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

* egil/percept/fix-unmatched_return/OTP-13595:
  egd: Fix unmatched return warnings
  egd: Small code style refactoring
  percept: Fix unmatched return warnings
  percept: Small code style refactoring

8 files changed, 126 insertions, 163 deletions

diff --git a/lib/percept/src/egd.erl b/lib/percept/src/egd.erl
index d57b7bb81d..fe52da71f1 100644
--- a/lib/percept/src/egd.erl
+++ b/lib/percept/src/egd.erl
@@ -37,9 +37,7 @@
 -include("egd.hrl").
 
 %%==========================================================================
-%%
-%% 		Type definitions 
-%%
+%% Type definitions
 %%==========================================================================
 
 %% @type egd_image()
@@ -54,9 +52,7 @@
 -type color() :: {float(), float(), float(), float()}.
 
 %%==========================================================================
-%%
-%%		Interface functions	
-%%
+%% Interface functions
 %%==========================================================================
 
 %% @spec create(integer(), integer()) -> egd_image()
@@ -74,8 +70,7 @@ create(Width,Height) ->
 -spec destroy(Image :: egd_image()) -> ok.
 
 destroy(Image) ->
-   cast(Image, destroy),
-   ok.
+   cast(Image, destroy).
 
 
 %% @spec render(egd_image()) -> binary()
@@ -113,8 +108,7 @@ render(Image, Type, Options) ->
 %%	mainly.
 
 information(Pid) ->
-    cast(Pid, information),
-    ok.
+    cast(Pid, information).
 
 %% @spec line(egd_image(), point(), point(), color()) -> ok
 %% @doc Creates a line object from P1 to P2 in the image.
@@ -126,8 +120,7 @@ information(Pid) ->
 	Color :: color()) -> 'ok'.
 
 line(Image, P1, P2, Color) ->
-    cast(Image, {line, P1, P2, Color}),
-    ok.
+    cast(Image, {line, P1, P2, Color}).
 
 %% @spec color( Value | Name ) -> color()
 %% where
@@ -152,74 +145,67 @@ color(_Image, Color) ->
 %% @doc Creates a text object.
 
 text(Image, P, Font, Text, Color) ->
-    cast(Image, {text, P, Font, Text, Color}),
-    ok.
+    cast(Image, {text, P, Font, Text, Color}).
 
 %% @spec rectangle(egd_image(), point(), point(), color()) -> ok
 %% @doc Creates a rectangle object.
 
 rectangle(Image, P1, P2, Color) ->
-    cast(Image, {rectangle, P1, P2, Color}),
-    ok.
+    cast(Image, {rectangle, P1, P2, Color}).
 
 %% @spec filledRectangle(egd_image(), point(), point(), color()) -> ok
 %% @doc Creates a filled rectangle object.
 
 filledRectangle(Image, P1, P2, Color) ->
-    cast(Image, {filled_rectangle, P1, P2, Color}),
-    ok.
+    cast(Image, {filled_rectangle, P1, P2, Color}).
 
 %% @spec filledEllipse(egd_image(), point(), point(), color()) -> ok
 %% @doc Creates a filled ellipse object.
 
 filledEllipse(Image, P1, P2, Color) ->
-    cast(Image, {filled_ellipse, P1, P2, Color}),
-    ok.
+    cast(Image, {filled_ellipse, P1, P2, Color}).
 
 %% @spec filledTriangle(egd_image(), point(), point(), point(), color()) -> ok
 %% @hidden
 %% @doc Creates a filled triangle object.
 
 filledTriangle(Image, P1, P2, P3, Color) ->
-    cast(Image, {filled_triangle, P1, P2, P3, Color}),
-    ok.
+    cast(Image, {filled_triangle, P1, P2, P3, Color}).
 
 %% @spec polygon(egd_image(), [point()], color()) -> ok
 %% @hidden
 %% @doc Creates a filled filled polygon object.
 
 polygon(Image, Pts, Color) ->
-    cast(Image, {polygon, Pts, Color}),
-    ok.
+    cast(Image, {polygon, Pts, Color}).
 
