Fix the features feature

erts/test/erlc_SUITE.erl

@@ -835,7 +835,7 @@ features_macros(Config) when is_list(Config) ->
         erpc:call(Node1, code, load_file, [f_macros]),
     %% Check features enabled during compilation
     [approved_ftr_1, approved_ftr_2, experimental_ftr_1] =
-        erpc:call(Node1, erl_features, used, [f_macros]),
+        lists:sort(erpc:call(Node1, erl_features, used, [f_macros])),
 
     peer:stop(Peer1),
 
@@ -903,7 +903,7 @@ features_all(Config) when is_list(Config) ->
     {Peer0, Node0} = peer(["-pa", OutDir]),
     %% Check features enabled during compilation
     [approved_ftr_1,approved_ftr_2,experimental_ftr_1,experimental_ftr_2] =
-        erpc:call(Node0, erl_features, used, [foo]),
+        lists:sort(erpc:call(Node0, erl_features, used, [foo])),
     peer:stop(Peer0),
 
     Compile("foo.erl", longopt(disable, all),
@@ -997,8 +997,8 @@ features_runtime(Config) when is_list(Config) ->
     peer:stop(Peer0),
 
     {Peer1, Node1} = peer(["-enable-feature", "experimental_ftr_2"]),
-    [experimental_ftr_2, approved_ftr_2, approved_ftr_1] =
-        erpc:call(Node1, erl_features, enabled, []),
+    [approved_ftr_1, approved_ftr_2, experimental_ftr_2] =
+        lists:sort(erpc:call(Node1, erl_features, enabled, [])),
     [while, until, unless] =  erpc:call(Node1, erl_features, keywords, []),
 
     peer:stop(Peer1),
@@ -1077,7 +1077,7 @@ features_include(Config) when is_list(Config) ->
     {conditional, off, none} = erpc:call(Node3, f_include_exp2, foo, []),
 
     [approved_ftr_1, approved_ftr_2, experimental_ftr_2] =
-        erpc:call(Node3, erl_features, used, [f_include_exp2]),
+        lists:sort(erpc:call(Node3, erl_features, used, [f_include_exp2])),
     peer:stop(Peer3),
 
     ok.

lib/compiler/src/compile.erl

@@ -1729,8 +1729,6 @@ abstr_passes(AbstrStatus) ->
         [
          {unless,no_docs,?pass(beam_docs)},
          ?pass(remove_doc_attributes),
-
-         %% Add all -compile() directives to #compile.options
          ?pass(compile_directives),
 
          {delay,[{iff,debug_info,?pass(save_abstract_code)}]},
@@ -1975,12 +1973,10 @@ do_parse_module(DefEncoding, #compile{ifile=File,options=Opts,dir=Dir}=St) ->
                                         []
                                 end]),
             case R of
-                %% FIXME Extra should include used features as well
                 {ok,Forms0,Extra} ->
                     Encoding = proplists:get_value(encoding, Extra),
                     %% Get features used in the module, indicated by
-                    %% enabling features with
-                    %% -compile({feature, .., enable}).
+                    %% enabling features with -feature(...).
                     UsedFtrs = proplists:get_value(features, Extra),
                     St1 = metadata_add_features(UsedFtrs, St),
                     Forms = case with_columns(Opts ++ compile_options(Forms0)) of
@@ -1989,7 +1985,8 @@ do_parse_module(DefEncoding, #compile{ifile=File,options=Opts,dir=Dir}=St) ->
                                 false ->
                                     strip_columns(Forms0)
                             end,
-                    {ok,Forms,St1#compile{encoding=Encoding}};
+                    {ok,Forms,St1#compile{encoding=Encoding,
+                                          options=[{features, UsedFtrs}|Opts]}};
                 {error,E} ->
                     Es = [{St#compile.ifile,[{none,?MODULE,{epp,E}}]}],
                     {error,St#compile{errors=St#compile.errors ++ Es}}
@@ -2423,6 +2420,7 @@ legalize_vars(Code0, St) ->
                end, Code0),
     {ok,Code,St}.
 
+%% Add all -compile() directives to #compile.options
 compile_directives(Forms, St) ->
     Opts = [C || {attribute,_,compile,C} <- Forms],
     compile_directives_1(Opts, Forms, St).

lib/stdlib/src/erl_features.erl

@@ -93,6 +93,10 @@ all() ->
           end,
     lists:sort(maps:keys(Map)).
 
+approved() ->
+    [Ftr || Ftr <- all(),
+            maps:get(status, info(Ftr)) =:= approved].
+
 -doc """
 Return a list of all configurable features, that is, features with status
 `experimental` or `approved`. These are the features that can be enabled or
@@ -228,8 +232,7 @@ keyword_fun(Opts, KeywordFun) ->
                (_) -> false
             end,
     FeatureOps = lists:filter(IsFtr, Opts),
-    {AddFeatures, DelFeatures, RawFtrs} = collect_features(FeatureOps),
-
+    {AddFeatures, DelFeatures, RawFtrs} = collect_features(FeatureOps, enabled()),
     case configurable_features(RawFtrs) of
         ok ->
             {ok, Fun} = add_features_fun(AddFeatures, KeywordFun),
@@ -401,7 +404,7 @@ init_features() ->
                 end
         end,
     FOps = lists:filtermap(F, FeatureOps),
-    {Features, _, _} = collect_features(FOps),
+    {Features, _, _} = collect_features(FOps, approved()),
     {Enabled0, Keywords} =
         lists:foldl(fun(Ftr, {Ftrs, Keys}) ->
                             case lists:member(Ftr, Ftrs) of
@@ -492,13 +495,10 @@ features_in(NameOrBin) ->
     end.
 
 %% Interpret feature ops (enable or disable) to build the full set of
-%% features.  The meta feature 'all' is expanded to all known
-%% features.
-collect_features(FOps) ->
-    %% Features enabled by default
-    Enabled = [Ftr || Ftr <- all(),
-            maps:get(status, info(Ftr)) == approved],
-    collect_features(FOps, Enabled, [], []).
+%% features, starting from the given set. The meta feature 'all' is
+%% expanded to all known features.
+collect_features(FOps, Inital) ->
+    collect_features(FOps, Inital, [], []).
 
 collect_features([], Add, Del, Raw) ->
     {Add, Del, Raw};

lib/stdlib/src/erl_lint.erl

@@ -221,6 +221,7 @@ value_option(Flag, Default, On, OnVal, Off, OffVal, Opts) ->
                    :: #{ta() => #typeinfo{}},
                exp_types=gb_sets:empty()        %Exported types
                    :: gb_sets:set(ta()),
+               features = [],                   %Enabled features
                feature_keywords =               %Keywords in
                                                 %configurable features
                    feature_keywords() :: #{atom() => atom()},
@@ -743,9 +744,6 @@ entries in the list of errors.
       ErrorInfo :: error_info()).
 
 module(Forms, FileName, Opts0) ->
-    %% FIXME Hmm, this is not coherent with the semantics of features
-    %% We want the options given on the command line to take
-    %% precedence over options in the module.
     Opts = Opts0 ++ compiler_options(Forms),
     St = forms(Forms, start(FileName, Opts)),
     return_status(St).
@@ -780,6 +778,7 @@ start(File, Opts) ->
 				     nowarn_format, 0, Opts),
 	  enabled_warnings = Enabled,
           nowarn_bif_clash = nowarn_function(nowarn_bif_clash, Opts),
+          features = proplists:get_value(features, Opts, []),
           file = File
          }.