Refine pretty-print indenting

tasks/mruby_build_commands.rake

@@ -214,7 +214,7 @@ module MRuby
       @command ||= @build.mrbcfile
       IO.popen("#{filename @command} #{@compile_options % {:funcname => funcname}}", 'r+') do |io|
         [infiles].flatten.each do |f|
-          _pp "  MRBC", "#{f}"
+          _pp "MRBC", "#{f}", nil, :indent => 2
           io.write IO.read(f)
         end
         io.close_write

tasks/ruby_ext.rake

@@ -57,6 +57,10 @@ else
   $pp_show = false if $verbose
 end
 
-def _pp(cmd, src, tgt=nil)
-  puts '%-5s %s %s' % [cmd, src, tgt ? "-> #{tgt}" : nil] if $pp_show
+def _pp(cmd, src, tgt=nil, options={})
+  return unless $pp_show
+
+  width = 5
+  template = options[:indent] ? "%#{width*options[:indent]}s %s %s" : "%-#{width}s %s %s"
+  puts template % [cmd, src, tgt ? "-> #{tgt}" : nil]
 end