Improve santiy check of formatter config

2 files changed, 60 insertions, 31 deletions

diff --git a/lib/kernel/src/logger_formatter.erl b/lib/kernel/src/logger_formatter.erl
index 624f523465..0d55244034 100644
--- a/lib/kernel/src/logger_formatter.erl
+++ b/lib/kernel/src/logger_formatter.erl
@@ -20,6 +20,7 @@
 -module(logger_formatter).
 
 -export([format/2]).
+-export([check_config/1]).
 
 -include("logger_internal.hrl").
 
@@ -309,3 +310,47 @@ get_utc_config() ->
                 undefined -> false
             end
     end.
+
+check_config(Config) when is_map(Config) ->
+    do_check_config(maps:to_list(Config));
+check_config(Config) ->
+    {error,{invalid_formatter_config,?MODULE,Config}}.
+
+do_check_config([{Type,L}|Config]) when Type == chars_limit;
+                                        Type == depth;
+                                        Type == max_size ->
+    case check_limit(L) of
+        ok -> do_check_config(Config);
+        error -> {error,{invalid_formatter_config,?MODULE,{Type,L}}}
+    end;
+do_check_config([{single_line,SL}|Config]) when is_boolean(SL) ->
+    do_check_config(Config);
+do_check_config([{legacy_header,LH}|Config]) when is_boolean(LH) ->
+    do_check_config(Config);
+do_check_config([{report_cb,RCB}|Config]) when is_function(RCB,1) ->
+    do_check_config(Config);
+do_check_config([{template,T}|Config]) when is_list(T) ->
+    case lists:all(fun(X) when is_atom(X) -> true;
+                      (X) when is_tuple(X), is_atom(element(1,X)) -> true;
+                      (X) when is_list(X) -> io_lib:printable_unicode_list(X);
+                      (_) -> false
+                   end,
+                   T) of
+        true ->
+            do_check_config(Config);
+        false ->
+            {error,{invalid_formatter_template,?MODULE,T}}
+    end;
+do_check_config([{utc,Utc}|Config]) when is_boolean(Utc) ->
+    do_check_config(Config);
+do_check_config([C|_]) ->
+    {error,{invalid_formatter_config,?MODULE,C}};
+do_check_config([]) ->
+    ok.
+
+check_limit(L) when is_integer(L), L>0 ->
+    ok;
+check_limit(unlimited) ->
+    ok;
+check_limit(_) ->
+    error.
diff --git a/lib/kernel/src/logger_server.erl b/lib/kernel/src/logger_server.erl
index 2a3723177f..f1b4a21c6a 100644
--- a/lib/kernel/src/logger_server.erl
+++ b/lib/kernel/src/logger_server.erl
@@ -416,40 +416,24 @@ check_filter_default(FD) when FD==stop; FD==log ->
 check_filter_default(FD) ->
     throw({invalid_filter_default,FD}).
 
-check_formatter({logger_formatter,Config}) when is_map(Config) ->
-    check_logger_formatter_config(maps:to_list(Config));
-check_formatter({logger_formatter,Config}) ->
-    throw({invalid_formatter_config,Config});
-check_formatter({Mod,_}) ->
-    %% no knowledge of other formatters
-    check_mod(Mod);
+check_formatter({Mod,Config}) ->
+    check_mod(Mod),
+    try Mod:check_config(Config) of
+        ok -> ok;
+        {error,Error} -> throw(Error)
+    catch
+        C:R:S ->
+            case {C,R,S} of
+                {error,undef,[{Mod,check_config,[Config],_}|_]} ->
+                    ok;
+                _ ->
+                    throw({callback_crashed,
+                           {C,R,logger:filter_stacktrace(?MODULE,S)}})
+            end
+    end;
 check_formatter(Formatter) ->
     throw({invalid_formatter,Formatter}).
 
-
-check_logger_formatter_config([{template,T}|Config]) when is_list(T) ->
-    case lists:all(fun(X) when is_atom(X) -> true;
-                      (X) when is_tuple(X), is_atom(element(1,X)) -> true;
-                      (X) when is_list(X) -> io_lib:printable_unicode_list(X);
-                      (_) -> false
-                   end,
-                   T) of
-        true ->
-            check_logger_formatter_config(Config);
-        false ->
-            throw({invalid_formatter_template,T})
-    end;
-check_logger_formatter_config([{legacy_header,LH}|Config]) when is_boolean(LH) ->
-    check_logger_formatter_config(Config);
-check_logger_formatter_config([{single_line,SL}|Config]) when is_boolean(SL) ->
-    check_logger_formatter_config(Config);
-check_logger_formatter_config([{utc,Utc}|Config]) when is_boolean(Utc) ->
-    check_logger_formatter_config(Config);
-check_logger_formatter_config([C|_]) ->
-    throw({invalid_formatter_config,C});
-check_logger_formatter_config([]) ->
-    ok.
-
 call_h(Module, Function, Args, DefRet) ->
     %% Not calling code:ensure_loaded + erlang:function_exported here,
     %% since in some rare terminal cases, the code_server might not