 %% @spec arc(egd_image(), point(), point(), color()) -> ok
 %% @hidden
 %% @doc Creates an arc with radius of bbx corner.
 
 arc(Image, P1, P2, Color) ->
-    cast(Image, {arc, P1, P2, Color}),
-    ok.
+    cast(Image, {arc, P1, P2, Color}).
 
 %% @spec arc(egd_image(), point(), point(), integer(), color()) -> ok
 %% @hidden
 %% @doc Creates an arc.
 
 arc(Image, P1, P2, D, Color) ->
-    cast(Image, {arc, P1, P2, D, Color}),
-    ok.
+    cast(Image, {arc, P1, P2, D, Color}).
 
 %% @spec save(binary(), string()) -> ok
 %% @doc Saves the binary to file. 
 
 save(Binary, Filename) when is_binary(Binary) ->
-    file:write_file(Filename, Binary),
+    ok = file:write_file(Filename, Binary),
     ok.
 % ---------------------------------
 % Aux functions 
 % ---------------------------------
 
 cast(Pid, Command) ->
-    Pid ! {egd, self(), Command}.
+    Pid ! {egd, self(), Command},
+    ok.
 
 call(Pid, Command) ->
     Pid ! {egd, self(), Command},
diff --git a/lib/percept/src/egd.hrl b/lib/percept/src/egd.hrl
index 1b125d3a08..fc0a7e10ee 100644
--- a/lib/percept/src/egd.hrl
+++ b/lib/percept/src/egd.hrl
@@ -41,6 +41,5 @@
 -ifdef(debug).
 -define(dbg(X), io:format("DEBUG: ~p:~p~n",[?MODULE, X])).
 -else.
--define(dbg(X), void).
+-define(dbg(X), ok).
 -endif.
-
diff --git a/lib/percept/src/egd_font.erl b/lib/percept/src/egd_font.erl
index 95203d5441..ef1cc434df 100644
--- a/lib/percept/src/egd_font.erl
+++ b/lib/percept/src/egd_font.erl
@@ -51,9 +51,7 @@
 %%
 
 %%==========================================================================
-%%
-%%		Interface functions	
-%%
+%% Interface functions
 %%==========================================================================
 
 size(Font) ->
@@ -70,15 +68,14 @@ load(Filename) ->
     load_font_header(Font).
 
 %%==========================================================================
-%%
-%%		Internal functions	
-%%
+%% Internal functions
 %%==========================================================================
 
 %% ETS handler functions
 
 initialize_table() ->
-    ets:new(egd_font_table, [named_table, ordered_set, public]).
+    egd_font_table = ets:new(egd_font_table, [named_table, ordered_set, public]),
+    ok.
 
 glyph_insert(Font, Code, Translation, LSs) ->
     Element = {{Font, Code}, Translation, LSs},
diff --git a/lib/percept/src/egd_render.erl b/lib/percept/src/egd_render.erl
index c0075b8c42..6c708e3e86 100644
--- a/lib/percept/src/egd_render.erl
+++ b/lib/percept/src/egd_render.erl
@@ -662,4 +662,3 @@ eps_header(W,H) ->
 
 eps_footer() -> 
     "%%EOF\n".
-
diff --git a/lib/percept/src/percept.erl b/lib/percept/src/percept.erl
index 24ddf1bd14..046e0b7518 100644
--- a/lib/percept/src/percept.erl
+++ b/lib/percept/src/percept.erl
@@ -26,27 +26,24 @@
 
 -module(percept).
 -behaviour(application).
--export([
-	profile/1, 
-	profile/2, 
-	profile/3,
-	stop_profile/0, 
-	start_webserver/0, 
-	start_webserver/1, 
-	stop_webserver/0, 
-	stop_webserver/1, 
-	analyze/1,
-	% Application behaviour
-	start/2, 
-	stop/1]).
+-export([profile/1,
+         profile/2,
+         profile/3,
+         stop_profile/0,
+         start_webserver/0,
+         start_webserver/1,
+         stop_webserver/0,
+         stop_webserver/1,
+         analyze/1,
+         % Application behaviour
+         start/2,
+         stop/1]).
 
