main_url

# File lib/rdoc/generators/html_generator.rb, line 1361
    def main_url
      main_page = @options.main_page
      ref = nil
      if main_page
        ref = AllReferences[main_page]
        if ref
          ref = ref.path
        else
          $stderr.puts "Could not find main page #{main_page}"
        end
      end

      unless ref
        for file in @files
          if file.document_self
            ref = file.path 
            break
          end
        end
      end

      unless ref
        $stderr.puts "Couldn't find anything to document"
        $stderr.puts "Perhaps you've used :stopdoc: in all classes"
        exit(1)
      end

      ref
    end