Fix gyptest-sdkroot when oldest SDK is >= 10.8

test/mac/gyptest-sdkroot.py

 #!/usr/bin/env python
 
 # Copyright (c) 2012 Google Inc. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """
 Verifies that setting SDKROOT works.
 """
 
 import TestGyp
 
 import os
 import subprocess
 import sys
 
 if sys.platform == 'darwin':
   test = TestGyp.TestGyp(formats=['ninja', 'make', 'xcode'])
 
+  def GetSDKPath(sdk):
+    """Return SDKROOT if the SDK version |sdk| is installed or empty string."""
+    DEVNULL = open(os.devnull, 'wb')
+    try:
+      proc = subprocess.Popen(
+          ['xcodebuild', '-version', '-sdk', 'macosx' + sdk, 'Path'],
+          stdout=subprocess.PIPE, stderr=DEVNULL)
+      return proc.communicate()[0].rstrip('\n')
+    finally:
+      DEVNULL.close()
+
+  def SelectSDK():
+    """Select the oldest SDK installed (greater than 10.6)."""
+    for sdk in ['10.6', '10.7', '10.8', '10.9']:
+      path = GetSDKPath(sdk)
+      if path:
+        return True, sdk, path
+    return False, '', ''
+
   # Make sure this works on the bots, which only have the 10.6 sdk, and on
-  # dev machines, which usually don't have the 10.6 sdk.
-  sdk = '10.6'
-  DEVNULL = open(os.devnull, 'wb')
-  proc = subprocess.Popen(['xcodebuild', '-version', '-sdk', 'macosx' + sdk],
-                          stdout=DEVNULL, stderr=DEVNULL)
-  proc.communicate()
-  DEVNULL.close()
-  if proc.returncode:
-    sdk = '10.7'
-
-  proc = subprocess.Popen(['xcodebuild', '-version',
-                           '-sdk', 'macosx' + sdk, 'Path'],
-                          stdout=subprocess.PIPE)
-  sdk_path = proc.communicate()[0].rstrip('\n')
-  if proc.returncode != 0:
+  # dev machines which usually don't have the 10.6 sdk.
+  sdk_found, sdk, sdk_path = SelectSDK()
+  if not sdk_found:
     test.fail_test()
 
   test.write('sdkroot/test.gyp', test.read('sdkroot/test.gyp') % sdk)
 
   test.run_gyp('test.gyp', '-D', 'sdk_path=%s' % sdk_path,
                chdir='sdkroot')
   test.build('test.gyp', test.ALL, chdir='sdkroot')
   test.pass_test()