Fix bootstraping issues

Author: José Valim

lib/elixir/lib/kernel.ex

@@ -2074,7 +2074,11 @@ defmodule Kernel do
         attr = Module.get_attribute(env_module(env), name, stack)
         :erlang.element(1, :elixir_quote.escape(attr, false))
       false ->
-        quote do: Module.get_attribute(__MODULE__, unquote(name), unquote(Macro.escape(stack)))
+        escaped = case stack do
+          [] -> []
+          _  -> Macro.escape(stack)
+        end
+        quote do: Module.get_attribute(__MODULE__, unquote(name), unquote(escaped))
     end
   end
 
@@ -2655,14 +2659,7 @@ defmodule Kernel do
 
     right = case bootstraped?(Macro.Env) do
       true  -> Macro.expand(right, __CALLER__)
-      false ->
-        case right do
-          # For bootstrapping we special case @attributes
-          { :@, _, [{ name, _, atom }] } when is_atom(name) and is_atom(atom) ->
-            Module.get_attribute(env_module(__CALLER__), name, true)
-          _ ->
-            right
-        end
+      false -> right
     end
 
     case right do
@@ -2684,7 +2681,8 @@ defmodule Kernel do
         in_range(left, Macro.escape(first), Macro.escape(last))
       _ ->
         raise ArgumentError, message: <<"invalid args for operator in, it expects a compile time list ",
-                                        "or range on the right side when used in guard expressions">>
+                                        "or range on the right side when used in guard expressions, got: ",
+                                        Macro.to_string(right) :: binary>>
     end
   end
 

lib/elixir/lib/macro.ex

@@ -362,7 +362,7 @@ defmodule Macro do
   end
 
   # Binary ops
-  def to_string({ op, _, [left, right] } = ast, fun) when op in @binary_ops do
+  def to_string({ op, _, [left, right] } = ast, fun) when op in unquote(@binary_ops) do
     fun.(ast, op_to_string(left, fun, op, :left) <> " #{op} " <> op_to_string(right, fun, op, :right))
   end
 
@@ -377,7 +377,7 @@ defmodule Macro do
     fun.(ast, "not " <> to_string(arg, fun))
   end
 
-  def to_string({ op, _, [arg] } = ast, fun) when op in @unary_ops do
+  def to_string({ op, _, [arg] } = ast, fun) when op in unquote(@unary_ops) do
     fun.(ast, atom_to_binary(op) <> to_string(arg, fun))
   end
 
@@ -421,7 +421,7 @@ defmodule Macro do
   @kw_keywords [:do, :catch, :rescue, :after, :else]
 
   defp kw_blocks?([_|_] = kw) do
-    Enum.all?(kw, &match?({x, _} when x in @kw_keywords, &1))
+    Enum.all?(kw, &match?({x, _} when x in unquote(@kw_keywords), &1))
   end
   defp kw_blocks?(_), do: false
 
@@ -488,7 +488,7 @@ defmodule Macro do
     "(" <> to_string(expr, fun) <> ")"
   end
 
-  defp op_to_string({ op, _, [_, _] } = expr, fun, parent_op, side) when op in @binary_ops do
+  defp op_to_string({ op, _, [_, _] } = expr, fun, parent_op, side) when op in unquote(@binary_ops) do
     { parent_assoc, parent_prec } = binary_op_props(parent_op)
     { _, prec }                   = binary_op_props(op)
     cond do