Fix default ARCHS value for iOS project.

pylib/gyp/xcode_emulation.py

 # 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.
 
 """
 This module contains classes that help to emulate xcodebuild behavior on top of
 other build systems, such as make and ninja.
 """
 
 import copy
@@ skipping 892 matching lines @@
       XcodeSettings._plist_cache[configname] = cache
 
     # Include extra plist items that are per-target, not per global
     # XcodeSettings.
     items = dict(XcodeSettings._plist_cache[configname])
     if self.isIOS:
       items['UIDeviceFamily'] = self._XcodeIOSDeviceFamily(configname)
     return items
 
   def _DefaultArch(self):
-    # The default value for ARCHS changed from ['i386'] to ['x86_64'] in
-    # Xcode 5.
+    # For Mac projects, Xcode changed the default value used when ARCHS is not
+    # set from "i386" to "x86_64".
+    #
+    # For iOS projects, if ARCHS is unset, it defaults to "armv7 armv7s" when
+    # building for a device, and the simulator binaries are always build for
+    # "i386".
+    #
+    # For new projects, ARCHS is set to $(ARCHS_STANDARD_INCLUDING_64_BIT),
+    # which correspond to "armv7 armv7s arm64", and when building the simulator
+    # the architecture is either "i386" or "x86_64" depending on the simulated
+    # device (respectively 32-bit or 64-bit device).
+    #
+    # Since the value returned by this function is only used when ARCHS is not
+    # set, then on iOS we return "i386", as the default xcode project generator
+    # does not set ARCHS if it is not set in the .gyp file.
+    if self.isIOS:
+      return 'i386'
     version, build = self._XcodeVersion()
     if version >= '0500':
       return 'x86_64'
     return 'i386'
 
 class MacPrefixHeader(object):
   """A class that helps with emulating Xcode's GCC_PREFIX_HEADER feature.
 
   This feature consists of several pieces:
   * If GCC_PREFIX_HEADER is present, all compilations in that project get an
@@ skipping 398 matching lines @@
         new_config_dict['xcode_settings']['SDKROOT'] = 'iphoneos'
       target_dict['configurations'][new_config_name] = new_config_dict
   return targets
 
 def CloneConfigurationForDeviceAndEmulator(target_dicts):
   """If |target_dicts| contains any iOS targets, automatically create -iphoneos
   targets for iOS device builds."""
   if _HasIOSTarget(target_dicts):
     return _AddIOSDeviceConfigurations(target_dicts)
   return target_dicts