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
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

length, opcode

Constructor Summary

Constructors

Modifier	Constructor	Description
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)	Reads needed data (for example index) from file.
void	setIndex(int n)	Sets the local variable index. also updates opcode and length TODO Why?
String	toString(boolean verbose)	Long output format: <name of opcode> "["<opcode number>"]" "("<length of instruction>")" "<"< local variable index>">"

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

accept, consumeStack, copy, equals, getComparator, getLength, getName, getOpcode, hashCode, isValidByte, isValidShort, produceStack, readInstruction, setComparator, 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

Constructor Details

LocalVariableInstruction

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

Parameters:

opcode - Instruction opcode

cTag - Instruction number for compact version, ALOAD_0, for example.

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, for example, 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

Reads needed data (for example 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)

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