Package org.apache.bcel.generic

Class InstructionFactory

java.lang.Object

org.apache.bcel.generic.InstructionFactory

All Implemented Interfaces:

InstructionConstants

public class InstructionFactory
extends Object
implements InstructionConstants

Instances of this class may be used, e.g., to generate typed versions of instructions. Its main purpose is to be used as the byte code generating backend of a compiler. You can subclass it to add your own create methods.

Note: The static createXXX methods return singleton instances from the InstructionConst class.

See Also:

• Const
• InstructionConst

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.bcel.generic.InstructionConstants

InstructionConstants.Clinit

Field Summary

Fields

Modifier and Type	Field	Description
protected ClassGen	cg	Deprecated. (since 6.0) will be made private; do not access directly, use getter/setter
protected ConstantPoolGen	cp	Deprecated. (since 6.0) will be made private; do not access directly, use getter/setter

Fields inherited from interface org.apache.bcel.generic.InstructionConstants

AALOAD, AASTORE, ACONST_NULL, ALOAD_0, ALOAD_1, ALOAD_2, ARETURN, ARRAYLENGTH, ASTORE_0, ASTORE_1, ASTORE_2, ATHROW, BALOAD, BASTORE, bla, CALOAD, CASTORE, D2F, D2I, D2L, DADD, DALOAD, DASTORE, DCMPG, DCMPL, DCONST_0, DCONST_1, DDIV, DMUL, DNEG, DREM, DRETURN, DSUB, DUP, DUP_X1, DUP_X2, DUP2, DUP2_X1, DUP2_X2, F2D, F2I, F2L, FADD, FALOAD, FASTORE, FCMPG, FCMPL, FCONST_0, FCONST_1, FCONST_2, FDIV, FMUL, FNEG, FREM, FRETURN, FSUB, I2B, I2C, I2D, I2F, I2L, I2S, IADD, IALOAD, IAND, IASTORE, ICONST_0, ICONST_1, ICONST_2, ICONST_3, ICONST_4, ICONST_5, ICONST_M1, IDIV, ILOAD_0, ILOAD_1, ILOAD_2, IMUL, INEG, INSTRUCTIONS, IOR, IREM, IRETURN, ISHL, ISHR, ISTORE_0, ISTORE_1, ISTORE_2, ISUB, IUSHR, IXOR, L2D, L2F, L2I, LADD, LALOAD, LAND, LASTORE, LCMP, LCONST_0, LCONST_1, LDIV, LMUL, LNEG, LOR, LREM, LRETURN, LSHL, LSHR, LSUB, LUSHR, LXOR, MONITORENTER, MONITOREXIT, NOP, POP, POP2, RETURN, SALOAD, SASTORE, SWAP, THIS

Constructor Summary

Constructors

Constructor	Description
InstructionFactory(ClassGen cg)	Initialize with ClassGen object
InstructionFactory(ClassGen cg, ConstantPoolGen cp)
InstructionFactory(ConstantPoolGen cp)	Initialize just with ConstantPoolGen object

Method Summary

Modifier and Type	Method	Description
Instruction	createAppend(Type type)
static ArrayInstruction	createArrayLoad(Type type)
static ArrayInstruction	createArrayStore(Type type)
static ArithmeticInstruction	createBinaryOperation(String op, Type type)	Create binary operation for simple basic types, such as int and float.
static BranchInstruction	createBranchInstruction(short opcode, InstructionHandle target)	Create branch instruction by given opcode, except LOOKUPSWITCH and TABLESWITCH.
Instruction	createCast(Type srcType, Type destType)	Create conversion operation for two stack operands, this may be an I2C, instruction, e.g., if the operands are basic types and CHECKCAST if they are reference types.
CHECKCAST	createCheckCast(ReferenceType t)
Instruction	createConstant(Object value)	Uses PUSH to push a constant value onto the stack.
static StackInstruction	createDup(int size)
static StackInstruction	createDup_1(int size)
static StackInstruction	createDup_2(int size)
FieldInstruction	createFieldAccess(String className, String name, Type type, short kind)	Create a field instruction.
GETFIELD	createGetField(String className, String name, Type t)
GETSTATIC	createGetStatic(String className, String name, Type t)
INSTANCEOF	createInstanceOf(ReferenceType t)
InvokeInstruction	createInvoke(String className, String name, Type retType, Type[] argTypes, short kind)	Create an invoke instruction.
InvokeInstruction	createInvoke(String className, String name, Type retType, Type[] argTypes, short kind, boolean useInterface)	Create an invoke instruction.
static LocalVariableInstruction	createLoad(Type type, int index)
NEW	createNew(String s)
NEW	createNew(ObjectType t)
Instruction	createNewArray(Type t, short dim)	Create new array of given size and type.
static Instruction	createNull(Type type)	Create "null" value for reference types, 0 for basic types like int
static StackInstruction	createPop(int size)
InstructionList	createPrintln(String s)	Create a call to the most popular System.out.println() method.
PUTFIELD	createPutField(String className, String name, Type t)
PUTSTATIC	createPutStatic(String className, String name, Type t)
static ReturnInstruction	createReturn(Type type)	Create typed return
static LocalVariableInstruction	createStore(Type type, int index)
static Instruction	createThis()	Create reference to 'this'
ClassGen	getClassGen()
ConstantPoolGen	getConstantPool()
void	setClassGen(ClassGen c)
void	setConstantPool(ConstantPoolGen c)

Methods inherited from class java.lang.Object

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

Field Details

cg

@Deprecated
protected ClassGen cg

Deprecated.

