File 3545-features-Use-real-features-support.patch of Package erlang

From 0a114f4d06e8c7634722c27788cbf9c13d8fd857 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Cons=20T=20=C3=85hs?= <cons@erlang.org>
Date: Mon, 14 Mar 2022 16:15:38 +0100
Subject: [PATCH 5/7] [features] Use real features support

---
 lib/stdlib/src/shell.erl            |  8 ++------
 lib/syntax_tools/src/epp_dodger.erl | 13 +++++--------
 lib/tools/test/cover_SUITE.erl      |  7 +++----
 3 files changed, 10 insertions(+), 18 deletions(-)

diff --git a/lib/stdlib/src/shell.erl b/lib/stdlib/src/shell.erl
index cc147848e3..7de78758b0 100644
--- a/lib/stdlib/src/shell.erl
+++ b/lib/stdlib/src/shell.erl
@@ -1,7 +1,7 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 1996-2021. All Rights Reserved.
+%% Copyright Ericsson AB 1996-2022. All Rights Reserved.
 %%
 %% Licensed under the Apache License, Version 2.0 (the "License");
 %% you may not use this file except in compliance with the License.
@@ -273,11 +273,7 @@ server_loop(N0, Eval_0, Bs00, RT, Ds00, History0, Results0) ->
     end.
 
 get_command(Prompt, Eval, Bs, RT, Ds) ->
-    ResWordFun =
-        fun('maybe') -> true;
-           ('else') -> true;
-           (Other) -> erl_scan:reserved_word(Other)
-        end,
+    ResWordFun = fun erl_scan:reserved_word/1,
     Parse =
         fun() ->
                 exit(
diff --git a/lib/syntax_tools/src/epp_dodger.erl b/lib/syntax_tools/src/epp_dodger.erl
index edf092bfcd..2e0694c2cf 100644
--- a/lib/syntax_tools/src/epp_dodger.erl
+++ b/lib/syntax_tools/src/epp_dodger.erl
@@ -431,14 +431,11 @@ parse_form(Dev, L0, Parser, Options) ->
     NoFail = proplists:get_bool(no_fail, Options),
     Opt = #opt{clever = proplists:get_bool(clever, Options)},
 
-    %% FIXME: This should not be hard-coded. Either all keywords from
-    %% all features should be retrieved here, or there should be an option
-    %% to passes in either the keywords or the feature names.
-    ResWordFun =
-        fun('maybe') -> true;
-           ('else') -> true;
-           (Other) -> erl_scan:reserved_word(Other)
-        end,
+    %% This as the *potential* to read options for enabling/disabling
+    %% features for the parsing of the file.
+    {ok, {_Ftrs, ResWordFun}} =
+        erl_features:keyword_fun(Options,
+                                 fun erl_scan:f_reserved_word/1),
 
     case io:scan_erl_form(Dev, "", L0, [{reserved_word_fun,ResWordFun}]) of
         {ok, Ts, L1} ->
diff --git a/lib/tools/test/cover_SUITE.erl b/lib/tools/test/cover_SUITE.erl
index a3dfa7a068..b02b3df0b6 100644
--- a/lib/tools/test/cover_SUITE.erl
+++ b/lib/tools/test/cover_SUITE.erl
@@ -1,7 +1,7 @@
 %%
 %% %CopyrightBegin%
 %% 
-%% Copyright Ericsson AB 2001-2021. All Rights Reserved.
+%% Copyright Ericsson AB 2001-2022. All Rights Reserved.
 %% 
 %% Licensed under the Apache License, Version 2.0 (the "License");
 %% you may not use this file except in compliance with the License.
@@ -1881,8 +1881,8 @@ eep49(Config) ->
 
     File = "t.erl",
     Test = <<"-module(t).
+              -feature(enable,maybe_expr).
               -export([t/0]).
-              -compile([{enable_feature,'maybe'}]).
 
               t() ->
                   t1(),                         %6
@@ -1920,8 +1920,7 @@ eep49(Config) ->
                   end.
              ">>,
     ok = file:write_file(File, Test),
-    %% FIXME: Remove `enable_feature` option here when it can be recognized inside a module.
-    {ok, t} = cover:compile(File, [{enable_feature,maybe_expr}]),
+    {ok, t} = cover:compile(File),
     ok = t:t(),
     {ok,[{{t,6},1}, {{t,8},1}, {{t,9},1}, {{t,10},1}, {{t,12},1},
          {{t,13},1}, {{t,14},1}, {{t,16},1},
-- 
2.34.1