Package serp.bytecode

Class StackInstruction

java.lang.Object
serp.bytecode.Instruction
serp.bytecode.TypedInstruction
serp.bytecode.StackInstruction
All Implemented Interfaces:
BCEntity, VisitAcceptor
public class StackInstruction extends TypedInstruction
Represents an instruction that manipulates the stack of the current frame. Using the setType(java.lang.String) methods is a hint about the type being manipulated that might cause this instruction to use the wide version of the opcode it represents (if manipulating a long or double). This saves the developer from having to decide at compile time whether to use pop or pop2, etc.
Author:
Abe White

  • Method Details

    • getStackChange

      public int getStackChange()
      Description copied from class: Instruction
      Return the number of stack positions this instruction pushes or pops during its execution.
      Overrides:
      getStackChange in class Instruction
      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

    • getTypeName

      public String getTypeName()
      This method will always return null; use isWide() to determine if this is pop2, dup2, etc.
      Specified by:
      getTypeName in class TypedInstruction

    • setType

      public TypedInstruction setType(String type)
      Description copied from class: TypedInstruction
      Set the type of this instruction. Types that have no direct support will be converted accordingly.
      Specified by:
      setType in class TypedInstruction
      Returns:
      this instruction, for method chaining

    • isWide

      public boolean isWide()
      Return whether to use the wide form of the current opcode for operations on longs or doubles.

    • setWide

      public StackInstruction setWide(boolean wide)
      Set whether to use the wide form of the current opcode for operations on longs or doubles.
      Returns:
      this instruction, for method chaining

    • 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
      Overrides:
      acceptVisit in class Instruction