setup the correct version of Xcode

scripts/slave/recipes/flutter/flutter.py

Index: scripts/slave/recipes/flutter/flutter.py
diff --git a/scripts/slave/recipes/flutter/flutter.py b/scripts/slave/recipes/flutter/flutter.py
index ca3dfb9c2aa110fee57c1e71aa8fce918a667be5..4cbfad54486ea783b7cf27c2883df82612cc4597 100644
--- a/scripts/slave/recipes/flutter/flutter.py
+++ b/scripts/slave/recipes/flutter/flutter.py
@@ -8,6 +8,7 @@ DEPS = [
   'depot_tools/git',
   'file',
   'gsutil',
+  'recipe_engine/json',
   'recipe_engine/path',
   'recipe_engine/platform',
   'recipe_engine/properties',
@@ -127,6 +128,63 @@ def BuildExamples(api, git_hash):
   ArchiveAPK(api, 'examples/material_gallery', 'Gallery.apk')
 
 
+def RunFindXcode(target_version=None):
+  """Runs the `build/scripts/slave/ios/find_xcode.py` utility to retrieve
+     information about xcode installations and to activate a specific version
+     of Xcode.
+  """
+  import json
+  import os
+  import string
+  import subprocess
+  import sys
+  import tempfile

[iannucci, 2016/03/04 17:58:05]

Whoops. This not lgtm for sure. This will break the recipes system entirely :).

+
+  scripts_dir = os.path.dirname(os.path.dirname(os.path.dirname(
+    os.path.dirname(os.path.abspath(__file__)))))
+
+  find_xcode_py_path = os.path.join(
+    scripts_dir,

[eseidel1, 2016/03/04 04:25:05]

I think this is api.path['build'].join('scripts'), but I'd have to look at other
recipes to be sure.

[yjbanov, 2016/03/04 17:45:50]

I tried that, but for some reason api.path['build'].join('foo') takes me to
'build/scripts/build/foo', and if I do api.path['foo'] it says it doesn't know
what 'foo' is.

[iannucci, 2016/03/04 17:58:05]

This should be rewritten to use the recipe apis to invoke this script.
api.path['build'] should be what you want... if it's not then there's a bug in
the recipe engine (but I think a lot of things would break in that case).

+    'slave/ios/find_xcode.py'
+  )
+
+  json_file = tempfile.mkstemp(prefix='xcode-info')[1]
+
+  args = [
+    find_xcode_py_path,
+    '--json-file', json_file,
+  ]
+
+  if target_version is not None:
+    args.extend(['--version', '7.2.1'])
+
+  find_proc = subprocess.Popen(args, stdout=subprocess.PIPE,
+    stderr=subprocess.PIPE, cwd=scripts_dir, env={'PYTHONPATH': scripts_dir})
+
+  (stdout, stderr) = find_proc.communicate()
+  if find_proc.returncode != 0:
+    raise Exception(find_proc.returncode, stdout, stderr)
+
+  with open(json_file, 'r') as xcode_info_reader:
+    return json.loads(xcode_info_reader.read())
+
+
+def SetupXcode(api):
+  if api.platform.is_mac:
+    xcode_json = RunFindXcode()
+    installations = xcode_json["installations"]
+    activate_version = None
+    for key in installations:
+      version = installations[key].split()[0]
+      if version.startswith('7.'):
+        activate_version = version
+        break
+    if activate_version is None:
+      raise Exception('Xcode version 7 or above not found')
+    print 'Activating Xcode version %s' % version
+    RunFindXcode(target_version=activate_version)
+
+
 def RunSteps(api):
   # buildbot sets 'clobber' to the empty string which is falsey, check with 'in'
   if 'clobber' in api.properties:
@@ -156,6 +214,8 @@ def RunSteps(api):
 
   # The context adds dart-sdk tools to PATH sets PUB_CACHE.
   with api.step.context({'env': env}):
+    SetupXcode(api)

[eseidel1, 2016/03/04 04:25:06]

Do you need to take the results of finding XCode to set the DEVELOPER_DIR env
variable for xcrun?

[yjbanov, 2016/03/04 17:45:50]

The `find_xcode.py` utility uses `xcode-select` to switch xcrun to the correct
version. We shouldn't need extra env variables.

+
     # Must be first to download dependencies for later steps.
     api.step('flutter doctor', ['flutter', 'doctor'])
     api.step('update packages', ['flutter', 'update-packages'])