Package org.apache.bcel.generic

Class BranchInstruction

java.lang.Object
org.apache.bcel.generic.Instruction
org.apache.bcel.generic.BranchInstruction
All Implemented Interfaces:
Cloneable, InstructionTargeter
Direct Known Subclasses:
GotoInstruction, IfInstruction, JsrInstruction, Select
public abstract class BranchInstruction extends Instruction implements InstructionTargeter
Abstract super class for branching instructions like GOTO, IFEQ, etc.. Branch instructions may have a variable length, namely GOTO, JSR, LOOKUPSWITCH and TABLESWITCH.
See Also:

  • Field Details

    • index

      @Deprecated protected int index
      Deprecated.
      (since 6.0) will be made private; do not access directly, use getter/setter

    • target

      @Deprecated protected InstructionHandle target
      Deprecated.
      (since 6.0) will be made private; do not access directly, use getter/setter

    • position

      @Deprecated protected int position
      Deprecated.
      (since 6.0) will be made private; do not access directly, use getter/setter

  • Constructor Details

    • BranchInstruction

      protected BranchInstruction(short opcode, InstructionHandle target)
      Common super constructor
      Parameters:
      opcode - Instruction opcode
      target - instruction to branch to

  • Method Details

    • containsTarget

      public boolean containsTarget(InstructionHandle ih)
      Description copied from interface: InstructionTargeter
      Tests whether this targeter targets the specified instruction handle.
      Specified by:
      containsTarget in interface InstructionTargeter
      Parameters:
      ih - the instruction handle to test.
      Returns:
      true, if ih is target of this instruction

    • 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 - Thrown when an I/O exception of some sort has occurred.

    • getIndex

      public final int getIndex()
      Returns:
      target offset in byte code

    • getPosition

      protected int getPosition()
      Returns:
      the position
      Since:
      6.0

    • getTarget

      public InstructionHandle getTarget()
      Returns:
      target of branch instruction

    • getTargetOffset

      protected int getTargetOffset()
      Returns:
      the offset to this instruction's target

    • getTargetOffset

      protected int getTargetOffset(InstructionHandle target)
      Parameters:
      target - branch target
      Returns:
      the offset to 'target' relative to this instruction

    • initFromFile

      protected void initFromFile(ByteSequence bytes, boolean wide) throws IOException
      Read needed data (e.g. index) from file. Conversion to a InstructionHandle is done in InstructionList(byte[]).
      Overrides:
      initFromFile in class Instruction
      Parameters:
      bytes - input stream
      wide - wide prefix?
      Throws:
      IOException - may be thrown if the implementation needs to read data from the file
      See Also:

    • setIndex

      protected void setIndex(int index)
      Parameters:
      index - the index to set
      Since:
      6.0

    • setPosition

      protected void setPosition(int position)
      Parameters:
      position - the position to set
      Since:
      6.0

    • setTarget

      public void setTarget(InstructionHandle target)
      Sets branch target
      Parameters:
      target - branch target

    • toString

      public String toString(boolean verbose)
      Long output format: <position in byte code> <name of opcode> "["<opcode number>"]" "("<length of instruction>")" "<"<target instruction>">" "@"<branch target offset>
      Overrides:
      toString in class Instruction
      Parameters:
      verbose - long/short format switch
      Returns:
      mnemonic for instruction

    • updatePosition

      protected int updatePosition(int offset, int maxOffset)
      Called by InstructionList.setPositions when setting the position for every instruction. In the presence of variable length instructions 'setPositions' performs multiple passes over the instruction list to calculate the correct (byte) positions and offsets by calling this function.
      Parameters:
      offset - additional offset caused by preceding (variable length) instructions
      maxOffset - the maximum offset that may be caused by these instructions
      Returns:
      additional offset caused by possible change of this instruction's length

    • updateTarget

      public void updateTarget(InstructionHandle oldIh, InstructionHandle newIh)
      Description copied from interface: InstructionTargeter
      Replaces the target of this targeter from this old handle to the new handle.
      Specified by:
      updateTarget in interface InstructionTargeter
      Parameters:
      oldIh - old target
      newIh - new target