Trace on load functions, see #14427

Author: josevalim

lib/elixir/src/elixir_module.erl

@@ -182,7 +182,7 @@ compile(Meta, Module, ModuleAsCharlist, Block, Vars, Prune, E) ->
          'Elixir.Module':'__check_attributes__'(E, DataSet, DataBag),
 
         AfterVerify = bag_lookup_element(DataBag, {accumulate, after_verify}, 2),
-        [elixir_env:trace({remote_function, [], VerifyMod, VerifyFun, 1}, CallbackE) ||
+        [elixir_env:trace({remote_function, [{line, Line}], VerifyMod, VerifyFun, 1}, CallbackE) ||
          {VerifyMod, VerifyFun} <- AfterVerify],
 
         %% Ensure there are no errors before we infer types
@@ -299,7 +299,8 @@ validate_on_load_attribute({on_load, Def}, Defs, Bag, Line, E) ->
       elixir_errors:module_error([{line, Line}], E, ?MODULE, {undefined_function, on_load, Def});
     {_Def, Kind, _Meta, _Clauses} when Kind == defmacro; Kind == defmacrop ->
       elixir_errors:module_error([{line, Line}], E, ?MODULE, {bad_macro, on_load, Def});
-    {_Def, Kind, _Meta, _Clauses} ->
+    {{Name, Arity}, Kind, _Meta, _Clauses} ->
+      elixir_env:trace({local_function, [{line, Line}], Name, Arity}, E),
       (Kind == defp) andalso ets:insert(Bag, {used_private, Def})
   end;
 validate_on_load_attribute(false, _Defs, _Bag, _Line, _E) -> ok.

lib/elixir/test/elixir/kernel/tracers_test.exs

@@ -14,18 +14,27 @@ defmodule Kernel.TracersTest do
   end
 
   def trace(event, %Macro.Env{} = env) do
-    send(self(), {event, env})
+    for {pid, _} <- Registry.lookup(__MODULE__, :tracers) do
+      send(pid, {event, env})
+    end
+
     :ok
   end
 
   setup_all do
+    start_supervised!({Registry, keys: :duplicate, name: __MODULE__})
     Code.put_compiler_option(:tracers, [__MODULE__])
 
     on_exit(fn ->
       Code.put_compiler_option(:tracers, [])
     end)
   end
 
+  setup do
+    Registry.register(__MODULE__, :tracers, :unused)
+    :ok
+  end
+
   test "traces start and stop" do
     compile_string("""
     Foo
@@ -259,7 +268,7 @@ defmodule Kernel.TracersTest do
     assert meta[:from_brackets]
 
     compile_string("""
-    defmodule Foo do
+    defmodule TracerBracketAccess do
       @foo %{bar: 3}
       def a() do
         @foo[:bar]
@@ -278,6 +287,18 @@ defmodule Kernel.TracersTest do
     assert meta[:from_brackets]
   end
 
+  test "traces on_load" do
+    compile_string("""
+    defmodule TracerOnLoad do
+      @on_load :init
+      def init, do: :ok
+    end
+    """)
+
+    assert_received {{:local_function, meta, :init, 0}, _}
+    assert meta[:line] == 1
+  end
+
   test "traces super" do
     compile_string("""
     defmodule TracerOverridable do