Class: Voodoo::NasmELFGenerator

Inherits:
Object
  • Object
show all
Includes:
CommandPostProcessor
Defined in:
lib/voodoo/generators/nasm_elf_generator.rb

Overview

Class that generates ELF object files by invoking nasm on the output of a code generator that generates NASM assembly.

Instance Method Summary collapse

Methods included from CommandPostProcessor

shell_encode, tempfile, write_file_to_io

Constructor Details

#initialize(nasmgenerator, nasm_extra_args) ⇒ NasmELFGenerator

Returns a new instance of NasmELFGenerator.



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# File 'lib/voodoo/generators/nasm_elf_generator.rb', line 8

def initialize nasmgenerator, nasm_extra_args
  @nasmgenerator = nasmgenerator
  @nasm_extra_args = nasm_extra_args
  @output_file_suffix = '.o'
end

Instance Method Details

#output_file_name(input_name) ⇒ Object 



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# File 'lib/voodoo/generators/nasm_elf_generator.rb', line 16

def output_file_name input_name
  input_name.sub(/\.voo$/, '') + @output_file_suffix
end

#output_file_suffix ⇒ Object 



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# File 'lib/voodoo/generators/nasm_elf_generator.rb', line 20

def output_file_suffix
  @output_file_suffix
end

#write(io) ⇒ Object

Writes the generated code to the given IO handle



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# File 'lib/voodoo/generators/nasm_elf_generator.rb', line 25

def write io
  # Create temporary file to write NASM code to
  if io.respond_to? :path
    base = File.basename(io.path).sub(/([^.]*).*/, "\\1")
  else
    base = self.class.name
  end
  
  Tempfile.open(base + '.asm') do |nasmfile|
    begin
      Tempfile.open(base + '.o') do |elffile|
        begin
          elffile.close
          # Write NASM code to nasmfile
          @nasmgenerator.write nasmfile
          nasmfile.close
          # Find out the name of the nasm executable
          if ENV.has_key? 'NASM'
            nasm = ENV['NASM']
          elsif ENV.has_key? 'YASM'
            nasm = ENV['YASM']
          else
            nasm = Voodoo::Config.nasm_command
          end
          # Invoke nasm on nasmfile
          command = "#{nasm} #{@nasm_extra_args}" +
            " -o #{shell_encode elffile.path}" +
            " #{shell_encode nasmfile.path}"
          if system(command)
            write_file_to_io elffile.path, io
          else
            raise "Command (#{command}) failed " +
              " with status #{$?.exitstatus}"
          end
        ensure
          elffile.unlink
        end
      end
    ensure
      nasmfile.unlink
    end
  end
end