Release v1.0.1

Since the manifest is shared, --elixirc-paths must
be a subset as we need to know what to change and what
to not change in the manifest file.

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

CHANGELOG.md

@@ -1,5 +1,25 @@
 # Changelog
 
+## v1.0.1 (2014-10-07)
+
+* Enhancements
+  * [Mix] Add MIX_ENV output to archive.build (as on escript.build)
+
+* Bug fixes
+  * [CLI] Fix Elixir CLI when running on Cygwin
+  * [ExUnit] Include stacktraces in ExUnit timeouts
+  * [Mix] Load dependencies before `deps.check` compiles dependencies
+  * [Mix] Ensure `Mix.Config` is deep merged
+  * [Mix] Change version requirement in new apps to `~> MAJOR.MINOR`
+  * [Mix] Report correct location if `local.hex` fails and give higher priority to powershell install on Windows
+  * [Mix] Ensure `--elixirc-paths` option for `compile.elixir` is a subset of the project `:elixirc_paths` configuration and it does not remove skipped entries from the manifest
+  * [Mix] Ensure `compile.elixir` writes to manifest when files are removed
+  * [Mix] Ensure `compile.elixir` purges and deletes modules before compiling
+  * [Mix] Do not crash on malformed proxy env var
+  * [Stream] Ensure `chunk/4` works correctly when halted
+  * [System] Do not allow relative paths in `System.cmd/3` as documented
+  * [System] Fix `:stderr_to_stdout` option in `System.cmd/3`
+
 ## v1.0.0 (2014-09-10)
 
 * Enhancements

Makefile

@@ -146,8 +146,8 @@ release_zip: compile
 
 release_docs: docs
 	cd ../docs
-	rm -rf ../docs/master
-	mv docs ../docs/master
+	rm -rf ../docs/stable
+	mv docs ../docs/stable
 
 #==> Tests tasks
 

RELEASE.md

@@ -1,28 +1,40 @@
 # Release process
 
+## All releases
+
 This document simply outlines the release process:
 
-1. Remove all `-dev` extension from versions (see below for all files)
+1. Ensure you are running on the oldest supported Erlang version
 
-2. Ensure CHANGELOG is updated and add current date
+2. Remove all `-dev` extension from versions (see below for all files)
 
-3. Commit changes above with title "Release vVERSION" and generate new tag
+3. Ensure CHANGELOG is updated and add current date
 
-4. Run `make clean test` to ensure all tests pass from scratch and the CI is green
+4. Commit changes above with title "Release vVERSION" and generate new tag
 
-5. Push master and the new tag
+5. Run `make clean test` to ensure all tests pass from scratch and the CI is green
 
-6. Release new docs with `make release_docs`, move docs to `docs/stable`
+6. Ensure minimum supported Hex works with new release (instructions upcoming)
 
-7. Release new zip with `make release_zip`, push new zip to GitHub Releases, name it `Precompiled.zip`
+7. Push master and the new tag
 
-8. Fast-forward merge master into stable branch with `git merge master --ff` and push it
+8. Release new docs with `make release_docs`, move docs to `docs/stable` and push them
 
-9. After release, bump versions, add `-dev` back and commit
+9. Release new zip with `make release_zip`, push `Precompiled.zip` to GitHub Releases
 
-10. `make release_docs` once again and push it to `elixir-lang/docs`
+10. Add the release to `elixir.csv` file in `elixir-lang/elixir-lang.github.com`
 
-11. Add the release to `elixir.csv` file in `elixir-lang/elixir-lang.github.com`
+## New vMAJOR.MINOR releases
+
+11. Create a new branch "vMAJOR.MINOR" release
+
+12. Move stable docs to `docs/vOLD-MAJOR.OLD-MINOR`
+
+13. Move master docs to `docs/stable`
+
+14. Bump versions, start new CHANGELOG, add `-dev` back and commit "Start vVERSION+1"
+
+15. `make release_docs` and push it to `elixir-lang/docs`
 
 ## Places where version is mentioned
 

VERSION

@@ -1 +1 @@
-1.0.0
+1.0.1

bin/elixir

@@ -81,7 +81,7 @@ done
 SELF=$(readlink_f "$0")
 SCRIPT_PATH=$(dirname "$SELF")
 
-if [ "$OSTYPE" = "cygwin" ]; then SCRIPT_PATH=$(cygpath -m "SCRIPT_PATH"); fi
+if [ "$OSTYPE" = "cygwin" ]; then SCRIPT_PATH=$(cygpath -m "$SCRIPT_PATH"); fi
 if [ "$MODE" != "iex" ]; then ERL="-noshell -s elixir start_cli $ERL"; fi
 
 # Check for terminal support

lib/elixir/lib/code.ex

@@ -260,7 +260,7 @@ defmodule Code do
   Accepts `relative_to` as an argument to tell where the file is located.
 
   While `load_file` loads a file and returns the loaded modules and their
-  byte code, `eval_file` simply evalutes the file contents and returns the
+  byte code, `eval_file` simply evaluates the file contents and returns the
   evaluation result and its bindings.
   """
   def eval_file(file, relative_to \\ nil) do

lib/elixir/lib/gen_event.ex

@@ -188,7 +188,7 @@ defmodule GenEvent do
   @type manager :: pid | name | {atom, node}
 
   @typedoc "Supported values for new handlers"
-  @type handler :: atom | {atom, term} | pid
+  @type handler :: atom | {atom, term} | {pid, reference}
 
   @doc false
   defmacro __using__(_) do
@@ -601,11 +601,7 @@ defmodule GenEvent do
         reply(tag, reply)
         loop(parent, name, handlers, debug, hib)
       {_from, tag, {:add_handler, handler, args}} ->
-        {hib, reply, handlers} = server_add_handler(handler, args, handlers, nil)
-        reply(tag, reply)
-        loop(parent, name, handlers, debug, hib)
-      {_from, tag, {:add_handler, handler, args, notify}} ->
-        {hib, reply, handlers} = server_add_handler(handler, args, handlers, notify)
+        {hib, reply, handlers} = server_add_handler(handler, args, handlers)
         reply(tag, reply)
         loop(parent, name, handlers, debug, hib)
       {_from, tag, {:add_mon_handler, handler, args, notify}} ->
@@ -739,13 +735,13 @@ defmodule GenEvent do
     IO.puts dev, "*DBG* #{inspect name}: #{inspect dbg}"
   end
 
-  defp server_add_handler({module, id}, args, handlers, notify) do
-    handler = handler(module: module, id: {module, id}, pid: notify)
+  defp server_add_handler({module, id}, args, handlers) do
+    handler = handler(module: module, id: {module, id})
     do_add_handler(module, handler, args, handlers, :ok)
   end
 
-  defp server_add_handler(module, args, handlers, notify) do
-    handler = handler(module: module, id: module, pid: notify)
+  defp server_add_handler(module, args, handlers) do
+    handler = handler(module: module, id: module)
     do_add_handler(module, handler, args, handlers, :ok)
   end
 
@@ -763,7 +759,7 @@ defmodule GenEvent do
 
   defp server_add_process_handler(pid, handlers, notify) do
     ref = Process.monitor(pid)
-    handler = handler(module: GenEvent.Stream, id: pid,
+    handler = handler(module: GenEvent.Stream, id: {self(), ref},
                       pid: notify, ref: ref)
     do_add_handler(GenEvent.Stream, handler, {pid, ref}, handlers, {self(), ref})
   end
@@ -779,7 +775,7 @@ defmodule GenEvent do
     if sup do
       server_add_mon_handler(module2, {args2, state}, handlers, sup)
     else
-      server_add_handler(module2, {args2, state}, handlers, nil)
+      server_add_handler(module2, {args2, state}, handlers)
     end
   end
 
@@ -796,7 +792,7 @@ defmodule GenEvent do
 
   defp server_split_process_handlers(mode, event, [handler|t], handlers, streams) do
     case handler(handler, :id) do
-      pid when is_pid(pid) ->
+      {pid, _ref} when is_pid(pid) ->
         server_process_notify(mode, event, handler)
         server_split_process_handlers(mode, event, t, handlers, [handler|streams])
       _ ->
@@ -858,16 +854,17 @@ defmodule GenEvent do
   end
 
   defp server_collect_process_handlers(mode, event, [handler|t], handlers, name) when mode in [:sync, :ack] do
-    handler(ref: ref) = handler
+    handler(ref: ref, id: id) = handler
 
     receive do
       {^ref, :ok} ->
         server_collect_process_handlers(mode, event, t, [handler|handlers], name)
-      {^ref, :done} ->
-        do_terminate(handler, :remove_handler, event, name, :normal)
+      {_from, tag, {:delete_handler, ^id, args}} ->
+        do_terminate(handler, args, :remove, name, :normal)
+        reply(tag, :ok)
         server_collect_process_handlers(mode, event, t, handlers, name)
       {:DOWN, ^ref, _, _, reason} ->
-        do_terminate(handler, {:stop, reason}, :remove, name, :shutdown)
+        do_terminate(handler, {:stop, reason}, :DOWN, name, :shutdown)
         server_collect_process_handlers(mode, event, t, handlers, name)
     end
   end
@@ -939,7 +936,7 @@ defmodule GenEvent do
     case :lists.keyfind(ref, handler(:ref) + 1, handlers) do
       false -> :error
       handler ->
-        do_terminate(handler, {:stop, reason}, :remove, name, :shutdown)
+        do_terminate(handler, {:stop, reason}, :DOWN, name, :shutdown)
         {:ok, :lists.keydelete(ref, handler(:ref) + 1, handlers)}
     end
   end

lib/elixir/lib/gen_event/stream.ex

@@ -80,7 +80,8 @@ defimpl Enumerable, for: GenEvent.Stream do
 
   defp start(%{manager: manager} = stream) do
     try do
-      {:ok, {pid, ref}} = :gen.call(manager, self(), {:add_process_handler, self(), self()}, :infinity)
+      {:ok, {pid, ref}} = :gen.call(manager, self(),
+                                    {:add_process_handler, self(), self()}, :infinity)
       mon_ref = Process.monitor(pid)
       {pid, ref, mon_ref}
     catch
@@ -92,19 +93,6 @@ defimpl Enumerable, for: GenEvent.Stream do
     self = self()
 
     receive do
-      # The handler was removed. Stop iteration, resolve the
-      # event later. We need to demonitor now, otherwise DOWN
-      # appears with higher priority in the shutdown process.
-      {:gen_event_EXIT, ^self, _reason} = event ->
-        Process.demonitor(mon_ref, [:flush])
-        send(self, event)
-        {:halt, {:removed, acc}}
-
-      # The manager died. Stop iteration, resolve the event later.
-      {:DOWN, ^mon_ref, _, _, _} = event ->
-        send(self, event)
-        {:halt, {:removed, acc}}
-
       # Got an async event.
       {_from, {^pid, ^ref}, {:notify, event}} ->
         {[{:async, pid, ref, event}], acc}
@@ -116,6 +104,19 @@ defimpl Enumerable, for: GenEvent.Stream do
       # Got an ack event.
       {_from, {^pid, ^ref}, {:ack_notify, event}} ->
         {[{:ack, pid, ref, event}], acc}
+
+      # The handler was removed. Stop iteration, resolve the
+      # event later. We need to demonitor now, otherwise DOWN
+      # appears with higher priority in the shutdown process.
+      {:gen_event_EXIT, {^pid, ^ref}, _reason} = event ->
+        Process.demonitor(mon_ref, [:flush])
+        send(self, event)
+        {:halt, {:removed, acc}}
+
+      # The manager died. Stop iteration, resolve the event later.
+      {:DOWN, ^mon_ref, _, _, _} = event ->
+        send(self, event)
+        {:halt, {:removed, acc}}
     after
       timeout ->
         exit({:timeout, {__MODULE__, :next, [stream, acc]}})
@@ -135,26 +136,20 @@ defimpl Enumerable, for: GenEvent.Stream do
 
