Make modules loading in a dependent order (#1191)

src/gen_mod.erl

@@ -53,6 +53,7 @@
 -callback start(binary(), opts()) -> any().
 -callback stop(binary()) -> any().
 -callback mod_opt_type(atom()) -> fun((term()) -> term()) | [atom()].
+-callback depends(binary(), opts()) -> [{module(), hard | soft}].
 
 -export_type([opts/0]).
 -export_type([db_type/0]).
@@ -77,18 +78,49 @@ start_modules() ->
 
 get_modules_options(Host) ->
     ejabberd_config:get_option(
-	{modules, Host},
-	fun(Mods) ->
-	    lists:map(
+      {modules, Host},
+      fun(Mods) ->
+	      lists:map(
 		fun({M, A}) when is_atom(M), is_list(A) ->
-		    {M, A}
+			{M, A}
 		end, Mods)
-	end, []).
+      end, []).
+
+sort_modules(Host, ModOpts) ->
+    G = digraph:new([acyclic]),
+    lists:foreach(
+      fun({Mod, Opts}) ->
+	      digraph:add_vertex(G, Mod, Opts),
+	      Deps = try Mod:depends(Host, Opts) catch _:undef -> [] end,
+	      lists:foreach(
+		fun({DepMod, Type}) ->
+			case lists:keyfind(DepMod, 1, ModOpts) of
+			    false when Type == hard ->
+				ErrTxt = io_lib:format(
+					   "failed to load module '~s' "
+					   "because it depends on module '~s' "
+					   "which is not found in the config",
+					   [Mod, DepMod]),
+				?ERROR_MSG(ErrTxt, []),
+				digraph:del_vertex(G, Mod),
+				maybe_halt_ejabberd(ErrTxt);
+			    false when Type == soft ->
+				?WARNING_MSG("module '~s' is recommended for "
+					     "module '~s' but is not found in "
+					     "the config",
+					     [DepMod, Mod]);
+			    {DepMod, DepOpts} ->
+				digraph:add_vertex(G, DepMod, DepOpts),
+				digraph:add_edge(G, DepMod, Mod)
+			end
+		end, Deps)
+      end, ModOpts),
+    [digraph:vertex(G, V) || V <- digraph_utils:topsort(G)].
 
 -spec start_modules(binary()) -> any().
 
 start_modules(Host) ->
-    Modules = get_modules_options(Host),
+    Modules = sort_modules(Host, get_modules_options(Host)),
     lists:foreach(
 	fun({Module, Opts}) ->
 	    start_module(Host, Module, Opts)
@@ -121,16 +153,20 @@ start_module(Host, Module, Opts0) ->
 			    [Module, Host, Opts, Class, Reason,
 			     erlang:get_stacktrace()]),
 	  ?CRITICAL_MSG(ErrorText, []),
-	  case is_app_running(ejabberd) of
-	    true ->
-		erlang:raise(Class, Reason, erlang:get_stacktrace());
-	    false ->
-		?CRITICAL_MSG("ejabberd initialization was aborted "
-			      "because a module start failed.",
-			      []),
-		timer:sleep(3000),
-		erlang:halt(string:substr(lists:flatten(ErrorText), 1, 199))
-	  end
+          maybe_halt_ejabberd(ErrorText),
+	  erlang:raise(Class, Reason, erlang:get_stacktrace())
+    end.
+
+maybe_halt_ejabberd(ErrorText) ->
+    case is_app_running(ejabberd) of
+	false ->
+	    ?CRITICAL_MSG("ejabberd initialization was aborted "
+			  "because a module start failed.",
+			  []),
+	    timer:sleep(3000),
+	    erlang:halt(string:substr(lists:flatten(ErrorText), 1, 199));
+	true ->
+	    ok
     end.
 
 is_app_running(AppName) ->

src/mod_adhoc.erl

@@ -35,7 +35,7 @@
 	 process_sm_iq/3, get_local_commands/5,
 	 get_local_identity/5, get_local_features/5,
 	 get_sm_commands/5, get_sm_identity/5, get_sm_features/5,
-	 ping_item/4, ping_command/4, mod_opt_type/1]).
+	 ping_item/4, ping_command/4, mod_opt_type/1, depends/2]).
 
 -include("ejabberd.hrl").
 -include("logger.hrl").
@@ -284,6 +284,9 @@ ping_command(_Acc, _From, _To,
     end;
 ping_command(Acc, _From, _To, _Request) -> Acc.
 
+depends(_Host, _Opts) ->
+    [].
+
 mod_opt_type(iqdisc) -> fun gen_iq_handler:check_type/1;
 mod_opt_type(report_commands_node) ->
     fun (B) when is_boolean(B) -> B end;

src/mod_admin_extra.erl

@@ -47,7 +47,7 @@
 	 srg_delete/2, srg_list/1, srg_get_info/2,
 	 srg_get_members/2, srg_user_add/4, srg_user_del/4,
 	 send_message/5, send_stanza/3, send_stanza_c2s/4, privacy_set/3,
-	 stats/1, stats/2, mod_opt_type/1, get_commands_spec/0]).
+	 stats/1, stats/2, mod_opt_type/1, get_commands_spec/0, depends/2]).
 
