Class LocalVarInstruction

  extended byorg.multijava.util.classfile.AbstractInstructionAccessor
      extended byorg.multijava.util.classfile.Instruction
          extended byorg.multijava.util.classfile.LocalVarInstruction
All Implemented Interfaces:
Constants, InstructionAccessor

public class LocalVarInstruction
extends Instruction

This class represents instructions that take a local variable as argument. Shortcuts (single byte instructions) are created for the opcodes: iload, fload, aload, lload, dload, istore, fstore, astore, lstore, dstore if the variable index is 0, 1, 2 or 3. An extra wide prefix is automatically added for these instructions if the numeric argument is larger than 255.

Field Summary
private  int index
static byte KND_LOAD
static byte KND_RET
static byte KND_STORE
private  int width
Fields inherited from class org.multijava.util.classfile.Instruction
Fields inherited from interface org.multijava.util.classfile.Constants
ACC_ABSTRACT, ACC_FINAL, ACC_INTERFACE, ACC_NATIVE, ACC_PRIVATE, ACC_PROTECTED, ACC_PUBLIC, ACC_STATIC, ACC_STRICT, ACC_SUPER, ACC_SYNCHRONIZED, ACC_SYNTHETIC, ACC_TRANSIENT, ACC_VOLATILE, ACCESS_FLAG_ARRAY, ACCESS_FLAG_NAMES, ATT_ANCHOR, ATT_BRIDGE, ATT_CODE, ATT_CONSTANTVALUE, ATT_DEPRECATED, ATT_DISPATCHER, ATT_EXCEPTIONS, ATT_GENERIC, ATT_GENERIC_FUNCTIONS, ATT_INNERCLASSES, ATT_LINENUMBERTABLE, ATT_LOCALVARIABLETABLE, ATT_MM_BODY, ATT_REDIRECTOR, ATT_RMJ_GLUE, ATT_RMJ_SIGNATURE, ATT_RUNTIME_VISIBLE_ANNOTATIONS, ATT_RUNTIME_VISIBLE_PARAMETER_ANNOTATIONS, ATT_SIGNATURE, ATT_SOURCEFILE, ATT_SYNTHETIC, ATT_UNIVERSE_FIELD, ATT_UNIVERSE_METHOD, ATT_UNIVERSE_VERSION, CST_CLASS, CST_DOUBLE, CST_FIELD, CST_FLOAT, CST_INTEGER, CST_INTERFACEMETHOD, CST_LONG, CST_METHOD, CST_NAMEANDTYPE, CST_STRING, CST_UTF8, ENV_DEBUG_MODE, ENV_USE_CACHE, JAVA_MAGIC, JAVA_MAJOR, JAVA_MINOR, MAX_CODE_PER_METHOD, 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_athrow, opc_baload, opc_bastore, opc_bipush, 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_dup2, opc_dup2_x1, opc_dup2_x2, opc_dup_x1, opc_dup_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_ldc2_w, opc_ldc_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_putstatic, opc_ret, opc_return, opc_saload, opc_sastore, opc_sipush, opc_swap, opc_tableswitch, opc_wide, opc_xxxunusedxxx, POO_ASCII_CONSTANT, POO_CLASS_CONSTANT, POO_DOUBLE_CONSTANT, POO_FLOAT_CONSTANT, POO_INTEGER_CONSTANT, POO_LONG_CONSTANT, POO_NAT_CONSTANT, POO_REF_CONSTANT, POO_STRING_CONSTANT, TYP_ADDRESS, TYP_DOUBLE, TYP_FLOAT, TYP_INT, TYP_LONG, TYP_REFERENCE, TYP_VOID
Constructor Summary
LocalVarInstruction(int opcode, int index)
          Constructs a new instruction that takes a local variable as argument.
Method Summary
 boolean canComplete()
          Returns true iff control flow can reach the next instruction in textual order.
 int getIndex()
          Returns the position of the variable in the local var set
(package private)  int getLocalVar()
          Returns the maximum index of local vars used by this instruction.
 byte getOperandType()
          Returns the type of the operand.
 byte getOperationKind()
          Returns the operation kind.
 int getPushedOnStack()
          Returns the size of data pushed on the stack by this instruction
 byte getReturnType()
          Returns the type pushed on the stack
(package private)  int getSize()
          Returns the number of bytes used by the the instruction in the code array.
 int getStack()
          Return the amount of stack (positive or negative) used by this instruction.
 boolean isLoad()
 boolean isStore()
(package private)  void resolveConstants(ConstantPool cp)
          Insert or check location of constant value on constant pool
(package private)  void write(ConstantPool cp, DataOutput out)
          Write this instruction into a file
Methods inherited from class org.multijava.util.classfile.Instruction
check, computeEndAddress, dump, getAddress, getOpcode, getPoppedFromStack, isLiteral, setAddress, setOpcode
Methods inherited from class org.multijava.util.classfile.AbstractInstructionAccessor
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail


public static final byte KND_LOAD


public static final byte KND_STORE


public static final byte KND_RET


private int index


private int width
Constructor Detail


public LocalVarInstruction(int opcode,
                           int index)
Constructs a new instruction that takes a local variable as argument.

opcode - the opcode of the instruction
index - the index of the local variable
Method Detail


public boolean canComplete()
Returns true iff control flow can reach the next instruction in textual order.


int getSize()
Returns the number of bytes used by the the instruction in the code array.


public int getIndex()
Returns the position of the variable in the local var set


public byte getReturnType()
Returns the type pushed on the stack


public byte getOperandType()
Returns the type of the operand.


public byte getOperationKind()
Returns the operation kind.


int getLocalVar()
Returns the maximum index of local vars used by this instruction. A variable of type

getLocalVar in class Instruction


public boolean isLoad()


public boolean isStore()


public int getPushedOnStack()
Returns the size of data pushed on the stack by this instruction


public int getStack()
Return the amount of stack (positive or negative) used by this instruction.


void resolveConstants(ConstantPool cp)
Insert or check location of constant value on constant pool

cp - the constant pool for this class


void write(ConstantPool cp,
           DataOutput out)
     throws IOException
Write this instruction into a file

cp - the constant pool that contain all data
out - the file where to write this object info
IOException - an io problem has occured


mjc is Copyright (C) 2000-2004 by Iowa State University and is distributed under the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. mjc is based in part on the Kopi project Copyright (C) 1990-99 DMS Decision Management Systems Ges.m.b.H.