Ensure hygiene also works with directl calls to Kernel.function

Author: José Valim

lib/elixir/src/elixir_dispatch.erl

@@ -25,9 +25,8 @@ find_import(Meta, Name, Arity, S) ->
 
   case find_dispatch(Meta, Tuple, S) of
     { function, Receiver } -> Receiver;
-    { import, Receiver } -> Receiver;
     { macro, Receiver } -> Receiver;
-    nomatch -> false
+    _ -> false
   end.
 
 %% Function retrieval

lib/elixir/src/elixir_macros.erl

@@ -59,11 +59,17 @@ translate({ function, Meta, [[{do,{ '->',_,Pairs}}]] }, S) ->
 translate({ function, _, [{ '/', _, [{{ '.', Meta, [M, F] }, _ , []}, A]}] }, S) when is_atom(F), is_integer(A) ->
   translate({ function, Meta, [M, F, A] }, S);
 
-translate({ function, _, [{ '/', _, [{F, Meta, C}, A]}] }, S) when is_atom(F), is_integer(A), is_atom(C) ->
+translate({ function, MetaFA, [{ '/', _, [{F, Meta, C}, A]}] }, S) when is_atom(F), is_integer(A), is_atom(C) ->
   assert_no_match_or_guard_scope(Meta, 'function', S),
 
-  case elixir_dispatch:import_function(Meta, F, A, S) of
-    false -> syntax_error(Meta, S#elixir_scope.file, "cannot convert a macro to a function");
+  WrappedMeta =
+    case (lists:keyfind(import, 1, Meta) == false) andalso lists:keyfind(import_fa, 1, MetaFA) of
+      { import_fa, Receiver } -> [{ import, Receiver }|Meta];
+      false -> Meta
+    end,
+
+  case elixir_dispatch:import_function(WrappedMeta, F, A, S) of
+    false -> syntax_error(WrappedMeta, S#elixir_scope.file, "cannot convert a macro to a function");
     Else  -> Else
   end;
 

lib/elixir/src/elixir_quote.erl

@@ -65,17 +65,13 @@ do_quote({ quote, _, Args } = Tuple, #elixir_quote{unquote=true} = Q, S) when le
 do_quote({ unquote, _Meta, [Expr] }, #elixir_quote{unquote=true}, S) ->
   elixir_translator:translate_each(Expr, S);
 
-do_quote({ function, Meta1, [{ '/', Meta2, [{F, Meta3, C}, A]}] } = Function,
+do_quote({ function, Meta, [{ '/', _, [{F, _, C}, A]}] = Args },
     #elixir_quote{imports_hygiene=true} = Q, S) when is_atom(F), is_integer(A), is_atom(C) ->
+  do_quote_fa(function, Meta, Args, F, A, Q, S);
 
-  case (lists:keyfind(import, 1, Meta3) == false) andalso
-      elixir_dispatch:find_import(Meta3, F, A, S) of
-    false    ->
-      do_quote_tuple(Function, Q, S);
-    Receiver ->
-      New = { function, Meta1, [{ '/', Meta2, [{F, [{import,Receiver}|Meta3], C}, A]}] },
-      do_quote_tuple(New, Q, S)
-  end;
+do_quote({ { '.', _, [_, function] } = Target, Meta, [{ '/', _, [{F, _, C}, A]}] = Args },
+    #elixir_quote{imports_hygiene=true} = Q, S) when is_atom(F), is_integer(A), is_atom(C) ->
+  do_quote_fa(Target, Meta, Args, F, A, Q, S);
 
 do_quote({ 'alias!', _Meta, [Expr] }, Q, S) ->
   do_quote(Expr, Q#elixir_quote{aliases_hygiene=false}, S);
@@ -165,6 +161,16 @@ do_quote_tuple({ Left, Meta, Right }, Q, S) ->
   Tuple = { tuple, ?line(Meta), [TLeft, meta(Meta, Q), TRight] },
   { Tuple, RS }.
 
+do_quote_fa(Target, Meta, Args, F, A, Q, S) ->
+  NewMeta =
+    case (lists:keyfind(import_fa, 1, Meta) == false) andalso
+        elixir_dispatch:find_import(Meta, F, A, S) of
+      false    -> Meta;
+      Receiver -> [{ import_fa, Receiver }|Meta]
+    end,
+
+  do_quote_tuple({ Target, NewMeta, Args }, Q, S).
+
 % Loop through the list finding each unquote_splicing entry.
 
 splice([{ unquote_splicing, _, [Args] }|T], #elixir_quote{unquote=true} = Q, Buffer, Acc, S) ->

lib/elixir/src/elixir_translator.erl

@@ -35,6 +35,9 @@ translate(Forms, S) ->
 %% Those macros are "low-level". They are the basic mechanism
 %% that makes the language work and cannot be partially applied
 %% nor overwritten.
+%%
+%% =, ^, import, require and alias could be made non-special
+%% forms without causing any side effects.
 
 %% Assignment operator
 

lib/elixir/test/elixir/kernel/quote_test.exs

@@ -248,11 +248,18 @@ defmodule Kernel.QuoteTest.ImportsHygieneTest do
     end
   end
 
+  defmacrop get_bin_size_with_kernel_function do
+    quote do
+      Kernel.function(size/1).("hello")
+    end
+  end
+
   test :expand_imports do
     import Kernel, except: [size: 1]
     assert get_bin_size == 5
     assert get_bin_size_with_partial == 5
     assert get_bin_size_with_function == 5
+    assert get_bin_size_with_kernel_function == 5
   end
 
   defmacrop get_dict_size do