 
 -include("ejabberd.hrl").
@@ -66,6 +66,8 @@ start(_Host, _Opts) ->
 stop(_Host) ->
     ejabberd_commands:unregister_commands(get_commands_spec()).
 
+depends(_Host, _Opts) ->
+    [].
 
 %%%
 %%% Register commands

src/mod_announce.erl

@@ -33,7 +33,7 @@
 
 -export([start/2, init/0, stop/1, export/1, import/1,
 	 import/3, announce/3, send_motd/1, disco_identity/5,
-	 disco_features/5, disco_items/5,
+	 disco_features/5, disco_items/5, depends/2,
 	 send_announcement_to_all/3, announce_commands/4,
 	 announce_items/4, mod_opt_type/1]).
 
@@ -74,6 +74,9 @@ start(Host, Opts) ->
     register(gen_mod:get_module_proc(Host, ?PROCNAME),
 	     proc_lib:spawn(?MODULE, init, [])).
 
+depends(_Host, _Opts) ->
+    [{mod_adhoc, hard}].
+
 init() ->
     loop().
 

src/mod_blocking.erl

@@ -30,7 +30,7 @@
 -protocol({xep, 191, '1.2'}).
 
 -export([start/2, stop/1, process_iq/3,
-	 process_iq_set/4, process_iq_get/5, mod_opt_type/1]).
+	 process_iq_set/4, process_iq_get/5, mod_opt_type/1, depends/2]).
 
 -include("ejabberd.hrl").
 -include("logger.hrl").
@@ -63,6 +63,9 @@ stop(Host) ->
     gen_iq_handler:remove_iq_handler(ejabberd_sm, Host,
 				     ?NS_BLOCKING).
 
+depends(_Host, _Opts) ->
+    [{mod_privacy, hard}].
+
 process_iq(_From, _To, IQ) ->
     SubEl = IQ#iq.sub_el,
     IQ#iq{type = error, sub_el = [SubEl, ?ERR_NOT_ALLOWED]}.

src/mod_caps.erl

@@ -41,7 +41,7 @@
          import_start/2, import_stop/2]).
 
 %% gen_mod callbacks
--export([start/2, start_link/2, stop/1]).
+-export([start/2, start_link/2, stop/1, depends/2]).
 
 %% gen_server callbacks
 -export([init/1, handle_info/2, handle_call/3,
@@ -306,6 +306,9 @@ c2s_broadcast_recipients(InAcc, Host, C2SState,
     end;
 c2s_broadcast_recipients(Acc, _, _, _, _, _) -> Acc.
 
+depends(_Host, _Opts) ->
+    [].
+
 init([Host, Opts]) ->
     Mod = gen_mod:db_mod(Host, Opts, ?MODULE),
     Mod:init(Host, Opts),

src/mod_configure.erl

@@ -35,7 +35,8 @@
 	 get_local_features/5, get_local_items/5,
 	 adhoc_local_items/4, adhoc_local_commands/4,
 	 get_sm_identity/5, get_sm_features/5, get_sm_items/5,
-	 adhoc_sm_items/4, adhoc_sm_commands/4, mod_opt_type/1]).
+	 adhoc_sm_items/4, adhoc_sm_commands/4, mod_opt_type/1,
+	 depends/2]).
 
 -include("ejabberd.hrl").
 -include("logger.hrl").
@@ -95,6 +96,9 @@ stop(Host) ->
     gen_iq_handler:remove_iq_handler(ejabberd_sm, Host,
 				     ?NS_COMMANDS).
 
+depends(_Host, _Opts) ->
+    [{mod_adhoc, hard}, {mod_last, soft}].
+
 %%%-----------------------------------------------------------------------
 
 -define(INFO_IDENTITY(Category, Type, Name, Lang),

src/mod_configure2.erl

@@ -32,7 +32,7 @@
 -behaviour(gen_mod).
 
 -export([start/2, stop/1, process_local_iq/3,
-	 mod_opt_type/1, opt_type/1]).
+	 mod_opt_type/1, opt_type/1, depends/2]).
 
 -include("ejabberd.hrl").
 -include("logger.hrl").
@@ -201,6 +201,9 @@ process_get(#xmlel{name = <<"last">>, attrs = Attrs}, Lang) ->
 %%    {result, };
 process_get(_, _) -> {error, ?ERR_BAD_REQUEST}.
 
+depends(_Host, _Opts) ->
+    [].
+
 mod_opt_type(iqdisc) -> fun gen_iq_handler:check_type/1;
 mod_opt_type(_) -> [iqdisc].
 

src/mod_disco.erl

@@ -39,7 +39,7 @@
 	 get_sm_identity/5, get_sm_features/5, get_sm_items/5,
 	 get_info/5, register_feature/2, unregister_feature/2,
 	 register_extra_domain/2, unregister_extra_domain/2,
-	 transform_module_options/1, mod_opt_type/1]).
+	 transform_module_options/1, mod_opt_type/1, depends/2]).
 
 -include("ejabberd.hrl").
 -include("logger.hrl").
@@ -534,6 +534,9 @@ values_to_xml(Values) ->
 	      end,
 	      Values).
 