 
 -include("percept.hrl").
 
 %%==========================================================================
-%%
-%% 		Type definitions 
-%%
+%% Type definitions
 %%==========================================================================
 
 %% @type percept_option() = procs | ports | exclusive
@@ -54,9 +51,7 @@
 -type percept_option() :: 'procs' | 'ports' | 'exclusive' | 'scheduler'.
 
 %%==========================================================================
-%%
-%% 		Application callback functions
-%%
+%% Application callback functions
 %%==========================================================================
 
 %% @spec start(Type, Args) -> {started, Hostname, Port} | {error, Reason} 
@@ -76,9 +71,7 @@ stop(_State) ->
     stop_webserver(0).
 
 %%==========================================================================
-%%
-%% 		Interface functions
-%%
+%% Interface functions
 %%==========================================================================
 
 %% @spec profile(Filename::string()) -> {ok, Port} | {already_started, Port}
@@ -158,11 +151,11 @@ start_webserver() ->
 	{'started', string(), pos_integer()} | {'error', any()}.
 
 start_webserver(Port) when is_integer(Port) ->
-    application:load(percept),
+    ok = ensure_loaded(percept),
     case whereis(percept_httpd) of
 	undefined ->
 	    {ok, Config} = get_webserver_config("percept", Port),
-	    inets:start(),
+	    ok = application:ensure_started(inets),
 	    case inets:start(httpd, Config) of
 		{ok, Pid} ->
 		    AssignedPort = find_service_port_from_pid(inets:services_info(), Pid),
@@ -217,9 +210,7 @@ stop_webserver(Port) ->
     do_stop(Port,[]).
 
 %%==========================================================================
-%%
-%% 		Auxiliary functions 
-%%
+%% Auxiliary functions
 %%==========================================================================
 
 %% parse_and_insert
@@ -337,3 +328,10 @@ get_webserver_config(Servername, Port) when is_list(Servername), is_integer(Port
 	{bind_address, any},
 	{port, Port}],
     {ok, Config}.
+
+ensure_loaded(App) ->
+    case application:load(App) of
+        ok -> ok;
+        {error,{already_loaded,App}} -> ok;
+        Error -> Error
+    end.
diff --git a/lib/percept/src/percept_db.erl b/lib/percept/src/percept_db.erl
index 6c2dddccac..6cbe3ce022 100644
--- a/lib/percept/src/percept_db.erl
+++ b/lib/percept/src/percept_db.erl
@@ -24,21 +24,17 @@
 
 -module(percept_db).
 
--export([
-	start/0,
-	stop/0,
-	insert/1,
-	select/2,
-	select/1,
-	consolidate/0
-	]).
+-export([start/0,
+         stop/0,
+         insert/1,
+         select/2,
+         select/1,
+         consolidate/0]).
 
 -include("percept.hrl").
 -define(STOP_TIMEOUT, 1000).
 %%==========================================================================
-%%
-%% 		Type definitions 
-%%
+%% Type definitions
 %%==========================================================================
 
 %% @type activity_option() = 
@@ -64,9 +60,7 @@
 
 
 %%==========================================================================
-%%
-%% 		Interface functions
-%%
+%% Interface functions
 %%==========================================================================
 
 %% @spec start() -> ok | {started, Pid} | {restarted, Pid}
@@ -100,7 +94,7 @@ restart(PerceptDB)->
 -spec do_start()-> pid().
 
 do_start()->
-    Pid = spawn( fun() -> init_percept_db() end),
+    Pid = spawn(fun() -> init_percept_db() end),
     erlang:register(percept_db, Pid),
     Pid.
 
