Have supervisor send errors up the chain

If a child fails to start, supervisor relies upon error_logger which does not
work when IO is inhibited. Instead pass the error up the chain and let someone
else use a proper Reason for any possible printouts.

8 files changed, 135 insertions, 12 deletions

diff --git a/lib/stdlib/doc/src/supervisor.xml b/lib/stdlib/doc/src/supervisor.xml
index f9a5e245b4..1a64b7a2af 100644
--- a/lib/stdlib/doc/src/supervisor.xml
+++ b/lib/stdlib/doc/src/supervisor.xml
@@ -295,7 +295,7 @@ child_spec() = {Id,StartFunc,Restart,Shutdown,Type,Modules}
           terminates with reason <c>Term</c>.</p>
         <p>If any child process start function fails or returns an error
           tuple or an erroneous value, the function returns
-          <c>{error,shutdown}</c> and the supervisor terminates all
+          <c>{error, {shutdown, Reason}}</c> and the supervisor terminates all
           started child processes and then itself with reason
           <c>shutdown</c>.</p>
       </desc>
diff --git a/lib/stdlib/src/supervisor.erl b/lib/stdlib/src/supervisor.erl
index 7d3c5a0e21..7624c6cd18 100644
--- a/lib/stdlib/src/supervisor.erl
+++ b/lib/stdlib/src/supervisor.erl
@@ -104,7 +104,9 @@
 %%% SupName = {local, atom()} | {global, atom()}.
 %%% ---------------------------------------------------
 
--type startlink_err() :: {'already_started', pid()} | 'shutdown' | term().
+-type startlink_err() :: {'already_started', pid()}
+                         | {'shutdown', term()}
+                         | term().
 -type startlink_ret() :: {'ok', pid()} | 'ignore' | {'error', startlink_err()}.
 
 -spec start_link(Module, Args) -> startlink_ret() when
@@ -221,8 +223,10 @@ cast(Supervisor, Req) ->
 
 -type init_sup_name() :: sup_name() | 'self'.
 
--type stop_rsn() :: 'shutdown' | {'bad_return', {module(),'init', term()}}
-                  | {'bad_start_spec', term()} | {'start_spec', term()}
+-type stop_rsn() :: {'shutdown', term()}
+                  | {'bad_return', {module(),'init', term()}}
+                  | {'bad_start_spec', term()}
+                  | {'start_spec', term()}
                   | {'supervisor_data', term()}.
 
 -spec init({init_sup_name(), module(), [term()]}) ->
@@ -253,9 +257,9 @@ init_children(State, StartSpec) ->
             case start_children(Children, SupName) of
                 {ok, NChildren} ->
                     {ok, State#state{children = NChildren}};
-                {error, NChildren} ->
+                {error, NChildren, Reason} ->
                     terminate_children(NChildren, SupName),
-                    {stop, shutdown}
+                    {stop, {shutdown, Reason}}
             end;
         Error ->
             {stop, {start_spec, Error}}
@@ -275,9 +279,9 @@ init_dynamic(_State, StartSpec) ->
 %% Func: start_children/2
 %% Args: Children = [child_rec()] in start order
 %%       SupName = {local, atom()} | {global, atom()} | {pid(), Mod}
-%% Purpose: Start all children.  The new list contains #child's 
+%% Purpose: Start all children.  The new list contains #child's
 %%          with pids.
-%% Returns: {ok, NChildren} | {error, NChildren}
+%% Returns: {ok, NChildren} | {error, NChildren, Reason}
 %%          NChildren = [child_rec()] in termination order (reversed
 %%                        start order)
 %%-----------------------------------------------------------------
@@ -293,7 +297,7 @@ start_children([Child|Chs], NChildren, SupName) ->
 	    start_children(Chs, [Child#child{pid = Pid}|NChildren], SupName);
 	{error, Reason} ->
 	    report_error(start_error, Reason, Child, SupName),
-	    {error, lists:reverse(Chs) ++ [Child | NChildren]}
+	    {error, lists:reverse(Chs) ++ [Child | NChildren], Reason}
     end;
 start_children([], NChildren, _SupName) ->
     {ok, NChildren}.
@@ -793,7 +797,7 @@ restart(rest_for_one, Child, State) ->
     case start_children(ChAfter2, State#state.name) of
 	{ok, ChAfter3} ->
 	    {ok, State#state{children = ChAfter3 ++ ChBefore}};
-	{error, ChAfter3} ->
+	{error, ChAfter3, _Reason} ->
 	    NChild = Child#child{pid=restarting(Child#child.pid)},
 	    NState = State#state{children = ChAfter3 ++ ChBefore},
 	    {try_again, replace_child(NChild,NState)}
@@ -804,7 +808,7 @@ restart(one_for_all, Child, State) ->
     case start_children(Children2, State#state.name) of
 	{ok, NChs} ->
 	    {ok, State#state{children = NChs}};
-	{error, NChs} ->
+	{error, NChs, _Reason} ->
 	    NChild = Child#child{pid=restarting(Child#child.pid)},
 	    NState = State#state{children = NChs},
 	    {try_again, replace_child(NChild,NState)}
diff --git a/lib/stdlib/test/supervisor_SUITE.erl b/lib/stdlib/test/supervisor_SUITE.erl
index 767ae3d62c..d9f2e82b31 100644
--- a/lib/stdlib/test/supervisor_SUITE.erl
+++ b/lib/stdlib/test/supervisor_SUITE.erl
@@ -46,6 +46,7 @@
 	  temporary_normal/1,
 	  permanent_shutdown/1, transient_shutdown/1,
 	  temporary_shutdown/1,
+          faulty_application_shutdown/1,
 	  permanent_abnormal/1, transient_abnormal/1,
 	  temporary_abnormal/1, temporary_bystander/1]).
 