+depends(_Host, _Opts) ->
+    [].
+
 mod_opt_type(extra_domains) ->
     fun (Hs) -> [iolist_to_binary(H) || H <- Hs] end;
 mod_opt_type(iqdisc) -> fun gen_iq_handler:check_type/1;

src/mod_echo.erl

@@ -37,7 +37,7 @@
 
 -export([init/1, handle_call/3, handle_cast/2,
 	 handle_info/2, terminate/2, code_change/3,
-	 mod_opt_type/1]).
+	 mod_opt_type/1, depends/2]).
 
 -include("ejabberd.hrl").
 -include("logger.hrl").
@@ -200,5 +200,8 @@ do_client_version(enabled, From, To) ->
     ?INFO_MSG("Information of the client: ~s~s",
 	      [ToS, Values_string2]).
 
+depends(_Host, _Opts) ->
+    [].
+
 mod_opt_type(host) -> fun iolist_to_binary/1;
 mod_opt_type(_) -> [host].

src/mod_fail2ban.erl

@@ -33,7 +33,7 @@
 
 -export([init/1, handle_call/3, handle_cast/2,
 	 handle_info/2, terminate/2, code_change/3,
-	 mod_opt_type/1]).
+	 mod_opt_type/1, depends/2]).
 
 -include_lib("stdlib/include/ms_transform.hrl").
 -include("ejabberd.hrl").
@@ -120,6 +120,9 @@ stop(Host) ->
     supervisor:terminate_child(ejabberd_sup, Proc),
     supervisor:delete_child(ejabberd_sup, Proc).
 
+depends(_Host, _Opts) ->
+    [].
+
 %%%===================================================================
 %%% gen_server callbacks
 %%%===================================================================

src/mod_http_api.erl

@@ -74,7 +74,7 @@
 
 -behaviour(gen_mod).
 
--export([start/2, stop/1, process/2, mod_opt_type/1]).
+-export([start/2, stop/1, process/2, mod_opt_type/1, depends/2]).
 
 -include("ejabberd.hrl").
 -include("jlib.hrl").
@@ -123,6 +123,9 @@ start(_Host, _Opts) ->
 stop(_Host) ->
     ok.
 
+depends(_Host, _Opts) ->
+    [].
+
 %% ----------
 %% basic auth
 %% ----------

src/mod_http_bind.erl

@@ -37,7 +37,7 @@
 
 -behaviour(gen_mod).
 
--export([start/2, stop/1, process/2, mod_opt_type/1]).
+-export([start/2, stop/1, process/2, mod_opt_type/1, depends/2]).
 
 -include("ejabberd.hrl").
 -include("logger.hrl").
@@ -109,6 +109,8 @@ mod_opt_type(max_pause) ->
     fun (I) when is_integer(I), I > 0 -> I end;
 mod_opt_type(_) -> [max_inactivity, max_pause].
 
+depends(_Host, _Opts) ->
+    [].
 
 %%%----------------------------------------------------------------------
 %%% Help Web Page

src/mod_http_fileserver.erl

@@ -46,7 +46,7 @@
 %% utility for other http modules
 -export([content_type/3]).
 
--export([reopen_log/1, mod_opt_type/1]).
+-export([reopen_log/1, mod_opt_type/1, depends/2]).
 
 -include("ejabberd.hrl").
 -include("logger.hrl").
@@ -109,6 +109,9 @@ stop(Host) ->
     supervisor:terminate_child(ejabberd_sup, Proc),
     supervisor:delete_child(ejabberd_sup, Proc).
 
+depends(_Host, _Opts) ->
+    [].
+
 %%====================================================================
 %% API
 %%====================================================================

src/mod_http_upload.erl

@@ -68,6 +68,7 @@
 -export([start_link/3,
 	 start/2,
 	 stop/1,
+	 depends/2,
 	 mod_opt_type/1]).
 
 %% gen_server callbacks.
@@ -222,6 +223,11 @@ mod_opt_type(_) ->
      dir_mode, docroot, put_url, get_url, service_url, custom_headers,
      rm_on_unregister, thumbnail].
 
+-spec depends(binary(), gen_mod:opts()) -> [{module(), hard | soft}].
+
+depends(_Host, _Opts) ->
+    [].
+
 %%--------------------------------------------------------------------
 %% gen_server callbacks.
 %%--------------------------------------------------------------------

src/mod_http_upload_quota.erl

@@ -39,6 +39,7 @@
 -export([start_link/3,
 	 start/2,
 	 stop/1,
+	 depends/2,
 	 mod_opt_type/1]).
 
 %% gen_server callbacks.
@@ -109,6 +110,11 @@ mod_opt_type(max_days) ->
 mod_opt_type(_) ->
     [access_soft_quota, access_hard_quota, max_days].
 
+-spec depends(binary(), gen_mod:opts()) -> [{module(), hard | soft}].
+
+depends(_Host, _Opts) ->
+    [].
+
 %%--------------------------------------------------------------------
 %% gen_server callbacks.
 %%--------------------------------------------------------------------

src/mod_ip_blacklist.erl

@@ -36,7 +36,7 @@
 
 -export([update_bl_c2s/0]).
 
