DLLからDEFファイルを作る

DLLファイルからDEFファイルを自動生成する必要があって、MinGWのpexportsを持っていなかったので、さくっと書いてみた。

dll_to_def.rb

#!ruby -Ku
# Generate the .def file from .dll using 'dumpbin.exe'
# 2009-04-30 23:43:20

class ExportsList
  FUNCTION_LINE_PATTERN = /^\s+(\d+)\s+[0-9A-Fa-f]+\s+[0-9A-Fa-f]+\s+(.*)$/

  def initialize(dllname)
    @dllname = dllname
    @max_name_length = 0
    @exports = []
    dumpbin(dllname) do |line|
      next unless line =~ FUNCTION_LINE_PATTERN
      @exports << [$1, $2]
      @max_name_length = $2.length if @max_name_length < $2.length
    end
  end

  def save_as_def
    width = ((@max_name_length + 7) / 8) * 8
    basename = File.basename(@dllname, '.dll')
    File.open(basename + '.def', 'w') do |f|
      f.puts(%Q|LIBRARY "#{basename}"|)
      f.puts
      f.puts('EXPORTS')
      @exports.each do |i, name|
        f.print("\t#{name}")
        f.print("\t" * ((width + 7 - name.length) / 8))
        f.puts("@#{i}")
      end
    end
  end

  private
  def dumpbin(dllname)
    raise "Command not found: dumpbin" unless cmd_exist?('dumpbin')
    Kernel.open("|dumpbin /exports #{dllname}") do |f|
      while line = f.gets
        yield(line)
      end
    end
  end

  def cmd_exist?(cmd)
    ENV['PATH'].split(';').each do |path|
      (';' + ENV['PATHEXT']).split(';').each do |ext|
        pathname = File.join(File.expand_path(path), cmd + ext)
        return true if File.exist?(pathname)
      end
    end
    nil
  end
end

if $0 == __FILE__
  ARGV.each do |dllname|
    ExportsList.new(dllname).save_as_def
  end
end