Introduce arm_version to allow building for armv5, v6 or v7.

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 193 matching lines @@
 
       # Disable file manager component extension by default.
       'file_manager_extension%': 0,
 
       # Disable image loader component extension by default.
       'image_loader_extension%': 0,
 
       # Python version.
       'python_ver%': '2.6',
 
-      # Set ARM-v7 compilation flags
-      'armv7%': 0,
+      # Set ARM architecture version.
+      'arm_version%': 7,

[Torne, 2013/04/11 13:04:22]

This changes the default; is this intentional?

[Fredrik Öhrn, 2013/04/11 13:42:19]

Maybe I misunderstood your comments on the previous version of the diff. I
thought you guys wanted the gyp defaults to be changed to match what was
previously configured in envsetup.

I can restore the armv5 defaults and set arm_version to 7 in an OS==android
condition if you prefer.

[Torne, 2013/04/11 13:55:00]

That envsetup.sh script is specifically for Android builds; what you've changed
is the global default for Chromium. I don't know what other users of Chromium on
ARM may want the defaults to be, so leaving it alone seems preferable.
I'm not sure that the default is intended to be armv5, either; the Android
config uses that when armv7 isn't set, but that's not true of linux/chromeos as
far as I can see..

[Fredrik Öhrn, 2013/04/11 15:18:46]

Well, I could perhaps add an arm_version 0 default that sets no compiler flags,
that would leave the defaults more or less unchanged for other products.

 
-      # Set Neon compilation flags (only meaningful if armv7==1).
-      'arm_neon%': 1,
+      # Set Neon compilation flags.
+      'arm_neon%': 0,

[Torne, 2013/04/11 13:04:22]

Same here.

[Fredrik Öhrn, 2013/04/11 15:18:46]

I have to keep arm_neon disabled when changing the arm_version default back to
<= 5 or it won't build.

This is because third_party/libvpx/libvpx.gyp uses arm_neon without testing that
it's also a v7 build.

[Fredrik Öhrn, 2013/04/11 15:37:13]

Turns out libvpx throws some handcrafted armv6 assembler into the mix as well,
so building armv5 isn't currently possible.

I'm guessing none of your projects are building anything less than armv7 or
these two problems would have been noticed.

Perhaps bumping the defaults to armv7 isn't such a bad idea?

 
       # The system root for cross-compiles. Default: none.
       'sysroot%': '',
 
       # The system libdir used for this ABI.
       'system_libdir%': 'lib',
 
       # On Linux, we build with sse2 for Chromium builds.
       'disable_sse2%': 0,
 
@@ skipping 374 matching lines @@
 
         # Enable Settings App only on Windows.
         ['enable_app_list==1 and OS=="win"', {
           'enable_settings_app%': 1,
         }, {
           'enable_settings_app%': 0,
         }],
 
         ['OS=="linux" and target_arch=="arm" and chromeos==0', {
           # Set some defaults for arm/linux chrome builds
-          'armv7%': 1,
+          'arm_version%': 7,

[Torne, 2013/04/11 13:04:22]

This is setting it to the same value as above; if the change of default is
intentional then this is unnecessary.

           'linux_breakpad%': 0,
           'linux_use_tcmalloc%': 0,
           # sysroot needs to be an absolute path otherwise it generates
           # incorrect results when passed to pkg-config
           'sysroot%': '<!(cd <(DEPTH) && pwd -P)/arm-sysroot',
         }], # OS=="linux" and target_arch=="arm" and chromeos==0
 
         ['target_arch=="mipsel"', {
           'sysroot%': '<!(cd <(DEPTH) && pwd -P)/mipsel-sysroot/sysroot',
           'CXX%': '<!(cd <(DEPTH) && pwd -P)/mipsel-sysroot/bin/mipsel-linux-gnu-gcc',
@@ skipping 78 matching lines @@
     'enable_viewport%': '<(enable_viewport)',
     'enable_hidpi%': '<(enable_hidpi)',
     'enable_touch_ui%': '<(enable_touch_ui)',
     'use_xi2_mt%':'<(use_xi2_mt)',
     'file_manager_extension%': '<(file_manager_extension)',
     'image_loader_extension%': '<(image_loader_extension)',
     'inside_chromium_build%': '<(inside_chromium_build)',
     'fastbuild%': '<(fastbuild)',
     'dcheck_always_on%': '<(dcheck_always_on)',
     'python_ver%': '<(python_ver)',
-    'armv7%': '<(armv7)',
+    'arm_version%': '<(arm_version)',
     'arm_neon%': '<(arm_neon)',
     'sysroot%': '<(sysroot)',
     'system_libdir%': '<(system_libdir)',
     'component%': '<(component)',
     'use_titlecase_in_grd_files%': '<(use_titlecase_in_grd_files)',
     'use_third_party_translations%': '<(use_third_party_translations)',
     'remoting%': '<(remoting)',
     'enable_one_click_signin%': '<(enable_one_click_signin)',
     'enable_webrtc%': '<(enable_webrtc)',
     'chromium_win_pch%': '<(chromium_win_pch)',
@@ skipping 196 matching lines @@
 
     # Disable shadow stack keeping used by heapcheck to unwind the stacks
     # better.
     'linux_keep_shadow_stacks%': 0,
 
     # Set to 1 to link against libgnome-keyring instead of using dlopen().
     'linux_link_gnome_keyring%': 0,
     # Set to 1 to link against gsettings APIs instead of using dlopen().
     'linux_link_gsettings%': 0,
 