--export([is_ip_in_c2s_blacklist/3, mod_opt_type/1]).
+-export([is_ip_in_c2s_blacklist/3, mod_opt_type/1, depends/2]).
 
 -include("ejabberd.hrl").
 -include("logger.hrl").
@@ -65,6 +65,9 @@ preinit(Parent, State) ->
       error:_ -> Parent ! {ok, Pid, true}
     end.
 
+depends(_Host, _Opts) ->
+    [].
+
 %% TODO:
 stop(_Host) -> ok.
 

src/mod_irc.erl

@@ -38,7 +38,7 @@
 
 -export([init/1, handle_call/3, handle_cast/2,
 	 handle_info/2, terminate/2, code_change/3,
-	 mod_opt_type/1]).
+	 mod_opt_type/1, depends/2]).
 
 -include("ejabberd.hrl").
 -include("logger.hrl").
@@ -99,6 +99,9 @@ stop(Host) ->
     gen_server:call(Proc, stop),
     supervisor:delete_child(ejabberd_sup, Proc).
 
+depends(_Host, _Opts) ->
+    [].
+
 %%====================================================================
 %% gen_server callbacks
 %%====================================================================

src/mod_last.erl

@@ -37,7 +37,7 @@
 	 process_sm_iq/3, on_presence_update/4, import/1,
 	 import/3, store_last_info/4, get_last_info/2,
 	 remove_user/2, transform_options/1, mod_opt_type/1,
-	 opt_type/1, register_user/2]).
+	 opt_type/1, register_user/2, depends/2]).
 
 -include("ejabberd.hrl").
 -include("logger.hrl").
@@ -255,6 +255,9 @@ transform_options({node_start, {_, _, _} = Now}, Opts) ->
 transform_options(Opt, Opts) ->
     [Opt|Opts].
 
+depends(_Host, _Opts) ->
+    [].
+
 mod_opt_type(db_type) -> fun(T) -> ejabberd_config:v_db(?MODULE, T) end;
 mod_opt_type(iqdisc) -> fun gen_iq_handler:check_type/1;
 mod_opt_type(_) -> [db_type, iqdisc].

src/mod_mam.erl

@@ -31,7 +31,7 @@
 -behaviour(gen_mod).
 
 %% API
--export([start/2, stop/1]).
+-export([start/2, stop/1, depends/2]).
 
 -export([user_send_packet/4, user_send_packet_strip_tag/4, user_receive_packet/5,
 	 process_iq_v0_2/3, process_iq_v0_3/3, disco_sm_features/5,
@@ -165,6 +165,9 @@ stop(Host) ->
     ejabberd_commands:unregister_commands(get_commands_spec()),
     ok.
 
+depends(_Host, _Opts) ->
+    [].
+
 remove_user(User, Server) ->
     LUser = jid:nodeprep(User),
     LServer = jid:nameprep(Server),

src/mod_metrics.erl

@@ -39,7 +39,8 @@
                 s2s_send_packet, s2s_receive_packet,
                 remove_user, register_user]).
 
--export([start/2, stop/1, send_metrics/4, opt_type/1, mod_opt_type/1]).
+-export([start/2, stop/1, send_metrics/4, opt_type/1, mod_opt_type/1,
+	 depends/2]).
 
 -export([offline_message_hook/3,
          sm_register_connection_hook/3, sm_remove_connection_hook/3,
@@ -59,6 +60,9 @@ stop(Host) ->
     [ejabberd_hooks:delete(Hook, Host, ?MODULE, Hook, 20)
      || Hook <- ?HOOKS].
 
+depends(_Host, _Opts) ->
+    [].
+
 %%====================================================================
 %% Hooks handlers
 %%====================================================================

src/mod_mix.erl

@@ -14,7 +14,7 @@
 %% API
 -export([start_link/2, start/2, stop/1, process_iq/3,
 	 disco_items/5, disco_identity/5, disco_info/5,
-	 disco_features/5, mod_opt_type/1]).
+	 disco_features/5, mod_opt_type/1, depends/2]).
 
 %% gen_server callbacks
 -export([init/1, handle_call/3, handle_cast/2, handle_info/2,
@@ -343,6 +343,9 @@ is_not_subscribed({error, ErrEl}) ->
 	_ -> false
     end.
 
+depends(_Host, _Opts) ->
+    [{mod_pubsub, hard}].
+
 mod_opt_type(iqdisc) -> fun gen_iq_handler:check_type/1;
 mod_opt_type(host) -> fun iolist_to_binary/1;
 mod_opt_type(_) -> [host, iqdisc].

src/mod_muc.erl

@@ -53,7 +53,7 @@
 
 -export([init/1, handle_call/3, handle_cast/2,
 	 handle_info/2, terminate/2, code_change/3,
-	 mod_opt_type/1]).
+	 mod_opt_type/1, depends/2]).
 
 -include("ejabberd.hrl").
 -include("logger.hrl").
@@ -105,6 +105,9 @@ stop(Host) ->
     supervisor:delete_child(ejabberd_sup, Proc),
     {wait, Rooms}.
 
+depends(_Host, _Opts) ->
+    [{mod_mam, soft}].
+
 shutdown_rooms(Host) ->
     MyHost = gen_mod:get_module_opt_host(Host, mod_muc,
 					 <<"conference.@HOST@">>),

src/mod_muc_admin.erl

@@ -11,7 +11,7 @@
 
 -behaviour(gen_mod).
 
