fix armv7 non-neon webrtc builds

webrtc/common_audio/common_audio.gyp

 # Copyright (c) 2011 The WebRTC project authors. All Rights Reserved.
 #
 # Use of this source code is governed by a BSD-style license
 # that can be found in the LICENSE file in the root of the source
 # tree. An additional intellectual property rights grant can be found
 # in the file PATENTS.  All contributing project authors may
 # be found in the AUTHORS file in the root of the source tree.
 
 {
   'includes': [
@@ skipping 128 matching lines @@
         ['target_arch=="arm"', {
           'sources': [
             'signal_processing/complex_bit_reverse_arm.S',
             'signal_processing/spl_sqrt_floor_arm.S',
           ],
           'sources!': [
             'signal_processing/complex_bit_reverse.c',
             'signal_processing/spl_sqrt_floor.c',
           ],
           'conditions': [
-            ['arm_version>=7', {
+            ['(arm_version>=7 and (arm_neon==1 or arm_neon_optional==1)) or target_arch=="arm64"', {

[Andrew MacDonald, 2015/06/17 03:29:23]

This is inside a target_arch=="arm" block so is certainly not right.

[Andrew MacDonald, 2015/06/17 05:36:32]

I think this should just be 'arm_neon==1 or arm_neon_optional == 1', but we
should update the other places we have neon targets as well.

We should probably add a build_arm_neon flag in common.gypi to consolidate this.

[Mostyn Bramley-Moore, 2015/06/17 07:42:26]

I tried this earlier, but got lost in the nested gyp scopes when trying to set
arm_neon to 1 whenever target_arch=="arm64".
Sounds good to me- I will experiment some more.

[Mostyn Bramley-Moore, 2015/06/17 07:42:26]

I don't think it's incorrect, but this is definitely not a good/final solution.

[zhongwei, 2015/06/17 11:44:50]

target_arch=="arm64" is not needed here.  arm64 is handled at line 160.

[jridges, 2015/06/17 15:56:49]

There is the same problem here with ARMv7 being confused with NEON. The
"filter_ar_fast_q12" module has nothing to do with NEON.

               'dependencies': ['common_audio_neon',],
               'sources': [
                 'signal_processing/filter_ar_fast_q12_armv7.S',
               ],
               'sources!': [
                 'signal_processing/filter_ar_fast_q12.c',
               ],
             }],
           ],  # conditions
         }],
@@ skipping 45 matching lines @@
             ['os_posix==1', {
               'cflags': [ '-msse2', ],
               'xcode_settings': {
                 'OTHER_CFLAGS': [ '-msse2', ],
               },
             }],
           ],
         },
       ],  # targets
     }],
-    ['target_arch=="arm" and arm_version>=7 or target_arch=="arm64"', {
+    ['(target_arch=="arm" and arm_version>=7 and (arm_neon==1 or arm_neon_optional==1)) or target_arch=="arm64"', {

[jridges, 2015/06/17 15:56:49]

Is there a definitive answer as to when the arm_neon and arm_neon_optional
variables get set? This seems like overkill to have to include the architecture
here as well.

       'targets': [
         {
           'target_name': 'common_audio_neon',
           'type': 'static_library',
           'includes': ['../build/arm_neon.gypi',],
           'sources': [
             'fir_filter_neon.cc',
             'resampler/sinc_resampler_neon.cc',
             'signal_processing/cross_correlation_neon.c',
             'signal_processing/downsample_fast_neon.c',
@@ skipping 88 matching lines @@
               'sources': [
                 'common_audio_unittests.isolate',
               ],
             },
           ],
         }],
       ],
     }],
   ],  # conditions
 }