Package serp.bytecode

Class Instruction

java.lang.Object
serp.bytecode.Instruction
All Implemented Interfaces:
BCEntity, VisitAcceptor
Direct Known Subclasses:
FieldInstruction, JumpInstruction, MethodInstruction, MonitorInstruction, TypedInstruction
public class Instruction extends Object implements BCEntity, VisitAcceptor
An opcode in a method of a class.
Author:
Abe White

  • Method Summary

    Modifier and Type
    Method
    Description
    void
    acceptVisit(BCVisitor visit)
    Accept a visit from a BCVisitor, calling the appropriate methods to notify the visitor that it has entered this entity, and to provide it with the proper callbacks for each sub-entity owned by this one.
    boolean
    equalsInstruction(Instruction other)
    Instructions are equal if their opcodes are the same.
    int
    getByteIndex()
    Return the index in the method code byte block at which this opcode starts.
    ClassLoader
    getClassLoader()
    Return the class loader to use when loading related classes.
    Code
    getCode()
    Return the code block that owns this instruction.
    LineNumber
    getLineNumber()
    Return the line number of this instruction, or null if none.
    int
    getLogicalStackChange()
    Return the logical number of stack positions changed by this instruction.
    String
    getName()
    Return the name of this instruction.
    int
    getOpcode()
    Return the opcode this instruction represents.
    ConstantPool
    getPool()
    Return the constant pool of the current class.
    Project
    getProject()
    Return the project of the current class.
    int
    getStackChange()
    Return the number of stack positions this instruction pushes or pops during its execution.
    boolean
    isValid()
    Return false if this entity has been removed from its parent; in this case the results of any operations on the entity are undefined.

    Methods inherited from class java.lang.Object

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

  • Method Details

    • getCode

      public Code getCode()
      Return the code block that owns this instruction.

    • getName

      public String getName()
      Return the name of this instruction.

    • getOpcode

      public int getOpcode()
      Return the opcode this instruction represents.

    • getByteIndex

      public int getByteIndex()
      Return the index in the method code byte block at which this opcode starts. Note that this information may be out of date if the code block has been modified since last read/written.

    • getLineNumber

      public LineNumber getLineNumber()
      Return the line number of this instruction, or null if none. This method is subject to the validity constraints of getByteIndex().
      See Also:

    • getLogicalStackChange

      public int getLogicalStackChange()
      Return the logical number of stack positions changed by this instruction. In other words, ignore weirdness with longs and doubles taking two stack positions.

    • getStackChange

      public int getStackChange()
      Return the number of stack positions this instruction pushes or pops during its execution.
      Returns:
      0 if the stack is not affected by this instruction, a positive number if it pushes onto the stack, and a negative number if it pops from the stack

    • equalsInstruction

      public boolean equalsInstruction(Instruction other)
      Instructions are equal if their opcodes are the same. Subclasses should override this method to perform a template comparison: instructions should compare equal to other instructions of the same type where the data is either the same or the data is unset.

    • getProject

      public Project getProject()
      Description copied from interface: BCEntity
      Return the project of the current class.
      Specified by:
      getProject in interface BCEntity

    • getPool

      public ConstantPool getPool()
      Description copied from interface: BCEntity
      Return the constant pool of the current class.
      Specified by:
      getPool in interface BCEntity

    • getClassLoader

      public ClassLoader getClassLoader()
      Description copied from interface: BCEntity
      Return the class loader to use when loading related classes.
      Specified by:
      getClassLoader in interface BCEntity

    • isValid

      public boolean isValid()
      Description copied from interface: BCEntity
      Return false if this entity has been removed from its parent; in this case the results of any operations on the entity are undefined.
      Specified by:
      isValid in interface BCEntity

    • acceptVisit

      public void acceptVisit(BCVisitor visit)
      Description copied from interface: VisitAcceptor
      Accept a visit from a BCVisitor, calling the appropriate methods to notify the visitor that it has entered this entity, and to provide it with the proper callbacks for each sub-entity owned by this one.
      Specified by:
      acceptVisit in interface VisitAcceptor