   # If we reach this branch, the handler was not removed yet,
   # so we trigger a request for doing so.
-  defp stop(stream, {pid, _, _} = acc) do
-    parent = self()
-    _ = Task.start(fn -> GenEvent.remove_handler(pid, parent, :shutdown) end)
+  defp stop(stream, {pid, ref, _} = acc) do
+    _ = GenEvent.remove_handler(pid, {pid, ref}, :shutdown)
     stop(stream, {:removed, acc})
   end
 
   defp wait_for_handler_removal(pid, ref, mon_ref) do
-    self = self()
-
     receive do
-      {_from, {^pid, ^ref}, {notify, _event}} when notify in [:ack_notify, :sync_notify] ->
-        send pid, {ref, :done}
-        wait_for_handler_removal(pid, ref, mon_ref)
-      {:gen_event_EXIT, ^self, reason}
+      {:gen_event_EXIT, {^pid, ^ref}, reason}
           when reason == :normal
           when reason == :shutdown
           when tuple_size(reason) == 3 and elem(reason, 0) == :swapped  ->
         Process.demonitor(mon_ref, [:flush])
         :ok
-      {:gen_event_EXIT, ^self, reason} ->
+      {:gen_event_EXIT, {^pid, ^ref}, reason} ->
         Process.demonitor(mon_ref, [:flush])
         {:error, reason}
       {:DOWN, ^mon_ref, _, _, reason} ->
@@ -164,7 +159,7 @@ defimpl Enumerable, for: GenEvent.Stream do
 
   defp flush_events(ref) do
     receive do
-      {_from, {_pid, ^ref}, {:notify, _event}} ->
+      {_from, {_pid, ^ref}, {notify, _event}} when notify in [:notify, :ack_notify, :sync_notify] ->
         flush_events(ref)
     after
       0 -> :ok

lib/elixir/lib/inspect/algebra.ex

@@ -435,7 +435,7 @@ defmodule Inspect.Algebra do
       iex> Inspect.Algebra.format(doc, 20) |> IO.iodata_to_binary
       "[1! 2! 3! ...]"
   """
-  @spec surround_many(binary, [any], binary, integer | :infinity, (term -> t), binary) :: t
+  @spec surround_many(binary, [any], binary, Inspect.Opts.t, (term, Inspect.Opts.t -> t), binary) :: t
   def surround_many(left, docs, right, opts, fun, separator \\ @surround_separator) do
     do_surround_many(left, docs, right, opts.limit, opts, fun, separator)
   end

lib/elixir/lib/io.ex

@@ -180,7 +180,7 @@ defmodule IO do
   Inspects and writes the given argument to the device.
 
   It enables pretty printing by default with width of
-  80 characters. Th width can be changed by explicitly
+  80 characters. The width can be changed by explicitly
   passing the `:width` option.
 
   ## Examples

lib/elixir/lib/kernel.ex

@@ -1813,7 +1813,9 @@ defmodule Kernel do
   end
 
   defp unnest({{:., _, [expr, key]}, _, []}, acc, kind)
-      when is_tuple(expr) and elem(expr, 0) != :__aliases__ and elem(expr, 0) != :__MODULE__ do
+      when is_tuple(expr) and
+           :erlang.element(1, expr) != :__aliases__ and
+           :erlang.element(1, expr) != :__MODULE__ do
     unnest(expr, [{:map, key}|acc], kind)
   end
 
@@ -1834,8 +1836,8 @@ defmodule Kernel do
 
   defp proper_start?({{:., _, [expr, _]}, _, _args})
     when is_atom(expr)
-    when elem(expr, 0) == :__aliases__
-    when elem(expr, 0) == :__MODULE__, do: true
+    when :erlang.element(1, expr) == :__aliases__
+    when :erlang.element(1, expr) == :__MODULE__, do: true
 
   defp proper_start?({atom, _, _args})
     when is_atom(atom), do: true
@@ -2057,7 +2059,7 @@ defmodule Kernel do
   end
 
   defp warn_info([entry|_]) do
-    opts = elem(entry, tuple_size(entry) - 1)
+    opts = :erlang.element(tuple_size(entry), entry)
     Exception.format_file_line(Keyword.get(opts, :file), Keyword.get(opts, :line)) <> " "
   end
 

lib/elixir/lib/kernel/cli.ex

@@ -113,7 +113,8 @@ defmodule Kernel.CLI do
     IO.puts :stderr, Exception.format(kind, reason, prune_stacktrace(trace))
   end
 
-  @elixir_internals [:elixir_compiler, :elixir_module, :elixir_translator, :elixir_expand]
+  @elixir_internals [:elixir, :elixir_exp, :elixir_compiler, :elixir_module, :elixir_translator,
+                     :elixir_expand, :elixir_lexical]
 
   defp prune_stacktrace([{mod, _, _, _}|t]) when mod in @elixir_internals do
     prune_stacktrace(t)

lib/elixir/lib/kernel/parallel_compiler.ex

@@ -215,7 +215,8 @@ defmodule Kernel.ParallelCompiler do
     IO.puts Exception.format(:exit, reason, [])
   end
 
-  @elixir_internals [:elixir_compiler, :elixir_module, :elixir_translator, :elixir_expand]
+  @elixir_internals [:elixir, :elixir_exp, :elixir_compiler, :elixir_module, :elixir_translator,
+                     :elixir_expand, :elixir_lexical]
 
   defp prune_stacktrace([{mod, _, _, _}|t]) when mod in @elixir_internals do
     prune_stacktrace(t)

lib/elixir/lib/stream.ex

@@ -156,18 +156,22 @@ defmodule Stream do
   @spec chunk(Enumerable.t, non_neg_integer, non_neg_integer, Enumerable.t | nil) :: Enumerable.t
   def chunk(enum, n, step, pad \\ nil) when n > 0 and step > 0 do
     limit = :erlang.max(n, step)
-    lazy enum, {[], 0},
-         fn(f1) -> R.chunk(n, step, limit, f1) end,
-         fn(f1) -> &do_chunk(&1, n, pad, f1) end
+    if is_nil(pad) do
+      lazy enum, {[], 0}, fn(f1) -> R.chunk(n, step, limit, f1) end
+    else
+      lazy enum, {[], 0},
+           fn(f1) -> R.chunk(n, step, limit, f1) end,
+           &do_chunk(&1, n, pad, &2)
+     end
   end
 
-  defp do_chunk(acc(h, {buffer, count} = old, t) = acc, n, pad, f1) do
-    if is_nil(pad) || count == 0 do
-      {:cont, acc}
-    else
-      buffer = :lists.reverse(buffer) ++ Enum.take(pad, n - count)
-      cont_with_acc(f1, buffer, h, old, t)
-    end
+  defp do_chunk(acc(_, {_, 0}, _) = acc, _, _, _) do
+    {:cont, acc}
+  end
+
+  defp do_chunk(acc(h, {buffer, count} = old, t), n, pad, f1) do
+    buffer = :lists.reverse(buffer) ++ Enum.take(pad, n - count)
+    cont_with_acc(f1, buffer, h, old, t)
   end
 
   @doc """
@@ -186,7 +190,7 @@ defmodule Stream do
   def chunk_by(enum, fun) do
     lazy enum, nil,
          fn(f1) -> R.chunk_by(fun, f1) end,
-         fn(f1) -> &do_chunk_by(&1, f1) end
+         &do_chunk_by(&1, &2)
   end
 
   defp do_chunk_by(acc(_, nil, _) = acc, _f1) do
@@ -1127,12 +1131,12 @@ defmodule Stream do
 
   @compile {:inline, lazy: 2, lazy: 3, lazy: 4}
 
-  defp lazy(%Stream{funs: funs} = lazy, fun),
+  defp lazy(%Stream{done: nil, funs: funs} = lazy, fun),
     do: %{lazy | funs: [fun|funs] }
   defp lazy(enum, fun),
     do: %Stream{enum: enum, funs: [fun]}
 
-  defp lazy(%Stream{funs: funs, accs: accs} = lazy, acc, fun),
+  defp lazy(%Stream{done: nil, funs: funs, accs: accs} = lazy, acc, fun),
     do: %{lazy | funs: [fun|funs], accs: [acc|accs] }
   defp lazy(enum, acc, fun),
     do: %Stream{enum: enum, funs: [fun], accs: [acc]}
@@ -1171,19 +1175,20 @@ defimpl Enumerable, for: Stream do
     case reduce.({command, [acc|accs]}) do
       {:suspended, [acc|accs], continuation} ->
         {:suspended, acc, &do_each(continuation, done, accs, &1)}
-      {:halted, [acc|_]} ->
-        {:halted, acc}
-      {:done, [acc|_] = accs} ->
-        case done do
-          nil ->
-            {:done, acc}
-          {done, fun} ->
-            case done.(fun).(accs) do
-              {:cont, [acc|_]}    -> {:done, acc}
-              {:halt, [acc|_]}    -> {:halted, acc}
-              {:suspend, [acc|_]} -> {:suspended, acc, &({:done, elem(&1, 1)})}
-            end
-        end
+      {:halted, accs} ->
+        do_done {:halted, accs}, done
+      {:done, accs} ->
+        do_done {:done, accs}, done
+    end
+  end
+
+  defp do_done({reason, [acc|_]}, nil), do: {reason, acc}
+  defp do_done({reason, [acc|t]}, {done, fun}) do
+    [h|_] = Enum.reverse(t)
+    case done.([acc, h], fun) do
+      {:cont, [acc|_]}    -> {reason, acc}
+      {:halt, [acc|_]}    -> {:halted, acc}
+      {:suspend, [acc|_]} -> {:suspended, acc, &({:done, elem(&1, 1)})}
     end
   end
 end

lib/elixir/lib/system.ex

@@ -431,18 +431,18 @@ defmodule System do
   @spec cmd(binary, [binary], Keyword.t) ::
         {Collectable.t, exit_status :: non_neg_integer}
   def cmd(command, args, opts \\ []) when is_binary(command) and is_list(args) do
-    command = String.to_char_list(command)
+    cmd = String.to_char_list(command)
 
