Mark defguard expansion outside of guards as generated

Author: josevalim

lib/elixir/lib/kernel/utils.ex

@@ -330,8 +330,11 @@ defmodule Kernel.Utils do
 
     quote do
       case Macro.Env.in_guard?(__CALLER__) do
-        true -> unquote(literal_quote(unquote_every_ref(expr, vars)))
-        false -> unquote(literal_quote(unquote_refs_once(expr, vars, env.module)))
+        true ->
+          unquote(literal_quote(unquote_every_ref(expr, vars), []))
+
+        false ->
+          unquote(literal_quote(unquote_refs_once(expr, vars, env.module), generated: true))
       end
     end
   end
@@ -396,8 +399,8 @@ defmodule Kernel.Utils do
     end
   end
 
-  defp literal_quote(ast) do
-    {:quote, [], [[do: ast]]}
+  defp literal_quote(ast, args) do
+    {:quote, [], [args, [do: ast]]}
   end
 
   defp literal_unquote(ast) do

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

@@ -54,7 +54,7 @@ defmodule Module.Types.IntegrationTest do
     end
   end
 
-  describe "undefined" do
+  describe "undefined warnings" do
     test "handles Erlang modules" do
       files = %{
         "a.ex" => """
@@ -604,6 +604,23 @@ defmodule Module.Types.IntegrationTest do
   end
 
   describe "regressions" do
+    test "does not emit false positives from defguard" do
+      files = %{
+        "a.ex" => """
+        defmodule A do
+          defguard is_non_nil_arity_function(fun, arity)
+                   when arity != nil and is_function(fun, arity)
+
+          def check(fun, args) do
+            is_non_nil_arity_function(fun, length(args))
+          end
+        end
+        """
+      }
+
+      assert_no_warnings(files)
+    end
+
     test "do not parse binary segments as variables" do
       files = %{
         "a.ex" => """