Do not include debug_info in metadata String modules

Signed-off-by: José Valim <jose.valim@plataformatec.com.br>

Author: José Valim

lib/elixir/src/elixir_compiler.erl

@@ -169,13 +169,17 @@ allows_fast_compilation(_) -> false.
 %% executes the callback in case of success. This automatically
 %% handles errors and warnings. Used by this module and elixir_module.
 module(Forms, Opts, E, Callback) ->
-  Final =
-    case (get_opt(debug_info) == true) orelse
-         lists:member(debug_info, Opts) of
-      true  -> [debug_info] ++ options();
-      false -> options()
+  Extra =
+    case proplists:get_value(debug_info, Opts) of
+      true -> [debug_info];
+      false -> [];
+      undefined ->
+        case get_opt(debug_info) of
+          true  -> [debug_info];
+          false -> []
+        end
     end,
-  inner_module(Forms, Final, false, E, Callback).
+  inner_module(Forms, Extra ++ options(), false, E, Callback).
 
 inner_module(Forms, Options, Bootstrap, #{file := File} = E, Callback) when
     is_list(Forms), is_list(Options), is_boolean(Bootstrap), is_function(Callback) ->

lib/elixir/test/elixir/string_test.exs

@@ -539,4 +539,10 @@ defmodule StringTest do
     assert String.jaro_distance("jon", "john") == 0.9166666666666666
     assert String.jaro_distance("jon", "jan") == 0.7777777777777777
   end
+
+  test "skip debug_info in metadata modules" do
+    assert String.Unicode.__info__(:compile)[:options] == []
+    assert String.Graphemes.__info__(:compile)[:options] == []
+    assert String.Normalizer.__info__(:compile)[:options] == []
+  end
 end

lib/elixir/unicode/unicode.ex

@@ -10,6 +10,7 @@ end
 
 defmodule String.Unicode do
   @moduledoc false
+  @compile {:debug_info, false}
   def version, do: {7, 0, 0}
 
   data_path = Path.join(__DIR__, "UnicodeData.txt")
@@ -204,6 +205,7 @@ end
 
 defmodule String.Graphemes do
   @moduledoc false
+  @compile {:debug_info, false}
 
   cluster_path = Path.join(__DIR__, "GraphemeBreakProperty.txt")
   regex = ~r/(?:^([0-9A-F]+)(?:\.\.([0-9A-F]+))?)\s+;\s(\w+)/m
@@ -413,6 +415,7 @@ end
 
 defmodule String.Normalizer do
   @moduledoc false
+  @compile {:debug_info, false}
 
   decomposition_path = Path.join(__DIR__, "Decomposition.txt")