@@ -123,17 +117,17 @@ stop() ->
 %% @private
 %% @doc Stops the percept database, with a synchronous call.
 
--spec stop_sync(pid())-> true.
+-spec stop_sync(pid()) -> true.
 
-stop_sync(Pid)->
+stop_sync(Pid) ->
     MonitorRef = erlang:monitor(process, Pid),
-    stop(),
+    _ = stop(),
     receive
         {'DOWN', MonitorRef, _Type, Pid, _Info}->
             true
     after ?STOP_TIMEOUT->
-            erlang:demonitor(MonitorRef, [flush]),
-            exit(Pid, kill)
+              erlang:demonitor(MonitorRef, [flush]),
+              exit(Pid, kill)
     end.
 
 %% @spec insert(tuple()) -> ok
@@ -186,26 +180,24 @@ consolidate() ->
     ok.
 
 %%==========================================================================
-%%
-%% 		Database loop 
-%%
+%% Database loop
 %%==========================================================================
 
 init_percept_db() ->
     % Proc and Port information
-    ets:new(pdb_info, [named_table, private, {keypos, #information.id}, set]),
+    pdb_info = ets:new(pdb_info, [named_table, private, {keypos, #information.id}, set]),
 
     % Scheduler runnability
-    ets:new(pdb_scheduler, [named_table, private, {keypos, #activity.timestamp}, ordered_set]),
+    pdb_scheduler = ets:new(pdb_scheduler, [named_table, private, {keypos, #activity.timestamp}, ordered_set]),
     
     % Process and Port runnability
-    ets:new(pdb_activity, [named_table, private, {keypos, #activity.timestamp}, ordered_set]),
+    pdb_activity = ets:new(pdb_activity, [named_table, private, {keypos, #activity.timestamp}, ordered_set]),
     
     % System status
-    ets:new(pdb_system, [named_table, private, {keypos, 1}, set]),
+    pdb_system = ets:new(pdb_system, [named_table, private, {keypos, 1}, set]),
     
     % System warnings
-    ets:new(pdb_warnings, [named_table, private, {keypos, 1}, ordered_set]),
+    pdb_warnings = ets:new(pdb_warnings, [named_table, private, {keypos, 1}, ordered_set]),
     put(debug, 0),
     loop_percept_db().
 
@@ -232,9 +224,7 @@ loop_percept_db() ->
     end.
 
 %%==========================================================================
-%%
-%% 		Auxiliary functions 
-%%
+%% Auxiliary functions
 %%==========================================================================
 
 %% cleans trace messages from external pids
@@ -788,5 +778,3 @@ update_system_stop_ts(TS) ->
 	Unhandled -> 
 	    io:format("update_system_stop_ts, unhandled ~p ~n", [Unhandled])
     end.
-	    
-
diff --git a/lib/percept/src/percept_graph.erl b/lib/percept/src/percept_graph.erl
index 1803e035ab..e5bbaca2b4 100644
--- a/lib/percept/src/percept_graph.erl
+++ b/lib/percept/src/percept_graph.erl
@@ -33,28 +33,28 @@
 %% 
 
 graph(SessionID, Env, Input) ->
-    mod_esi:deliver(SessionID, header()),
-    mod_esi:deliver(SessionID, binary_to_list(graph(Env, Input))).
+    ok = mod_esi:deliver(SessionID, header()),
+    ok = mod_esi:deliver(SessionID, binary_to_list(graph(Env, Input))).
  