--export([start/2, stop/1, muc_online_rooms/1,
+-export([start/2, stop/1, depends/2, muc_online_rooms/1,
 	 muc_unregister_nick/1, create_room/3, destroy_room/2,
 	 create_rooms_file/1, destroy_rooms_file/1,
 	 rooms_unused_list/2, rooms_unused_destroy/2,
@@ -49,6 +49,9 @@ stop(Host) ->
     ejabberd_hooks:delete(webadmin_page_main, ?MODULE, web_page_main, 50),
     ejabberd_hooks:delete(webadmin_page_host, Host, ?MODULE, web_page_host, 50).
 
+depends(_Host, _Opts) ->
+    [{mod_muc, hard}].
+
 %%%
 %%% Register commands
 %%%

src/mod_muc_log.erl

@@ -41,7 +41,7 @@
 
 -export([init/1, handle_call/3, handle_cast/2,
 	 handle_info/2, terminate/2, code_change/3,
-	 mod_opt_type/1, opt_type/1]).
+	 mod_opt_type/1, opt_type/1, depends/2]).
 
 -include("ejabberd.hrl").
 -include("logger.hrl").
@@ -109,6 +109,9 @@ transform_module_options(Opts) ->
               Opt
       end, Opts).
 
+depends(_Host, _Opts) ->
+    [{mod_muc, hard}].
+
 %%====================================================================
 %% gen_server callbacks
 %%====================================================================

src/mod_multicast.erl

@@ -40,7 +40,7 @@
 -export([init/1, handle_info/2, handle_call/3,
 	 handle_cast/2, terminate/2, code_change/3]).
 
--export([purge_loop/1, mod_opt_type/1]).
+-export([purge_loop/1, mod_opt_type/1, depends/2]).
 
 -include("ejabberd.hrl").
 -include("logger.hrl").
@@ -1219,6 +1219,9 @@ stj(String) -> jid:from_string(String).
 
 jts(String) -> jid:to_string(String).
 
+depends(_Host, _Opts) ->
+    [].
+
 mod_opt_type(access) ->
     fun acl:access_rules_validator/1;
 mod_opt_type(host) -> fun iolist_to_binary/1;

src/mod_offline.erl

@@ -66,7 +66,7 @@
 
 -export([init/1, handle_call/3, handle_cast/2,
 	 handle_info/2, terminate/2, code_change/3,
-	 mod_opt_type/1]).
+	 mod_opt_type/1, depends/2]).
 
 -deprecated({get_queue_length,2}).
 
@@ -125,6 +125,8 @@ stop(Host) ->
     supervisor:delete_child(ejabberd_sup, Proc),
     ok.
 
+depends(_Host, _Opts) ->
+    [].
 
 %%====================================================================
 %% gen_server callbacks

src/mod_privacy.erl

@@ -36,7 +36,7 @@
 	 check_packet/6, remove_user/2,
 	 is_list_needdb/1, updated_list/3,
          item_to_xml/1, get_user_lists/2, import/3,
-	 set_privacy_list/1, mod_opt_type/1]).
+	 set_privacy_list/1, mod_opt_type/1, depends/2]).
 
 -include("ejabberd.hrl").
 -include("logger.hrl").
@@ -593,6 +593,9 @@ import(LServer, DBType, Data) ->
     Mod = gen_mod:db_mod(DBType, ?MODULE),
     Mod:import(LServer, Data).
 
+depends(_Host, _Opts) ->
+    [].
+
 mod_opt_type(db_type) -> fun(T) -> ejabberd_config:v_db(?MODULE, T) end;
 mod_opt_type(iqdisc) -> fun gen_iq_handler:check_type/1;
 mod_opt_type(_) -> [db_type, iqdisc].

src/mod_private.erl

@@ -33,7 +33,7 @@
 
 -export([start/2, stop/1, process_sm_iq/3, import/3,
 	 remove_user/2, get_data/2, export/1, import/1,
-	 mod_opt_type/1, set_data/3]).
+	 mod_opt_type/1, set_data/3, depends/2]).
 
 -include("ejabberd.hrl").
 -include("logger.hrl").
@@ -173,6 +173,9 @@ import(LServer, DBType, PD) ->
     Mod = gen_mod:db_mod(DBType, ?MODULE),
     Mod:import(LServer, PD).
 
+depends(_Host, _Opts) ->
+    [].
+
 mod_opt_type(db_type) -> fun(T) -> ejabberd_config:v_db(?MODULE, T) end;
 mod_opt_type(iqdisc) -> fun gen_iq_handler:check_type/1;
 mod_opt_type(_) -> [db_type, iqdisc].

src/mod_proxy65.erl

@@ -39,7 +39,7 @@
 %% supervisor callbacks.
 -export([init/1]).
 
--export([start_link/2, mod_opt_type/1]).
+-export([start_link/2, mod_opt_type/1, depends/2]).
 
 -define(PROCNAME, ejabberd_mod_proxy65).
 
