Merge pull request #2513 from ericmj/mix-mtimes

Warn and reset mime on future files

Author: ericmj

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

@@ -26,7 +26,8 @@ defmodule Mix.Compilers.Elixir do
         # changed, let's just compile everything
         all
       else
-        modified = Mix.Utils.last_modified(manifest)
+        modified   = Mix.Utils.last_modified(manifest)
+        all_mtimes = mtimes(all_entries)
 
         # Otherwise let's start with the new ones
         # plus the ones that have changed
@@ -35,7 +36,8 @@ defmodule Mix.Compilers.Elixir do
             do: source)
           ++
         for({_b, _m, source, _d, files} <- all_entries,
-            Mix.Utils.stale?([source|files], [modified]),
+            times = Enum.map([source|files], &HashDict.fetch!(all_mtimes, &1)),
+            Mix.Utils.stale?(times, [modified]),
             do: source)
       end
 
@@ -53,6 +55,18 @@ defmodule Mix.Compilers.Elixir do
     end
   end
 
+  defp mtimes(entries) do
+    Enum.reduce(entries, HashDict.new, fn {_b, _m, source, _d, files}, dict ->
+      Enum.reduce([source|files], dict, fn file, dict ->
+        if HashDict.has_key?(dict, file) do
+          dict
+        else
+          HashDict.put(dict, file, Mix.Utils.last_modified(file))
+        end
+      end)
+    end)
+  end
+
   @doc """
   Removes compiled files.
   """

lib/mix/lib/mix/utils.ex

@@ -99,9 +99,17 @@ defmodule Mix.Utils do
   end
 
   def last_modified(path) do
+    now = :calendar.local_time
+
     case File.stat(path) do
-      {:ok, %File.Stat{mtime: mtime}} -> mtime
-      {:error, _} -> {{1970, 1, 1}, {0, 0, 0}}
+      {:ok, %File.Stat{mtime: mtime}} when mtime > now ->
+        Mix.shell.error("warning: mtime (modified time) for \"#{path}\" was set to the future, resetting to now")
+        File.touch!(path, now)
+        mtime
+      {:ok, %File.Stat{mtime: mtime}} ->
+        mtime
+      {:error, _} ->
+        {{1970, 1, 1}, {0, 0, 0}}
     end
   end
 

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

@@ -79,6 +79,9 @@ defmodule Mix.Tasks.Compile.ElixirTest do
       File.touch!("lib/a.ex", future)
       Mix.Tasks.Compile.Elixir.run []
 
+      assert_received {:mix_shell, :error, ["warning: mtime (modified time) for \"lib/a.ex\" was set to the future, resetting to now"]}
+      refute_received {:mix_shell, :error, ["warning: mtime (modified time) for \"lib/b.ex\" was set to the future, resetting to now"]}
+
       assert_received {:mix_shell, :info, ["Compiled lib/a.ex"]}
       refute_received {:mix_shell, :info, ["Compiled lib/b.ex"]}