Keep line information in defstruct

Author: josevalim

lib/elixir/lib/kernel.ex

@@ -5468,33 +5468,21 @@ defmodule Kernel do
   use `@type`.
   """
   defmacro defstruct(fields) do
-    header =
-      quote bind_quoted: [fields: fields, bootstrapped?: bootstrapped?(Enum)] do
-        {struct, derive, escaped_struct, kv, body} =
-          Kernel.Utils.defstruct(__MODULE__, fields, bootstrapped?, __ENV__)
-
-        case derive do
-          [] -> :ok
-          _ -> Protocol.__derive__(derive, __MODULE__, __ENV__)
-        end
-      end
+    quote bind_quoted: [fields: fields, bootstrapped?: bootstrapped?(Enum)] do
+      {struct, derive, escaped_struct, kv, body} =
+        Kernel.Utils.defstruct(__MODULE__, fields, bootstrapped?, __ENV__)
 
-    # We attach the line: 0 to struct functions because we don't want
-    # the generated callbacks to count towards code coverage and metrics,
-    # especially since they are often expanded at compile-time.
-    functions =
-      quote line: 0, unquote: false do
-        def __struct__(), do: unquote(escaped_struct)
-        def __struct__(unquote(kv)), do: unquote(body)
+      case derive do
+        [] -> :ok
+        _ -> Protocol.__derive__(derive, __MODULE__, __ENV__)
       end
 
-    footer =
-      quote do
-        Kernel.Utils.announce_struct(__MODULE__)
-        struct
-      end
+      def __struct__(), do: unquote(escaped_struct)
+      def __struct__(unquote(kv)), do: unquote(body)
 
-    {:__block__, [], [header, functions, footer]}
+      Kernel.Utils.announce_struct(__MODULE__)
+      struct
+    end
   end
 
   @doc ~S"""

lib/elixir/lib/kernel/utils.ex

@@ -174,14 +174,14 @@ defmodule Kernel.Utils do
         true ->
           case enforce_keys do
             [] ->
-              quote do
+              quote line: 0, generated: true do
                 Enum.reduce(kv, unquote(escaped_struct), fn {key, val}, map ->
                   %{map | key => val}
                 end)
               end
 
             _ ->
-              quote do
+              quote line: 0, generated: true do
                 {map, keys} =
                   Enum.reduce(kv, {unquote(escaped_struct), unquote(enforce_keys)}, fn
                     {key, val}, {map, keys} ->
@@ -201,7 +201,7 @@ defmodule Kernel.Utils do
           end
 
         false ->
-          quote do
+          quote line: 0, generated: true do
             :lists.foldl(
               fn {key, val}, acc -> %{acc | key => val} end,
               unquote(escaped_struct),

lib/elixir/test/elixir/kernel_test.exs

@@ -205,6 +205,10 @@ defmodule KernelTest do
 
   defmodule User do
     assert is_map(defstruct name: "john")
+    # Ensure we keep the line information around.
+    # It is important for debugging tools, ExDoc, etc.
+    {:v1, :def, anno, _clauses} = Module.get_definition(__MODULE__, {:__struct__, 1})
+    anno[:line] == __ENV__.line - 4
   end
 
   test "struct/1 and struct/2" do