Merge pull request #9020 from bjorng/bjorn/stdlib/behaviour-warnings/G…

…H-8985/OTP-19334

Add options for silencing warnings for behaviours

lib/compiler/src/compile.erl

@@ -736,6 +736,37 @@ value are listed.
   this kind of warning for the types in `Types`, where `Types` is a tuple
   `{TypeName,Arity}` or a list of such tuples.
 
+- **`nowarn_behaviours`** - By default, warnings are emitted for issues
+  with behaviours. Use this option to turn off all warnings of this kind.
+
+- **`nowarn_conflicting_behaviours`** - By default, warnings are emitted when
+  a module opts in to multiple behaviours that share the names of one or more
+  callback functions. Use this option to turn off this kind of warning.
+
+- **`nowarn_undefined_behaviour_func`** - By default, a warning is
+  emitted when a module that uses a behaviour does not export a
+  mandatory callback function required by that behaviour. Use this
+  option to turn off this kind of warning.
+
+- **`nowarn_undefined_behaviour`** - By default, a warning is emitted
+  when a module attempts to us an unknown behaviour. Use this option
+  to turn off this kind of warning.
+
+- **`nowarn_undefined_behaviour_callbacks`** - By default, a warning
+  is emitted when `behaviour_info(callbacks)` in the behaviour module
+  returns `undefined` instead of a list of callback functions. Use this
+  option to turn off this kind of warning.
+
+- **`nowarn_ill_defined_behaviour_callbacks`** - By default, a warning
+  is emitted when `behaviour_info(callbacks)` in the behaviour module
+  returns a badly formed list of functions. Use this option to turn
+  off this kind of warning.
+
+- **`nowarn_ill_defined_optional_callbacks`** - By default, a warning
+  is emitted when `behaviour_info(optional_callbacks)` in the
+  behaviour module returns a badly formed list of functions. Use this
+  option to turn off this kind of warning.
+
 Other kinds of warnings are _opportunistic warnings_. They are generated when
 the compiler happens to notice potential issues during optimization and code
 generation.

lib/stdlib/src/erl_lint.erl

@@ -823,6 +823,35 @@ start(File, Opts) ->
                       true, Opts)},
          {update_literal,
           bool_option(warn_update_literal, nowarn_update_literal,
+                      true, Opts)},
+         %% Behaviour warnings.
+         {behaviours,
+          bool_option(warn_behaviours,
+                      nowarn_behaviours,
+                      true, Opts)},
+         {conflicting_behaviours,
+          bool_option(warn_conflicting_behaviours,
+                      nowarn_conflicting_behaviours,
+                      true, Opts)},
+         {undefined_behaviour_func,
+          bool_option(warn_undefined_behaviour_func,
+                      nowarn_undefined_behaviour_func,
+                      true, Opts)},
+         {undefined_behaviour,
+          bool_option(warn_undefined_behaviour,
+                      nowarn_undefined_behaviour,
+                      true, Opts)},
+         {undefined_behaviour_callbacks,
+          bool_option(warn_undefined_behaviour_callbacks,
+                      nowarn_undefined_behaviour_callbacks,
+                      true, Opts)},
+         {ill_defined_behaviour_callbacks,
+          bool_option(warn_ill_defined_behaviour_callbacks,
+                      nowarn_ill_defined_behaviour_callbacks,
+                      true, Opts)},
+         {ill_defined_optional_callbacks,
+          bool_option(warn_ill_defined_optional_callbacks,
+                      nowarn_ill_defined_optional_callbacks,
                       true, Opts)}
 	],
     Enabled1 = [Category || {Category,true} <- Enabled0],
@@ -1233,8 +1262,13 @@ post_traversal_check(Forms, St0) ->
 %% check_behaviour(State0) -> State
 %% Check that the behaviour attribute is valid.
 
-check_behaviour(St0) ->
-    behaviour_check(St0#lint.behaviour, St0).
+check_behaviour(St) ->
+    case is_warn_enabled(behaviours, St) of
+        true ->
+            behaviour_check(St#lint.behaviour, St);
+        false ->
+            St
+    end.
 
