Package EDU.purdue.cs.bloat.editor

Class Instruction

java.lang.Object

EDU.purdue.cs.bloat.editor.Instruction

All Implemented Interfaces:

Opcode

public class Instruction
extends java.lang.Object
implements Opcode

Instruction represents a single instruction in the JVM. All Instructions known their opcode. Some instructions have an operand. Operands are integers, floats, or one of the special classes that represent multiple operands such as IncOperand and Switch.

See Also:

IncOperand, Switch, MultiArrayOperand

Field Summary

Fields inherited from interface EDU.purdue.cs.bloat.editor.Opcode

opc_aaload, opc_aastore, opc_aconst_null, opc_aload, opc_aload_0, opc_aload_1, opc_aload_2, opc_aload_3, opc_anewarray, opc_areturn, opc_arraylength, opc_astore, opc_astore_0, opc_astore_1, opc_astore_2, opc_astore_3, opc_aswizzle, opc_aswrange, opc_athrow, opc_aupdate, opc_baload, opc_bastore, opc_bipush, opc_breakpoint, opc_caload, opc_castore, opc_checkcast, opc_d2f, opc_d2i, opc_d2l, opc_dadd, opc_daload, opc_dastore, opc_dcmpg, opc_dcmpl, opc_dconst_0, opc_dconst_1, opc_ddiv, opc_dload, opc_dload_0, opc_dload_1, opc_dload_2, opc_dload_3, opc_dmul, opc_dneg, opc_drem, opc_dreturn, opc_dstore, opc_dstore_0, opc_dstore_1, opc_dstore_2, opc_dstore_3, opc_dsub, opc_dup, opc_dup_x1, opc_dup_x2, opc_dup2, opc_dup2_x1, opc_dup2_x2, opc_f2d, opc_f2i, opc_f2l, opc_fadd, opc_faload, opc_fastore, opc_fcmpg, opc_fcmpl, opc_fconst_0, opc_fconst_1, opc_fconst_2, opc_fdiv, opc_fload, opc_fload_0, opc_fload_1, opc_fload_2, opc_fload_3, opc_fmul, opc_fneg, opc_frem, opc_freturn, opc_fstore, opc_fstore_0, opc_fstore_1, opc_fstore_2, opc_fstore_3, opc_fsub, opc_getfield, opc_getstatic, opc_goto, opc_goto_w, opc_i2b, opc_i2c, opc_i2d, opc_i2f, opc_i2l, opc_i2s, opc_iadd, opc_iaload, opc_iand, opc_iastore, opc_iconst_0, opc_iconst_1, opc_iconst_2, opc_iconst_3, opc_iconst_4, opc_iconst_5, opc_iconst_m1, opc_idiv, opc_if_acmpeq, opc_if_acmpne, opc_if_icmpeq, opc_if_icmpge, opc_if_icmpgt, opc_if_icmple, opc_if_icmplt, opc_if_icmpne, opc_ifeq, opc_ifge, opc_ifgt, opc_ifle, opc_iflt, opc_ifne, opc_ifnonnull, opc_ifnull, opc_iinc, opc_iload, opc_iload_0, opc_iload_1, opc_iload_2, opc_iload_3, opc_imul, opc_ineg, opc_instanceof, opc_invokeinterface, opc_invokespecial, opc_invokestatic, opc_invokevirtual, opc_ior, opc_irem, opc_ireturn, opc_ishl, opc_ishr, opc_istore, opc_istore_0, opc_istore_1, opc_istore_2, opc_istore_3, opc_isub, opc_iushr, opc_ixor, opc_jsr, opc_jsr_w, opc_l2d, opc_l2f, opc_l2i, opc_ladd, opc_laload, opc_land, opc_lastore, opc_lcmp, opc_lconst_0, opc_lconst_1, opc_ldc, opc_ldc_w, opc_ldc2_w, opc_ldiv, opc_lload, opc_lload_0, opc_lload_1, opc_lload_2, opc_lload_3, opc_lmul, opc_lneg, opc_lookupswitch, opc_lor, opc_lrem, opc_lreturn, opc_lshl, opc_lshr, opc_lstore, opc_lstore_0, opc_lstore_1, opc_lstore_2, opc_lstore_3, opc_lsub, opc_lushr, opc_lxor, opc_monitorenter, opc_monitorexit, opc_multianewarray, opc_new, opc_newarray, opc_nop, opc_pop, opc_pop2, opc_putfield, opc_putfield_nowb, opc_putstatic, opc_putstatic_nowb, opc_rc, opc_ret, opc_return, opc_saload, opc_sastore, opc_sipush, opc_supdate, opc_swap, opc_tableswitch, opc_wide, opc_xxxunusedxxx, opcNames, opcSize, opcx_aaload, opcx_aastore, opcx_aload, opcx_areturn, opcx_arraylength, opcx_astore, opcx_aswizzle, opcx_aswrange, opcx_athrow, opcx_aupdate, opcx_baload, opcx_bastore, opcx_caload, opcx_castore, opcx_checkcast, opcx_d2f, opcx_d2i, opcx_d2l, opcx_dadd, opcx_daload, opcx_dastore, opcx_dcmpg, opcx_dcmpl, opcx_ddiv, opcx_dload, opcx_dmul, opcx_dneg, opcx_drem, opcx_dreturn, opcx_dstore, opcx_dsub, opcx_dup, opcx_dup_x1, opcx_dup_x2, opcx_dup2, opcx_dup2_x1, opcx_dup2_x2, opcx_f2d, opcx_f2i, opcx_f2l, opcx_fadd, opcx_faload, opcx_fastore, opcx_fcmpg, opcx_fcmpl, opcx_fdiv, opcx_fload, opcx_fmul, opcx_fneg, opcx_frem, opcx_freturn, opcx_fstore, opcx_fsub, opcx_getfield, opcx_getstatic, opcx_goto, opcx_i2b, opcx_i2c, opcx_i2d, opcx_i2f, opcx_i2l, opcx_i2s, opcx_iadd, opcx_iaload, opcx_iand, opcx_iastore, opcx_idiv, opcx_if_acmpeq, opcx_if_acmpne, opcx_if_icmpeq, opcx_if_icmpge, opcx_if_icmpgt, opcx_if_icmple, opcx_if_icmplt, opcx_if_icmpne, opcx_ifeq, opcx_ifge, opcx_ifgt, opcx_ifle, opcx_iflt, opcx_ifne, opcx_ifnonnull, opcx_ifnull, opcx_iinc, opcx_iload, opcx_imul, opcx_ineg, opcx_instanceof, opcx_invokeinterface, opcx_invokespecial, opcx_invokestatic, opcx_invokevirtual, opcx_ior, opcx_irem, opcx_ireturn, opcx_ishl, opcx_ishr, opcx_istore, opcx_isub, opcx_iushr, opcx_ixor, opcx_jsr, opcx_l2d, opcx_l2f, opcx_l2i, opcx_ladd, opcx_laload, opcx_land, opcx_lastore, opcx_lcmp, opcx_ldc, opcx_ldiv, opcx_lload, opcx_lmul, opcx_lneg, opcx_lor, opcx_lrem, opcx_lreturn, opcx_lshl, opcx_lshr, opcx_lstore, opcx_lsub, opcx_lushr, opcx_lxor, opcx_monitorenter, opcx_monitorexit, opcx_multianewarray, opcx_new, opcx_newarray, opcx_nop, opcx_pop, opcx_pop2, opcx_putfield, opcx_putfield_nowb, opcx_putstatic, opcx_putstatic_nowb, opcx_rc, opcx_ret, opcx_return, opcx_saload, opcx_sastore, opcx_supdate, opcx_swap, opcx_switch, opcXMap, VARIABLE

