Mark module attributes as generated in case they contain opaque terms

Author: sabiwara

lib/elixir/lib/kernel.ex

@@ -3864,6 +3864,11 @@ defmodule Kernel do
         raise ArgumentError,
               "cannot inject attribute @#{name} into function/macro because " <>
                 Exception.message(ex)
+    else
+      # mark module attrs as shallow-generated since the ast for their representation
+      # might contain opaque terms
+      {caller, meta, args} when is_list(meta) -> {caller, [generated: true] ++ meta, args}
+      ast -> ast
     end
   end
 

lib/elixir/test/elixir/fixtures/dialyzer/opaqueness.ex

@@ -4,11 +4,16 @@ defmodule Dialyzer.Opaqueness do
     set
   end
 
-  def foo() do
+  def inlined do
     # inlining of literals should not violate opaqueness check
     bar(MapSet.new([1, 2, 3]))
   end
 
+  @my_set MapSet.new([1, 2, 3])
+  def module_attr do
+    bar(@my_set)
+  end
+
   # Task.Supervisor returns a Task.t() containing an opaque Task.ref()
   @spec run_task() :: Task.t()
   def run_task do