 %% behaviour_check([{Anno,Behaviour}], State) -> State'
 %%  Check behaviours for existence and defined functions.
@@ -1258,10 +1292,21 @@ all_behaviour_callbacks([{Anno,B}|Bs], Acc, St0) ->
     all_behaviour_callbacks(Bs, [{{Anno,B},Bfs0,OBfs0}|Acc], St);
 all_behaviour_callbacks([], Acc, St) -> {reverse(Acc),St}.
 
+add_behaviour_warning(Anno, Warning, St) when is_tuple(Warning) ->
+    Tag = element(1, Warning),
+    case is_warn_enabled(Tag, St) of
+        true ->
+            add_warning(Anno, Warning, St);
+        false ->
+            St
+    end.
+
 behaviour_callbacks(Anno, B, St0) ->
     try B:behaviour_info(callbacks) of
         undefined ->
-            St1 = add_warning(Anno, {undefined_behaviour_callbacks, B}, St0),
+            St1 = add_behaviour_warning(Anno,
+                                        {undefined_behaviour_callbacks, B},
+                                        St0),
             {[], [], St1};
         Funcs ->
             case is_fa_list(Funcs) of
@@ -1277,22 +1322,22 @@ behaviour_callbacks(Anno, B, St0) ->
                                     {Funcs, OptFuncs, St0};
                                 false ->
                                     W = {ill_defined_optional_callbacks, B},
-                                    St1 = add_warning(Anno, W, St0),
+                                    St1 = add_behaviour_warning(Anno, W, St0),
                                     {Funcs, [], St1}
                             end
                     catch
                         _:_ ->
                             {Funcs, [], St0}
                     end;
                 false ->
-                    St1 = add_warning(Anno,
-                                      {ill_defined_behaviour_callbacks, B},
-                                      St0),
+                    St1 = add_behaviour_warning(Anno,
+                                                {ill_defined_behaviour_callbacks, B},
+                                                St0),
                     {[], [], St1}
             end
     catch
         _:_ ->
-            St1 = add_warning(Anno, {undefined_behaviour, B}, St0),
+            St1 = add_behaviour_warning(Anno, {undefined_behaviour, B}, St0),
             St2 = check_module_name(B, Anno, St1),
             {[], [], St2}
     end.
@@ -1336,7 +1381,7 @@ behaviour_missing_callbacks([{{Anno,B},Bfs0,OBfs}|T], St0) ->
                        case is_fa(F) of
                            true ->
                                M = {undefined_behaviour_func,F,B},
-                               add_warning(Anno, M, S0);
+                               add_behaviour_warning(Anno, M, S0);
                            false ->
                                S0 % ill_defined_behaviour_callbacks
                        end
@@ -1360,7 +1405,9 @@ behaviour_add_conflicts([{Cb,[{FirstAnno,FirstB}|Cs]}|T], St0) ->
 behaviour_add_conflicts([], St) -> St.
 
 behaviour_add_conflict([{Anno,B}|Cs], Cb, FirstL, FirstB, St0) ->
-    St = add_warning(Anno, {conflicting_behaviours,Cb,B,FirstL,FirstB}, St0),
+    St = add_behaviour_warning(Anno,
+                               {conflicting_behaviours,Cb,B,FirstL,FirstB},
+                               St0),
     behaviour_add_conflict(Cs, Cb, FirstL, FirstB, St);
 behaviour_add_conflict([], _, _, _, St) -> St.
 

lib/stdlib/test/erl_lint_SUITE.erl

@@ -3473,6 +3473,15 @@ behaviour_basic(Config) when is_list(Config) ->
            {warnings,[{{1,22},erl_lint,{undefined_behaviour_func,{start,2},application}}]}}
 	 ],
     [] = run(Config, Ts),
+
+    Subst0 = #{behaviour1 => [nowarn_undefined_behaviour_func],
+               behaviour2 => [nowarn_undefined_behaviour_func],
+               behaviour4 => [nowarn_undefined_behaviour_func]},
+    [] = run(Config, rewrite(Ts, Subst0)),
+
+    Subst = #{K => [nowarn_behaviours] || K := _ <- Subst0},
+    [] = run(Config, rewrite(Ts, Subst)),
+
     ok.
 
