Merge branch 'egil/runtime_tools/fix-unmatched_return/OTP-13595'

* egil/runtime_tools/fix-unmatched_return/OTP-13595:
  runtime_tools: Fix unmatched return warnings

6 files changed, 53 insertions, 35 deletions

diff --git a/lib/runtime_tools/src/appmon_info.erl b/lib/runtime_tools/src/appmon_info.erl
index fead724373..b5500085a3 100644
--- a/lib/runtime_tools/src/appmon_info.erl
+++ b/lib/runtime_tools/src/appmon_info.erl
@@ -307,9 +307,10 @@ do_work(Key, State) ->
     {Cmd, Aux, From, _OldRef, Old, Opts} = retrieve(WorkStore, Key),
     {ok, Result} = do_work2(Cmd, Aux, From, Old, Opts),
     if
-	Result==Old -> ok;
-	true ->
-	    From ! {delivery, self(), Cmd, Aux, Result}
+        Result==Old -> ok;
+        true ->
+            From ! {delivery, self(), Cmd, Aux, Result},
+            ok
     end,
     case get_opt(timeout, Opts) of
 	at_most_once ->
@@ -393,7 +394,7 @@ del_task(Key, WorkStore) ->
 	{_Cmd, _Aux, _From, Ref, _Old, Opts} ->
 	    if
 		Ref /= nil ->
-		    timer:cancel(Ref),
+                    {ok,_} = timer:cancel(Ref),
 		    receive
 			{do_it, Key} ->
 			    Opts
diff --git a/lib/runtime_tools/src/dbg.erl b/lib/runtime_tools/src/dbg.erl
index 1620f52789..8cdb5a43e3 100644
--- a/lib/runtime_tools/src/dbg.erl
+++ b/lib/runtime_tools/src/dbg.erl
@@ -217,7 +217,7 @@ ctpg({_Module, _Function, _Arity} = X) ->
     do_ctp(X,[global]).
 
 do_ctp({Module, Function, Arity},[]) ->
-    do_ctp({Module, Function, Arity},[global]),
+    {ok,_} = do_ctp({Module, Function, Arity},[global]),
     do_ctp({Module, Function, Arity},[local]);
 do_ctp({_Module, _Function, _Arity}=MFA,Flags) ->
     Nodes = req(get_nodes),
@@ -271,8 +271,7 @@ wtp(FileName) ->
 				ok
 			end,
 			[]),
-	    file:close(File),
-	    ok
+	    ok = file:close(File)
     end.
 
 %%
@@ -600,7 +599,7 @@ stop() ->
     end.
 
 stop_clear() ->
-    ctp(),
+    {ok, _} = ctp(),
     stop().
 
 %%% Calling the server.
@@ -791,7 +790,8 @@ loop({C,T}=SurviveLinks, Table) ->
     end.
 
 reply(Pid, Reply) ->
-    Pid ! {dbg,Reply}.
+    Pid ! {dbg,Reply},
+    ok.
 
 
 %%% A process-based tracer.
@@ -944,9 +944,11 @@ do_relay(Parent,RelP) ->
     case RelP of
 	{Type,Data} -> 
 	    {ok,Tracer} = remote_tracer(Type,Data),
-	    Parent ! {started,Tracer};
+	    Parent ! {started,Tracer},
+            ok;
 	Pid when is_pid(Pid) ->
-	    Parent ! {started,self()}
+	    Parent ! {started,self()},
+            ok
     end,
     do_relay_1(RelP).
 
@@ -1366,7 +1368,7 @@ mk_reader_wrap([_Hd | Tail] = WrapFiles, File) ->
 		{ok, Term} ->
 		    [Term | mk_reader_wrap(WrapFiles, File)];
 		eof ->
-		    file:close(File),
+		    ok = file:close(File),
 		    case Tail of
 			[_|_] ->
 			    mk_reader_wrap(Tail);
diff --git a/lib/runtime_tools/src/erts_alloc_config.erl b/lib/runtime_tools/src/erts_alloc_config.erl
index e94cced911..514530332c 100644
--- a/lib/runtime_tools/src/erts_alloc_config.erl
+++ b/lib/runtime_tools/src/erts_alloc_config.erl
@@ -128,7 +128,7 @@ make_config(FileName) when is_list(FileName) ->
     case file:open(FileName, [write]) of
 	{ok, IODev} ->
 	    Res = req({make_config, IODev}),
-	    file:close(IODev),
+	    ok = file:close(IODev),
 	    Res;
 	Error ->
 	    Error
@@ -200,9 +200,11 @@ server_loop(State) ->
 			       Conf = #conf{segments = ?MBC_MSEG_LIMIT,
 					    format_to = IODev},
 			       Res = mk_config(Conf, State#state.alloc),
-			       From ! {response, Ref, Res};
+			       From ! {response, Ref, Res},
+                               ok;
 			   _ ->
-			       From ! {response, Ref, no_scenario_saved}
+			       From ! {response, Ref, no_scenario_saved},
+                               ok
 		       end,
 		       State;
 		   {request, From, Ref, stop} ->
diff --git a/lib/runtime_tools/src/observer_backend.erl b/lib/runtime_tools/src/observer_backend.erl
index 30df3b0b8b..66653c5b7f 100644
--- a/lib/runtime_tools/src/observer_backend.erl
+++ b/lib/runtime_tools/src/observer_backend.erl
@@ -259,7 +259,8 @@ etop_collect(Collector) ->
 
