Make cr build run goma_ctl.py ensure_start before building.

tools/cr/cr/actions/ninja.py

 # Copyright 2013 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """A module to add ninja support to cr."""
 
 import os
 
 import cr
 
@@ skipping 12 matching lines @@
       GOMA_DIR=os.path.join('{GOOGLE_CODE}', 'goma'),
   )
   # A placeholder for the system detected configuration
   DETECTED = cr.Config('DETECTED')
 
   def __init__(self):
     super(NinjaBuilder, self).__init__()
     self._targets = []
 
   def Build(self, context, targets, arguments):
+    # Make sure Goma is started, if Ninja is set to use it.
+    # This may be redundant, but it currently improves reliability.
+    try:

[ian_cottrell, 2014/01/09 17:00:21]

I would change how you build paths.
Use
  NINJA_BUILD_FILE=os.path.join('GOMA_DIR', 'build.ninja'),
  GOMA_CTL=os.path.join('{GOMA_DIR}', 'goma_clt.py'),
  GOMA_CC=os.path.join('{GOMA_DIR}', 'gomacc'),
  NINJA_GOMA_LINE='cc = {GOMA_CC} $',
up in the ENABLED block
also, just try to open the file, and trust the IOError to tell you if the
filename was bad because the variables did not expand, so
  try:
    with open(context.Get('NINJA_BUILD_FILE'), 'r') as f:
      ....
  except IOError:
    pass
and cr.Host.Execute will expand variales for you, so just run 
  '{GOMA_CTL}', 'ensure_start'

[johnme, 2014/01/09 19:06:11]

Done.

+      goma_dir = context.Get('GOMA_DIR', raise_errors=True)
+      build_dir = context.Get('CR_BUILD_DIR', raise_errors=True)
+      build_ninja = os.path.join(build_dir, 'build.ninja')
+      if os.path.exists(build_ninja):
+        goma_cc = 'cc = {} $\n'.format(os.path.join(goma_dir, 'gomacc'))
+        with open(build_ninja, 'r') as f:

[ian_cottrell, 2014/01/09 17:00:21]

This is vile, but I don't have a better suggestion.
I guess it's kind of safe because worst case things underneath change and we
stop detecting goma when we should be, it's never going to try to run goma when
it should not.

+          if f.readline() == goma_cc:
+            # Goma is active, so make sure it's started.
+            cr.Host.ExecuteSilently(
+                context,
+                os.path.join('{GOMA_DIR}', 'goma_ctl.py'),
+                'ensure_start'
+            )
+    except KeyError:
+      pass
+
+
     build_arguments = [target.build_target for target in targets]
     build_arguments.extend(arguments)
     cr.Host.Execute(
         context,
         '{NINJA_BINARY}',
         '-C{CR_BUILD_DIR}',
         '-j{NINJA_JOBS}',
         '-l{NINJA_PROCESSORS}',
         *build_arguments
     )
@@ skipping 34 matching lines @@
     return self._targets
 
   @classmethod
   def DetectNinja(cls):
     # TODO(iancottrell): If we can't detect ninja, we should be disabled.
     ninja_binaries = cr.Host.SearchPath('ninja')
     if ninja_binaries:
       cls.DETECTED.Set(NINJA_BINARY=ninja_binaries[0])
 
 NinjaBuilder.DetectNinja()