-    command =
-      if Path.type(command) == :absolute do
-        command
+    cmd =
+      if Path.type(cmd) == :absolute do
+        cmd
       else
-        :os.find_executable(command) || command
+        :os.find_executable(cmd) || :erlang.error(:enoent, [command, args, opts])
       end
 
     {into, opts} = cmd_opts(opts, [:use_stdio, :exit_status, :binary, :hide, args: args], "")
     {initial, fun} = Collectable.into(into)
-    do_cmd Port.open({:spawn_executable, command}, opts), initial, fun
+    do_cmd Port.open({:spawn_executable, cmd}, opts), initial, fun
   end
 
   defp do_cmd(port, acc, fun) do
@@ -463,9 +463,12 @@ defmodule System do
   defp cmd_opts([{:arg0, bin}|t], opts, into) when is_binary(bin),
     do: cmd_opts(t, [{:arg0, bin}|opts], into)
 
-  defp cmd_opts([{:stderr_to_stdout, bool}|t], opts, into) when is_boolean(bool),
+  defp cmd_opts([{:stderr_to_stdout, true}|t], opts, into),
     do: cmd_opts(t, [:stderr_to_stdout|opts], into)
 
+  defp cmd_opts([{:stderr_to_stdout, false}|t], opts, into),
+    do: cmd_opts(t, opts, into)
+
   defp cmd_opts([{:parallelism, bool}|t], opts, into) when is_boolean(bool),
     do: cmd_opts(t, [{:parallelism, bool}|opts], into)
 

lib/elixir/src/elixir_dispatch.erl

@@ -9,20 +9,7 @@
   find_import/4, format_error/1]).
 -include("elixir.hrl").
 -import(ordsets, [is_element/2]).
-
--define(atom, 'Elixir.Atom').
--define(float, 'Elixir.Float').
--define(io, 'Elixir.IO').
--define(integer, 'Elixir.Integer').
 -define(kernel, 'Elixir.Kernel').
--define(list, 'Elixir.List').
--define(map, 'Elixir.Map').
--define(node, 'Elixir.Node').
--define(port, 'Elixir.Port').
--define(process, 'Elixir.Process').
--define(string, 'Elixir.String').
--define(system, 'Elixir.System').
--define(tuple, 'Elixir.Tuple').
 
 default_functions() ->
   [{?kernel, elixir_imported_functions()}].
@@ -82,7 +69,7 @@ remote_function(Meta, Receiver, Name, Arity, E) ->
   check_deprecation(Meta, Receiver, Name, Arity, E),
 
   elixir_lexical:record_remote(Receiver, ?m(E, lexical_tracker)),
-  case inline(Receiver, Name, Arity) of
+  case elixir_rewrite:inline(Receiver, Name, Arity) of
     {AR, AN} -> {remote, AR, AN, Arity};
     false    -> {remote, Receiver, Name, Arity}
   end.
@@ -103,9 +90,9 @@ dispatch_import(Meta, Name, Args, E, Callback) ->
 dispatch_require(Meta, Receiver, Name, Args, E, Callback) when is_atom(Receiver) ->
   Arity = length(Args),
 
-  case rewrite(Receiver, Name, Args, Arity) of
-    {ok, AR, AN, AA} ->
-      Callback(AR, AN, AA);
+  case elixir_rewrite:inline(Receiver, Name, Arity) of
+    {AR, AN} ->
+      Callback(AR, AN, Args);
     false ->
       case expand_require(Meta, Receiver, {Name, Arity}, Args, E) of
         {ok, Receiver, Quoted} -> expand_quoted(Meta, Receiver, Name, Arity, Quoted, E);
@@ -151,11 +138,7 @@ do_expand_import(Meta, {Name, Arity} = Tuple, Args, Module, E, Result) ->
     {function, Receiver} ->
       elixir_lexical:record_import(Receiver, ?m(E, lexical_tracker)),
       elixir_locals:record_import(Tuple, Receiver, Module, ?m(E, function)),
-
-      case rewrite(Receiver, Name, Args, Arity) of
-        {ok, _, _, _} = Res -> Res;
-        false -> {ok, Receiver, Name, Args}
-      end;
+      {ok, Receiver, Name, Args};
     {macro, Receiver} ->
       check_deprecation(Meta, Receiver, Name, Arity, E),
       elixir_lexical:record_import(Receiver, ?m(E, lexical_tracker)),
@@ -167,8 +150,8 @@ do_expand_import(Meta, {Name, Arity} = Tuple, Args, Module, E, Result) ->
         error -> {ok, Receiver, Name, Args}
       end;
     false when Module == ?kernel ->
-      case rewrite(Module, Name, Args, Arity) of
-        {ok, _, _, _} = Res -> Res;
+      case elixir_rewrite:inline(Module, Name, Arity) of
+        {AR, AN} -> {ok, AR, AN, Args};
         false -> error
       end;
     false ->
@@ -342,163 +325,6 @@ elixir_imported_macros() ->
     error:undef -> []
   end.
 
-rewrite(?atom, to_string, [Arg], _) ->
-  {ok, erlang, atom_to_binary, [Arg, utf8]};
-rewrite(?kernel, elem, [Tuple, Index], _) ->
-  {ok, erlang, element, [increment(Index), Tuple]};
-rewrite(?kernel, put_elem, [Tuple, Index, Value], _) ->
-  {ok, erlang, setelement, [increment(Index), Tuple, Value]};
-rewrite(?map, 'has_key?', [Map, Key], _) ->
-  {ok, maps, is_key, [Key, Map]};
-rewrite(?map, fetch, [Map, Key], _) ->
-  {ok, maps, find, [Key, Map]};
-rewrite(?map, put, [Map, Key, Value], _) ->
-  {ok, maps, put, [Key, Value, Map]};
-rewrite(?map, delete, [Map, Key], _) ->
-  {ok, maps, remove, [Key, Map]};
-rewrite(?process, monitor, [Arg], _) ->
-  {ok, erlang, monitor, [process, Arg]};
-rewrite(?string, to_atom, [Arg], _) ->
-  {ok, erlang, binary_to_atom, [Arg, utf8]};
-rewrite(?string, to_existing_atom, [Arg], _) ->
-  {ok, erlang, binary_to_existing_atom, [Arg, utf8]};
-rewrite(?tuple, insert_at, [Tuple, Index, Term], _) ->
-  {ok, erlang, insert_element, [increment(Index), Tuple, Term]};
-rewrite(?tuple, delete_at, [Tuple, Index], _) ->
-  {ok, erlang, delete_element, [increment(Index), Tuple]};
-rewrite(?tuple, duplicate, [Data, Size], _) ->
-  {ok, erlang, make_tuple, [Size, Data]};
-
-rewrite(Receiver, Name, Args, Arity) ->
-  case inline(Receiver, Name, Arity) of
-    {AR, AN} -> {ok, AR, AN, Args};
-    false    -> false
-  end.
-
-increment(Number) when is_number(Number) ->
-  Number + 1;
-increment(Other) ->
-  {{'.', [], [erlang, '+']}, [], [Other, 1]}.
-
-inline(?atom, to_char_list, 1) -> {erlang, atom_to_list};
-inline(?io, iodata_length, 1) -> {erlang, iolist_size};
-inline(?io, iodata_to_binary, 1) -> {erlang, iolist_to_binary};
-inline(?integer, to_string, 1) -> {erlang, integer_to_binary};
-inline(?integer, to_string, 2) -> {erlang, integer_to_binary};
-inline(?integer, to_char_list, 1) -> {erlang, integer_to_list};
-inline(?integer, to_char_list, 2) -> {erlang, integer_to_list};
-inline(?float, to_string, 1) -> {erlang, float_to_binary};
-inline(?float, to_char_list, 1) -> {erlang, float_to_list};
-inline(?list, to_atom, 1) -> {erlang, list_to_atom};
-inline(?list, to_existing_atom, 1) -> {erlang, list_to_existing_atom};
-inline(?list, to_float, 1) -> {erlang, list_to_float};
-inline(?list, to_integer, 1) -> {erlang, list_to_integer};
-inline(?list, to_integer, 2) -> {erlang, list_to_integer};
-inline(?list, to_tuple, 1) -> {erlang, list_to_tuple};
-
-inline(?kernel, '+', 2) -> {erlang, '+'};
-inline(?kernel, '-', 2) -> {erlang, '-'};
-inline(?kernel, '+', 1) -> {erlang, '+'};
-inline(?kernel, '-', 1) -> {erlang, '-'};
-inline(?kernel, '*', 2) -> {erlang, '*'};
-inline(?kernel, '/', 2) -> {erlang, '/'};
-inline(?kernel, '++', 2) -> {erlang, '++'};
-inline(?kernel, '--', 2) -> {erlang, '--'};
-inline(?kernel, 'not', 1) -> {erlang, 'not'};
-inline(?kernel, '<', 2) -> {erlang, '<'};
-inline(?kernel, '>', 2) -> {erlang, '>'};
-inline(?kernel, '<=', 2) -> {erlang, '=<'};
-inline(?kernel, '>=', 2) -> {erlang, '>='};
-inline(?kernel, '==', 2) -> {erlang, '=='};
-inline(?kernel, '!=', 2) -> {erlang, '/='};
-inline(?kernel, '===', 2) -> {erlang, '=:='};
-inline(?kernel, '!==', 2) -> {erlang, '=/='};
-inline(?kernel, abs, 1) -> {erlang, abs};
-inline(?kernel, apply, 2) -> {erlang, apply};
-inline(?kernel, apply, 3) -> {erlang, apply};
-inline(?kernel, binary_part, 3) -> {erlang, binary_part};
-inline(?kernel, bit_size, 1) -> {erlang, bit_size};
-inline(?kernel, byte_size, 1) -> {erlang, byte_size};
-inline(?kernel, 'div', 2) -> {erlang, 'div'};
-inline(?kernel, exit, 1) -> {erlang, exit};
-inline(?kernel, hd, 1) -> {erlang, hd};
-inline(?kernel, is_atom, 1) -> {erlang, is_atom};
-inline(?kernel, is_binary, 1) -> {erlang, is_binary};
-inline(?kernel, is_bitstring, 1) -> {erlang, is_bitstring};
-inline(?kernel, is_boolean, 1) -> {erlang, is_boolean};
-inline(?kernel, is_float, 1) -> {erlang, is_float};
-inline(?kernel, is_function, 1) -> {erlang, is_function};
-inline(?kernel, is_function, 2) -> {erlang, is_function};
-inline(?kernel, is_integer, 1) -> {erlang, is_integer};
-inline(?kernel, is_list, 1) -> {erlang, is_list};
-inline(?kernel, is_map, 1) -> {erlang, is_map};
-inline(?kernel, is_number, 1) -> {erlang, is_number};
-inline(?kernel, is_pid, 1) -> {erlang, is_pid};
-inline(?kernel, is_port, 1) -> {erlang, is_port};
-inline(?kernel, is_reference, 1) -> {erlang, is_reference};
-inline(?kernel, is_tuple, 1) -> {erlang, is_tuple};
-inline(?kernel, length, 1) -> {erlang, length};
-inline(?kernel, make_ref, 0) -> {erlang, make_ref};
-inline(?kernel, map_size, 1) -> {erlang, map_size};
-inline(?kernel, max, 2) -> {erlang, max};
-inline(?kernel, min, 2) -> {erlang, min};
-inline(?kernel, node, 0) -> {erlang, node};
-inline(?kernel, node, 1) -> {erlang, node};
-inline(?kernel, 'rem', 2) -> {erlang, 'rem'};
-inline(?kernel, round, 1) -> {erlang, round};
-inline(?kernel, self, 0) -> {erlang, self};
-inline(?kernel, send, 2) -> {erlang, send};
-inline(?kernel, spawn, 1) -> {erlang, spawn};
-inline(?kernel, spawn, 3) -> {erlang, spawn};
-inline(?kernel, spawn_link, 1) -> {erlang, spawn_link};
-inline(?kernel, spawn_link, 3) -> {erlang, spawn_link};
-inline(?kernel, spawn_monitor, 1) -> {erlang, spawn_monitor};
-inline(?kernel, spawn_monitor, 3) -> {erlang, spawn_monitor};
-inline(?kernel, throw, 1) -> {erlang, throw};
-inline(?kernel, tl, 1) -> {erlang, tl};
-inline(?kernel, trunc, 1) -> {erlang, trunc};
-inline(?kernel, tuple_size, 1) -> {erlang, tuple_size};
-
-inline(?map, keys, 1) -> {maps, keys};
-inline(?map, merge, 2) -> {maps, merge};
-inline(?map, size, 1) -> {maps, size};
-inline(?map, values, 1) -> {maps, values};
-inline(?map, to_list, 1) -> {maps, to_list};
-
-inline(?node, spawn, 2) -> {erlang, spawn};
-inline(?node, spawn, 3) -> {erlang, spawn_opt};
-inline(?node, spawn, 4) -> {erlang, spawn};
-inline(?node, spawn, 5) -> {erlang, spawn_opt};
-inline(?node, spawn_link, 2) -> {erlang, spawn_link};
-inline(?node, spawn_link, 4) -> {erlang, spawn_link};
-
-inline(?process, exit, 2) -> {erlang, exit};
-inline(?process, spawn, 2) -> {erlang, spawn_opt};
-inline(?process, spawn, 4) -> {erlang, spawn_opt};
-inline(?process, demonitor, 1) -> {erlang, demonitor};
-inline(?process, demonitor, 2) -> {erlang, demonitor};
-inline(?process, link, 1) -> {erlang, link};
-inline(?process, unlink, 1) -> {erlang, unlink};
-
-inline(?port, open, 2) -> {erlang, open_port};
-inline(?port, call, 3) -> {erlang, port_call};
-inline(?port, close, 1) -> {erlang, port_close};
-inline(?port, command, 2) -> {erlang, port_command};
-inline(?port, command, 3) -> {erlang, port_command};
-inline(?port, connect, 2) -> {erlang, port_connect};
-inline(?port, control, 3) -> {erlang, port_control};
-inline(?port, info, 1) -> {erlang, port_info};
-inline(?port, info, 2) -> {erlang, port_info};
-inline(?port, list, 0) -> {erlang, ports};
-
-inline(?string, to_float, 1) -> {erlang, binary_to_float};
-inline(?string, to_integer, 1) -> {erlang, binary_to_integer};
-inline(?string, to_integer, 2) -> {erlang, binary_to_integer};
-inline(?system, stacktrace, 0) -> {erlang, get_stacktrace};
-inline(?tuple, to_list, 1) -> {erlang, tuple_to_list};
-
-inline(_, _, _) -> false.
-
 check_deprecation(Meta, Receiver, Name, Arity, #{file := File}) ->
   case deprecation(Receiver, Name, Arity) of
     false -> ok;