Constructor Summary

Constructors

Constructor	Description
Instruction(byte[] code, int index, int[] targets, int[] lookups, LocalVariable[] locals, ConstantPool constants)	Constructor.
Instruction(int opcode)	Constructor.
Instruction(int opcode, java.lang.Object operand)	Constructor.

Method Summary

Modifier and Type	Method	Description
int	category()	Returns the category of this instruction.
boolean	isConditionalJump()	Check if the instruction is a conditional jump.
boolean	isGoto()	Check if the instruction is a goto.
boolean	isInc()	Check if the instruction is an increment.
boolean	isInvoke()	Returns true if this instruction invokes a method.
boolean	isJsr()	Check if the instruction is a jsr.
boolean	isJump()	Check if the instruction is a jump.
boolean	isLoad()	Check if the instruction is a load.
boolean	isRet()	Check if the instruction is a subroutine return instruction.
boolean	isReturn()	Returns true if the instruction returns from a method.
boolean	isStore()	Check if the instruction is a store.
boolean	isSwitch()	Check if the instruction is a switch.
boolean	isThrow()	Check if the instruction is an exception throw instruction.
int	opcodeClass()	Get the opcode class of the instruction.
java.lang.Object	operand()	Get the operand of the instruction.
int	origOpcode()	Returns the original (non-mapped) opcode used to create this Instruction.
void	setOpcodeClass(int opcode)	Set the opcode class of the instruction.
void	setOperand(java.lang.Object operand)	Set the operand of the instruction.
void	setUseSlow(boolean useSlow)	Sets a flag that determines whether or not the "slow" version of the instruction should be generated.
protected static int	toInt(byte b1, byte b2, byte b3, byte b4)	Utility function to join 4 bytes into an signed int.
protected static short	toShort(byte b1, byte b2)	Utility function to join 2 bytes into an signed short.
java.lang.String	toString()	Convert the instruction to a string.
protected static int	toUByte(byte b)	Utility function to convert a byte into an unsigned byte.
protected static int	toUShort(byte b1, byte b2)	Utility function to join 2 bytes into an unsigned short.
boolean	useSlow()	Returns whether or not the "slow" version of this instruction is generated.
void	visit(InstructionVisitor visitor)	Big switch statement to call the appropriate method of an instruction visitor.