 %% activity
 %% @spec activity(SessionID, Env, Input) -> term() 
 %% @doc An ESI callback implementation used by the httpd server.
 
 activity(SessionID, Env, Input) ->
-    mod_esi:deliver(SessionID, header()),
-    mod_esi:deliver(SessionID, binary_to_list(activity_bar(Env, Input))).
+    ok = mod_esi:deliver(SessionID, header()),
+    ok = mod_esi:deliver(SessionID, binary_to_list(activity_bar(Env, Input))).
 
 proc_lifetime(SessionID, Env, Input) ->
-    mod_esi:deliver(SessionID, header()),
-    mod_esi:deliver(SessionID, binary_to_list(proc_lifetime(Env, Input))).
+    ok = mod_esi:deliver(SessionID, header()),
+    ok = mod_esi:deliver(SessionID, binary_to_list(proc_lifetime(Env, Input))).
 
 percentage(SessionID, Env, Input) ->
-    mod_esi:deliver(SessionID, header()),
-    mod_esi:deliver(SessionID, binary_to_list(percentage(Env,Input))).
+    ok = mod_esi:deliver(SessionID, header()),
+    ok = mod_esi:deliver(SessionID, binary_to_list(percentage(Env,Input))).
 
 scheduler_graph(SessionID, Env, Input) ->
-    mod_esi:deliver(SessionID, header()),
-    mod_esi:deliver(SessionID, binary_to_list(scheduler_graph(Env, Input))).
+    ok = mod_esi:deliver(SessionID, header()),
+    ok = mod_esi:deliver(SessionID, binary_to_list(scheduler_graph(Env, Input))).
 
 graph(_Env, Input) ->
     Query    = httpd:parse_query(Input),
diff --git a/lib/percept/src/percept_html.erl b/lib/percept/src/percept_html.erl
index a8eb29b741..a675227584 100644
--- a/lib/percept/src/percept_html.erl
+++ b/lib/percept/src/percept_html.erl
@@ -18,22 +18,18 @@
 %% %CopyrightEnd%
 
 -module(percept_html).
--export([
-	page/3, 
-	codelocation_page/3, 
-	databases_page/3, 
-	load_database_page/3, 
-	processes_page/3, 
-	concurrency_page/3,
-	process_info_page/3
-	]).
-
--export([
-	value2pid/1, 
-	pid2value/1, 
-	get_option_value/2,
-	join_strings_with/2
-	]).
+-export([page/3,
+         codelocation_page/3,
+         databases_page/3,
+         load_database_page/3,
+         processes_page/3,
+         concurrency_page/3,
+         process_info_page/3]).
+
+-export([value2pid/1,
+         pid2value/1,
+         get_option_value/2,
+         join_strings_with/2]).
 
 -include("percept.hrl").
 -include_lib("kernel/include/file.hrl").
@@ -42,47 +38,47 @@
 %% API
 
 page(SessionID, Env, Input) ->
-    mod_esi:deliver(SessionID, header()),
-    mod_esi:deliver(SessionID, menu()), 
-    mod_esi:deliver(SessionID, overview_content(Env, Input)),
-    mod_esi:deliver(SessionID, footer()).
+    ok = mod_esi:deliver(SessionID, header()),
+    ok = mod_esi:deliver(SessionID, menu()),
+    ok = mod_esi:deliver(SessionID, overview_content(Env, Input)),
+    ok = mod_esi:deliver(SessionID, footer()).
 
 processes_page(SessionID, _, _) ->
-    mod_esi:deliver(SessionID, header()),
-    mod_esi:deliver(SessionID, menu()), 
-    mod_esi:deliver(SessionID, processes_content()),
-    mod_esi:deliver(SessionID, footer()).
+    ok = mod_esi:deliver(SessionID, header()),
+    ok = mod_esi:deliver(SessionID, menu()),
+    ok = mod_esi:deliver(SessionID, processes_content()),
+    ok = mod_esi:deliver(SessionID, footer()).
 
 concurrency_page(SessionID, Env, Input) ->
-    mod_esi:deliver(SessionID, header()),
-    mod_esi:deliver(SessionID, menu()), 
-    mod_esi:deliver(SessionID, concurrency_content(Env, Input)),
-    mod_esi:deliver(SessionID, footer()).
+    ok = mod_esi:deliver(SessionID, header()),
+    ok = mod_esi:deliver(SessionID, menu()),
+    ok = mod_esi:deliver(SessionID, concurrency_content(Env, Input)),
+    ok = mod_esi:deliver(SessionID, footer()).
 
