jdk7u.jaxp.org.apache.bcel.external.generic

Class LocalVariableInstruction

java.lang.Object

jdk7u.jaxp.org.apache.bcel.external.generic.Instruction

jdk7u.jaxp.org.apache.bcel.external.generic.LocalVariableInstruction

All Implemented Interfaces:

Serializable, 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.

Author:

M. Dahm

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
protected int	n

Fields inherited from class jdk7u.jaxp.org.apache.bcel.external.generic.Instruction

length, opcode

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	LocalVariableInstruction(short opcode, short c_tag, int n)

Method Summary

Methods

Modifier and Type	Method and Description
void	dump(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. index) from file.
void	setIndex(int n) Set the local variable index
String	toString(boolean verbose) Long output format: <name of opcode> "["<opcode number>"]" "("<length of instruction>")" "<"< local variable index>">"

Methods inherited from class jdk7u.jaxp.org.apache.bcel.external.generic.Instruction

accept, consumeStack, copy, 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

Constructor Detail

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

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

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

initFromFile

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

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