profile_requires

# File tools/profile, line 21
    def profile_requires
      GC.start
      before_rss = `ps -o rss= -p #{Process.pid}`.to_i

      if mode
        require 'ruby-prof'
        RubyProf.measure_mode = RubyProf.const_get(mode.upcase)
        RubyProf.start
      else
        Object.instance_eval { include RequireProfiler }
      end

      elapsed = Benchmark.realtime { require path }
      results = RubyProf.stop if mode

      GC.start
      after_rss = `ps -o rss= -p #{Process.pid}`.to_i

      if mode
        if printer = ARGV.shift
          puts "RubyProf outputting to stderr with printer #{printer}"
          RubyProf.const_get("#{printer.to_s.classify}Printer").new(results).print($stdout)
        elsif RubyProf.const_defined?(:CallStackPrinter)
          filename = "#{File.basename(path, '.rb')}.#{mode}.html"
          puts "RubyProf outputting to #{filename}"
          File.open(filename, 'w') do |out|
            RubyProf::CallStackPrinter.new(results).print(out)
          end
        else
          filename = "#{File.basename(path, '.rb')}.#{mode}.callgrind"
          puts "RubyProf outputting to #{filename}"
          File.open(filename, 'w') do |out|
            RubyProf::CallTreePrinter.new(results).print(out)
          end
        end
      end

      RequireProfiler.stats.each do |file, depth, sec|
        if sec
          puts "%8.1f ms  %s%s" % [sec * 1000, ' ' * depth, file]
        else
          puts "#{' ' * (13 + depth)}#{file}"
        end
      end
      puts "%8.1f ms  %d KB RSS" % [elapsed * 1000, after_rss - before_rss]
    end