Compile BoringSSL for arm64 iOS

third_party/boringssl/boringssl.gyp

 # Copyright 2014 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.
 
 {
   'targets': [
     {
       'target_name': 'boringssl',
       'type': '<(component)',
       'includes': [
         'boringssl.gypi',
       ],
       'sources': [
         '<@(boringssl_lib_sources)',
       ],
       'defines': [
         'BORINGSSL_IMPLEMENTATION',
         'BORINGSSL_NO_STATIC_INITIALIZER',
       ],
       # TODO(davidben): Fix size_t truncations in BoringSSL.
       # https://crbug.com/429039
       'msvs_disabled_warnings': [ 4267, ],
       'conditions': [
         ['component == "shared_library"', {
           'defines': [
             'BORINGSSL_SHARED_LIBRARY',
           ],
         }],
         ['target_arch == "arm"', {

[davidben, 2015/04/06 21:15:02]

Why only arm64? Is iOS only 64-bit? (I'm not familiar with iOS.)

[tkchin, 2015/04/06 21:35:01]

The reason is actually because the various gyp files in third party dependencies
aren't consistent in their use of target_arch. The correct way is likely to use
target_arch="arm" and target_subarch="armv7" or target_subarch="arm64". However,
most projects just use target_arch="armv7" and target_arch="arm64" rules.

In this case when specifying armv7 we'll short circuit to the OPENSSL_NO_ASM
block below.

[davidben, 2015/04/06 21:54:39]

Huh, interesting. Yeah, doing codesearch I see a lot of (target_arch == "arm" or
target_arch == "armv7") rules. Never armv7 on its own though.

Since GN doesn't seem to have that separation, how about switching the
target_arch == "arm" line to check both and then add the same OS=linux/android
condition in the arm block? Is that a correct use of target_arch? (Mostly I want
to avoid it being confusing when glancing at it why only one of the two blocks
checks the OS. And since presumably we'll want to eventually ship the assembly
on iOS too, this seems a reasonable thing to do now. Also nice to keep GN and
GYP in sync.)

           'sources': [ '<@(boringssl_linux_arm_sources)' ],
         }],
         ['target_arch == "arm64"', {
-          'sources': [ '<@(boringssl_linux_aarch64_sources)' ],
+          'conditions': [
+            ['OS == "linux" or OS == "android"', {
+              'sources': [ '<@(boringssl_linux_aarch64_sources)' ],
+            }, {
+              'defines': [ 'OPENSSL_NO_ASM' ],
+            }],
+          ],
         }],
         ['target_arch == "ia32"', {
           'conditions': [
             ['OS == "mac"', {
               'sources': [ '<@(boringssl_mac_x86_sources)' ],
             }],
             ['OS == "linux" or OS == "android"', {
               'sources': [ '<@(boringssl_linux_x86_sources)' ],
             }],
             ['OS == "win"', {
@@ skipping 55 matching lines @@
           ['component == "shared_library"', {
             'defines': [
               'BORINGSSL_SHARED_LIBRARY',
             ],
           }],
         ],
       },
     },
   ],
 }