lib/elixir/src/elixir_exp.erl

@@ -474,7 +474,8 @@ expand_remote(Receiver, DotMeta, Right, Meta, Args, E, EL) ->
     true -> ok
   end,
   {EArgs, EA} = expand_args(Args, E),
-  {{{'.', DotMeta, [Receiver, Right]}, Meta, EArgs}, elixir_env:mergev(EL, EA)}.
+  {elixir_rewrite:rewrite(Receiver, DotMeta, Right, Meta, EArgs),
+   elixir_env:mergev(EL, EA)}.
 
 %% Lexical helpers
 

lib/elixir/src/elixir_rewrite.erl

@@ -0,0 +1,224 @@
+-module(elixir_rewrite).
+-export([rewrite/5, inline/3]).
+
+%% Convenience variables
+
+-define(hidden, [{line,-1}]).
+
+-define(atom, 'Elixir.Atom').
+-define(enum, 'Elixir.Enum').
+-define(float, 'Elixir.Float').
+-define(io, 'Elixir.IO').
+-define(integer, 'Elixir.Integer').
+-define(kernel, 'Elixir.Kernel').
+-define(list, 'Elixir.List').
+-define(map, 'Elixir.Map').
+-define(node, 'Elixir.Node').
+-define(port, 'Elixir.Port').
+-define(process, 'Elixir.Process').
+-define(string, 'Elixir.String').
+-define(string_chars, 'Elixir.String.Chars').
+-define(system, 'Elixir.System').
+-define(tuple, 'Elixir.Tuple').
+
+%% Inline
+
+%% Inline rules are straight-forward, they keep the same
+%% number and order of arguments and show up on captures.
+
+inline(?atom, to_char_list, 1) -> {erlang, atom_to_list};
+inline(?io, iodata_length, 1) -> {erlang, iolist_size};
+inline(?io, iodata_to_binary, 1) -> {erlang, iolist_to_binary};
+inline(?integer, to_string, 1) -> {erlang, integer_to_binary};
+inline(?integer, to_string, 2) -> {erlang, integer_to_binary};
+inline(?integer, to_char_list, 1) -> {erlang, integer_to_list};
+inline(?integer, to_char_list, 2) -> {erlang, integer_to_list};
+inline(?float, to_string, 1) -> {erlang, float_to_binary};
+inline(?float, to_char_list, 1) -> {erlang, float_to_list};
+inline(?list, to_atom, 1) -> {erlang, list_to_atom};
+inline(?list, to_existing_atom, 1) -> {erlang, list_to_existing_atom};
+inline(?list, to_float, 1) -> {erlang, list_to_float};
+inline(?list, to_integer, 1) -> {erlang, list_to_integer};
+inline(?list, to_integer, 2) -> {erlang, list_to_integer};
+inline(?list, to_tuple, 1) -> {erlang, list_to_tuple};
+
+inline(?kernel, '+', 2) -> {erlang, '+'};
+inline(?kernel, '-', 2) -> {erlang, '-'};
+inline(?kernel, '+', 1) -> {erlang, '+'};
+inline(?kernel, '-', 1) -> {erlang, '-'};
+inline(?kernel, '*', 2) -> {erlang, '*'};
+inline(?kernel, '/', 2) -> {erlang, '/'};
+inline(?kernel, '++', 2) -> {erlang, '++'};
+inline(?kernel, '--', 2) -> {erlang, '--'};
+inline(?kernel, 'not', 1) -> {erlang, 'not'};
+inline(?kernel, '<', 2) -> {erlang, '<'};
+inline(?kernel, '>', 2) -> {erlang, '>'};
+inline(?kernel, '<=', 2) -> {erlang, '=<'};
+inline(?kernel, '>=', 2) -> {erlang, '>='};
+inline(?kernel, '==', 2) -> {erlang, '=='};
+inline(?kernel, '!=', 2) -> {erlang, '/='};
+inline(?kernel, '===', 2) -> {erlang, '=:='};
+inline(?kernel, '!==', 2) -> {erlang, '=/='};
+inline(?kernel, abs, 1) -> {erlang, abs};
+inline(?kernel, apply, 2) -> {erlang, apply};
+inline(?kernel, apply, 3) -> {erlang, apply};
+inline(?kernel, binary_part, 3) -> {erlang, binary_part};
+inline(?kernel, bit_size, 1) -> {erlang, bit_size};
+inline(?kernel, byte_size, 1) -> {erlang, byte_size};
+inline(?kernel, 'div', 2) -> {erlang, 'div'};
+inline(?kernel, exit, 1) -> {erlang, exit};
+inline(?kernel, hd, 1) -> {erlang, hd};
+inline(?kernel, is_atom, 1) -> {erlang, is_atom};
+inline(?kernel, is_binary, 1) -> {erlang, is_binary};
+inline(?kernel, is_bitstring, 1) -> {erlang, is_bitstring};
+inline(?kernel, is_boolean, 1) -> {erlang, is_boolean};
+inline(?kernel, is_float, 1) -> {erlang, is_float};
+inline(?kernel, is_function, 1) -> {erlang, is_function};
+inline(?kernel, is_function, 2) -> {erlang, is_function};
+inline(?kernel, is_integer, 1) -> {erlang, is_integer};
+inline(?kernel, is_list, 1) -> {erlang, is_list};
+inline(?kernel, is_map, 1) -> {erlang, is_map};
+inline(?kernel, is_number, 1) -> {erlang, is_number};
+inline(?kernel, is_pid, 1) -> {erlang, is_pid};
+inline(?kernel, is_port, 1) -> {erlang, is_port};
+inline(?kernel, is_reference, 1) -> {erlang, is_reference};
+inline(?kernel, is_tuple, 1) -> {erlang, is_tuple};
+inline(?kernel, length, 1) -> {erlang, length};
+inline(?kernel, make_ref, 0) -> {erlang, make_ref};
+inline(?kernel, map_size, 1) -> {erlang, map_size};
+inline(?kernel, max, 2) -> {erlang, max};
+inline(?kernel, min, 2) -> {erlang, min};
+inline(?kernel, node, 0) -> {erlang, node};
+inline(?kernel, node, 1) -> {erlang, node};
+inline(?kernel, 'rem', 2) -> {erlang, 'rem'};
+inline(?kernel, round, 1) -> {erlang, round};
+inline(?kernel, self, 0) -> {erlang, self};
+inline(?kernel, send, 2) -> {erlang, send};
+inline(?kernel, spawn, 1) -> {erlang, spawn};
+inline(?kernel, spawn, 3) -> {erlang, spawn};
+inline(?kernel, spawn_link, 1) -> {erlang, spawn_link};
+inline(?kernel, spawn_link, 3) -> {erlang, spawn_link};
+inline(?kernel, spawn_monitor, 1) -> {erlang, spawn_monitor};
+inline(?kernel, spawn_monitor, 3) -> {erlang, spawn_monitor};
+inline(?kernel, throw, 1) -> {erlang, throw};
+inline(?kernel, tl, 1) -> {erlang, tl};
+inline(?kernel, trunc, 1) -> {erlang, trunc};
+inline(?kernel, tuple_size, 1) -> {erlang, tuple_size};
+
+inline(?map, keys, 1) -> {maps, keys};
+inline(?map, merge, 2) -> {maps, merge};
+inline(?map, size, 1) -> {maps, size};
+inline(?map, values, 1) -> {maps, values};
+inline(?map, to_list, 1) -> {maps, to_list};
+
+inline(?node, spawn, 2) -> {erlang, spawn};
+inline(?node, spawn, 3) -> {erlang, spawn_opt};
+inline(?node, spawn, 4) -> {erlang, spawn};
+inline(?node, spawn, 5) -> {erlang, spawn_opt};
+inline(?node, spawn_link, 2) -> {erlang, spawn_link};
+inline(?node, spawn_link, 4) -> {erlang, spawn_link};
+
+inline(?process, exit, 2) -> {erlang, exit};
+inline(?process, spawn, 2) -> {erlang, spawn_opt};
+inline(?process, spawn, 4) -> {erlang, spawn_opt};
+inline(?process, demonitor, 1) -> {erlang, demonitor};
+inline(?process, demonitor, 2) -> {erlang, demonitor};
+inline(?process, link, 1) -> {erlang, link};
+inline(?process, unlink, 1) -> {erlang, unlink};
+
+inline(?port, open, 2) -> {erlang, open_port};
+inline(?port, call, 3) -> {erlang, port_call};
+inline(?port, close, 1) -> {erlang, port_close};
+inline(?port, command, 2) -> {erlang, port_command};
+inline(?port, command, 3) -> {erlang, port_command};
+inline(?port, connect, 2) -> {erlang, port_connect};
+inline(?port, control, 3) -> {erlang, port_control};
+inline(?port, info, 1) -> {erlang, port_info};
+inline(?port, info, 2) -> {erlang, port_info};
+inline(?port, list, 0) -> {erlang, ports};
+
+inline(?string, to_float, 1) -> {erlang, binary_to_float};
+inline(?string, to_integer, 1) -> {erlang, binary_to_integer};
+inline(?string, to_integer, 2) -> {erlang, binary_to_integer};
+inline(?system, stacktrace, 0) -> {erlang, get_stacktrace};
+inline(?tuple, to_list, 1) -> {erlang, tuple_to_list};
+
+inline(_, _, _) -> false.
+
+%% Rewrite rules
+%% Rewrite rules are more complex than regular inlining code.
+%% It receives all remote call arguments and return quoted
+%% expressions with the new environment.
+
+%% Complex rewrite rules
+
+rewrite(?string_chars, _DotMeta, 'to_string', _Meta, [String]) when is_binary(String) ->
+  String;
+rewrite(?string_chars, DotMeta, 'to_string', Meta, [String]) ->
+  Var   = {'_rewrite', ?hidden, nil},
+  Guard = {{'.', ?hidden, [erlang, is_binary]}, ?hidden, [Var]},
+  Slow  = remote(?string_chars, DotMeta, 'to_string', Meta, [Var]),
+  Fast  = Var,
+
+  {'case', ?hidden, [String, [{do,
+    [{'->', ?hidden, [[{'when', ?hidden, [Var, Guard]}], Fast]},
+     {'->', ?hidden, [[Var], Slow]}]
+  }]]};
+
+rewrite(?enum, DotMeta, 'reverse', Meta, [List]) when is_list(List) ->
+  remote(lists, DotMeta, 'reverse', Meta, [List]);
+rewrite(?enum, DotMeta, 'reverse', Meta, [List]) ->
+  Var   = {'_rewrite', ?hidden, nil},
+  Guard = {{'.', ?hidden, [erlang, is_list]}, ?hidden, [Var]},
+  Slow  = remote(?enum, DotMeta, 'reverse', Meta, [Var]),
+  Fast  = remote(lists, DotMeta, 'reverse', Meta, [Var]),
+
+  {'case', ?hidden, [List, [{do,
+    [{'->', ?hidden, [[{'when', ?hidden, [Var, Guard]}], Fast]},
+     {'->', ?hidden, [[Var], Slow]}]
+  }]]};
+
+rewrite(Receiver, DotMeta, Right, Meta, Args) ->
+  {EReceiver, ERight, EArgs} = rewrite(Receiver, Right, Args),
+  remote(EReceiver, DotMeta, ERight, Meta, EArgs).
+
+%% Simple rewrite rules
+
+rewrite(?atom, to_string, [Arg]) ->
+  {erlang, atom_to_binary, [Arg, utf8]};
+rewrite(?kernel, elem, [Tuple, Index]) ->
+  {erlang, element, [increment(Index), Tuple]};
+rewrite(?kernel, put_elem, [Tuple, Index, Value]) ->
+  {erlang, setelement, [increment(Index), Tuple, Value]};
+rewrite(?map, 'has_key?', [Map, Key]) ->
+  {maps, is_key, [Key, Map]};
+rewrite(?map, fetch, [Map, Key]) ->
+  {maps, find, [Key, Map]};
+rewrite(?map, put, [Map, Key, Value]) ->
+  {maps, put, [Key, Value, Map]};
+rewrite(?map, delete, [Map, Key]) ->
+  {maps, remove, [Key, Map]};
+rewrite(?process, monitor, [Arg]) ->
+  {erlang, monitor, [process, Arg]};
+rewrite(?string, to_atom, [Arg]) ->
+  {erlang, binary_to_atom, [Arg, utf8]};
+rewrite(?string, to_existing_atom, [Arg]) ->
+  {erlang, binary_to_existing_atom, [Arg, utf8]};
+rewrite(?tuple, insert_at, [Tuple, Index, Term]) ->
+  {erlang, insert_element, [increment(Index), Tuple, Term]};
+rewrite(?tuple, delete_at, [Tuple, Index]) ->
+  {erlang, delete_element, [increment(Index), Tuple]};
+rewrite(?tuple, duplicate, [Data, Size]) ->
+  {erlang, make_tuple, [Size, Data]};
+rewrite(Receiver, Fun, Args) ->
+  {Receiver, Fun, Args}.
+
+%% Rewrite helpers
+
+remote(Receiver, DotMeta, Right, Meta, Args) ->
+  {{'.', DotMeta, [Receiver, Right]}, Meta, Args}.
+
+increment(Number) when is_number(Number) ->
+  Number + 1;
+increment(Other) ->
+  {{'.', [], [erlang, '+']}, [], [Other, 1]}.

