Class InstructionVector

  • All Implemented Interfaces:
    CodeGenerator

    public class InstructionVector
    extends java.lang.Object
    implements CodeGenerator
    A list of Instructions and/or other CodeGenerator objects.
    Author:
    Thomas Down, Matthew Pocock
    • Constructor Detail

      • InstructionVector

        public InstructionVector()
    • Method Detail

      • size

        public int size()
      • remove

        public void remove​(int pos)
      • getStartLabel

        public Label getStartLabel()
      • getEndLabel

        public Label getEndLabel()
      • writeCode

        public void writeCode​(CodeContext ctx)
                       throws CodeException
        Description copied from interface: CodeGenerator
        Write the byte or bytes for this CodeGenerator to a CodeContext.
        Specified by:
        writeCode in interface CodeGenerator
        Parameters:
        ctx - a CodeContext to write to
        Throws:
        CodeException - if there was some failure in writing to the context
      • stackDepth

        public int stackDepth()
        Description copied from interface: CodeGenerator
        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.

        Specified by:
        stackDepth in interface CodeGenerator
        Returns:
        the stack depth needed
      • stackDelta

        public int stackDelta()
        Description copied from interface: CodeGenerator
        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.

        Specified by:
        stackDelta in interface CodeGenerator
        Returns:
        the change between stack depth before and after execution of this code