@@ -84,6 +84,9 @@ init([Host, Opts]) ->
      {{one_for_one, 10, 1},
       [StreamManager, StreamSupervisor, Service]}}.
 
+depends(_Host, _Opts) ->
+    [].
+
 mod_opt_type(auth_type) ->
     fun (plain) -> plain;
 	(anonymous) -> anonymous

src/mod_pubsub.erl

@@ -77,7 +77,7 @@
 %% API and gen_server callbacks
 -export([start_link/2, start/2, stop/1, init/1,
     handle_call/3, handle_cast/2, handle_info/2,
-    terminate/2, code_change/3]).
+    terminate/2, code_change/3, depends/2]).
 
 -export([send_loop/1, mod_opt_type/1]).
 
@@ -347,6 +347,18 @@ init_send_loop(ServerHost) ->
     end,
     {Pid, State}.
 
+depends(ServerHost, Opts) ->
+    Host = gen_mod:get_opt_host(ServerHost, Opts, <<"pubsub.@HOST@">>),
+    Plugins = gen_mod:get_opt(plugins, Opts,
+			      fun(A) when is_list(A) -> A end, [?STDNODE]),
+    lists:flatmap(
+      fun(Name) ->
+	      Plugin = plugin(ServerHost, Name),
+	      try apply(Plugin, depends, [Host, ServerHost, Opts])
+	      catch _:undef -> []
+	      end
+      end, Plugins).
+
 %% @doc Call the init/1 function for each plugin declared in the config file.
 %% The default plugin module is implicit.
 %% <p>The Erlang code for the plugin is located in a module called

src/mod_register.erl

@@ -37,7 +37,7 @@
 	 unauthenticated_iq_register/4, try_register/5,
 	 process_iq/3, send_registration_notifications/3,
 	 transform_options/1, transform_module_options/1,
-	 mod_opt_type/1, opt_type/1]).
+	 mod_opt_type/1, opt_type/1, depends/2]).
 
 -include("ejabberd.hrl").
 -include("logger.hrl").
@@ -72,6 +72,9 @@ stop(Host) ->
     gen_iq_handler:remove_iq_handler(ejabberd_sm, Host,
 				     ?NS_REGISTER).
 
+depends(_Host, _Opts) ->
+    [].
+
 stream_feature_register(Acc, Host) ->
     AF = gen_mod:get_module_opt(Host, ?MODULE, access_from,
                                           fun(A) -> A end,

src/mod_register_web.erl

@@ -55,7 +55,7 @@
 
 -behaviour(gen_mod).
 
--export([start/2, stop/1, process/2, mod_opt_type/1]).
+-export([start/2, stop/1, process/2, mod_opt_type/1, depends/2]).
 
 -include("ejabberd.hrl").
 -include("logger.hrl").
@@ -76,6 +76,9 @@ start(_Host, _Opts) ->
 
 stop(_Host) -> ok.
 
+depends(_Host, _Opts) ->
+    [{mod_register, hard}].
+
 %%%----------------------------------------------------------------------
 %%% HTTP handlers
 %%%----------------------------------------------------------------------

src/mod_roster.erl

@@ -49,7 +49,7 @@
 	 get_jid_info/4, item_to_xml/1, webadmin_page/3,
 	 webadmin_user/4, get_versioning_feature/2,
 	 roster_versioning_enabled/1, roster_version/2,
-	 mod_opt_type/1, set_roster/1]).
+	 mod_opt_type/1, set_roster/1, depends/2]).
 
 -include("ejabberd.hrl").
 -include("logger.hrl").
@@ -136,6 +136,9 @@ stop(Host) ->
     gen_iq_handler:remove_iq_handler(ejabberd_sm, Host,
 				     ?NS_ROSTER).
 
+depends(_Host, _Opts) ->
+    [].
+
 process_iq(From, To, IQ) when ((From#jid.luser == <<"">>) andalso (From#jid.resource == <<"">>)) ->
     process_iq_manager(From, To, IQ);
 

src/mod_service_log.erl

@@ -30,7 +30,7 @@
 -behaviour(gen_mod).
 
 -export([start/2, stop/1, log_user_send/4,
-	 log_user_receive/5, mod_opt_type/1]).
+	 log_user_receive/5, mod_opt_type/1, depends/2]).
 
 -include("ejabberd.hrl").
 -include("logger.hrl").
@@ -51,6 +51,9 @@ stop(Host) ->
 			  ?MODULE, log_user_receive, 50),
     ok.
 
+depends(_Host, _Opts) ->
+    [].
+
 log_user_send(Packet, _C2SState, From, To) ->
     log_packet(From, To, Packet, From#jid.lserver),
     Packet.

src/mod_shared_roster.erl

@@ -39,7 +39,7 @@
 	 delete_group/2, get_group_opts/2, set_group_opts/3,
 	 get_group_users/2, get_group_explicit_users/2,
 	 is_user_in_group/3, add_user_to_group/3, opts_to_binary/1,
-	 remove_user_from_group/3, mod_opt_type/1]).
+	 remove_user_from_group/3, mod_opt_type/1, depends/2]).
 
