n65/lib/directives/inc.rb

require_relative '../instruction_base'

module Assembler6502


  ####
  ##  This directive instruction can include another asm file
  class Inc < InstructionBase

    ####  System include directory
    SystemInclude = File.dirname(__FILE__) + "/../../nes_lib"

    ####  Custom Exceptions
    class FileNotFound < StandardError; end


    ####
    ##  Try to parse an incbin directive
    def self.parse(line)
      ##  Do We have a system directory include?
      match_data = line.match(/^\.inc <([^>]+)>$/)
      unless match_data.nil?
        filename = File.join(SystemInclude, match_data[1])
        return Inc.new(filename)
      end

      ##  Do We have a project relative directory include?
      match_data = line.match(/^\.inc "([^"]+)"$/)
      unless match_data.nil?
        filename = File.join(Dir.pwd, match_data[1])
        return Inc.new(filename)
      end

      ##  Nope, not an inc directive
      nil
    end


    ####
    ##  Initialize with filename
    def initialize(filename)
      @filename = filename
    end


    ####
    ##  Execute on the assembler
    def exec(assembler)
      unless File.exists?(@filename)
        fail(FileNotFound, ".inc can't find #{@filename}")
      end
      File.read(@filename).split(/\n/).each do |line|
        assembler.assemble_one_line(line)
      end
    end


    ####
    ##  Display
    def to_s
      ".inc \"#{@filename}\""
    end


  end

end