org.apache.bcel.generic
Class LocalVariableInstruction

java.lang.Object
  org.apache.bcel.generic.Instruction
      org.apache.bcel.generic.LocalVariableInstruction

All Implemented Interfaces:

java.io.Serializable, java.lang.Cloneable, IndexedInstruction, TypedInstruction

Direct Known Subclasses:

IINC, LoadInstruction, StoreInstruction

public abstract class LocalVariableInstruction
extends Instruction
implements TypedInstruction, IndexedInstruction

Abstract super class for instructions dealing with local variables.

Version:

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

Author:

M. Dahm

See Also:

Serialized Form

Field Summary

private short	c_tag
private short	canon_tag
protected int	n

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

length, opcode

Constructor Summary

(package private)	LocalVariableInstruction() Empty constructor needed for the Class.newInstance() statement in Instruction.readInstruction().
(package private)	LocalVariableInstruction(short canon_tag, short c_tag) Empty constructor needed for the Class.newInstance() statement in Instruction.readInstruction().
protected	LocalVariableInstruction(short opcode, short c_tag, int n)

Method Summary

void	dump(java.io.DataOutputStream out) Dump instruction as byte code to stream out.
short	getCanonicalTag()
int	getIndex()
Type	getType(ConstantPoolGen cp) Returns the type associated with the instruction - in case of ALOAD or ASTORE Type.OBJECT is returned.
protected void	initFromFile(ByteSequence bytes, boolean wide) Read needed data (e.g.
void	setIndex(int n) Set the local variable index
java.lang.String	toString(boolean verbose) Long output format: <name of opcode> "["<opcode number>"]" "("<length of instruction>")" "<"< local variable index>">"
private boolean	wide()

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

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

Methods inherited from class java.lang.Object

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

Field Detail

n

protected int n

c_tag

private short c_tag

canon_tag

private short canon_tag

Constructor Detail

LocalVariableInstruction

LocalVariableInstruction(short canon_tag,
                         short c_tag)

Empty constructor needed for the Class.newInstance() statement in Instruction.readInstruction(). Not to be used otherwise. tag and length are defined in readInstruction and initFromFile, respectively.

LocalVariableInstruction

LocalVariableInstruction()

Empty constructor needed for the Class.newInstance() statement in Instruction.readInstruction(). Also used by IINC()!

LocalVariableInstruction

protected LocalVariableInstruction(short opcode,
                                   short c_tag,
                                   int n)

Parameters:

opcode - Instruction opcode

c_tag - Instruction number for compact version, ALOAD_0, e.g.

n - local variable index (unsigned short)

Method Detail

wide

private final boolean wide()

dump

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

Dump instruction as byte code to stream out.

Overrides:

dump in class Instruction

Parameters:

out - Output stream

Throws:

java.io.IOException

toString

public java.lang.String toString(boolean verbose)

Long output format: <name of opcode> "["<opcode number>"]" "("<length of instruction>")" "<"< local variable index>">"

Overrides:

toString in class Instruction

Parameters:

verbose - long/short format switch

Returns:

mnemonic for instruction

initFromFile

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

Read needed data (e.g. index) from file. PRE: (ILOAD <= tag <= ALOAD_3) || (ISTORE <= tag <= ASTORE_3)

Overrides:

initFromFile in class Instruction

Parameters:

bytes - byte sequence to read from

wide - "wide" instruction flag

Throws:

java.io.IOException

getIndex

public final int getIndex()

Specified by:

getIndex in interface IndexedInstruction

Returns:

local variable index referred by this instruction.

setIndex

public void setIndex(int n)

Set the local variable index

Specified by:

setIndex in interface IndexedInstruction

getCanonicalTag

public short getCanonicalTag()

Returns:

canonical tag for instruction, e.g., ALOAD for ALOAD_0

getType

public Type getType(ConstantPoolGen cp)

Returns the type associated with the instruction - in case of ALOAD or ASTORE Type.OBJECT is returned. This is just a bit incorrect, because ALOAD and ASTORE may work on every ReferenceType (including Type.NULL) and ASTORE may even work on a ReturnaddressType .

Specified by:

getType in interface TypedInstruction

Returns:

type associated with the instruction