 -include("ejabberd.hrl").
 -include("logger.hrl").
@@ -132,6 +132,9 @@ stop(Host) ->
     %%ejabberd_hooks:delete(remove_user, Host,
     %%    		  ?MODULE, remove_user, 50),
 
+depends(_Host, _Opts) ->
+    [].
+
 get_user_roster(Items, US) ->
     {U, S} = US,
     DisplayedGroups = get_user_displayed_groups(US),

src/mod_shared_roster_ldap.erl

@@ -41,7 +41,7 @@
 
 -export([get_user_roster/2, get_subscription_lists/3,
 	 get_jid_info/4, process_item/2, in_subscription/6,
-	 out_subscription/4, mod_opt_type/1, opt_type/1]).
+	 out_subscription/4, mod_opt_type/1, opt_type/1, depends/2]).
 
 -include("ejabberd.hrl").
 -include("logger.hrl").
@@ -105,6 +105,9 @@ stop(Host) ->
     supervisor:terminate_child(ejabberd_sup, Proc),
     supervisor:delete_child(ejabberd_sup, Proc).
 
+depends(_Host, _Opts) ->
+    [{mod_roster, hard}].
+
 %%--------------------------------------------------------------------
 %% Hooks
 %%--------------------------------------------------------------------

src/mod_sic.erl

@@ -32,7 +32,7 @@
 -behaviour(gen_mod).
 
 -export([start/2, stop/1, process_local_iq/3,
-	 process_sm_iq/3, mod_opt_type/1]).
+	 process_sm_iq/3, mod_opt_type/1, depends/2]).
 
 -include("ejabberd.hrl").
 -include("logger.hrl").
@@ -55,6 +55,9 @@ stop(Host) ->
     gen_iq_handler:remove_iq_handler(ejabberd_sm, Host,
 				     ?NS_SIC).
 
+depends(_Host, _Opts) ->
+    [].
+
 process_local_iq(#jid{user = User, server = Server,
 		      resource = Resource},
 		 _To, #iq{type = get, sub_el = _SubEl} = IQ) ->

src/mod_sip.erl

@@ -34,7 +34,7 @@
 
 -export([data_in/2, data_out/2, message_in/2,
 	 message_out/2, request/2, request/3, response/2,
-	 locate/1, mod_opt_type/1]).
+	 locate/1, mod_opt_type/1, depends/2]).
 
 -include("ejabberd.hrl").
 -include("logger.hrl").
@@ -62,6 +62,9 @@ start(_Host, _Opts) ->
 stop(_Host) ->
     ok.
 
+depends(_Host, _Opts) ->
+    [].
+
 data_in(Data, #sip_socket{type = Transport,
                           addr = {MyIP, MyPort},
                           peer = {PeerIP, PeerPort}}) ->

src/mod_stats.erl

@@ -32,7 +32,7 @@
 -behaviour(gen_mod).
 
 -export([start/2, stop/1, process_local_iq/3,
-	 mod_opt_type/1]).
+	 mod_opt_type/1, depends/2]).
 
 -include("ejabberd.hrl").
 -include("logger.hrl").
@@ -48,6 +48,9 @@ stop(Host) ->
     gen_iq_handler:remove_iq_handler(ejabberd_local, Host,
 				     ?NS_STATS).
 
+depends(_Host, _Opts) ->
+    [].
+
 process_local_iq(_From, To,
 		 #iq{id = _ID, type = Type, xmlns = XMLNS,
 		     sub_el = SubEl, lang = Lang} =

src/mod_time.erl

@@ -33,7 +33,7 @@
 -behaviour(gen_mod).
 
 -export([start/2, stop/1, process_local_iq/3,
-	 mod_opt_type/1]).
+	 mod_opt_type/1, depends/2]).
 
 -include("ejabberd.hrl").
 -include("logger.hrl").
@@ -86,5 +86,8 @@ process_local_iq(_From, _To,
 sign(N) when N < 0 -> <<"-">>;
 sign(_) -> <<"+">>.
 
+depends(_Host, _Opts) ->
+    [].
+
 mod_opt_type(iqdisc) -> fun gen_iq_handler:check_type/1;
 mod_opt_type(_) -> [iqdisc].

src/mod_vcard.erl

@@ -34,7 +34,7 @@
 
 -export([start/2, init/3, stop/1, get_sm_features/5,
 	 process_local_iq/3, process_sm_iq/3, string2lower/1,
-	 remove_user/2, export/1, import/1, import/3,
+	 remove_user/2, export/1, import/1, import/3, depends/2,
 	 mod_opt_type/1, set_vcard/3, make_vcard_search/4]).
 
 -include("ejabberd.hrl").
@@ -594,6 +594,9 @@ import(LServer, DBType, VCard) ->
     Mod = gen_mod:db_mod(DBType, ?MODULE),
     Mod:import(LServer, VCard).
 
+depends(_Host, _Opts) ->
+    [].
+
 mod_opt_type(allow_return_all) ->
     fun (B) when is_boolean(B) -> B end;
 mod_opt_type(db_type) -> fun(T) -> ejabberd_config:v_db(?MODULE, T) end;

src/mod_vcard_ldap.erl

@@ -40,7 +40,7 @@
 -export([start/2, start_link/2, stop/1,
 	 get_sm_features/5, process_local_iq/3, process_sm_iq/3,
 	 remove_user/1, route/4, transform_module_options/1,
-	 mod_opt_type/1, opt_type/1]).
+	 mod_opt_type/1, opt_type/1, depends/2]).
 
