user_default.erl

-module(user_default).
-author('serge@hq.idt.net').

%% Compile this file and use this line in your ~/.erlang file (with
%% correct path, of course!) to where the user_default.beam file is stored.
%%
%%    code:load_abs("/home/fritchie/erlang/user_default").

-export([help/0,dbgtc/1, dbgtc_follow/1, dbgon/1, dbgon/2,
         dbgadd/1, dbgadd/2, dbgdel/1, dbgdel/2, dbgoff/0,
	 dbg_ip_trace/1,
         l/0, mm/0, la/0]).
-export([my_tracer/0, my_dhandler/2, filt_state_from_term/1]).

-import(io, [format/1]).

help() ->
     shell_default:help(),
     format("** user extended commands **~n"),
     format("dbgtc(File)   -- use dbg:trace_client() to read data from File\n"),
     format("dbgon(M)      -- enable dbg tracer on all funs in module M\n"),
     format("dbgon(M,Fun)  -- enable dbg tracer for module M and function F\n"),
     format("dbgon(M,File) -- enable dbg tracer for module M and log to File\n"),
     format("dbgadd(M)     -- enable call tracer for module M\n"),
     format("dbgadd(M,F)   -- enable call tracer for function M:F\n"),
     format("dbgdel(M)     -- disable call tracer for module M\n"),
     format("dbgdel(M,F)   -- disable call tracer for function M:F\n"),
     format("dbgoff()      -- disable dbg tracer (calls dbg:stop/0)\n"),
     format("l()           -- load all changed modules\n"),
     format("la()          -- load all modules\n"),
%     format("nl()          -- load all changed modules on all known nodes\n"),
     format("mm()          -- list modified modules\n"),
     true.

dbgtc(File) ->
    Fun = fun({trace,_,call,{M,F,A}}, _) ->
                 io:format("call: ~w:~w~w~n", [M,F,A]);
             ({trace,_,return_from,{M,F,A},R}, _) ->
                 io:format("retn: ~w:~w/~w -> ~w~n", [M,F,A,R]);
             (A,B) ->
                 io:format("~w: ~w~n", [A,B])
          end,
    dbg:trace_client(file, File, {Fun, []}).

dbgtc_follow(File) ->
    Fun = fun({trace,_,call,{M,F,A}}, _) ->
                 io:format("call: ~w:~w~w~n", [M,F,A]);
             ({trace,_,return_from,{M,F,A},R}, _) ->
                 io:format("retn: ~w:~w/~w -> ~w~n", [M,F,A,R]);
             (A,B) ->
                 io:format("~w: ~w~n", [A,B])
          end,
    dbg:trace_client(follow_file, File, {Fun, []}).

dbgon(Module) ->
    case dbg:tracer() of
    {ok,_} ->
       dbg:p(all,call),
       dbg:tpl(Module, [{'_',[],[{return_trace}]}]),
       ok;
    Else ->
       Else
    end.

dbgon(Module, Fun) when is_atom(Fun) ->
    {ok,_} = dbg:tracer(),
    dbg:p(all,call),
    %%dbg:tpl(Module, Fun, [{'_',[],[{return_trace}]}]),
    dbg:tpl(Module, Fun, [{'_',[],[{return_trace},{exception_trace}]}]),
    ok;

dbgon(Module, File) when is_list(File) ->
    {ok,_} = dbg:tracer(port, dbg:trace_port(file, File)),
    dbg:p(all, call),
    dbg:tpl(Module, [{'_',[],[{return_trace},{exception_trace}]}]),
    ok;

dbgon(Module, TcpPort) when is_integer(TcpPort) ->
    io:format("Use this command on the node you're tracing (-remsh ...)\n"),
    io:format("Use dbg:stop() on target node when done.\n"),
    {ok,_} = dbg:tracer(port, dbg:trace_port(ip, TcpPort)),
    dbg:p(all,call),
    %%dbg:tpl(Module, [{'_',[],[{return_trace}]}]),
    dbg:tpl(Module, [{'_',[],[{return_trace},{exception_trace}]}]),
    ok.

