Emit warning when variable is being expanded to function call

lib/eex/lib/eex.ex

@@ -111,7 +111,7 @@ defmodule EEx do
 
   """
   defmacro function_from_string(kind, name, source, args \\ [], options \\ []) do
-    quote bind_quoted: binding do
+    quote bind_quoted: binding() do
       info = Keyword.merge [file: __ENV__.file, line: __ENV__.line], options
       args = Enum.map args, fn arg -> {arg, [line: info[:line]], nil} end
       compiled = EEx.compile_string(source, info)
@@ -148,7 +148,7 @@ defmodule EEx do
 
   """
   defmacro function_from_file(kind, name, file, args \\ [], options \\ []) do
-    quote bind_quoted: binding do
+    quote bind_quoted: binding() do
       info = Keyword.merge options, [file: file, line: 1]
       args = Enum.map args, fn arg -> {arg, [line: 1], nil} end
       compiled = EEx.compile_file(file, info)

lib/eex/test/eex_test.exs

@@ -4,7 +4,7 @@ require EEx
 
 defmodule EExTest.Compiled do
   def before_compile do
-    fill_in_stacktrace
+    fill_in_stacktrace()
     {__ENV__.line, hd(tl(System.stacktrace))}
   end
 
@@ -19,13 +19,13 @@ defmodule EExTest.Compiled do
   def file_sample(arg), do: private_file_sample(arg)
 
   def after_compile do
-    fill_in_stacktrace
+    fill_in_stacktrace()
     {__ENV__.line, hd(tl(System.stacktrace))}
   end
 
   @file "unknown"
   def unknown do
-    fill_in_stacktrace
+    fill_in_stacktrace()
     {__ENV__.line, hd(tl(System.stacktrace))}
   end
 

lib/elixir/lib/dict.ex

@@ -72,7 +72,7 @@ defmodule Dict do
       end
 
       def take(dict, keys) do
-        Enum.reduce(keys, new, fn key, acc ->
+        Enum.reduce(keys, new(), fn key, acc ->
           case fetch(dict, key) do
             {:ok, value} -> put(acc, key, value)
             :error -> acc
@@ -166,7 +166,7 @@ defmodule Dict do
       end
 
       def split(dict, keys) do
-        Enum.reduce(keys, {new, dict}, fn key, {inc, exc} = acc ->
+        Enum.reduce(keys, {new(), dict}, fn key, {inc, exc} = acc ->
           case fetch(exc, key) do
             {:ok, value} ->
               {put(inc, key, value), delete(exc, key)}

lib/elixir/lib/exception.ex

@@ -380,7 +380,7 @@ defmodule Exception do
   is retrieved from `Process.info/2`.
   """
   def format_stacktrace(trace \\ nil) do
-    trace = trace || case Process.info(self, :current_stacktrace) do
+    trace = trace || case Process.info(self(), :current_stacktrace) do
       {:current_stacktrace, t} -> Enum.drop(t, 3)
     end
 

lib/elixir/lib/file.ex

@@ -1139,7 +1139,7 @@ defmodule File do
   """
   @spec cd!(Path.t, (() -> res)) :: res | no_return when res: var
   def cd!(path, function) do
-    old = cwd!
+    old = cwd!()
     cd!(path)
     try do
       function.()

lib/elixir/lib/inspect/algebra.ex

@@ -337,7 +337,7 @@ defmodule Inspect.Algebra do
   Inserts a break between two docs. See `break/1` for more info.
   """
   @spec glue(t, t) :: doc_cons
-  def glue(x, y), do: concat(x, concat(break, y))
+  def glue(x, y), do: concat(x, concat(break(), y))
 
   @doc """
   Inserts a break, passed as the second argument, between two docs,
@@ -420,7 +420,7 @@ defmodule Inspect.Algebra do
   """
   @spec fold_doc([t], ((t, t) -> t)) :: t
   def fold_doc(list, fun)
-  def fold_doc([], _), do: empty
+  def fold_doc([], _), do: empty()
   def fold_doc([doc], _), do: doc
   def fold_doc([d | ds], fun), do: fun.(d, fold_doc(ds, fun))
 

lib/elixir/lib/io.ex

@@ -277,7 +277,7 @@ defmodule IO do
   def getn(prompt, count \\ 1)
 
   def getn(prompt, count) when is_integer(count) and count > 0 do
-    getn(group_leader, prompt, count)
+    getn(group_leader(), prompt, count)
   end
 
   def getn(device, prompt) when not is_integer(prompt) do

lib/elixir/lib/io/ansi.ex

@@ -186,7 +186,7 @@ defmodule IO.ANSI do
       [[[[[[], "Hello, "] | "\e[31m"] | "\e[1m"], "world!"] | "\e[0m"]
 
   """
-  def format(chardata, emit? \\ enabled?) when is_boolean(emit?) do
+  def format(chardata, emit? \\ enabled?()) when is_boolean(emit?) do
     do_format(chardata, [], [], emit?, :maybe)
   end
 
