Measure the time to boot the CLI

Author: josevalim

lib/mix/lib/mix/cli.ex

@@ -8,7 +8,14 @@ defmodule Mix.CLI do
     Mix.start()
 
     if env_variable_activated?("MIX_QUIET"), do: Mix.shell(Mix.Shell.Quiet)
-    if env_variable_activated?("MIX_DEBUG"), do: Mix.debug(true)
+
+    debug? =
+      if env_variable_activated?("MIX_DEBUG") do
+        Mix.debug(true)
+        true
+      else
+        false
+      end
 
     if profile = System.get_env("MIX_PROFILE") do
       Mix.State.put(:profile, String.split(profile, ","))
@@ -22,6 +29,13 @@ defmodule Mix.CLI do
       :version ->
         display_version()
 
+      nil when debug? ->
+        shell = Mix.shell()
+        shell.info("-> Running mix CLI")
+        {time, res} = :timer.tc(&proceed/1, [args])
+        shell.info(["<- Ran mix CLI in ", Integer.to_string(div(time, 1000)), "ms"])
+        res
+
       nil ->
         proceed(args)
     end

lib/mix/lib/mix/task.ex

@@ -523,7 +523,7 @@ defmodule Mix.Task do
       task in Mix.State.get(:profile, []) ->
         shell = Mix.shell()
         shell.info(["-> Profiling mix ", task_to_string(task, args), project_to_string(proj)])
-        Mix.Tasks.Profile.Eprof.profile(fun, warmup: false, set_on_spawn: false)
+        Mix.Tasks.Profile.Tprof.profile(fun, warmup: false, set_on_spawn: false)
 
       true ->
         fun.()