lib/elixir/test/elixir/gen_event_test.exs

@@ -432,6 +432,23 @@ defmodule GenEventTest do
     Logger.add_backend(:console, flush: true)
   end
 
+  test "add_process_handler/2 with GenEvent" do
+    {:ok, snd} = GenEvent.start_link()
+    GenEvent.add_handler(snd, ReplyHandler, {self(), false})
+
+    {:ok, fst} = GenEvent.start_link()
+    :gen.call(fst, self(), {:add_process_handler, snd, snd})
+
+    assert GenEvent.notify(fst, :hello) == :ok
+    assert_receive {:event, :hello}
+
+    assert GenEvent.ack_notify(fst, :hello) == :ok
+    assert_receive {:event, :hello}
+
+    assert GenEvent.sync_notify(fst, :hello) == :ok
+    assert_received {:event, :hello}
+  end
+
   test ":sys.get_status/2" do
     {:ok, pid} = GenEvent.start(name: :my_gen_event_name)
     :ok = GenEvent.add_handler(pid, {ReplyHandler, :ok}, {self(), true})

lib/elixir/test/elixir/stream_test.exs

@@ -67,6 +67,19 @@ defmodule StreamTest do
     assert Enum.zip(list, list) == Enum.zip(stream, stream)
   end
 
+  test "chunk/4 is haltable" do
+    assert 1..10 |> Stream.take(6) |> Stream.chunk(4, 4, [7, 8]) |> Enum.to_list ==
+           [[1, 2, 3, 4], [5, 6, 7, 8]]
+    assert 1..10 |> Stream.take(6) |> Stream.chunk(4, 4, [7, 8]) |> Stream.take(3) |> Enum.to_list ==
+           [[1, 2, 3, 4], [5, 6, 7, 8]]
+    assert 1..10 |> Stream.take(6) |> Stream.chunk(4, 4, [7, 8]) |> Stream.take(2) |> Enum.to_list ==
+           [[1, 2, 3, 4], [5, 6, 7, 8]]
+    assert 1..10 |> Stream.take(6) |> Stream.chunk(4, 4, [7, 8]) |> Stream.take(1) |> Enum.to_list ==
+           [[1, 2, 3, 4]]
+    assert 1..6 |> Stream.take(6) |> Stream.chunk(4, 4, [7, 8]) |> Enum.to_list ==
+           [[1, 2, 3, 4], [5, 6, 7, 8]]
+  end
+
   test "chunk_by/2" do
     stream = Stream.chunk_by([1, 2, 2, 3, 4, 4, 6, 7, 7], &(rem(&1, 2) == 1))
 

lib/elixir/test/elixir/system_test.exs

@@ -65,6 +65,16 @@ defmodule SystemTest do
     opts = [into: [], cd: System.cwd!, env: %{"foo" => "bar"},
             arg0: "hecho", stderr_to_stdout: true, parallelism: true]
     assert {["hello\n"], 0} = System.cmd "echo", ["hello"], opts
+
+    with_tmp_dir(fn dir ->
+      new_path = Path.join([dir, "echo2"])
+      File.cp!(System.find_executable("echo"), new_path)
+      assert :enoent = catch_error(System.cmd(new_path, ["hello"]))
+
+      File.cd!(dir)
+      assert :enoent = catch_error(System.cmd("echo2", ["hello"]))
+      assert {"hello\n", 0} = System.cmd(Path.join([System.cwd, "echo2"]), ["hello"])
+    end)
   end
 
   test "find_executable/1" do
@@ -72,4 +82,17 @@ defmodule SystemTest do
     assert is_binary System.find_executable("erl")
     assert !System.find_executable("does-not-really-exist-from-elixir")
   end
+
+  defp with_tmp_dir(function) do
+    dir = tmp_dir_name()
+    tmp_dir = System.tmp_dir!
+    tmp_path = Path.join [tmp_dir, dir]
+    File.rm_rf! tmp_path
+    File.mkdir_p! tmp_path
+    File.cd! tmp_dir, fn -> function.(dir) end
+  end
+
+  defp tmp_dir_name do
+    :crypto.rand_bytes(4) |> Base.encode16
+  end
 end

lib/ex_unit/lib/ex_unit/runner.ex

@@ -220,9 +220,17 @@ defmodule ExUnit.Runner do
           %{test | state: {:failed, {{:EXIT, test_pid}, error, []}}}
       after
         timeout ->
+          stacktrace =
+            try do
+              Process.info(test_pid, :current_stacktrace)
+            catch
+              _, _ -> []
+            else
+              {:current_stacktrace, stacktrace} -> stacktrace
+            end
           Process.exit(test_pid, :kill)
           Process.demonitor(test_ref, [:flush])
-          %{test | state: {:failed, {:error, %ExUnit.TimeoutError{timeout: timeout}, []}}}
+          %{test | state: {:failed, {:error, %ExUnit.TimeoutError{timeout: timeout}, stacktrace}}}
       end
 
     exec_on_exit(test, test_pid)

lib/ex_unit/test/ex_unit_test.exs

@@ -50,8 +50,9 @@ defmodule ExUnitTest do
       end
     end
 
-    assert capture_io(fn -> ExUnit.run end) =~
-           "** (ExUnit.TimeoutError) test timed out after 10ms"
+    output = capture_io(fn -> ExUnit.run end)
+    assert output =~ "** (ExUnit.TimeoutError) test timed out after 10ms"
+    assert output =~ ~r"\(stdlib\) timer\.erl:\d+: :timer\.sleep/1"
   end
 
   test "filtering cases with tags" do

lib/iex/lib/iex/helpers.ex

@@ -42,7 +42,7 @@ defmodule IEx.Helpers do
       h(Enum.reverse/1)
       