@@ -98,7 +99,8 @@ groups() ->
      {normal_termination, [],
       [permanent_normal, transient_normal, temporary_normal]},
      {shutdown_termination, [],
-      [permanent_shutdown, transient_shutdown, temporary_shutdown]},
+      [permanent_shutdown, transient_shutdown, temporary_shutdown,
+       faulty_application_shutdown]},
      {abnormal_termination, [],
       [permanent_abnormal, transient_abnormal,
        temporary_abnormal]},
@@ -659,6 +661,32 @@ temporary_shutdown(Config) when is_list(Config) ->
     [0,0,0,0] = get_child_counts(sup_test).
 
 %%-------------------------------------------------------------------------
+%% Faulty application should shutdown and pass on errors
+faulty_application_shutdown(Config) when is_list(Config) ->
+
+    %% Set some paths
+    AppDir  = filename:join(?config(data_dir, Config), "app_faulty"),
+    EbinDir = filename:join(AppDir, "ebin"),
+
+    %% Start faulty app
+    code:add_patha(EbinDir),
+
+    % {error,
+    %   {{shutdown,
+    %     {undef,[
+    %       {an_undefined_module_with,an_undefined_function,[argument1,argument2],[]},
+    %       {app_faulty_server,init,1,[{file,"app_faulty/src/app_faulty_server.erl"},{line,16}]},
+    %       {gen_server,init_it,6,[{file,"gen_server.erl"},{line,304}]},
+    %       {proc_lib,init_p_do_apply,3,[{file,"proc_lib.erl"},{line,227}]}
+    %   ]}},{app_faulty,start,[normal,[]]}}}
+
+    {error, Error} = application:start(app_faulty),
+    {{shutdown, {undef, CallStack}},{app_faulty,start,_}} = Error,
+    [{an_undefined_module_with,an_undefined_function,_,_}|_] = CallStack,
+    ok = application:unload(app_faulty),
+    ok.
+
+%%-------------------------------------------------------------------------
 %% A permanent child should always be restarted.
 permanent_abnormal(Config) when is_list(Config) ->
     {ok, SupPid} = start_link({ok, {{one_for_one, 2, 3600}, []}}),
diff --git a/lib/stdlib/test/supervisor_SUITE_data/Makefile.src b/lib/stdlib/test/supervisor_SUITE_data/Makefile.src
new file mode 100644
index 0000000000..dbc5729f47
--- /dev/null
+++ b/lib/stdlib/test/supervisor_SUITE_data/Makefile.src
@@ -0,0 +1,15 @@
+EFLAGS=+debug_info
+
+APP_FAULTY= \
+     app_faulty/ebin/app_faulty_sup.@EMULATOR@ \
+     app_faulty/ebin/app_faulty_server.@EMULATOR@ \
+     app_faulty/ebin/app_faulty.@EMULATOR@ \
+
+all: $(APP_FAULTY)
+
+app_faulty/ebin/app_faulty_server.@EMULATOR@: app_faulty/src/app_faulty_server.erl
+	erlc $(EFLAGS) -oapp_faulty/ebin app_faulty/src/app_faulty_server.erl
+app_faulty/ebin/app_faulty_sup.@EMULATOR@: app_faulty/src/app_faulty_sup.erl
+	erlc $(EFLAGS) -oapp_faulty/ebin app_faulty/src/app_faulty_sup.erl
+app_faulty/ebin/app_faulty.@EMULATOR@: app_faulty/src/app_faulty.erl
+	erlc $(EFLAGS) -oapp_faulty/ebin app_faulty/src/app_faulty.erl
