Package javassist.bytecode

Class StackMapTable.Walker

java.lang.Object
javassist.bytecode.StackMapTable.Walker
Direct Known Subclasses:
StackMapTable.OffsetShifter, StackMapTable.Printer, StackMapTable.Shifter, StackMapTable.SimpleCopy
Enclosing class:
StackMapTable
public static class StackMapTable.Walker extends Object
A code walker for a StackMapTable attribute.

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    (package private) byte[]
    info
     
    (package private) int
    numOfEntries
     

  • Constructor Summary

    Constructors
    Constructor
    Description
    Walker(byte[] data)
    Constructs a walker.
    Walker(StackMapTable smt)
    Constructs a walker.

  • Method Summary

    Modifier and Type
    Method
    Description
    private int
    appendFrame(int pos, int type)
     
    void
    appendFrame(int pos, int offsetDelta, int[] tags, int[] data)
    Invoked if the visited frame is a append_frame.
    void
    chopFrame(int pos, int offsetDelta, int k)
    Invoked if the visited frame is a chop_frame.
    private int
    fullFrame(int pos)
     
    void
    fullFrame(int pos, int offsetDelta, int[] localTags, int[] localData, int[] stackTags, int[] stackData)
    Invoked if the visited frame is full_frame.
    void
    objectOrUninitialized(int tag, int data, int pos)
    Invoked if Object_variable_info or Uninitialized_variable_info is visited.
    void
    parse()
    Visits each entry of the stack map frames.
    void
    sameFrame(int pos, int offsetDelta)
    Invoked if the visited frame is a same_frame or a same_frame_extended.
    private int
    sameLocals(int pos, int type)
     
    void
    sameLocals(int pos, int offsetDelta, int stackTag, int stackData)
    Invoked if the visited frame is a same_locals_1_stack_item_frame or a same_locals_1_stack_item_frame_extended.
    final int
    size()
    Returns the number of the entries.
    (package private) int
    stackMapFrames(int pos, int nth)
    Invoked when the next entry of the stack map frames is visited.
    private int
    verifyTypeInfo(int pos, int n, int[] tags, int[] data)
     

    Methods inherited from class java.lang.Object

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

  • Field Details

    • info

      byte[] info

    • numOfEntries

      int numOfEntries

  • Constructor Details

    • Walker

      public Walker(StackMapTable smt)
      Constructs a walker.
      Parameters:
      smt - the StackMapTable that this walker walks around.

    • Walker

      public Walker(byte[] data)
      Constructs a walker.
      Parameters:
      data - the info field of the attribute_info structure. It can be obtained by get() in the AttributeInfo class.

  • Method Details

    • size

      public final int size()
      Returns the number of the entries.

    • parse

      public void parse() throws BadBytecode
      Visits each entry of the stack map frames.
      Throws:
      BadBytecode

    • stackMapFrames

      int stackMapFrames(int pos, int nth) throws BadBytecode
      Invoked when the next entry of the stack map frames is visited.
      Parameters:
      pos - the position of the frame in the info field of attribute_info structure.
      nth - the frame is the N-th (0, 1st, 2nd, 3rd, 4th, ...) entry.
      Returns:
      the position of the next frame.
      Throws:
      BadBytecode

    • sameFrame

      public void sameFrame(int pos, int offsetDelta) throws BadBytecode
      Invoked if the visited frame is a same_frame or a same_frame_extended.
      Parameters:
      pos - the position of this frame in the info field of attribute_info structure.
      offsetDelta -
      Throws:
      BadBytecode

    • sameLocals

      private int sameLocals(int pos, int type) throws BadBytecode
      Throws:
      BadBytecode

    • sameLocals

      public void sameLocals(int pos, int offsetDelta, int stackTag, int stackData) throws BadBytecode
      Invoked if the visited frame is a same_locals_1_stack_item_frame or a same_locals_1_stack_item_frame_extended.
      Parameters:
      pos - the position.
      offsetDelta -
      stackTag - stack[0].tag.
      stackData - stack[0].cpool_index if the tag is OBJECT, or stack[0].offset if the tag is UNINIT.
      Throws:
      BadBytecode

    • chopFrame

      public void chopFrame(int pos, int offsetDelta, int k) throws BadBytecode
      Invoked if the visited frame is a chop_frame.
      Parameters:
      pos - the position.
      offsetDelta -
      k - the k last locals are absent.
      Throws:
      BadBytecode

    • appendFrame

      private int appendFrame(int pos, int type) throws BadBytecode
      Throws:
      BadBytecode

    • appendFrame

      public void appendFrame(int pos, int offsetDelta, int[] tags, int[] data) throws BadBytecode
      Invoked if the visited frame is a append_frame.
      Parameters:
      pos - the position.
      offsetDelta -
      tags - locals[i].tag.
      data - locals[i].cpool_index or locals[i].offset.
      Throws:
      BadBytecode

    • fullFrame

      private int fullFrame(int pos) throws BadBytecode
      Throws:
      BadBytecode

    • fullFrame

      public void fullFrame(int pos, int offsetDelta, int[] localTags, int[] localData, int[] stackTags, int[] stackData) throws BadBytecode
      Invoked if the visited frame is full_frame.
      Parameters:
      pos - the position.
      offsetDelta -
      localTags - locals[i].tag
      localData - locals[i].cpool_index or locals[i].offset
      stackTags - stack[i].tag
      stackData - stack[i].cpool_index or stack[i].offset
      Throws:
      BadBytecode

    • verifyTypeInfo

      private int verifyTypeInfo(int pos, int n, int[] tags, int[] data)

    • objectOrUninitialized

      public void objectOrUninitialized(int tag, int data, int pos)
      Invoked if Object_variable_info or Uninitialized_variable_info is visited.
      Parameters:
      tag - OBJECT or UNINIT.
      data - the value of cpool_index or offset.
      pos - the position of cpool_index or offset.