   To discover all available functions for a module, type the module name
-  follow by a dot, then press tab to trigger autocomplete. For example:
+  followed by a dot, then press tab to trigger autocomplete. For example:
   
       Enum.
 

lib/mix/lib/mix/compilers/elixir.ex

@@ -13,12 +13,12 @@ defmodule Mix.Compilers.Elixir do
   in between modules, which helps it recompile only the modules that
   have changed at runtime.
   """
-  def compile(manifest, srcs, exts, dest, force, on_start) do
-    all = Mix.Utils.extract_files(srcs, exts)
-    all_entries = read_manifest(manifest)
+  def compile(manifest, srcs, skip, exts, dest, force, on_start) do
+    all = Mix.Utils.extract_files(srcs -- skip, exts)
+    {all_entries, skip_entries} = read_manifest(manifest, skip)
 
     removed =
-      for {_b, _m, source, _d, _f} <- all_entries, not(source in all), do: source
+      for {_b, _m, source, _d, _f, _bin} <- all_entries, not(source in all), do: source
 
     changed =
       if force do
@@ -32,23 +32,24 @@ defmodule Mix.Compilers.Elixir do
         # Otherwise let's start with the new ones
         # plus the ones that have changed
         for(source <- all,
-            not Enum.any?(all_entries, fn {_b, _m, s, _d, _f} -> s == source end),
+            not Enum.any?(all_entries, fn {_b, _m, s, _d, _f, _bin} -> s == source end),
             do: source)
           ++
-        for({_b, _m, source, _d, files} <- all_entries,
+        for({_b, _m, source, _d, files, _bin} <- all_entries,
             times = Enum.map([source|files], &HashDict.fetch!(all_mtimes, &1)),
             Mix.Utils.stale?(times, [modified]),
             do: source)
       end
 
-    {entries, changed} = remove_stale_entries(all_entries, removed ++ changed, [], [])
+    {entries, changed} = remove_stale_entries(all_entries, removed ++ changed)
     stale = changed -- removed
 
     cond do
       stale != [] ->
-        do_compile(manifest, entries, stale, dest, on_start)
+        compile_manifest(manifest, entries ++ skip_entries, stale, dest, on_start)
         :ok
       removed != [] ->
+        write_manifest(manifest, entries ++ skip_entries)
         :ok
       true ->
         :noop
@@ -56,7 +57,7 @@ defmodule Mix.Compilers.Elixir do
   end
 
   defp mtimes(entries) do
-    Enum.reduce(entries, HashDict.new, fn {_b, _m, source, _d, files}, dict ->
+    Enum.reduce(entries, HashDict.new, fn {_b, _m, source, _d, files, _bin}, dict ->
       Enum.reduce([source|files], dict, fn file, dict ->
         if HashDict.has_key?(dict, file) do
           dict
@@ -82,16 +83,14 @@ defmodule Mix.Compilers.Elixir do
     end
   end
 
-  defp do_compile(manifest, entries, stale, dest, on_start) do
+  defp compile_manifest(manifest, entries, stale, dest, on_start) do
     Mix.Project.build_structure
     on_start.()
     cwd = File.cwd!
 
     # Starts a server responsible for keeping track which files
     # were compiled and the dependencies in between them.
-    {:ok, pid} = Agent.start_link(fn ->
-      Enum.map(entries, &Tuple.insert_at(&1, 5, nil))
-    end)
+    {:ok, pid} = Agent.start_link(fn -> entries end)
 
     try do
       _ = Kernel.ParallelCompiler.files :lists.usort(stale),
@@ -103,7 +102,7 @@ defmodule Mix.Compilers.Elixir do
         entries
       end
     after
-      Agent.stop pid
+      Agent.stop(pid, :infinity)
     end
 
     :ok
@@ -145,7 +144,7 @@ defmodule Mix.Compilers.Elixir do
 
   # This function receives the manifest entries and some source
   # files that have changed. It then, recursively, figures out
-  # all the files that changed (thanks to the dependencies) and
+  # all the files that changed (via the module dependencies) and
   # return their sources as the remaining entries.
   defp remove_stale_entries(all, []) do
     {all, []}
@@ -155,9 +154,12 @@ defmodule Mix.Compilers.Elixir do
     remove_stale_entries(all, :lists.usort(changed), [], [])
   end
 
-  defp remove_stale_entries([{beam, module, source, _d, _f} = entry|t], changed, removed, acc) do
+  defp remove_stale_entries([{beam, module, source, _d, _f, _bin} = entry|t], changed, removed, acc) do
     if source in changed do
+      atom = String.to_atom(module)
       _ = File.rm(beam)
+      _ = :code.purge(atom)
+      _ = :code.delete(atom)
       remove_stale_entries(t, changed, [module|removed], acc)
     else
       remove_stale_entries(t, changed, removed, [entry|acc])
@@ -167,7 +169,7 @@ defmodule Mix.Compilers.Elixir do
   defp remove_stale_entries([], changed, removed, acc) do
     # If any of the dependencies for the remaining entries
     # were removed, get its source so we can remove them.
-    next_changed = for {_b, _m, source, deps, _f} <- acc,
+    next_changed = for {_b, _m, source, deps, _f, _bin} <- acc,
                     Enum.any?(deps, &(&1 in removed)),
                     do: source
 
@@ -179,27 +181,40 @@ defmodule Mix.Compilers.Elixir do
 
   # Reads the manifest returning the results as tuples.
   # The beam files are read, removed and stored in memory.
-  defp read_manifest(manifest) do
+  defp read_manifest(manifest, skip_paths) do
+    initial = {[], []}
+
     case File.read(manifest) do
       {:ok, contents} ->
-        Enum.reduce String.split(contents, "\n"), [], fn x, acc ->
-          case String.split(x, "\t") do
-            [beam, module, source|deps] ->
-              {deps, files} =
-                case Enum.split_while(deps, &(&1 != "Elixir")) do
-                  {deps, ["Elixir"|files]} -> {deps, files}
-                  {deps, _} -> {deps, []}
-                end
-              [{beam, module, source, deps, files}|acc]
-            _ ->
-              acc
-          end
+        skip_paths = Enum.map(skip_paths, &(&1 <> "/"))
+        Enum.reduce String.split(contents, "\n"), initial, fn x, acc ->
+          read_manifest_entry(String.split(x, "\t"), acc, skip_paths)
         end
       {:error, _} ->
-        []
+        initial
     end
   end
 
+  defp read_manifest_entry([beam, module, source|deps], {keep, skip}, skip_paths) do
+    {deps, files} =
+      case Enum.split_while(deps, &(&1 != "Elixir")) do
+        {deps, ["Elixir"|files]} -> {deps, files}
+        {deps, _} -> {deps, []}
+      end
+
+    entry = {beam, module, source, deps, files, nil}
+
+    if String.starts_with?(source, skip_paths) do
+      {keep, [entry|skip]}
+    else
+      {[entry|keep], skip}
+    end
+  end
+
+  defp read_manifest_entry(_, acc, _skip_paths) do
+    acc
+  end
+
   # Writes the manifest separating entries by tabs.
   defp write_manifest(_manifest, []) do
     :ok
@@ -213,6 +228,11 @@ defmodule Mix.Compilers.Elixir do
         [beam, module, source | tail] |> Enum.join("\t")
     end)
 
+    # The Mix.Dep.Lock keeps all the project dependencies. Since Elixir
+    # is a dependency itself, we need to touch the lock so the current
+    # Elixir version, used to compile the files above, is properly stored.
+    Mix.Dep.Lock.touch
+
     File.mkdir_p!(Path.dirname(manifest))
     File.write!(manifest, Enum.join(lines, "\n"))
   end

lib/mix/lib/mix/config.ex

@@ -40,6 +40,8 @@ defmodule Mix.Config do
   @doc """
   Configures the given application.
 
+  Keyword lists are always deep merged.
+
   ## Examples
 
   The given `opts` are merged into the existing configuration
@@ -69,6 +71,8 @@ defmodule Mix.Config do
   @doc """
   Configures the given key for the given application.
 
+  Keyword lists are always deep merged.
+
   ## Examples
 
   The given `opts` are merged into the existing values for `key`
@@ -91,8 +95,7 @@ defmodule Mix.Config do
     quote do
       var!(config, Mix.Config) =
         Mix.Config.merge(var!(config, Mix.Config),
-                         [{unquote(app), [{unquote(key), unquote(opts)}]}],
-                         fn _app, _key, v1, v2 -> Keyword.merge(v1, v2) end)
+                         [{unquote(app), [{unquote(key), unquote(opts)}]}])
     end
   end
 
@@ -116,7 +119,7 @@ defmodule Mix.Config do
   defmacro import_config(file) do
     quote do
       var!(config, Mix.Config) =
-        Mix.Config.read_wildcard!(Path.expand(unquote(file), __DIR__), var!(config, Mix.Config))
+        Mix.Config.read_wildcard!(var!(config, Mix.Config), Path.expand(unquote(file), __DIR__))
     end
   end
 
@@ -142,7 +145,7 @@ defmodule Mix.Config do
   @doc """
   Reads many configuration files given by wildcard into a single config.
   """
-  def read_wildcard!(path, config) do
+  def read_wildcard!(config, path) do
     paths = case Path.wildcard(path) do
       [] -> [path]
       o  -> o
@@ -201,34 +204,15 @@ defmodule Mix.Config do
   """
   def merge(config1, config2) do
     Keyword.merge(config1, config2, fn _, app1, app2 ->
-      Keyword.merge(app1, app2)
+      Keyword.merge(app1, app2, &deep_merge/3)
     end)
   end
 
-  @doc """
-  Merges two configurations.
-
-  The configuration of each application is merged together
-  and a callback is invoked in case of conflicts receiving
-  the app, the conflicting key and both values. It must return
-  a value that will be used as part of the conflict resolution.
-
-  ## Examples
-
-      iex> Mix.Config.merge([app: [k: :v1]], [app: [k: :v2]],
-      ...>   fn app, k, v1, v2 -> {app, k, v1, v2} end)
-      [app: [k: {:app, :k, :v1, :v2}]]
-
-  """
-  def merge(config1, config2, callback) do
-    Keyword.merge(config1, config2, fn app, app1, app2 ->
-      Keyword.merge(app1, app2, fn k, v1, v2 ->
-        if v1 == v2 do
-          v1
-        else
-          callback.(app, k, v1, v2)
-        end
-      end)
-    end)
+  defp deep_merge(_key, value1, value2) do
+    if Keyword.keyword?(value1) and Keyword.keyword?(value2) do
+      Keyword.merge(value1, value2, &deep_merge/3)
+    else
+      value2
+    end
   end
 end

lib/mix/lib/mix/generator.ex

@@ -17,7 +17,7 @@ defmodule Mix.Generator do
   def create_file(path, contents, opts \\ []) when is_binary(path) do
     Mix.shell.info [:green, "* creating ", :reset, Path.relative_to_cwd(path)]
 