dbg_ip_trace(TcpPort) ->
    io:format("Run on same machine as target but NOT -remsh target-node\n"),
    io:format("Use dbg:stop() when done.\n"),
    dbg:trace_client(ip, TcpPort).

dbgadd(Module) ->
    %%dbg:tpl(Module, [{'_',[],[{return_trace}]}]),
    dbg:tpl(Module, [{'_',[],[{return_trace},{exception_trace}]}]),
    ok.

dbgadd(Module, Fun) ->
    %%dbg:tpl(Module, Fun, [{'_',[],[{return_trace}]}]),
    dbg:tpl(Module, Fun, [{'_',[],[{return_trace},{exception_trace}]}]),
    ok.

dbgdel(Module) ->
    dbg:ctpl(Module),
    ok.

dbgdel(Module, Fun) ->
    dbg:ctpl(Module, Fun),
    ok.

dbgoff() ->
    dbg:stop().

%% Reload modules that have been modified since last load.  From Tobbe
%% Tornqvist, http://blog.tornkvist.org/, "Easy load of recompiled
%% code", which may in turn have come from Serge?

l() ->
    [c:l(M) || M <- mm()].

mm() ->
    modified_modules().

modified_modules() ->
    [M || {M, _} <- code:all_loaded(), 
	  module_modified(M) == true].

module_modified(Module) ->
    case code:is_loaded(Module) of
	{file, preloaded} ->
	    false;
	{file, Path} ->
	    CompileOpts = 
		proplists:get_value(compile, Module:module_info()),
	    CompileTime = proplists:get_value(time, CompileOpts),
	    Src = proplists:get_value(source, CompileOpts),
	    module_modified(Path, CompileTime, Src);
	_ ->
	    false
    end.

module_modified(Path, PrevCompileTime, PrevSrc) ->
    case find_module_file(Path) of
	false ->
	    false;
	ModPath ->
	    case beam_lib:chunks(ModPath, ["CInf"]) of
		{ok, {_, [{_, CB}]}} ->
		    CompileOpts =  binary_to_term(CB),
		    CompileTime = proplists:get_value(time,                             
						      CompileOpts),
		    Src = proplists:get_value(source, CompileOpts),
		    not (CompileTime == PrevCompileTime) and 
							   (Src == PrevSrc);
		_ ->
		    false
	    end
    end.

find_module_file(Path) ->
    case file:read_file_info(Path) of
	{ok, _} ->
	    Path;
	_ ->
	    %% may be the path was changed
	    case code:where_is_file(filename:basename(Path)) of
		non_existing ->
		    false;
		NewPath ->
		    NewPath
	    end
    end.

%% Reload all modules, regardless of age.
la() ->
    FiltZip = lists:filter(
	fun({_Mod, Path}) when is_list(Path) ->
		case string:str(Path, "/kernel-") +
		     string:str(Path, "/stdlib-") of
			0 -> true;
			_ -> false
		end;
	    (_) -> false
	end, code:all_loaded()),
    {Ms, _} = lists:unzip(FiltZip),
    lists:foldl(fun(M, Acc) ->
			case shell_default:l(M) of
				{error, _} -> Acc;
				_          -> [M|Acc]
			end
		end, [], Ms).

my_tracer() ->
    dbg:tracer(process, {fun my_dhandler/2, user}).

my_dhandler(TraceMsg, Acc) ->
    dbg:dhandler(filt_state_from_term(TraceMsg), Acc).

filt_state_from_term(T) when is_tuple(T), element(1, T) == state ->
    sTatE;
filt_state_from_term(T) when is_tuple(T), element(1, T) == chain_r ->
    cHain_R;
filt_state_from_term(T) when is_tuple(T), element(1, T) == g_hash_r ->
    g_Hash_R;
filt_state_from_term(T) when is_tuple(T), element(1, T) == hash_r ->
    hAsh_R;
filt_state_from_term(T) when is_tuple(T) ->
    list_to_tuple(filt_state_from_term(tuple_to_list(T)));
filt_state_from_term([H|T]) ->
    [filt_state_from_term(H)|filt_state_from_term(T)];
filt_state_from_term(X) ->
    X.