lib/voodoo/generators/nasm_elf_generator.rb

   1 require 'voodoo/config'
   2 require 'voodoo/generators/command_postprocessor'
   3
   4 module Voodoo
   5   # Class that generates ELF object files by invoking nasm on
   6   # the output of a code generator that generates NASM assembly.
   7   class NasmELFGenerator
   8     def initialize nasmgenerator, nasm_extra_args
   9       @nasmgenerator = nasmgenerator
  10       @nasm_extra_args = nasm_extra_args
  11       @output_file_suffix = '.o'
  12     end
  13
  14     include CommandPostProcessor
  15
  16     def output_file_name input_name
  17       input_name.sub(/\.voo$/, '') + @output_file_suffix
  18     end
  19
  20     def output_file_suffix
  21       @output_file_suffix
  22     end
  23
  24     # Writes the generated code to the given IO handle
  25     def write io
  26       # Create temporary file to write NASM code to
  27       if io.respond_to? :path
  28         base = File.basename(io.path).sub(/([^.]*).*/, "\\1")
  29       else
  30         base = self.class.name
  31       end
  32
  33       Tempfile.open(base + '.asm') do |nasmfile|
  34         begin
  35           Tempfile.open(base + '.o') do |elffile|
  36             begin
  37               elffile.close
  38               # Write NASM code to nsamfile
  39               @nasmgenerator.write nasmfile
  40               nasmfile.close
  41               # Find out the name of the nasm executable
  42               if ENV.has_key? 'NASM'
  43                 nasm = ENV['NASM']
  44               elsif ENV.has_key? 'YASM'
  45                 nasm = ENV['YASM']
  46               else
  47                 nasm = Voodoo::Config.nasm_command
  48               end
  49               # Invoke nasm on nasmfile
  50               command = "#{nasm} #{@nasm_extra_args}" +
  51                 " -o #{shell_encode elffile.path}" +
  52                 " #{shell_encode nasmfile.path}"
  53               if system(command)
  54                 write_file_to_io elffile.path, io
  55               else
  56                 raise "Command (#{command}) failed " +
  57                   " with status #{$?.exitstatus}"
  58               end
  59             ensure
  60               elffile.unlink
  61             end
  62           end
  63         ensure
  64           nasmfile.unlink
  65         end
  66       end
  67     end
  68   end
  69 end