Methods inherited from class java.lang.Object

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

Constructor Detail

Instruction

public Instruction(int opcode)

Constructor.

Parameters:

opcode - The opcode class of the instruction.

Instruction

public Instruction(int opcode,
                   java.lang.Object operand)

Constructor.

Parameters:

opcode - The opcode class of the instruction.

operand - The operand of the instruction, or null.

Instruction

public Instruction(byte[] code,
                   int index,
                   int[] targets,
                   int[] lookups,
                   LocalVariable[] locals,
                   ConstantPool constants)

Constructor.

Parameters:

code - The raw byte code array of the method.

index - This index into the byte array of the instruction.

targets - Indices of the branch targets of the instruction.

lookups - Values of the switch lookups of the instruction.

locals - The local variables defined at this index.

constants - The constant pool for the class.

Method Detail

origOpcode

public int origOpcode()

Returns the original (non-mapped) opcode used to create this Instruction.

setUseSlow

public void setUseSlow(boolean useSlow)

Sets a flag that determines whether or not the "slow" version of the instruction should be generated. For example, if useSlow is true, "iload 2" is generated instead of "iload_2".

useSlow

public boolean useSlow()

Returns whether or not the "slow" version of this instruction is generated.

isLoad

public boolean isLoad()

Check if the instruction is a load.

Returns:

true if the instruction is a load, false if not.

isStore

public boolean isStore()

Check if the instruction is a store.

Returns:

true if the instruction is a store, false if not.

isInc

public boolean isInc()

Check if the instruction is an increment.

Returns:

true if the instruction is an increment, false if not.

isThrow

public boolean isThrow()

Check if the instruction is an exception throw instruction.

Returns:

true if the instruction is a throw, false if not.

isInvoke

public boolean isInvoke()

Returns true if this instruction invokes a method.

isRet

public boolean isRet()

Check if the instruction is a subroutine return instruction.

Returns:

true if the instruction is a ret, false if not.

isReturn

public boolean isReturn()

Returns true if the instruction returns from a method.

isSwitch

public boolean isSwitch()

Check if the instruction is a switch.

Returns:

true if the instruction is a switch, false if not.

isJump

public boolean isJump()

Check if the instruction is a jump.

Returns:

true if the instruction is a jump, false if not.

isJsr

public boolean isJsr()

Check if the instruction is a jsr.

Returns:

true if the instruction is a jsr, false if not.

isGoto

public boolean isGoto()

Check if the instruction is a goto.

Returns:

true if the instruction is a goto, false if not.

isConditionalJump

public boolean isConditionalJump()

Check if the instruction is a conditional jump.

Returns:

true if the instruction is a conditional jump, false if not.

opcodeClass

public int opcodeClass()

Get the opcode class of the instruction.

Returns:

The opcode class of the instruction.

setOpcodeClass

public void setOpcodeClass(int opcode)

Set the opcode class of the instruction.

Parameters:

opcode - The opcode class of the instruction.

setOperand

public void setOperand(java.lang.Object operand)

Set the operand of the instruction.

Parameters:

operand - The operand of the instruction.

operand

public java.lang.Object operand()

Get the operand of the instruction.

Returns:

The operand of the instruction.

toString

public java.lang.String toString()

Convert the instruction to a string.

Overrides:

toString in class java.lang.Object

Returns:

A string representation of the instruction.

toUShort

protected static int toUShort(byte b1,
                              byte b2)

Utility function to join 2 bytes into an unsigned short.

Parameters:

b1 - The upper byte.

b2 - The lower byte.

Returns:

The unsigned short.

toShort

protected static short toShort(byte b1,
                               byte b2)

Utility function to join 2 bytes into an signed short.

Parameters:

b1 - The upper byte.

b2 - The lower byte.

Returns:

The signed short.

toInt

protected static int toInt(byte b1,
                           byte b2,
                           byte b3,
                           byte b4)

Utility function to join 4 bytes into an signed int.

Parameters:

b1 - The upper byte.

b2 - The next-to-upper byte.

b3 - The next-to-lower byte.

b4 - The lower byte.

Returns:

The signed int.

toUByte

protected static int toUByte(byte b)

Utility function to convert a byte into an unsigned byte.

Parameters:

b - The byte.

Returns:

The unsigned byte.

category

public int category()

Returns the category of this instruction. An instruction's category is basically the width of the value the instruction places on the stack. Types long and double are Category 2. All other types are Category 1.

visit

public void visit(InstructionVisitor visitor)

Big switch statement to call the appropriate method of an instruction visitor.

Parameters:

visitor - The instruction visitor.