 %% Basic tests with multiple behaviours.
@@ -3570,12 +3579,21 @@ behaviour_multiple(Config) when is_list(Config) ->
 		       {conflicting_behaviours,{init,1},supervisor,{1,22},gen_server}}]}}
 	 ],
     [] = run(Config, Ts),
+
+    Subst = #{behaviour3 => [nowarn_undefined_behaviour_func,
+                             nowarn_conflicting_behaviours],
+              american_behavior3 => [nowarn_undefined_behaviour_func,
+                                     nowarn_conflicting_behaviours],
+              behaviour4 => [nowarn_conflicting_behaviours]},
+    [] = run(Config, rewrite(Ts, Subst)),
+
     ok.
 
 %% OTP-11861. behaviour_info() and -callback.
 otp_11861(Conf) when is_list(Conf) ->
     CallbackFiles = [callback1, callback2, callback3,
-                     bad_behaviour1, bad_behaviour2],
+                     bad_behaviour1, bad_behaviour2,
+                     bad_behaviour3],
     lists:foreach(fun(M) ->
                           F = filename:join(?datadir, M),
                           Opts = [{outdir,?privdir}, return],
@@ -3756,9 +3774,31 @@ otp_11861(Conf) when is_list(Conf) ->
               f1(_) -> ok.
              ">>,
            [],
-           []}
+           []},
+
+          {otp_11861_19,
+           <<"
+              -export([good/1]).
+              -behaviour(bad_behaviour3).
+              good(_) -> ok.
+             ">>,
+           [],
+           {warnings,[{{3,16},erl_lint,{ill_defined_optional_callbacks,bad_behaviour3}}]}}
 	 ],
     [] = run(Conf, Ts),
+
+    Subst0 = #{otp_11861_1 => [nowarn_conflicting_behaviours],
+               otp_11861_11 => [nowarn_ill_defined_behaviour_callbacks],
+               otp_11861_12 => [nowarn_undefined_behaviour],
+               otp_11861_13 => [nowarn_undefined_behaviour],
+               otp_11861_17 => [nowarn_undefined_behaviour_callbacks],
+               otp_11861_19 => [nowarn_ill_defined_optional_callbacks]
+              },
+    [] = run(Conf, rewrite(Ts, Subst0)),
+
+    Subst = #{K => [nowarn_behaviours] || K := _ <- Subst0},
+    [] = run(Conf, rewrite(Ts, Subst)),
+
     true = code:set_path(CodePath),
     ok.
 
@@ -5475,6 +5515,19 @@ illegal_zip_generator(Config) ->
 %%% Common utilities.
 %%%
 
+rewrite([{Name,Code,[],{warnings,_}}=H|T], Subst) ->
+    case Subst of
+        #{Name := Opts} ->
+            io:format("~s: testing with options ~p\n", [Name,Opts]),
+            [{Name,Code,Opts,[]}|rewrite(T, Subst)];
+        #{} ->
+            [H|rewrite(T, Subst)]
+    end;
+rewrite([H|T], Subst) ->
+    [H|rewrite(T, Subst)];
+rewrite([], _Subst) ->
+    [].
+
 format_error(E) ->
     lists:flatten(erl_lint:format_error(E)).
 

lib/stdlib/test/erl_lint_SUITE_data/bad_behaviour1.erl

@@ -3,4 +3,6 @@
 -export([behaviour_info/1]).
 
 behaviour_info(callbacks) ->
-    [{a,1,bad}].
+    [{a,1,bad}];
+behaviour_info(optional_callbacks) ->
+    [{b,1,bad}].

lib/stdlib/test/erl_lint_SUITE_data/bad_behaviour3.erl

@@ -0,0 +1,7 @@
+-module(bad_behaviour3).
+-export([behaviour_info/1]).
+
+behaviour_info(callbacks) ->
+    [{good,1}];
+behaviour_info(optional_callbacks) ->
+    [{b,1,bad}].