anchor.diff:      select_cond(Flag, true, Pass, Ps, Opts);
   select_passes([{unless,Flag,Pass}|Ps], Opts) ->
       select_cond(Flag, false, Pass, Ps, Opts);
  -select_passes([{_,Fun}=P|Ps], Opts) when is_function(Fun) ->
  -    [P|select_passes(Ps, Opts)];
   select_passes([{delay,Passes0}|Ps], Opts) when is_list(Passes0) ->
       %% Delay evaluation of compiler options and which compiler passes to run.
       %% Since we must know beforehand whether a listing will be produced, we
  
positive.code: 		end
  	end,
      [{Mod,F}|select_passes(Ps, Opts)];
  select_passes([{src_listing,Ext}|_], _Opts) ->
      [{listing,fun (Code, St) -> src_listing(Ext, Code, St) end}];
  select_passes([{listing,Ext}|_], _Opts) ->
  
negative.code: 	{not_done,Passes} ->
  	    [{delay,Passes}|select_passes(Ps, Opts)]
      end;
  select_passes([], _Opts) ->
      [];
  select_passes([List|Ps], Opts) when is_list(List) ->
  