at.dms.classfile
Class JumpInstruction

java.lang.Object
  |
  +--at.dms.classfile.AbstractInstructionAccessor
        |
        +--at.dms.classfile.Instruction
              |
              +--at.dms.classfile.JumpInstruction
All Implemented Interfaces:
AccessorContainer, Constants, InstructionAccessor

public class JumpInstruction
extends Instruction
implements AccessorContainer

Representation of a JVM-bytecode Jump instruction.


Fields inherited from interface at.dms.classfile.Constants
ACC_ABSTRACT, ACC_FINAL, ACC_INTERFACE, ACC_NATIVE, ACC_NBR_FLAGS, ACC_PRIVATE, ACC_PROTECTED, ACC_PUBLIC, ACC_STATIC, ACC_STRICT, ACC_SUPER, ACC_SYNCHRONIZED, ACC_TRANSIENT, ACC_VOLATILE, ATT_CODE, ATT_CONSTANTVALUE, ATT_DEPRECATED, ATT_EXCEPTIONS, ATT_GENERIC, ATT_INNERCLASSES, ATT_LINENUMBERTABLE, ATT_LOCALVARIABLETABLE, ATT_SOURCEFILE, ATT_SYNTHETIC, 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_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_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
JumpInstruction(int opcode, InstructionAccessor target)
          Constructs a new instruction that takes a label as argument.
JumpInstruction(int opcode, InstructionAccessor target, java.lang.String debugIdent)
          Constructs a new instruction that takes a label as argument.
 
Method Summary
 boolean canComplete()
          Returns true iff control flow can reach the next instruction in textual order.
(package private)  void check(CodeEnv env, int curStack)
          Verifies the enclosed instruction and computes the stack height.
(package private)  void computeEndAddress(CodePosition position)
          Computes the address of the end of the instruction.
 void dump()
          Debugging method.
 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.
 InstructionAccessor getTarget()
          Return the target of this instruction
(package private)  void resolveConstants(ConstantPool cp)
          Insert or check location of constant value on constant pool
 void setTarget(InstructionAccessor target)
          Sets the target for this instruction
 void transformAccessors(AccessorTransformer transformer)
          Transforms targets (deferences to actual instructions).
(package private)  void write(ConstantPool cp, java.io.DataOutput out)
          Write this instruction into a file
 
Methods inherited from class at.dms.classfile.Instruction
getAddress, getLocalVar, getOpcode, getPoppedFromStack, isLiteral, setAddress, setOpcode
 
Methods inherited from class at.dms.classfile.AbstractInstructionAccessor
transform
 
Methods inherited from class java.lang.Object
, clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

JumpInstruction

public JumpInstruction(int opcode,
                       InstructionAccessor target)
Constructs a new instruction that takes a label as argument.
Parameters:
opcode - The opcode of the instruction.
target - The referenced instruction.

JumpInstruction

public JumpInstruction(int opcode,
                       InstructionAccessor target,
                       java.lang.String debugIdent)
Constructs a new instruction that takes a label as argument.
Parameters:
opcode - The opcode of the instruction.
target - The referenced instruction.
debugIdent - Can be used to trace wrong jump instructions back to the generator of that instruction.
Method Detail

canComplete

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

transformAccessors

public void transformAccessors(AccessorTransformer transformer)
                        throws BadAccessorException
Transforms targets (deferences to actual instructions).
Specified by:
transformAccessors in interface AccessorContainer
Following copied from interface: at.dms.classfile.AccessorContainer
Parameters:
transformer - The transformer used to transform accessors.

setTarget

public void setTarget(InstructionAccessor target)
Sets the target for this instruction

getTarget

public InstructionAccessor getTarget()
Return the target of this instruction

getSize

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

check

void check(CodeEnv env,
           int curStack)
     throws ClassFileFormatException
Verifies the enclosed instruction and computes the stack height.
Overrides:
check in class Instruction
Parameters:
env - the check environment
curStack - the stack height at the end of the execution of the instruction
Returns:
true iff the next instruction in textual order needs to be checked, i.e. this instruction has not been checked before and it can complete normally
Throws:
ClassFileFormatException - a problem was detected

computeEndAddress

void computeEndAddress(CodePosition position)
Computes the address of the end of the instruction.
Overrides:
computeEndAddress in class Instruction
Parameters:
position - the minimum and maximum address of the begin of this instruction. This parameter is changed to the minimum and maximum address of the end of this instruction.

getPushedOnStack

public int getPushedOnStack()
Returns the size of data pushed on the stack by this instruction
Overrides:
getPushedOnStack in class Instruction

getReturnType

public byte getReturnType()
Returns the type pushed on the stack
Overrides:
getReturnType in class Instruction

getStack

public int getStack()
Return the amount of stack (positive or negative) used by this instruction.
Overrides:
getStack in class Instruction

resolveConstants

void resolveConstants(ConstantPool cp)
Insert or check location of constant value on constant pool
Overrides:
resolveConstants in class Instruction
Parameters:
cp - the constant pool for this class

write

void write(ConstantPool cp,
           java.io.DataOutput out)
     throws java.io.IOException
Write this instruction into a file
Overrides:
write in class Instruction
Parameters:
cp - the constant pool that contain all data
out - the file where to write this object info
Throws:
java.io.IOException - an io problem has occured

dump

public void dump()
Debugging method.
Overrides:
dump in class Instruction