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

cp

@Deprecated
protected ConstantPoolGen cp

Deprecated.

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

Constructor Details

InstructionFactory

public InstructionFactory(ClassGen cg)

Initialize with ClassGen object

InstructionFactory

public InstructionFactory(ClassGen cg,
 ConstantPoolGen cp)

InstructionFactory

public InstructionFactory(ConstantPoolGen cp)

Initialize just with ConstantPoolGen object

Method Details

createArrayLoad

public static ArrayInstruction createArrayLoad(Type type)

Parameters:

type - type of elements of array, i.e., array.getElementType()

createArrayStore

public static ArrayInstruction createArrayStore(Type type)

Parameters:

type - type of elements of array, i.e., array.getElementType()

createBinaryOperation

public static ArithmeticInstruction createBinaryOperation(String op,
 Type type)

Create binary operation for simple basic types, such as int and float.

Parameters:

op - operation, such as "+", "*", "<<", etc.

createBranchInstruction

public static BranchInstruction createBranchInstruction(short opcode,
 InstructionHandle target)

Create branch instruction by given opcode, except LOOKUPSWITCH and TABLESWITCH. For those you should use the SWITCH compound instruction.

createDup

public static StackInstruction createDup(int size)

Parameters:

size - size of operand, either 1 (int, e.g.) or 2 (double)

createDup_1

public static StackInstruction createDup_1(int size)

Parameters:

size - size of operand, either 1 (int, e.g.) or 2 (double)

createDup_2

public static StackInstruction createDup_2(int size)

Parameters:

size - size of operand, either 1 (int, e.g.) or 2 (double)

createLoad

public static LocalVariableInstruction createLoad(Type type,
 int index)

Parameters:

index - index of local variable

createNull

public static Instruction createNull(Type type)

Create "null" value for reference types, 0 for basic types like int

createPop

public static StackInstruction createPop(int size)

Parameters:

size - size of operand, either 1 (int, e.g.) or 2 (double)

createReturn

public static ReturnInstruction createReturn(Type type)

Create typed return

createStore

public static LocalVariableInstruction createStore(Type type,
 int index)

Parameters:

index - index of local variable

createThis

public static Instruction createThis()

Create reference to 'this'

createAppend

public Instruction createAppend(Type type)

createCast

public Instruction createCast(Type srcType,
 Type destType)

Create conversion operation for two stack operands, this may be an I2C, instruction, e.g., if the operands are basic types and CHECKCAST if they are reference types.

createCheckCast

public CHECKCAST createCheckCast(ReferenceType t)

createConstant

public Instruction createConstant(Object value)

Uses PUSH to push a constant value onto the stack.

Parameters:

value - must be of type Number, Boolean, Character or String

createFieldAccess

public FieldInstruction createFieldAccess(String className,
 String name,
 Type type,
 short kind)

Create a field instruction.

Parameters:

className - name of the accessed class

name - name of the referenced field

type - type of field

kind - how to access, i.e., GETFIELD, PUTFIELD, GETSTATIC, PUTSTATIC

See Also:

• Const

createGetField

public GETFIELD createGetField(String className,
 String name,
 Type t)

createGetStatic

public GETSTATIC createGetStatic(String className,
 String name,
 Type t)

createInstanceOf

public INSTANCEOF createInstanceOf(ReferenceType t)

createInvoke

public InvokeInstruction createInvoke(String className,
 String name,
 Type retType,
 Type[] argTypes,
 short kind)

Create an invoke instruction. (Except for invokedynamic.)

Parameters:

className - name of the called class

name - name of the called method

retType - return type of method

argTypes - argument types of method

kind - how to invoke, i.e., INVOKEINTERFACE, INVOKESTATIC, INVOKEVIRTUAL, or INVOKESPECIAL

See Also:

• Const

createInvoke

public InvokeInstruction createInvoke(String className,
 String name,
 Type retType,
 Type[] argTypes,
 short kind,
 boolean useInterface)

Create an invoke instruction. (Except for invokedynamic.)

Parameters:

className - name of the called class

name - name of the called method

retType - return type of method

argTypes - argument types of method

kind - how to invoke: INVOKEINTERFACE, INVOKESTATIC, INVOKEVIRTUAL, or INVOKESPECIAL

useInterface - force use of InterfaceMethodref

Returns:

A new InvokeInstruction.

Since:

6.5.0

createNew

public NEW createNew(ObjectType t)

createNew

public NEW createNew(String s)

createNewArray

public Instruction createNewArray(Type t,
 short dim)

Create new array of given size and type.

Returns:

an instruction that creates the corresponding array at runtime, i.e. is an AllocationInstruction

createPrintln

public InstructionList createPrintln(String s)

Create a call to the most popular System.out.println() method.

Parameters:

s - the string to print

createPutField

public PUTFIELD createPutField(String className,
 String name,
 Type t)

createPutStatic

public PUTSTATIC createPutStatic(String className,
 String name,
 Type t)

getClassGen

public ClassGen getClassGen()

getConstantPool

public ConstantPoolGen getConstantPool()

setClassGen

public void setClassGen(ClassGen c)

setConstantPool

public void setConstantPool(ConstantPoolGen c)