@@ -206,7 +206,7 @@ defmodule IO.ANSI do
       [[[[[[] | "\e[1m"], 87], 111], 114], 100]
 
   """
-  def format_fragment(chardata, emit? \\ enabled?) when is_boolean(emit?) do
+  def format_fragment(chardata, emit? \\ enabled?()) when is_boolean(emit?) do
     do_format(chardata, [], [], emit?, false)
   end
 

lib/elixir/lib/io/ansi/docs.ex

@@ -40,12 +40,12 @@ defmodule IO.ANSI.Docs do
   """
   def print_heading(heading, options \\ []) do
     IO.puts IO.ANSI.reset
-    options = Keyword.merge(default_options, options)
+    options = Keyword.merge(default_options(), options)
     width   = options[:width]
     padding = div(width + String.length(heading), 2)
     heading = heading |> String.pad_leading(padding) |> String.pad_trailing(width)
     write(:doc_title, heading, options)
-    newline_after_block
+    newline_after_block()
   end
 
   @doc """
@@ -55,7 +55,7 @@ defmodule IO.ANSI.Docs do
   defined in `default_options/1`.
   """
   def print(doc, options \\ []) do
-    options = Keyword.merge(default_options, options)
+    options = Keyword.merge(default_options(), options)
     doc
     |> String.split(["\r\n", "\n"], trim: false)
     |> Enum.map(&String.trim_trailing/1)
@@ -124,13 +124,13 @@ defmodule IO.ANSI.Docs do
 
   defp write_h2(heading, options) do
     write(:doc_headings, heading, options)
-    newline_after_block
+    newline_after_block()
   end
 
   defp write_h3(heading, indent, options) do
     IO.write(indent)
     write(:doc_headings, heading, options)
-    newline_after_block
+    newline_after_block()
   end
 
   ## Lists
@@ -256,15 +256,15 @@ defmodule IO.ANSI.Docs do
 
   defp write_code(code, indent, options) do
     write(:doc_code, "#{indent}┃ #{Enum.join(Enum.reverse(code), "\n#{indent}┃ ")}", options)
-    newline_after_block
+    newline_after_block()
   end
 
   ## Tables
 
   defp process_table(lines, indent, options) do
     {table, rest} = Enum.split_while(lines, &table_line?/1)
     table_lines(table, options)
-    newline_after_block
+    newline_after_block()
     process(rest, [], indent, options)
   end
 

lib/elixir/lib/kernel/cli.ex

@@ -76,22 +76,22 @@ defmodule Kernel.CLI do
           fun.(elem(res, 1))
         catch
           :exit, {:shutdown, int} when is_integer(int) ->
-            send parent, {self, {:shutdown, int}}
+            send parent, {self(), {:shutdown, int}}
             exit({:shutdown, int})
           :exit, reason
               when reason == :normal
               when reason == :shutdown
               when tuple_size(reason) == 2 and elem(reason, 0) == :shutdown ->
-            send parent, {self, {:shutdown, 0}}
+            send parent, {self(), {:shutdown, 0}}
             exit(reason)
           kind, reason ->
             stack = System.stacktrace
             print_error(kind, reason, stack)
-            send parent, {self, {:shutdown, 1}}
+            send parent, {self(), {:shutdown, 1}}
             exit(to_exit(kind, reason, stack))
         else
           _ ->
-            send parent, {self, res}
+            send parent, {self(), res}
         end
       end)
 

lib/elixir/lib/kernel/error_handler.ex

@@ -28,7 +28,7 @@ defmodule Kernel.ErrorHandler do
     parent = :erlang.get(:elixir_compiler_pid)
     ref    = :erlang.make_ref
     send parent, {:waiting, kind, self(), ref, module, :elixir_module.compiler_modules()}
-    :erlang.garbage_collect(self)
+    :erlang.garbage_collect(self())
     receive do
       {^ref, :found}     -> true
       {^ref, :not_found} -> false

lib/elixir/lib/path.ex

@@ -187,7 +187,7 @@ defmodule Path do
   """
   @spec type(t) :: :absolute | :relative | :volumerelative
   def type(name) when is_list(name) or is_binary(name) do
-    pathtype(name, major_os_type) |> elem(0)
+    pathtype(name, major_os_type()) |> elem(0)
   end
 
   @doc """
@@ -625,7 +625,7 @@ defmodule Path do
   defp resolve_home(""), do: System.user_home!
 
   defp resolve_home(rest) do
-    case {rest, major_os_type} do
+    case {rest, major_os_type()} do
       {"\\" <> _, :win32} ->
         System.user_home! <> rest
       {"/" <> _, _} ->

lib/elixir/lib/protocol.ex

@@ -420,7 +420,7 @@ defmodule Protocol do
         _ = unquote(block)
 
         # Finalize expansion
-        unquote(after_defprotocol)
+        unquote(after_defprotocol())
       end
     end
   end
@@ -446,7 +446,7 @@ defmodule Protocol do
         Kernel.def impl_for(data) when :erlang.unquote(guard)(data) do
           case impl_for?(unquote(target)) do
             true  -> unquote(target).__impl__(:target)
-            false -> any_impl_for
+            false -> any_impl_for()
           end
         end
       end, builtin)
@@ -459,17 +459,17 @@ defmodule Protocol do
 
