Update common.gypi to set clang=1 for all iOS builds.

build/common.gypi

 # Copyright (c) 2012 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.
 
 # IMPORTANT:
 # Please don't directly include this file if you are building via gyp_chromium,
 # since gyp_chromium is automatically forcing its inclusion.
 {
   # Variables expected to be overriden on the GYP command line (-D) or by
   # ~/.gyp/include.gypi.
@@ skipping 1081 matching lines @@
     # is some third party code that takes a long time to fix/roll. So, this
     # flag allows us to have warnings as errors in general to prevent
     # regressions in most modules, while working on the bits that are
     # remaining.
     'win_third_party_warn_as_error%': 'true',
 
     # Clang stuff.
     'clang%': '<(clang)',
     'make_clang_dir%': 'third_party/llvm-build/Release+Asserts',
 
-    # Control which version of clang to use when 'clang' is set to 1 when
-    # building for iOS (Apple has not yet open-sourced support for "arm64"
-    # so when building for that 'target_arch' we have to use clang shipped
-    # with Xcode that does not supports some flags).
-    # TODO(sdefresne): remove this once http://crbug.com/341453 is fixed.
+    # Control which version of clang to use when building for iOS.  If set to
+    # '1', uses the version of clang that ships with Xcode.  If set to '0', uses
+    # the version of clang that ships with the Chromium source.  This variable
+    # is automatically set to '1' when using the Xcode generator.
     'clang_xcode%': 0,
 
     # These two variables can be set in GYP_DEFINES while running
     # |gclient runhooks| to let clang run a plugin in every compilation.
     # Only has an effect if 'clang=1' is in GYP_DEFINES as well.
     # Example:
     #     GYP_DEFINES='clang=1 clang_load=/abs/path/to/libPrintFunctionNames.dylib clang_add_plugin=print-fns' gclient runhooks
 
     'clang_load%': '',
     'clang_add_plugin%': '',
@@ skipping 399 matching lines @@
 
         # Copy it out one scope.
         'android_webview_build%': '<(android_webview_build)',
       }],  # OS=="android"
       ['android_webview_build==1', {
         # When building the WebView in the Android tree, jarjar will remap all
         # the class names, so the JNI generator needs to know this.
         'jni_generator_jarjar_file': '../android_webview/build/jarjar-rules.txt',
       }],
       ['OS=="mac"', {
-        # Enable clang on mac by default!
-        'clang%': 1,
         'conditions': [
           # All Chrome builds have breakpad symbols, but only process the
           # symbols from official builds.
           ['(branding=="Chrome" and buildtype=="Official")', {
             'mac_strip_release%': 1,
           }],
         ],
       }],  # OS=="mac"
       ['OS=="mac" or OS=="ios"', {
+        # Enable clang on mac by default!  All iOS builds already use clang.

[Nico, 2014/03/13 15:43:38]

nit: This comment can probably go away. It was (maybe) useful when clang being
on by default was noteworthy, but that was long ago.

+        'clang%': 1,
+
         'variables': {
           # Mac OS X SDK and deployment target support.  The SDK identifies
           # the version of the system headers that will be used, and
           # corresponds to the MAC_OS_X_VERSION_MAX_ALLOWED compile-time
           # macro.  "Maximum allowed" refers to the operating system version
           # whose APIs are available in the headers.  The deployment target
           # identifies the minimum system version that the built products are
           # expected to function on.  It corresponds to the
           # MAC_OS_X_VERSION_MIN_REQUIRED compile-time macro.  To ensure these
           # macros are available, #include <AvailabilityMacros.h>.  Additional
@@ skipping 198 matching lines @@
       ['OS=="mac" or OS=="ios"', {
         'grit_defines': ['-D', 'scale_factors=2x'],
       }],
       ['OS == "ios"', {
         'grit_defines': [
           '-t', 'ios',
           # iOS uses a whitelist to filter resources.
           '-w', '<(DEPTH)/build/ios/grit_whitelist.txt'
         ],
 
-        # Enable clang and host builds when generating with ninja-ios.
+        # Enable host builds when generating with ninja-ios.
         'conditions': [
           ['"<(GENERATOR)"=="ninja"', {
-            'clang%': 1,
             'host_os%': "mac",
           }],
-          # Apple has not upstreamed the support for "arm64" yet, so when
-          # building for "arm64" or "both", we need to use the clang that
-          # is provided with Xcode.
-          ['target_subarch!="arm32"', {
+
+          # TODO(sdefresne): Remove the target_subarch check once Apple has
+          # upstreamed the support for "arm64". http://crbug.com/341453
+          ['target_subarch!="arm32" or "<(GENERATOR)"=="xcode"', {
             'clang_xcode%': 1,
           }],
         ],
       }],
       ['enable_extensions==1', {
         'grit_defines': ['-D', 'enable_extensions'],
       }],
       ['enable_plugins!=0', {
         'grit_defines': ['-D', 'enable_plugins'],
       }],
@@ skipping 2354 matching lines @@
                 # which we no longer use. Check if it makes sense to remove
                 # this as well. http://crbug.com/316352
                 '-Wno-unneeded-internal-declaration',
 
