3 files changed, 29 insertions, 27 deletions

diff --git a/lib/dialyzer/src/dialyzer_cl.erl b/lib/dialyzer/src/dialyzer_cl.erl
index fe4ec41359..4386a8d52a 100644
--- a/lib/dialyzer/src/dialyzer_cl.erl
+++ b/lib/dialyzer/src/dialyzer_cl.erl
@@ -656,15 +656,15 @@ return_value(State = #cl_state{erlang_mode = ErlangMode,
 			       mod_deps = ModDeps,
 			       output_plt = OutputPlt,
 			       plt_info = PltInfo,
-			       stored_warnings = StoredWarnings,
-                               legal_warnings = LegalWarnings},
+			       stored_warnings = StoredWarnings},
 	     Plt) ->
   case OutputPlt =:= none of
     true -> ok;
     false -> dialyzer_plt:to_file(OutputPlt, Plt, ModDeps, PltInfo)
   end,
+  UnknownWarnings = unknown_warnings(State),
   RetValue =
-    case StoredWarnings =:= [] of
+    case StoredWarnings =:= [] andalso UnknownWarnings =:= [] of
       true -> ?RET_NOTHING_SUSPICIOUS;
       false -> ?RET_DISCREPANCIES
     end,
@@ -677,22 +677,22 @@ return_value(State = #cl_state{erlang_mode = ErlangMode,
       maybe_close_output_file(State),
       {RetValue, []};
     true -> 
-      Unknown =
-        case ordsets:is_element(?WARN_UNKNOWN, LegalWarnings) of
-          true ->
-            unknown_functions(State) ++
-              unknown_types(State) ++
-              unknown_behaviours(State);
-          false -> []
-        end,
-      WarningInfo = {_Filename = "", _Line = 0, _MorMFA = ''},
-      UnknownWarnings =
-        [{?WARN_UNKNOWN, WarningInfo, W} || W <- Unknown],
       AllWarnings =
         UnknownWarnings ++ process_warnings(StoredWarnings),
       {RetValue, set_warning_id(AllWarnings)}
   end.
 
+unknown_warnings(State = #cl_state{legal_warnings = LegalWarnings}) ->
+  Unknown = case ordsets:is_element(?WARN_UNKNOWN, LegalWarnings) of
+              true ->
+                unknown_functions(State) ++
+                  unknown_types(State) ++
+                  unknown_behaviours(State);
+              false -> []
+            end,
+  WarningInfo = {_Filename = "", _Line = 0, _MorMFA = ''},
+  [{?WARN_UNKNOWN, WarningInfo, W} || W <- Unknown].
+
 unknown_functions(#cl_state{external_calls = Calls}) ->
   [{unknown_function, MFA} || MFA <- Calls].
 
@@ -706,10 +706,8 @@ print_ext_calls(#cl_state{report_mode = quiet}) ->
 print_ext_calls(#cl_state{output = Output,
 			  external_calls = Calls,
 			  stored_warnings = Warnings,
-			  output_format = Format,
-                          legal_warnings = LegalWarnings}) ->
-  case not ordsets:is_element(?WARN_UNKNOWN, LegalWarnings)
-    orelse Calls =:= [] of
+			  output_format = Format}) ->
+  case Calls =:= [] of
     true -> ok;
     false ->
       case Warnings =:= [] of
@@ -741,10 +739,8 @@ print_ext_types(#cl_state{output = Output,
                           external_calls = Calls,
                           external_types = Types,
                           stored_warnings = Warnings,
-                          output_format = Format,
-                          legal_warnings = LegalWarnings}) ->
-  case not ordsets:is_element(?WARN_UNKNOWN, LegalWarnings)
-    orelse Types =:= [] of
+                          output_format = Format}) ->
+  case Types =:= [] of
     true -> ok;
     false ->
       case Warnings =:= [] andalso Calls =:= [] of
diff --git a/lib/dialyzer/src/dialyzer_cl_parse.erl b/lib/dialyzer/src/dialyzer_cl_parse.erl
index ace2116fbe..21fc424a1b 100644
--- a/lib/dialyzer/src/dialyzer_cl_parse.erl
+++ b/lib/dialyzer/src/dialyzer_cl_parse.erl
@@ -2,7 +2,7 @@
 %%-----------------------------------------------------------------------
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 2006-2014. All Rights Reserved.
+%% Copyright Ericsson AB 2006-2015. All Rights Reserved.
 %%
 %% The contents of this file are subject to the Erlang Public License,
 %% Version 1.1, (the "License"); you may not use this file except in
@@ -524,6 +524,13 @@ warning_options_msg() ->
   -Wunderspecs ***
      Warn about underspecified functions
      (those whose -spec is strictly more allowing than the success typing).
+  -Wunknown ***
+     Let warnings about unknown functions and types affect the
+     exit status of the command line version. The default is to ignore
+     warnings about unknown functions and types when setting the exit
+     status. When using the Dialyzer from Erlang, warnings about unknown
+     functions and types are returned; the default is not to return
+     such warnings.
 
 The following options are also available but their use is not recommended:
 (they are mostly for Dialyzer developers and internal debugging)
diff --git a/lib/dialyzer/src/dialyzer_options.erl b/lib/dialyzer/src/dialyzer_options.erl
index 2d6a489695..81907f7995 100644
--- a/lib/dialyzer/src/dialyzer_options.erl
+++ b/lib/dialyzer/src/dialyzer_options.erl
@@ -50,8 +50,7 @@ build(Opts) ->
 		  ?WARN_CONTRACT_TYPES,
 		  ?WARN_CONTRACT_SYNTAX,
 		  ?WARN_BEHAVIOUR,
-		  ?WARN_UNDEFINED_CALLBACK,
-                  ?WARN_UNKNOWN],
+		  ?WARN_UNDEFINED_CALLBACK],
   DefaultWarns1 = ordsets:from_list(DefaultWarns),
   InitPlt = dialyzer_plt:get_default_plt(),
   DefaultOpts = #options{},
@@ -312,8 +311,8 @@ build_warnings([Opt|Opts], Warnings) ->
 	ordsets:add_element(?WARN_CONTRACT_SUBTYPE, Warnings);
       underspecs ->
 	ordsets:add_element(?WARN_CONTRACT_SUPERTYPE, Warnings);
-      no_unknown ->
-	ordsets:del_element(?WARN_UNKNOWN, Warnings);
+      unknown ->
+	ordsets:add_element(?WARN_UNKNOWN, Warnings);
       OtherAtom ->
 	bad_option("Unknown dialyzer warning option", OtherAtom)
     end,