     case SchedulerWallTime of
 	undefined ->
-	    spawn(fun() -> flag_holder_proc(Collector) end);
+	    spawn(fun() -> flag_holder_proc(Collector) end),
+            ok;
 	_ ->
 	    ok
     end,
@@ -334,8 +335,8 @@ ttb_init_node(MetaFile_0,PI,Traci) ->
     MetaPid ! {metadata,Traci},
     case PI of
 	true ->
-	    Proci = pnames(),
-	    MetaPid ! {metadata,Proci};
+	    MetaPid ! {metadata,pnames()},
+            ok;
 	false ->
 	    ok
     end,
@@ -354,7 +355,8 @@ ttb_meta_tracer(MetaFile,PI,Parent,SessionData) ->
 	    erlang:trace_pattern({erlang,spawn_link,3},ReturnMS,[meta]),
 	    erlang:trace_pattern({erlang,spawn_opt,1},ReturnMS,[meta]),
 	    erlang:trace_pattern({erlang,register,2},[],[meta]),
-	    erlang:trace_pattern({global,register_name,2},[],[meta]);
+	    erlang:trace_pattern({global,register_name,2},[],[meta]),
+            ok;
 	false ->
 	    ok
     end,
@@ -362,7 +364,8 @@ ttb_meta_tracer(MetaFile,PI,Parent,SessionData) ->
     case proplists:get_value(overload_check, SessionData) of
         {Ms, M, F} ->
             catch M:F(init),
-            erlang:send_after(Ms, self(), overload_check);
+            erlang:send_after(Ms, self(), overload_check),
+            ok;
         _ ->
             ok
     end,
@@ -371,10 +374,10 @@ ttb_meta_tracer(MetaFile,PI,Parent,SessionData) ->
 ttb_meta_tracer_loop(MetaFile,PI,Acc,State) ->
     receive
 	{trace_ts,_,call,{erlang,register,[Name,Pid]},_} ->
-	    ttb_store_meta({pid,{Pid,Name}},MetaFile),
+	    ok = ttb_store_meta({pid,{Pid,Name}},MetaFile),
 	    ttb_meta_tracer_loop(MetaFile,PI,Acc,State);
 	{trace_ts,_,call,{global,register_name,[Name,Pid]},_} ->
-	    ttb_store_meta({pid,{Pid,{global,Name}}},MetaFile),
+	    ok = ttb_store_meta({pid,{Pid,{global,Name}}},MetaFile),
 	    ttb_meta_tracer_loop(MetaFile,PI,Acc,State);
 	{trace_ts,CallingPid,call,{erlang,spawn_opt,[{M,F,Args,_}]},_} ->
 	    MFA = {M,F,length(Args)},
@@ -390,7 +393,7 @@ ttb_meta_tracer_loop(MetaFile,PI,Acc,State) ->
 	    NewAcc = 
 		dict:update(CallingPid,
 			    fun([H|T]) -> 
-				    ttb_store_meta({pid,{NewPid,H}},MetaFile),
+				    ok = ttb_store_meta({pid,{NewPid,H}},MetaFile),
 				    T 
 			    end,
 			    Acc),
@@ -408,22 +411,22 @@ ttb_meta_tracer_loop(MetaFile,PI,Acc,State) ->
 	    NewAcc = 
 		dict:update(CallingPid,
 			    fun([H|T]) -> 
-				    ttb_store_meta({pid,{NewPid,H}},MetaFile),
+				    ok = ttb_store_meta({pid,{NewPid,H}},MetaFile),
 				    T
 			    end,
 			    Acc),
 	    ttb_meta_tracer_loop(MetaFile,PI,NewAcc,State);
 
 	{metadata,Data} when is_list(Data) ->
-	    ttb_store_meta(Data,MetaFile),
+	    ok = ttb_store_meta(Data,MetaFile),
 	    ttb_meta_tracer_loop(MetaFile,PI,Acc,State);
 
 	{metadata,Key,Fun} when is_function(Fun) ->
-	    ttb_store_meta([{Key,Fun()}],MetaFile),
+	    ok = ttb_store_meta([{Key,Fun()}],MetaFile),
 	    ttb_meta_tracer_loop(MetaFile,PI,Acc,State);
 