                 # Warns on switches on enums that cover all enum values but
                 # also contain a default: branch. Chrome is full of that.
                 '-Wno-covered-switch-default',
 
                 # Warns when a const char[] is converted to bool.
                 '-Wstring-conversion',
+
+                # Clang considers the `register` keyword as deprecated, but
+                # e.g. code generated by flex (used in angle) contains that
+                # keyword. http://crbug.com/255186
+                '-Wno-deprecated-register',
               ],
 
               'conditions': [
                 ['clang_xcode==0', {
                   'CC': '$(SOURCE_ROOT)/<(clang_dir)/clang',
                   'LDPLUSPLUS': '$(SOURCE_ROOT)/<(clang_dir)/clang++',
-
-                  'WARNING_CFLAGS': [
-                    # Clang considers the `register` keyword as deprecated, but
-                    # e.g. code generated by flex (used in angle) contains that
-                    # keyword. http://crbug.com/255186
-                    #
-                    # Note: clang as shipped with Xcode is older and does not
-                    # treat the `register` as deprecated and does not define
-                    # this flag, so don't enable it if "clang_xcode" is "1".
-                    '-Wno-deprecated-register',
-                  ],
                 }],
               ],
             }],
             ['clang==1 and clang_xcode==0 and clang_use_chrome_plugins==1', {
               'OTHER_CFLAGS': [
                 '<@(clang_chrome_plugins_flags)',
               ],
             }],
             ['clang==1 and clang_xcode==0 and clang_load!=""', {
               'OTHER_CFLAGS': [
@@ skipping 253 matching lines @@
               }],  # mac_real_dsym
             ],  # target_conditions
           }],  # (_type=="executable" or _type=="shared_library" or
                #  _type=="loadable_module") and mac_strip!=0
         ],  # target_conditions
       },  # target_defaults
     }],  # OS=="mac"
     ['OS=="ios"', {
       'target_defaults': {
         'xcode_settings' : {
-          'GCC_VERSION': 'com.apple.compilers.llvm.clang.1_0',
-
-          # This next block is mostly common with the 'mac' section above,
-          # but keying off (or setting) 'clang' isn't valid for iOS as it
-          # also means using Chromium's build of clang.
-
           # TODO(stuartmorgan): switch to c++0x (see TODOs in the clang
           # section above).
           'CLANG_CXX_LANGUAGE_STANDARD': 'gnu++0x',
-          # Warn if automatic synthesis is triggered with
-          # the -Wobjc-missing-property-synthesis flag.
-          'CLANG_WARN_OBJC_MISSING_PROPERTY_SYNTHESIS': 'YES',
-          'WARNING_CFLAGS': [
-            '-Wheader-hygiene',
-            # Don't die on dtoa code that uses a char as an array index.
-            # This is required solely for base/third_party/dmg_fp/dtoa.cc.
-            '-Wno-char-subscripts',
-            # See comment in the mac clang section above for this flag.
-            '-Wno-unneeded-internal-declaration',
-            # Match OS X clang C++11 warning settings.
-            '-Wno-c++11-narrowing',
-            # As of Xcode 5.1, the register keyword is deprecated, but Chromium
-            # code still uses it.
-            '-Wno-deprecated-register',
-          ],
 
           'conditions': [
             # Older Xcodes do not support -Wno-deprecated-register, so pass an
             # additional flag to suppress the "unknown compiler option" error.
             # Restrict this flag to builds that are either compiling with Xcode
             # or compiling with Xcode's Clang.  This will allow Ninja builds to
             # continue failing on unknown compiler options.
             # TODO(rohitrao): This flag is temporary and should be removed as
             # soon as the iOS bots are updated to use Xcode 5.1.
-            ['"<(GENERATOR)"=="xcode" or clang_xcode==1', {
+            ['clang_xcode==1', {
               'WARNING_CFLAGS': [
                 '-Wno-unknown-warning-option',
               ],
             }],
 
             # Limit the valid architectures depending on "target_subarch".
             # This need to include the "arm" architectures but also the "x86"
             # ones (they are used when building for the simulator).
             ['target_subarch=="arm32"', {
               'VALID_ARCHS': ['armv7', 'i386'],
@@ skipping 578 matching lines @@
     # settings in target dicts.  SYMROOT is a special case, because many other
     # Xcode variables depend on it, including variables such as
     # PROJECT_DERIVED_FILE_DIR.  When a source group corresponding to something
     # like PROJECT_DERIVED_FILE_DIR is added to a project, in order for the
     # files to appear (when present) in the UI as actual files and not red
     # red "missing file" proxies, the correct path to PROJECT_DERIVED_FILE_DIR,
     # and therefore SYMROOT, needs to be set at the project level.
     'SYMROOT': '<(DEPTH)/xcodebuild',
   },
 }