 databases_page(SessionID, _, _) ->
-    mod_esi:deliver(SessionID, header()),
-    mod_esi:deliver(SessionID, menu()), 
-    mod_esi:deliver(SessionID, databases_content()),
-    mod_esi:deliver(SessionID, footer()).
+    ok = mod_esi:deliver(SessionID, header()),
+    ok = mod_esi:deliver(SessionID, menu()),
+    ok = mod_esi:deliver(SessionID, databases_content()),
+    ok = mod_esi:deliver(SessionID, footer()).
     
 codelocation_page(SessionID, Env, Input) ->
-    mod_esi:deliver(SessionID, header()),
-    mod_esi:deliver(SessionID, menu()), 
-    mod_esi:deliver(SessionID, codelocation_content(Env, Input)),
-    mod_esi:deliver(SessionID, footer()).
+    ok = mod_esi:deliver(SessionID, header()),
+    ok = mod_esi:deliver(SessionID, menu()),
+    ok = mod_esi:deliver(SessionID, codelocation_content(Env, Input)),
+    ok = mod_esi:deliver(SessionID, footer()).
 
 process_info_page(SessionID, Env, Input) ->
-    mod_esi:deliver(SessionID, header()),
-    mod_esi:deliver(SessionID, menu()), 
-    mod_esi:deliver(SessionID, process_info_content(Env, Input)),
-    mod_esi:deliver(SessionID, footer()).
+    ok = mod_esi:deliver(SessionID, header()),
+    ok = mod_esi:deliver(SessionID, menu()),
+    ok = mod_esi:deliver(SessionID, process_info_content(Env, Input)),
+    ok = mod_esi:deliver(SessionID, footer()).
 
 load_database_page(SessionID, Env, Input) ->
-    mod_esi:deliver(SessionID, header()),
+    ok = mod_esi:deliver(SessionID, header()),
 
     % Very dynamic page, handled differently
     load_database_content(SessionID, Env, Input),
-    mod_esi:deliver(SessionID, footer()).
+    ok = mod_esi:deliver(SessionID, footer()).
 
 
 %%% --------------------------- %%%
@@ -446,24 +442,24 @@ load_database_content(SessionId, _Env, Input) ->
     Filename = filename:join(Path, File),
     % Check path/file/filename
     
-    mod_esi:deliver(SessionId, "<div id=\"content\">"), 
+    ok = mod_esi:deliver(SessionId, "<div id=\"content\">"),
     case file:read_file_info(Filename) of
 	{ok, _} ->
     	    Content = "<center>
     	    Parsing: " ++ Filename ++ "<br>
     	    </center>",
-	    mod_esi:deliver(SessionId, Content),
-	    case percept:analyze(Filename) of
-		{error, Reason} ->
-	    	    mod_esi:deliver(SessionId, error_msg("Analyze" ++ term2html(Reason)));
-		_ ->
-		    Complete = "<center><a href=\"/cgi-bin/percept_html/page\">View</a></center>",
-	    	   mod_esi:deliver(SessionId, Complete)
-	    end;
+	    ok = mod_esi:deliver(SessionId, Content),
+            case percept:analyze(Filename) of
+                {error, Reason} ->
+                    ok = mod_esi:deliver(SessionId, error_msg("Analyze" ++ term2html(Reason)));
+                _ ->
+                    Complete = "<center><a href=\"/cgi-bin/percept_html/page\">View</a></center>",
+                    ok = mod_esi:deliver(SessionId, Complete)
+            end;
 	{error, Reason} ->
-	    mod_esi:deliver(SessionId, error_msg("File" ++ term2html(Reason)))
+	    ok = mod_esi:deliver(SessionId, error_msg("File" ++ term2html(Reason)))
     end,
-    mod_esi:deliver(SessionId, "</div>"). 
+    ok = mod_esi:deliver(SessionId, "</div>").
 
 codelocation_content(_Env, Input) ->
     Query   = httpd:parse_query(Input),