Do not validate clauses of overridable functions, closes #14094

Author: josevalim

lib/elixir/lib/module/types.ex

@@ -182,9 +182,12 @@ defmodule Module.Types do
   end
 
   defp warn_unused_clauses(defs, stack, context) do
-    for {fun_arity, pending} <- context.local_used, pending != [], reduce: context do
+    for {fun_arity, pending} <- context.local_used,
+        pending != [],
+        {_fun_arity, kind, meta, clauses} = List.keyfind(defs, fun_arity, 0),
+        not Keyword.get(meta, :from_super, false),
+        reduce: context do
       context ->
-        {_fun_arity, kind, _meta, clauses} = List.keyfind(defs, fun_arity, 0)
         {_kind, _inferred, mapping} = Map.fetch!(context.local_sigs, fun_arity)
 
         clauses_indexes =

lib/elixir/src/elixir_overridable.erl

@@ -75,8 +75,9 @@ store_not_overridden(Module) ->
 %% Private
 
 store(Set, Module, Tuple, {_, Count, Def, Overridden}, Hidden) ->
-  {{{def, {Name, Arity}}, Kind, Meta, File, _Check,
+  {{{def, {Name, Arity}}, Kind, BaseMeta, File, _Check,
    {Defaults, _HasBody, _LastDefaults}}, Clauses} = Def,
+  Meta = [{from_super, Hidden} | BaseMeta],
 
   {FinalKind, FinalName, FinalArity, FinalClauses} =
     case Hidden of

lib/elixir/test/elixir/module/types/integration_test.exs

@@ -196,7 +196,30 @@ defmodule Module.Types.IntegrationTest do
       assert_warnings(files, warnings)
     end
 
-    test "unused generated overridable private clauses" do
+    test "unused generated private clauses" do
+      files = %{
+        "a.ex" => """
+        defmodule A do
+          use B
+          def public(x), do: private(List.to_tuple(x))
+        end
+        """,
+        "b.ex" => """
+        defmodule B do
+          defmacro __using__(_) do
+            quote generated: true do
+              defp private({:ok, ok}), do: ok
+              defp private(:error), do: :error
+            end
+          end
+        end
+        """
+      }
+
+      assert_no_warnings(files)
+    end
+
+    test "unused overridable private clauses" do
       files = %{
         "a.ex" => """
         defmodule A do
@@ -208,7 +231,7 @@ defmodule Module.Types.IntegrationTest do
         "b.ex" => """
         defmodule B do
           defmacro __using__(_) do
-            quote generated: true do
+            quote do
               defp private({:ok, ok}), do: ok
               defp private(:error), do: :error
               defoverridable private: 1