-    if opts[:force] || overwriting?(path) do
+    if opts[:force] || Mix.Utils.overwriting?(path) do
       File.mkdir_p!(Path.dirname(path))
       File.write!(path, contents)
     end
@@ -31,15 +31,6 @@ defmodule Mix.Generator do
     File.mkdir_p! path
   end
 
-  defp overwriting?(path) do
-    if File.exists?(path) do
-      full = Path.expand(path)
-      Mix.shell.yes?(Path.relative_to_cwd(full) <> " already exists, overwrite?")
-    else
-      true
-    end
-  end
-
   @doc false
   defmacro from_file(path) do
     quote do

lib/mix/lib/mix/tasks/archive.build.ex

@@ -72,5 +72,8 @@ defmodule Mix.Tasks.Archive.Build do
     end
 
     Mix.Archive.create(source, target)
+
+    Mix.shell.info "Generated archive #{target} with MIX_ENV=#{Mix.env}"
+    :ok
   end
 end

lib/mix/lib/mix/tasks/archive.install.ex

@@ -54,13 +54,12 @@ defmodule Mix.Tasks.Archive.Install do
     if opts[:force] || should_install?(src, previous) do
       remove_previous_versions(previous)
 
-      dest = Mix.Local.archives_path()
-      archive = Path.join(dest, basename(src))
+      archive = Path.join(Mix.Local.archives_path(), basename(src))
       check_file_exists(archive)
 
-      File.mkdir_p!(dest)
-      File.write!(archive, Mix.Utils.read_path!(src, opts))
-      Mix.shell.info [:green, "* creating ", :reset, Path.relative_to_cwd(archive)]
+      if Mix.Utils.copy_path!(src, archive, opts) do
+        Mix.shell.info [:green, "* creating ", :reset, Path.relative_to_cwd(archive)]
+      end
 
       true = Code.append_path(Mix.Archive.ebin(archive))
     else
@@ -80,7 +79,7 @@ defmodule Mix.Tasks.Archive.Install do
   defp should_install?(_src, previous_files) do
     files = Enum.map_join(previous_files, ", ", &Path.basename/1)
 
-    Mix.shell.yes?("Found existing archives: #{files}.\n" <>
+    Mix.shell.yes?("Found existing archive(s): #{files}.\n" <>
                    "Are you sure you want to replace them?")
   end
 

lib/mix/lib/mix/tasks/compile.elixir.ex

@@ -22,8 +22,8 @@ defmodule Mix.Tasks.Compile.Elixir do
     * `--debug-info` (`--no-debug-info`) - attach (or not) debug info to compiled modules
     * `--ignore-module-conflict` - do not emit warnings if a module was previously defined
     * `--warnings-as-errors` - treat warnings as errors and return a non-zero exit code
-    * `--elixirc-paths` - paths to lookup for Elixir source.
-      Can be given multiple times and, once given, overrides the project elixirc_paths config.
+    * `--elixirc-paths` - restrict the original elixirc paths to
+      a subset of the ones specified. Can be given multiple times.
 
   ## Configuration
 
@@ -51,10 +51,12 @@ defmodule Mix.Tasks.Compile.Elixir do
 
     project = Mix.Project.config
     dest = Mix.Project.compile_path(project)
-    srcs = case Keyword.get_values(opts, :elixirc_paths) do
-      [] -> project[:elixirc_paths]
-      ep -> ep
-    end
+    srcs = project[:elixirc_paths]
+    skip =
+      case Keyword.get_values(opts, :elixirc_paths) do
+        [] -> []
+        ep -> srcs -- ep
+      end
 
     manifest = manifest()
     configs  = Mix.Project.config_files ++ Mix.Tasks.Compile.Erlang.manifests
@@ -62,16 +64,10 @@ defmodule Mix.Tasks.Compile.Elixir do
     force = opts[:force] || local_deps_changed?(manifest)
               || Mix.Utils.stale?(configs, [manifest])
 
-    result = Mix.Compilers.Elixir.compile(manifest, srcs, [:ex], dest, force, fn ->
+    Mix.Compilers.Elixir.compile(manifest, srcs, skip, [:ex], dest, force, fn ->
       true = Code.prepend_path(dest)
       set_compiler_opts(project, opts, [])
     end)
-
-    # The Mix.Dep.Lock keeps all the project dependencies. Since Elixir
-    # is a dependency itself, we need to touch the lock so the current
-    # Elixir version, used to compile the files above, is properly stored.
-    unless result == :noop, do: Mix.Dep.Lock.touch
-    result
   end
 
   @doc """

lib/mix/lib/mix/tasks/deps.compile.ex

@@ -26,11 +26,10 @@ defmodule Mix.Tasks.Deps.Compile do
 
   import Mix.Dep, only: [loaded: 1, available?: 1, loaded_by_name: 2,
                          format_dep: 1, make?: 1, mix?: 1, rebar?: 1]
-  
+
   @spec run(OptionParser.argv) :: :ok
   def run(args) do
     Mix.Project.get!
-    Mix.Task.run "deps.loadpaths"
 
     case OptionParser.parse(args) do
       {_, [], _} ->
@@ -45,6 +44,8 @@ defmodule Mix.Tasks.Deps.Compile do
     shell  = Mix.shell
     config = Mix.Project.deps_config
 
+    Mix.Task.run "deps.loadpaths"
+
     compiled =
       Enum.map(deps, fn %Mix.Dep{app: app, status: status, opts: opts, scm: scm} = dep ->
         check_unavailable!(app, status)

lib/mix/lib/mix/tasks/local.hex.ex

@@ -2,7 +2,7 @@ defmodule Mix.Tasks.Local.Hex do
   use Mix.Task
 
   @hex_url "https://hex.pm/installs/hex.ez"
-  @hex_requirement ">= 0.4.3"
+  @hex_requirement ">= 0.5.0"
 
   @shortdoc "Install hex locally"
 
@@ -18,7 +18,8 @@ defmodule Mix.Tasks.Local.Hex do
   """
   @spec run(OptionParser.argv) :: boolean
   def run(args) do
-    Mix.Tasks.Archive.Install.run [@hex_url, "--shell" | args]
+    url = @hex_url <> "?elixir=" <> System.version
+    Mix.Tasks.Archive.Install.run [url, "--shell" | args]
   end
 
   @doc false

lib/mix/lib/mix/tasks/local.rebar.ex

@@ -1,8 +1,6 @@
 defmodule Mix.Tasks.Local.Rebar do
   use Mix.Task
 
-  import Mix.Generator, only: [create_file: 3]
-
   @rebar_url "http://s3.hex.pm/rebar"
   @shortdoc  "Install rebar locally"
 
@@ -31,11 +29,13 @@ defmodule Mix.Tasks.Local.Rebar do
   end
 
   defp do_install(path, opts) do
-    rebar = Mix.Utils.read_path!(path)
     local_rebar_path = Mix.Rebar.local_rebar_path
-    File.mkdir_p! Path.dirname(local_rebar_path)
-    create_file local_rebar_path, rebar, opts
-    :ok = :file.change_mode local_rebar_path, 0o755
+
+    if Mix.Utils.copy_path!(path, local_rebar_path, opts) do
+      :ok = :file.change_mode local_rebar_path, 0o755
+      Mix.shell.info [:green, "* creating ", :reset, Path.relative_to_cwd(local_rebar_path)]
+    end
+
     true
   end
 end

lib/mix/lib/mix/tasks/new.ex

@@ -68,7 +68,8 @@ defmodule Mix.Tasks.New do
   end
 
   defp do_generate(app, mod, path, opts) do
-    assigns = [app: app, mod: mod, otp_app: otp_app(mod, !!opts[:sup])]
+    assigns = [app: app, mod: mod, otp_app: otp_app(mod, !!opts[:sup]),
+               version: get_version(System.version)]
 
     create_file "README.md",  readme_template(assigns)
     create_file ".gitignore", gitignore_text
@@ -162,6 +163,15 @@ defmodule Mix.Tasks.New do
     end
   end
 
+  defp get_version(version) do
+    {:ok, version} = Version.parse(version)
+    "#{version.major}.#{version.minor}" <>
+      case version.pre do
+        [h|_] -> "-#{h}"
+        []    -> ""
+      end
+  end
+
   defp in_umbrella? do
     apps = Path.dirname(File.cwd!)
 
@@ -196,7 +206,7 @@ defmodule Mix.Tasks.New do
     def project do
       [app: :<%= @app %>,
        version: "0.0.1",
-       elixir: "~> <%= System.version %>",
+       elixir: "~> <%= @version %>",
        deps: deps]
     end
 
@@ -231,7 +241,7 @@ defmodule Mix.Tasks.New do
        version: "0.0.1",
        deps_path: "../../deps",
        lockfile: "../../mix.lock",
-       elixir: "~> <%= System.version %>",
+       elixir: "~> <%= @version %>",
        deps: deps]
     end
 

lib/mix/lib/mix/utils.ex

@@ -354,10 +354,8 @@ defmodule Mix.Utils do
   end
 
   @doc """
-  Opens and reads content from either a URL or a local filesystem path.
-
-  Used by tasks like `archive.install` and `local.rebar` that support
-  installation either from a URL or a local file.
+  Opens and reads content from either a URL or a local filesystem path
+  and returns the contents as a binary.
 