       # Internal handler for Any
       if @fallback_to_any do
-        Kernel.defp any_impl_for, do: __MODULE__.Any.__impl__(:target)
+        Kernel.defp any_impl_for(), do: __MODULE__.Any.__impl__(:target)
       else
-        Kernel.defp any_impl_for, do: nil
+        Kernel.defp any_impl_for(), do: nil
       end
 
       # Internal handler for Structs
       Kernel.defp struct_impl_for(struct) do
         target = Module.concat(__MODULE__, struct)
         case impl_for?(target) do
           true  -> target.__impl__(:target)
-          false -> any_impl_for
+          false -> any_impl_for()
         end
       end
 

lib/elixir/lib/stream.ex

@@ -340,7 +340,7 @@ defmodule Stream do
 
   ## Examples
 
-      iex> stream = Stream.each([1, 2, 3], fn(x) -> send self, x end)
+      iex> stream = Stream.each([1, 2, 3], fn(x) -> send self(), x end)
       iex> Enum.to_list(stream)
       iex> receive do: (x when is_integer(x) -> x)
       1

lib/elixir/lib/system.ex

@@ -117,7 +117,7 @@ defmodule System do
     |> strip
   end
 
-  defp revision, do: get_revision
+  defp revision, do: get_revision()
 
   # Get the date at compilation time.
   defmacrop get_date do
@@ -145,7 +145,7 @@ defmodule System do
   Returns Elixir's version as binary.
   """
   @spec version() :: String.t
-  def version, do: get_version
+  def version, do: get_version()
 
   @doc """
   Elixir build information.
@@ -154,22 +154,22 @@ defmodule System do
   """
   @spec build_info() :: map
   def build_info do
-    %{build:    build,
-      date:     get_date,
-      revision: revision,
-      version:  version,
+    %{build:    build(),
+      date:     get_date(),
+      revision: revision(),
+      version:  version(),
       }
   end
 
   # Returns a string of the build info
   defp build do
-    {:ok, v} = Version.parse(version)
+    {:ok, v} = Version.parse(version())
 
     cond do
-      ([] == v.pre) or ("" == revision) ->
-        version
+      ([] == v.pre) or ("" == revision()) ->
+        version()
       true ->
-        "#{version} (#{revision})"
+        "#{version()} (#{revision()})"
     end
   end
 
@@ -222,7 +222,7 @@ defmodule System do
   Returns the current working directory or raises `RuntimeError`.
   """
   def cwd! do
-    cwd ||
+    cwd() ||
       raise RuntimeError, message: "could not get a current working directory, the current location is not accessible"
   end
 
@@ -242,7 +242,7 @@ defmodule System do
   instead of returning `nil` if no user home is set.
   """
   def user_home! do
-    user_home ||
+    user_home() ||
       raise RuntimeError, message: "could not find the user home, please set the HOME environment variable"
   end
 
@@ -275,7 +275,7 @@ defmodule System do
   instead of returning `nil` if no temp dir is set.
   """
   def tmp_dir! do
-    tmp_dir ||
+    tmp_dir() ||
       raise RuntimeError, message: "could not get a writable temporary directory, " <>
                                    "please set the TMPDIR environment variable"
   end

lib/elixir/lib/task.ex

@@ -165,7 +165,7 @@ defmodule Task do
   """
   @spec start_link(module, atom, [term]) :: {:ok, pid}
   def start_link(mod, fun, args) do
-    Task.Supervised.start_link(get_info(self), {mod, fun, args})
+    Task.Supervised.start_link(get_info(self()), {mod, fun, args})
   end
 
   @doc """
@@ -189,7 +189,7 @@ defmodule Task do
   """
   @spec start(module, atom, [term]) :: {:ok, pid}
   def start(mod, fun, args) do
-    Task.Supervised.start(get_info(self), {mod, fun, args})
+    Task.Supervised.start(get_info(self()), {mod, fun, args})
   end
 
   @doc """

lib/elixir/lib/task/supervised.ex

@@ -120,7 +120,7 @@ defmodule Task.Supervised do
       '** When function  == ~p~n' ++
       '**      arguments == ~p~n' ++
       '** Reason for termination == ~n' ++
-      '** ~p~n', [self, get_from(info), fun, args, get_reason(log_reason)])
+      '** ~p~n', [self(), get_from(info), fun, args, get_reason(log_reason)])
 
     exit(reason)
   end

lib/elixir/lib/task/supervisor.ex

@@ -144,7 +144,7 @@ defmodule Task.Supervisor do
   """
   @spec start_child(Supervisor.supervisor, module, atom, [term]) :: {:ok, pid}
   def start_child(supervisor, module, fun, args) do
-    Supervisor.start_child(supervisor, [get_info(self), {module, fun, args}])
+    Supervisor.start_child(supervisor, [get_info(self()), {module, fun, args}])
   end
 
   defp get_info(self) do