Package org.biojava.utils.bytecode

Interface CodeGenerator

All Known Subinterfaces:
Instruction, ParametricCodeGenerator, PParametricCodeGenerator
All Known Implementing Classes:
IfExpression, InstructionVector, Label, MarkLabel
public interface CodeGenerator
Interface for an object which can produce Java bytecode.
Author:
Thomas Down, Matthew Pocock

  • Method Summary

    Modifier and Type
    Method
    Description
    int
    stackDelta()
    Return the change in the stack dept this generator will cause.
    int
    stackDepth()
    Return the total depth of the stack required by this CodeGenerator.
    void
    writeCode(CodeContext ctx)
    Write the byte or bytes for this CodeGenerator to a CodeContext.

  • Method Details

    • writeCode

      void writeCode(CodeContext ctx) throws CodeException
      Write the byte or bytes for this CodeGenerator to a CodeContext.
      Parameters:
      ctx - a CodeContext to write to
      Throws:
      CodeException - if there was some failure in writing to the context

    • stackDepth

      int stackDepth()
      Return the total depth of the stack required by this CodeGenerator.

      For single byte-code instructions, this will be the same as stackDelta() if stackDelta() is positive, zero otherwise. For a compound instruction, this will be the maximum stack depth required to execute all sub-instructions.

      Returns:
      the stack depth needed

    • stackDelta

      int stackDelta()
      Return the change in the stack dept this generator will cause.

      In the case of an instruction that adds items to the stack, stackDelta will be positive. For instructions that removes items from the stack, this will be negative.

      Returns:
      the change between stack depth before and after execution of this code