   Raises if the given path is not a URL, nor a file or if the
   file or URL are invalid.
@@ -370,9 +368,9 @@ defmodule Mix.Utils do
   def read_path!(path, opts \\ []) do
     cond do
       url?(path) && opts[:shell] ->
-        read_shell(path)
+        read_shell(path, nil)
       url?(path) ->
-        read_httpc(path)
+        read_httpc(path, nil)
       file?(path) ->
         read_file(path)
       true ->
@@ -380,11 +378,65 @@ defmodule Mix.Utils do
     end
   end
 
+  @doc """
+  Copies content from either a URL or a local filesystem path to
+  target path.
+
+  Used by tasks like `archive.install` and `local.rebar` that support
+  installation either from a URL or a local file.
+
+  Raises if the given path is not a URL, nor a file or if the
+  file or URL are invalid.
+
+  ## Options
+
+    * `:shell` - Forces the use of `wget` or `curl` to fetch the file if the
+      given path is a URL.
+
+    * `:force` - Forces overwriting target file without a shell prompt.
+  """
+  def copy_path!(source, target, opts \\ []) when is_binary(source) and is_binary(target) do
+    if opts[:force] || overwriting?(target) do
+      cond do
+        url?(source) && opts[:shell] ->
+          read_shell(source, target)
+        url?(source) ->
+          read_httpc(source, target)
+        file?(source) ->
+          copy_file(source, target)
+        true ->
+          Mix.raise "Expected #{source} to be a url or a local file path"
+      end
+
+      true
+    else
+      false
+    end
+  end
+
+  @doc """
+  Prompts the user to overwrite the file if it exists. Returns
+  the user input.
+  """
+  def overwriting?(path) do
+    if File.exists?(path) do
+      full = Path.expand(path)
+      Mix.shell.yes?(Path.relative_to_cwd(full) <> " already exists, overwrite?")
+    else
+      true
+    end
+  end
+
   defp read_file(path) do
     File.read!(path)
   end
 
-  defp read_httpc(path) do
+  defp copy_file(source, target) do
+    File.mkdir_p!(Path.dirname(target))
+    File.cp!(source, target)
+  end
+
+  defp read_httpc(path, target) do
     {:ok, _} = Application.ensure_all_started(:ssl)
     {:ok, _} = Application.ensure_all_started(:inets)
 
@@ -401,11 +453,21 @@ defmodule Mix.Utils do
     if http_proxy,  do: proxy(http_proxy)
     if https_proxy, do: proxy(https_proxy)
 
-    # We are using relaxed: true because some clients is returning a Location
+    if target do
+      File.mkdir_p!(Path.dirname(target))
+      File.rm(target)
+      req_opts = [stream: String.to_char_list(target)]
+    else
+      req_opts = [body_format: :binary]
+    end
+
+    # We are using relaxed: true because some servers is returning a Location
     # header with relative paths, which does not follow the spec. This would
     # cause the request to fail with {:error, :no_scheme} unless :relaxed
     # is given.
-    case :httpc.request(:get, request, [relaxed: true], [body_format: :binary], :mix) do
+    case :httpc.request(:get, request, [relaxed: true], req_opts, :mix) do
+      {:ok, :saved_to_file} ->
+        :ok
       {:ok, {{_, status, _}, _, body}} when status in 200..299 ->
         body
       {:ok, {{_, status, _}, _, _}} ->
@@ -418,9 +480,12 @@ defmodule Mix.Utils do
   end
 
   defp proxy(proxy) do
-    uri = URI.parse(proxy)
-    :ok = :httpc.set_options([{proxy_scheme(uri.scheme),
-            {{String.to_char_list(uri.host), uri.port}, []}}], :mix)
+    uri  = URI.parse(proxy)
+
+    if uri.host && uri.port do
+      host = String.to_char_list(uri.host)
+      :httpc.set_options([{proxy_scheme(uri.scheme), {{host, uri.port}, []}}], :hex)
+    end
   end
 
   defp proxy_scheme(scheme) do
@@ -430,34 +495,44 @@ defmodule Mix.Utils do
     end
   end
 
-  defp read_shell(path) do
+  defp read_shell(path, target) do
     filename = URI.parse(path).path |> Path.basename
-    out_path = Path.join(System.tmp_dir!, filename)
+    out_path = target || Path.join(System.tmp_dir!, filename)
+
+    File.mkdir_p!(Path.dirname(out_path))
     File.rm(out_path)
 
     status = cond do
-      System.find_executable("wget") ->
-        Mix.shell.cmd(~s(wget -nv -O "#{out_path}" "#{path}"))
-      System.find_executable("curl") ->
-        Mix.shell.cmd(~s(curl -s -S -L -o "#{out_path}" "#{path}"))
       windows? && System.find_executable("powershell") ->
         command = ~s[$ErrorActionPreference = 'Stop'; ] <>
                   ~s[$client = new-object System.Net.WebClient; ] <>
                   ~s[$client.DownloadFile(\\"#{path}\\", \\"#{out_path}\\")]
         Mix.shell.cmd(~s[powershell -Command "& {#{command}}"])
+      System.find_executable("wget") ->
+        Mix.shell.cmd(~s(wget -nv -O "#{out_path}" "#{path}"))
+      System.find_executable("curl") ->
+        Mix.shell.cmd(~s(curl -s -S -L -o "#{out_path}" "#{path}"))
+      windows? ->
+        Mix.shell.error "powershell, wget or curl not installed"
       true ->
         Mix.shell.error "wget or curl not installed"
         1
     end
 
-    check_command!(status, path, out_path)
+    check_command!(status, path, target)
 
-    data = File.read!(out_path)
-    File.rm!(out_path)
-    data
+    unless target do
+      data = File.read!(out_path)
+      File.rm!(out_path)
+      data
+    end
   end
 
   defp check_command!(0, _path, _out_path), do: :ok
+  defp check_command!(_status, path, nil) do
+    Mix.raise "Could not fetch data, please download manually from " <>
+              "#{inspect path}"
+  end
   defp check_command!(_status, path, out_path) do
     Mix.raise "Could not fetch data, please download manually from " <>
               "#{inspect path} and copy it to #{inspect out_path}"

lib/mix/test/fixtures/configs/nested.exs

@@ -0,0 +1,2 @@
+use Mix.Config
+config :app, Repo, key: [nested: true]

lib/mix/test/mix/config_test.exs

@@ -13,7 +13,7 @@ defmodule Mix.ConfigTest do
     assert var!(config, Mix.Config) == [lager: [key: :value]]
 
     config :lager, other: :value
-    assert var!(config, Mix.Config) == [lager: [other: :value, key: :value]]
+    assert var!(config, Mix.Config) == [lager: [key: :value, other: :value]]
 
     config :lager, key: :other
     assert var!(config, Mix.Config) == [lager: [key: :other, other: :value]]
@@ -26,10 +26,19 @@ defmodule Mix.ConfigTest do
     assert var!(config, Mix.Config) == [app: [{Repo, key: :value}]]
 
     config :app, Repo, other: :value
-    assert var!(config, Mix.Config) == [app: [{Repo, other: :value, key: :value}]]
+    assert var!(config, Mix.Config) == [app: [{Repo, key: :value, other: :value}]]
 
     config :app, Repo, key: :other
-    assert var!(config, Mix.Config) == [app: [{Repo, [key: :other, other: :value]}]]
+    assert var!(config, Mix.Config) == [app: [{Repo, key: :other, other: :value}]]
+
+    config :app, Repo, key: [nested: false]
+    assert var!(config, Mix.Config) == [app: [{Repo, key: [nested: false], other: :value}]]
+
+    config :app, Repo, key: [nested: true]
+    assert var!(config, Mix.Config) == [app: [{Repo, key: [nested: true], other: :value}]]
+
+    config :app, Repo, key: :other
+    assert var!(config, Mix.Config) == [app: [{Repo, key: :other, other: :value}]]
   end
 
   test "import_config/1" do
@@ -44,6 +53,14 @@ defmodule Mix.ConfigTest do
     assert var!(config, Mix.Config) == [my_app: [key: :value]]
   end
 
+  test "import_config/1 with nested" do
+    use Mix.Config
+    config :app, Repo, key: [nested: false, other: true]
+
+    import_config fixture_path("configs/nested.exs")
+    assert var!(config, Mix.Config) == [app: [{Repo, key: [nested: true, other: true]}]]
+  end
+
   test "import_config/1 with bad path" do
     use Mix.Config
 

lib/mix/test/mix/tasks/archive_test.exs

@@ -24,6 +24,7 @@ defmodule Mix.Tasks.ArchiveTest do
       # Install it!
       Mix.Tasks.Archive.Build.run ["--no-elixir-version-check"]
       assert File.regular? "archive-0.1.0.ez"
+      assert_received {:mix_shell, :info, ["Generated archive archive-0.1.0.ez with MIX_ENV=dev"]}
 
       send self, {:mix_shell_input, :yes?, true}
       Mix.Tasks.Archive.Install.run []
@@ -54,6 +55,7 @@ defmodule Mix.Tasks.ArchiveTest do
       Mix.Project.push(ArchiveProject2)
       Mix.Tasks.Archive.Build.run ["--no_compile"]
       assert File.regular? "archive-0.2.0.ez"
+      assert_received {:mix_shell, :info, ["Generated archive archive-0.2.0.ez with MIX_ENV=dev"]}
 
       send self, {:mix_shell_input, :yes?, true}
       Mix.Tasks.Archive.Install.run []

lib/mix/test/mix/tasks/compile.elixir_test.exs

@@ -55,14 +55,18 @@ defmodule Mix.Tasks.Compile.ElixirTest do
     end
   end
 
-  test "removes old artifact files" do
+  test "removes, purges and deletes old artifacts" do
     in_fixture "no_mixfile", fn ->
       assert Mix.Tasks.Compile.Elixir.run([]) == :ok
       assert File.regular?("_build/dev/lib/sample/ebin/Elixir.A.beam")
+      assert Code.ensure_loaded?(A)
 
       File.rm!("lib/a.ex")
       assert Mix.Tasks.Compile.Elixir.run([]) == :ok
       refute File.regular?("_build/dev/lib/sample/ebin/Elixir.A.beam")
+      refute Code.ensure_loaded?(A)
+      refute String.contains?(File.read!("_build/dev/lib/sample/.compile.elixir"),
+                              "Elixir.A.beam")
     end
   end
 
@@ -169,7 +173,7 @@ defmodule Mix.Tasks.Compile.ElixirTest do
 
   defmodule SourcePathsProject do
     def project do
-      [app: :source_paths, elixirc_paths: ["unknown"]]
+      [app: :source_paths, elixirc_paths: ["web", "lib"]]
     end
   end
 
@@ -178,11 +182,18 @@ defmodule Mix.Tasks.Compile.ElixirTest do
 
     in_fixture "no_mixfile", fn ->
       # Nothing to compile with the custom source paths
-      assert Mix.Tasks.Compile.Elixir.run([])
+      assert Mix.Tasks.Compile.Elixir.run(["--elixirc-paths", "web"])
       refute_received {:mix_shell, :info, ["Compiled lib/a.ex"]}
 
       assert Mix.Tasks.Compile.Elixir.run(["--elixirc-paths", "lib"])
       assert_received {:mix_shell, :info, ["Compiled lib/a.ex"]}
+
+      # Compiling just web does not remove lib artifacts
+      assert Mix.Tasks.Compile.Elixir.run(["--elixirc-paths", "web"])
+      refute_received {:mix_shell, :info, ["Compiled lib/a.ex"]}
+
+      assert Mix.Tasks.Compile.Elixir.run(["--elixirc-paths", "lib"])
+      refute_received {:mix_shell, :info, ["Compiled lib/a.ex"]}
     end
   end
 end

lib/mix/test/test_helper.exs

@@ -58,8 +58,8 @@ defmodule MixTest.Case do
 
   def purge(modules) do
     Enum.each modules, fn(m) ->
-      :code.delete(m)
       :code.purge(m)
+      :code.delete(m)
     end
   end
 

src/elixir.app.src

@@ -1,6 +1,6 @@
 {application, elixir,
 [{description, "elixir"},
- {vsn, "1.0.0"},
+ {vsn, "1.0.1"},
  {modules, [
 	elixir
   ]},