diff --git a/lib/stdlib/test/supervisor_SUITE_data/app_faulty/ebin/app_faulty.app b/lib/stdlib/test/supervisor_SUITE_data/app_faulty/ebin/app_faulty.app
new file mode 100644
index 0000000000..d4ab07e485
--- /dev/null
+++ b/lib/stdlib/test/supervisor_SUITE_data/app_faulty/ebin/app_faulty.app
@@ -0,0 +1,10 @@
+{application, app_faulty,
+ [{description, "very simple example faulty application"},
+  {id, "app_faulty"},
+  {vsn, "1.0"},
+  {modules, [app_faulty, app_faulty_sup, app_faulty_server]},
+  {registered, [app_faulty]},
+  {applications, [kernel, stdlib]},
+  {env, [{var,val1}]},
+  {mod, {app_faulty, []}}
+  ]}.
diff --git a/lib/stdlib/test/supervisor_SUITE_data/app_faulty/src/app_faulty.erl b/lib/stdlib/test/supervisor_SUITE_data/app_faulty/src/app_faulty.erl
new file mode 100644
index 0000000000..c65b411cd6
--- /dev/null
+++ b/lib/stdlib/test/supervisor_SUITE_data/app_faulty/src/app_faulty.erl
@@ -0,0 +1,17 @@
+-module(app_faulty).
+
+-behaviour(application).
+
+%% Application callbacks
+-export([start/2, stop/1]).
+
+start(_Type, _StartArgs) ->
+    case app_faulty_sup:start_link() of
+	{ok, Pid} ->
+	    {ok, Pid};
+	Error ->
+	    Error
+    end.
+
+stop(_State) ->
+    ok.
diff --git a/lib/stdlib/test/supervisor_SUITE_data/app_faulty/src/app_faulty_server.erl b/lib/stdlib/test/supervisor_SUITE_data/app_faulty/src/app_faulty_server.erl
new file mode 100644
index 0000000000..6628f92210
--- /dev/null
+++ b/lib/stdlib/test/supervisor_SUITE_data/app_faulty/src/app_faulty_server.erl
@@ -0,0 +1,32 @@
+-module(app_faulty_server).
+
+-behaviour(gen_server).
+
+%% API
+-export([start_link/0]).
+
+%% gen_server callbacks
+-export([init/1, handle_call/3, handle_cast/2, handle_info/2,
+	 terminate/2, code_change/3]).
+
+start_link() ->
+    gen_server:start_link({local, ?MODULE}, ?MODULE, [], []).
+
+init([]) ->
+    an_undefined_module_with:an_undefined_function(argument1, argument2),
+    {ok, []}.
+
+handle_call(_Request, _From, State) ->
+    {reply, ok, State}.
+
+handle_cast(_Msg, State) ->
+    {noreply, State}.
+
+handle_info(_Info, State) ->
+    {noreply, State}.
+
+terminate(_Reason, _State) ->
+    ok.
+
+code_change(_OldVsn, State, _Extra) ->
+    {ok, State}.
diff --git a/lib/stdlib/test/supervisor_SUITE_data/app_faulty/src/app_faulty_sup.erl b/lib/stdlib/test/supervisor_SUITE_data/app_faulty/src/app_faulty_sup.erl
new file mode 100644
index 0000000000..8115a88809
--- /dev/null
+++ b/lib/stdlib/test/supervisor_SUITE_data/app_faulty/src/app_faulty_sup.erl
@@ -0,0 +1,17 @@
+-module(app_faulty_sup).
+
+-behaviour(supervisor).
+
+%% API
+-export([start_link/0]).
+
+%% Supervisor callbacks
+-export([init/1]).
+
+start_link() ->
+    supervisor:start_link(?MODULE, []).
+
+init([]) ->
+    AChild = {app_faulty,{app_faulty_server,start_link,[]},
+	      permanent,2000,worker,[app_faulty_server]},
+    {ok,{{one_for_all,0,1}, [AChild]}}.