 	{metadata,Key,What} ->
-	    ttb_store_meta([{Key,What}],MetaFile),
+	    ok = ttb_store_meta([{Key,What}],MetaFile),
 	    ttb_meta_tracer_loop(MetaFile,PI,Acc,State);
         overload_check ->
             {Ms, M, F} = proplists:get_value(overload_check, State),
@@ -439,7 +442,7 @@ ttb_meta_tracer_loop(MetaFile,PI,Acc,State) ->
                     ttb_meta_tracer_loop(MetaFile,PI,Acc, State)
             end;
      {'DOWN', _, _, _, _} ->
-            stop_seq_trace(),
+            _ = stop_seq_trace(),
             self() ! stop,
             ttb_meta_tracer_loop(MetaFile,PI,Acc, State);
      stop when PI=:=true ->
@@ -528,7 +531,7 @@ ttb_store_meta(Data,MetaFile) ->
     ttb_store_meta([Data],MetaFile).
 
 ttb_write_binary(Fd,[H|T]) ->
-    file:write(Fd,ttb_make_binary(H)),
+    ok = file:write(Fd,ttb_make_binary(H)),
     ttb_write_binary(Fd,T);
 ttb_write_binary(_Fd,[]) ->
     ok.
@@ -585,9 +588,9 @@ ttb_fetch(MetaFile,{Port,Host}) ->
 
 send_files({Sock,Host},[File|Files]) ->
     {ok,Fd} = file:open(File,[raw,read,binary]),
-    gen_tcp:send(Sock,<<1,(list_to_binary(filename:basename(File)))/binary>>),
+    ok = gen_tcp:send(Sock,<<1,(list_to_binary(filename:basename(File)))/binary>>),
     send_chunks(Sock,Fd),
-    file:delete(File),
+    ok = file:delete(File),
     send_files({Sock,Host},Files);
 send_files({_Sock,_Host},[]) ->
     done.
diff --git a/lib/runtime_tools/src/percept_profile.erl b/lib/runtime_tools/src/percept_profile.erl
index ceec4d3b89..1e8e913b80 100644
--- a/lib/runtime_tools/src/percept_profile.erl
+++ b/lib/runtime_tools/src/percept_profile.erl
@@ -87,7 +87,7 @@ start(Filename, Options) ->
 start(Filename, {Module, Function, Args}, Options) ->
     case whereis(percept_port) of
 	undefined ->
-	    profile_to_file(Filename, Options),
+            {ok, _} = profile_to_file(Filename, Options),
 	    erlang:apply(Module, Function, Args),
 	    stop();
 	Port ->
@@ -113,7 +113,7 @@ deliver_all_trace() ->
 -spec stop() -> 'ok' | {'error', 'not_started'}.
 
 stop() ->
-    erlang:system_profile(undefined, [runnable_ports, runnable_procs]),
+    _ = erlang:system_profile(undefined, [runnable_ports, runnable_procs]),
     erlang:trace(all, false, [procs, ports, timestamp]),
     deliver_all_trace(), 
     case whereis(percept_port) of
@@ -158,7 +158,8 @@ set_tracer(Port, Opts) ->
     {TOpts, POpts} = parse_profile_options(Opts),
     % Setup profiling and tracing
     erlang:trace(all, true, [{tracer, Port}, timestamp | TOpts]),
-    erlang:system_profile(Port, POpts).
+    _ = erlang:system_profile(Port, POpts),
+    ok.
 
 %% parse_profile_options
 
diff --git a/lib/runtime_tools/src/system_information.erl b/lib/runtime_tools/src/system_information.erl
index 1add01612d..df25297eb9 100644
--- a/lib/runtime_tools/src/system_information.erl
+++ b/lib/runtime_tools/src/system_information.erl
@@ -31,6 +31,7 @@
 -export([report/0,
 	from_file/1,
 	to_file/1]).
+
 -export([start/0, stop/0,
          load_report/0, load_report/2,
          applications/0, applications/1,
@@ -64,6 +65,7 @@
 start() ->
     gen_server:start({local, ?SERVER}, ?MODULE, [], []).
 
+
 stop() ->
     gen_server:call(?SERVER, stop, infinity).
 
@@ -71,7 +73,7 @@ load_report() -> load_report(data, report()).
 
 load_report(file, File)   -> load_report(data, from_file(File));
 load_report(data, Report) ->
-    start(), gen_server:call(?SERVER, {load_report, Report}, infinity).
+    ok = start_internal(), gen_server:call(?SERVER, {load_report, Report}, infinity).
 
 report() -> [
 	{init_arguments,    init:get_arguments()},
@@ -219,6 +221,13 @@ code_change(_OldVsn, State, _Extra) ->
 %% Internal functions
 %%===================================================================
 
+start_internal() ->
+    case start() of
+        {ok,_} -> ok;
+        {error, {already_started,_}} -> ok;
+        Error -> Error
+    end.
+
 %% handle report values
 
 get_value([], Data) -> Data;