refactor(logger): delete log header parse-transform

because now we have MFA in log

apps/emqx/include/logger.hrl

@@ -17,8 +17,6 @@
 -ifndef(EMQX_LOGGER_HRL).
 -define(EMQX_LOGGER_HRL, true).
 
--compile({parse_transform, emqx_logger}).
-
 %% debug | info | notice | warning | error | critical | alert | emergency
 -define(DEBUG(Format), ?LOG(debug, Format, [])).
 -define(DEBUG(Format, Args), ?LOG(debug, Format, Args)).

apps/emqx/src/emqx_logger.erl

@@ -56,8 +56,6 @@
         , stop_log_handler/1
         ]).
 
--export([parse_transform/2]).
-
 -type(peername_str() :: list()).
 -type(logger_dst() :: file:filename() | console | unknown).
 -type(logger_handler_info() :: #{
@@ -234,13 +232,6 @@ set_log_level(Level) ->
         {error, Error} -> {error, {primary_logger_level, Error}}
     end.
 
-%% @doc The parse transform for prefixing a module-specific logger header to the logs.
-%% The logger header can be specified by "-logger_header(Header)", where Header
-%% must be a string (list).
-%% @end
-parse_transform(AST, _Opts) ->
-    trans(AST, "", []).
-
 %%--------------------------------------------------------------------
 %% Internal Functions
 %%--------------------------------------------------------------------
@@ -307,31 +298,3 @@ list_stopped_handler_config() ->
         undefined -> [];
         ConfList -> maps:values(ConfList)
     end.
-
-%% @doc The following parse-transforms stripped off the module attribute named
-%% `-logger_header(Header)` (if there's one) from the source code, and then
-%% generate a function named '$logger_header'/0, which returns the logger header.
-%% @end
-trans([], LogHeader, ResAST) ->
-    lists:reverse([header_fun(LogHeader) | ResAST]);
-trans([{eof, L} | AST], LogHeader, ResAST) ->
-    lists:reverse([{eof, L}, header_fun(LogHeader) | ResAST]) ++ AST;
-trans([{attribute, _, module, _Mod} = M | AST], Header, ResAST) ->
-    trans(AST, Header, [export_header_fun(), M | ResAST]);
-trans([{attribute, _, logger_header, Header} | AST], _, ResAST) ->
-    io_lib:printable_list(Header) orelse erlang:error({invalid_string, Header}),
-    trans(AST, Header, ResAST);
-trans([F | AST], LogHeader, ResAST) ->
-    trans(AST, LogHeader, [F | ResAST]).
-
-export_header_fun() ->
-    {attribute,erl_anno:new(0),export,[{'$logger_header',0}]}.
-
-header_fun(LogHeader) ->
-    L = erl_anno:new(0),
-    {function,L,'$logger_header',0,
-         [{clause,L,
-             [], [], [{string,L,pad(LogHeader)}]}]}.
-
-pad("") -> "";
-pad(Str) -> Str ++ " ".

apps/emqx/test/emqx_logger_SUITE.erl

@@ -25,19 +25,6 @@
 -define(a, "a").
 -define(SUPPORTED_LEVELS, [emergency, alert, critical, error, warning, notice, info, debug]).
 
--define(PARSE_TRANS_TEST_CODE,
-        "-module(mytest).\n"
-        "-logger_header(\"[MyTest]\").\n"
-        "-export([run/0]).\n"
-        "-compile({parse_transform, logger_header}).\n"
-        "run() -> '$logger_header'().").
-
--define(PARSE_TRANS_TEST_CODE2,
-        "-module(mytest).\n"
-        "-export([run/0]).\n"
-        "-compile({parse_transform, logger_header}).\n"
-        "run() -> '$logger_header'().").
-
 all() -> emqx_ct:all(?MODULE).
 
 init_per_testcase(_TestCase, Config) ->
@@ -132,37 +119,6 @@ t_start_stop_log_handler2(_) ->
     ?assertMatch({error, {not_started, default}},
                  ?LOGGER:stop_log_handler(default)).
 
-t_parse_transform(_) ->
-    {ok, Toks, _EndLine} = erl_scan:string(?PARSE_TRANS_TEST_CODE),
-    FormToks = split_toks_at_dot(Toks),
-    Forms = [case erl_parse:parse_form(Ts) of
-                 {ok, Form} ->
-                     Form;
-                 {error, Reason} ->
-                     erlang:error({parse_form_error, Ts, Reason})
-             end
-             || Ts <- FormToks],
-    %ct:log("=====: ~p", [Forms]),
-    AST1 = emqx_logger:parse_transform(Forms, []),
-    %ct:log("=====: ~p", [AST1]),
-    ?assertNotEqual(false, lists:keyfind('$logger_header', 3, AST1)).
-
-t_parse_transform_empty_header(_) ->
-    {ok, Toks, _EndLine} = erl_scan:string(?PARSE_TRANS_TEST_CODE2),
-    FormToks = split_toks_at_dot(Toks),
-    Forms = [case erl_parse:parse_form(Ts) of
-                 {ok, Form} ->
-                     Form;
-                 {error, Reason} ->
-                     erlang:error({parse_form_error, Ts, Reason})
-             end
-             || Ts <- FormToks],
-    %ct:log("=====: ~p", [Forms]),
-    AST2 = emqx_logger:parse_transform(Forms++[{eof, 15}], []),
-    %ct:log("=====: ~p", [AST2]),
-    ?assertNotEqual(false, lists:keyfind('$logger_header', 3, AST2)).
-
-
 t_set_metadata_peername(_) ->
     ?assertEqual(ok, ?LOGGER:set_metadata_peername("for_test")).