a variable length instruction, it may shift the following instructions which then need to update their position.
void	updateTarget(InstructionHandle old_ih, InstructionHandle new_ih)

Methods inherited from class org.apache.bcel.generic.BranchInstruction

getIndex, getTarget, getTargetOffset, getTargetOffset, notifyTarget, setTarget

Methods inherited from class org.apache.bcel.generic.Instruction

accept, consumeStack, copy, equals, getComparator, getLength, getName, getOpcode, produceStack, readInstruction, setComparator, toString, toString

Methods inherited from class java.lang.Object

finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.apache.bcel.generic.StackProducer

produceStack

Field Detail

match

protected int[] match

indices

protected int[] indices

targets

protected InstructionHandle[] targets

fixed_length

protected int fixed_length

match_length

protected int match_length

padding

protected int padding

Constructor Detail

Select

Select()

Empty constructor needed for the Class.newInstance() statement in Instruction.readInstruction(). Not to be used otherwise.

Select

Select(short opcode,
       int[] match,
       InstructionHandle[] targets,
       InstructionHandle defaultTarget)

(Match, target) pairs for switch. `Match' and `targets' must have the same length of course.

Parameters:

match - array of matching values

targets - instruction targets

defaultTarget - default instruction target

Method Detail

updatePosition

protected int updatePosition(int offset,
                             int max_offset)

Since this is a variable length instruction, it may shift the following instructions which then need to update their position. Called by InstructionList.setPositions when setting the position for every instruction. In the presence of variable length instructions `setPositions' performs multiple passes over the instruction list to calculate the correct (byte) positions and offsets by calling this function.

Overrides:

updatePosition in class BranchInstruction

Parameters:

offset - additional offset caused by preceding (variable length) instructions

max_offset - the maximum offset that may be caused by these instructions

Returns:

additional offset caused by possible change of this instruction's length

dump

public void dump(java.io.DataOutputStream out)
          throws java.io.IOException

Dump instruction as byte code to stream out.

Overrides:

dump in class BranchInstruction

Parameters:

out - Output stream

Throws:

java.io.IOException

initFromFile

protected void initFromFile(ByteSequence bytes,
                            boolean wide)
                     throws java.io.IOException

Read needed data (e.g. index) from file.

Overrides:

initFromFile in class BranchInstruction

Parameters:

bytes - input stream

wide - wide prefix?

Throws:

java.io.IOException

See Also:

InstructionList

toString

public java.lang.String toString(boolean verbose)

Description copied from class: BranchInstruction

Long output format: <position in byte code> <name of opcode> "["<opcode number>"]" "("<length of instruction>")" "<"<target instruction>">" "@"<branch target offset>

Overrides:

toString in class BranchInstruction

Parameters:

verbose - long/short format switch

Returns:

mnemonic for instruction

setTarget

public void setTarget(int i,
                      InstructionHandle target)

Set branch target for `i'th case

updateTarget

public void updateTarget(InstructionHandle old_ih,
                         InstructionHandle new_ih)

Specified by:

updateTarget in interface InstructionTargeter

Overrides:

updateTarget in class BranchInstruction

Parameters:

old_ih - old target

new_ih - new target

containsTarget

public boolean containsTarget(InstructionHandle ih)

Specified by:

containsTarget in interface InstructionTargeter

Overrides:

containsTarget in class BranchInstruction

Returns:

true, if ih is target of this instruction

clone

protected java.lang.Object clone()
                          throws java.lang.CloneNotSupportedException

Overrides:

clone in class java.lang.Object

Throws:

java.lang.CloneNotSupportedException

dispose

void dispose()

Inform targets that they're not targeted anymore.

Overrides:

dispose in class BranchInstruction

getMatchs

public int[] getMatchs()

Returns:

array of match indices

getIndices

public int[] getIndices()

Returns:

array of match target offsets

getTargets

public InstructionHandle[] getTargets()

Returns:

array of match targets