test(emqx_mgmt): Exempt do_query function from BPAPI static check

apps/emqx/test/emqx_bpapi_static_checks.erl

@@ -52,6 +52,11 @@
 -define(RPC_FUNCTIONS, "emqx_cluster_rpc:multicall/3, emqx_cluster_rpc:multicall/5").
 %% List of functions in the RPC backend modules that we can ignore:
 -define(IGNORED_RPC_CALLS, "gen_rpc:nodes/0").
+%% List of business-layer functions that are exempt from the checks:
+-define(EXEMPTIONS, "emqx_mgmt_api:do_query/6"  % Reason: legacy code. A fun and a QC query are
+                                                % passed in the args, it's futile to try to statically
+                                                % check it
+       ).
 
 -define(XREF, myxref).
 
@@ -207,7 +212,7 @@ prepare(#{reldir := RelDir, plt := PLT}) ->
     dialyzer_plt:from_file(PLT).
 
 find_remote_calls(_Opts) ->
-    Query = "XC | (A - [" ?IGNORED_APPS "]:App - [" ?IGNORED_MODULES "] : Mod)
+    Query = "XC | (A - [" ?IGNORED_APPS "]:App - [" ?IGNORED_MODULES "]:Mod - [" ?EXEMPTIONS "])
                || (([" ?RPC_MODULES "] : Mod + [" ?RPC_FUNCTIONS "]) - " ?IGNORED_RPC_CALLS ")",
     {ok, Calls} = xref:q(?XREF, Query),
     ?INFO("Calls to RPC modules ~p", [Calls]),

apps/emqx_management/src/emqx_mgmt_api.erl

@@ -197,12 +197,15 @@ do_cluster_query([Node | Tail] = Nodes, Tab, Qs, QueryFun, Continuation,
 %% Do Query (or rpc query)
 %%--------------------------------------------------------------------
 
-%% @private
+%% @private This function is exempt from BPAPI
 do_query(Node, Tab, Qs, {M,F}, Continuation, Limit) when Node =:= node() ->
     erlang:apply(M, F, [Tab, Qs, Continuation, Limit]);
 do_query(Node, Tab, Qs, QueryFun, Continuation, Limit) ->
-    rpc_call(Node, ?MODULE, do_query,
+    case rpc:call(Node, ?MODULE, do_query,
-             [Node, Tab, Qs, QueryFun, Continuation, Limit], 50000).
+                  [Node, Tab, Qs, QueryFun, Continuation, Limit], 50000) of
+        {badrpc, _} = R -> {error, R};
+        Ret -> Ret
+    end.
 
 sub_query_result(Len, Rows, Limit, Results, Meta) ->
     {Flag, NMeta} = judge_page_with_counting(Len, Meta),
@@ -219,13 +222,6 @@ sub_query_result(Len, Rows, Limit, Results, Meta) ->
         end,
     {NMeta, NResults}.
 
-%% @private
-rpc_call(Node, M, F, A, T) ->
-    case rpc:call(Node, M, F, A, T) of
-        {badrpc, _} = R -> {error, R};
-        Res -> Res
-    end.
-
 %%--------------------------------------------------------------------
 %% Table Select
 %%--------------------------------------------------------------------