 -include("ejabberd.hrl").
 -include("logger.hrl").
@@ -138,6 +138,9 @@ stop(Host) ->
     supervisor:terminate_child(ejabberd_sup, Proc),
     supervisor:delete_child(ejabberd_sup, Proc).
 
+depends(_Host, _Opts) ->
+    [].
+
 terminate(_Reason, State) ->
     Host = State#state.serverhost,
     gen_iq_handler:remove_iq_handler(ejabberd_local, Host,

src/mod_vcard_xupdate.erl

@@ -13,7 +13,7 @@
 -export([start/2, stop/1]).
 
 -export([update_presence/3, vcard_set/3, export/1,
-	 import/1, import/3, mod_opt_type/1]).
+	 import/1, import/3, mod_opt_type/1, depends/2]).
 
 -include("ejabberd.hrl").
 -include("logger.hrl").
@@ -46,6 +46,9 @@ stop(Host) ->
 			  vcard_set, 100),
     ok.
 
+depends(_Host, _Opts) ->
+    [].
+
 %%====================================================================
 %% Hooks
 %%====================================================================

src/mod_version.erl

@@ -32,7 +32,7 @@
 -behaviour(gen_mod).
 
 -export([start/2, stop/1, process_local_iq/3,
-	 mod_opt_type/1]).
+	 mod_opt_type/1, depends/2]).
 
 -include("ejabberd.hrl").
 -include("logger.hrl").
@@ -93,6 +93,9 @@ get_os() ->
     #xmlel{name = <<"os">>, attrs = [],
 	   children = [{xmlcdata, OS}]}.
 
+depends(_Host, _Opts) ->
+    [].
+
 mod_opt_type(iqdisc) -> fun gen_iq_handler:check_type/1;
 mod_opt_type(show_os) ->
     fun (B) when is_boolean(B) -> B end;

src/node_pep.erl

@@ -45,11 +45,13 @@
     get_pending_nodes/2, get_states/1, get_state/2,
     set_state/1, get_items/7, get_items/3, get_item/7,
     get_item/2, set_item/1, get_item_name/3, node_to_path/1,
-    path_to_node/1]).
+    path_to_node/1, depends/3]).
+
+depends(_Host, _ServerHost, _Opts) ->
+    [{mod_caps, hard}].
 
 init(Host, ServerHost, Opts) ->
     node_flat:init(Host, ServerHost, Opts),
-    complain_if_modcaps_disabled(ServerHost),
     ok.
 
 terminate(Host, ServerHost) ->
@@ -245,21 +247,3 @@ node_to_path(Node) ->
 
 path_to_node(Path) ->
     node_flat:path_to_node(Path).
-
-%%%
-%%% Internal
-%%%
-
-%% @doc Check mod_caps is enabled, otherwise show warning.
-%% The PEP plugin for mod_pubsub requires mod_caps to be enabled in the host.
-%% Check that the mod_caps module is enabled in that Jabber Host
-%% If not, show a warning message in the ejabberd log file.
-complain_if_modcaps_disabled(ServerHost) ->
-    case gen_mod:is_loaded(ServerHost, mod_caps) of
-	false ->
-	    ?WARNING_MSG("The PEP plugin is enabled in mod_pubsub "
-		"of host ~p. This plugin requires mod_caps "
-		"but it does not seems enabled, please check config.",
-		[ServerHost]);
-	true -> ok
-    end.

src/node_pep_sql.erl

@@ -45,12 +45,14 @@
     get_pending_nodes/2, get_states/1, get_state/2,
     set_state/1, get_items/7, get_items/3, get_item/7,
     get_item/2, set_item/1, get_item_name/3, node_to_path/1,
-    path_to_node/1,
+    path_to_node/1, depends/3,
     get_entity_subscriptions_for_send_last/2, get_last_items/3]).
 
+depends(_Host, _ServerHost, _Opts) ->
+    [{mod_caps, hard}].
+
 init(Host, ServerHost, Opts) ->
     node_flat_sql:init(Host, ServerHost, Opts),
-    complain_if_modcaps_disabled(ServerHost),
     ok.
 
 terminate(Host, ServerHost) ->
@@ -237,21 +239,3 @@ node_to_path(Node) ->
 
 path_to_node(Path) ->
     node_flat_sql:path_to_node(Path).
-
-%%%
-%%% Internal
-%%%
-
-%% @doc Check mod_caps is enabled, otherwise show warning.
-%% The PEP plugin for mod_pubsub requires mod_caps to be enabled in the host.
-%% Check that the mod_caps module is enabled in that Jabber Host
-%% If not, show a warning message in the ejabberd log file.
-complain_if_modcaps_disabled(ServerHost) ->
-    case gen_mod:is_loaded(ServerHost, mod_caps) of
-	false ->
-	    ?WARNING_MSG("The PEP plugin is enabled in mod_pubsub "
-		"of host ~p. This plugin requires mod_caps "
-		"to be enabled, but it isn't.",
-		[ServerHost]);
-	true -> ok
-    end.