Package org.apache.bcel.generic

Class LocalVariableInstruction

java.lang.Object

org.apache.bcel.generic.Instruction

org.apache.bcel.generic.LocalVariableInstruction

All Implemented Interfaces:

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.

Field Summary

Fields

Modifier and Type	Field	Description
private short	canonTag
private short	cTag
protected int	n	Deprecated. (since 6.0) will be made private; do not access directly, use getter/setter

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

EMPTY_ARRAY, length, opcode

Constructor Summary

Constructors

Modifier	Constructor	Description
(package private)	LocalVariableInstruction()	Empty constructor needed for Instruction.readInstruction.
(package private)	LocalVariableInstruction(short canonTag, short cTag)	Empty constructor needed for Instruction.readInstruction.
protected	LocalVariableInstruction(short opcode, short cTag, int n)

Method Summary

Modifier and Type	Method	Description
void	dump(DataOutputStream out)	Dump instruction as byte code to stream out.
short	getCanonicalTag()
final 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)	Sets the local variable index.
(package private) final void	setIndexOnly(int n)	Sets the index of the referenced variable (n) only
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, hashCode, isValidByte, isValidShort, produceStack, readInstruction, setComparator, setLength, setOpcode, toString, toString

Methods inherited from class java.lang.Object

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

Field Details

n

@Deprecated
protected int n

Deprecated.

(since 6.0) will be made private; do not access directly, use getter/setter

cTag

private short cTag

canonTag

private short canonTag

Constructor Details

LocalVariableInstruction

LocalVariableInstruction()

Empty constructor needed for Instruction.readInstruction. Also used by IINC()!

LocalVariableInstruction

LocalVariableInstruction(short canonTag,
 short cTag)

Empty constructor needed for Instruction.readInstruction. Not to be used otherwise. tag and length are defined in readInstruction and initFromFile, respectively.

LocalVariableInstruction

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

Parameters:

opcode - Instruction opcode

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

n - local variable index (unsigned short)

Method Details

dump

public void dump(DataOutputStream out)
          throws IOException

Dump instruction as byte code to stream out.

Overrides:

dump in class Instruction

Parameters:

out - Output stream

Throws:

IOException - Thrown when an I/O exception of some sort has occurred.

getCanonicalTag

public short getCanonicalTag()

Returns:

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

getIndex

public final int getIndex()

Specified by:

getIndex in interface IndexedInstruction

Returns:

local variable index (n) referred by this instruction.

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

initFromFile

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

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

 (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:

IOException - may be thrown if the implementation needs to read data from the file

setIndex

public void setIndex(int n)

Sets the local variable index. also updates opcode and length TODO Why?

Specified by:

setIndex in interface IndexedInstruction

See Also:

• setIndexOnly(int)

setIndexOnly

final void setIndexOnly(int n)

Sets the index of the referenced variable (n) only

Since:

6.0

See Also:

• setIndex(int)

toString

public 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

wide

private boolean wide()