-    # Set Thumb compilation flags.
-    'arm_thumb%': 0,
-
-    # Set ARM fpu compilation flags (only meaningful if armv7==1 and
-    # arm_neon==0).
-    'arm_fpu%': 'vfpv3',
-
-    # Set ARM float abi compilation flag.
-    'arm_float_abi%': 'softfp',
-
     # Enable use of OpenMAX DL FFT routines.
     'use_openmax_dl_fft%': '<(use_openmax_dl_fft)',
     
     # Enable new NPDevice API.
     'enable_new_npdevice_api%': 0,
 
     # Enable EGLImage support in OpenMAX
     'enable_eglimage%': 1,
 
     # Enable a variable used elsewhere throughout the GYP files to determine
@@ skipping 80 matching lines @@
     # Temporarily set android_build_type until all uses of it have been renamed.
     # http://crbug.com/184431
     'android_build_type%': '<(android_webview_build)',
 
     'sas_dll_exists': '<!(python <(DEPTH)/build/dir_exists.py <(sas_dll_path))',
     'wix_exists': '<!(python <(DEPTH)/build/dir_exists.py <(wix_path))',
 
     'windows_sdk_default_path': '<(DEPTH)/third_party/platformsdk_win8/files',
     'directx_sdk_default_path': '<(DEPTH)/third_party/directxsdk/files',
 
+    # Backward compatibility only, use arm_version.
+    'armv7': 0,

[Torne, 2013/04/11 13:04:22]

This shouldn't be necessary; this value will always be overwritten by the one
set below.

[Fredrik Öhrn, 2013/04/11 13:42:19]

I had to put it in or gyp would throw and undefined error for no good reason
when reading a gyp file in third_party.

This was when I initially wrote the patch back on top of 25.0.1364. Seems the
problem is gone now, I'll remove it.

+
     # Whether we are using the rlz library or not.  Platforms like Android send
     # rlz codes for searches but do not use the library.
     'enable_rlz%': 0,
 
     'conditions': [
       ['OS=="win" and "<!(python <(DEPTH)/build/dir_exists.py <(windows_sdk_default_path))"=="True"', {
         'windows_sdk_path%': '<(windows_sdk_default_path)',
       }, {
         'windows_sdk_path%': 'C:/Program Files (x86)/Windows Kits/8.0',
       }],
@@ skipping 118 matching lines @@
           # code compilation.
           'conditions': [
             ['target_arch == "ia32"', {
               'android_app_abi%': 'x86',
               'android_gdbserver%': '<(android_ndk_root)/prebuilt/android-x86/gdbserver/gdbserver',
               'android_ndk_sysroot%': '<(android_ndk_root)/platforms/android-14/arch-x86',
               'android_toolchain%': '<(android_ndk_root)/toolchains/x86-4.6/prebuilt/<(host_os)-<(android_host_arch)/bin',
             }],
             ['target_arch=="arm"', {
               'conditions': [
-                ['armv7==0', {
+                ['arm_version<7', {
                   'android_app_abi%': 'armeabi',
                 }, {
                   'android_app_abi%': 'armeabi-v7a',
                 }],
               ],
               'android_gdbserver%': '<(android_ndk_root)/prebuilt/android-arm/gdbserver/gdbserver',
               'android_ndk_sysroot%': '<(android_ndk_root)/platforms/android-14/arch-arm',
               'android_toolchain%': '<(android_ndk_root)/toolchains/arm-linux-androideabi-4.6/prebuilt/<(host_os)-<(android_host_arch)/bin',
             }],
           ],
@@ skipping 398 matching lines @@
         'win_debug_InlineFunctionExpansion': 0,
         'win_debug_OmitFramePointers': 0,
         # Keep the code under #ifndef NVALGRIND.
         'release_valgrind_build': 1,
       }],
 
       # Enable RLZ on Win, Mac and ChromeOS.
       ['branding=="Chrome" and (OS=="win" or OS=="mac" or chromeos==1)', {
         'enable_rlz%': 1,
       }],
+
+      ['android_webview_build==1', {
+        # The WebView build gets its cpu-specific flags from the Android build system.
+        'arm_arch%': '',
+        'arm_tune%': '',
+        'arm_fpu%': '',
+        'arm_float_abi%': '',
+        'arm_thumb%': 0,
+      }, {
+        'conditions': [

[Torne, 2013/04/11 13:04:22]

I generally prefer not to use nested conditions sections like this because deep
gyp nesting is hard to read; it may be neater to just repeat "and
android_webview_build==0" and have all of these blocks at the same level.

+          # Set default compiler flags depending on ARM version.
+          ['arm_version==5', {
+            # Flags suitable for Android emulator
+            'arm_arch%': 'armv5te',
+            'arm_tune%': 'xscale',
+            'arm_fpu%': '',
+            'arm_float_abi%': 'soft',
+            'arm_thumb%': 0,
+          }],
+          ['arm_version==6', {
+            'arm_arch%': 'armv6',
+            'arm_tune%': '',
+            'arm_fpu%': '',
+            'arm_float_abi%': 'soft',
+            'arm_thumb%': 0,
+          }],
+          ['arm_version==7', {
+            'arm_arch%': 'armv7-a',
+            'arm_tune%': 'cortex-a8',
+            'conditions': [
+              ['arm_neon==1', {
+                'arm_fpu%': 'neon',
+              }, {
+                'arm_fpu%': 'vfpv3-d16',
+              }],
+            ],
+            'arm_float_abi%': 'softfp',
+            'arm_thumb%': 1,
+          }],
+        ],
+      }],
+
+      # Set armv7 for backward compatibility.
+      ['arm_version==7', {
+        'armv7': 1,
+      }, {
+        'armv7': 0,
+      }],
     ],
 
     # List of default apps to install in new profiles.  The first list contains
     # the source files as found in svn.  The second list, used only for linux,
     # contains the destination location for each of the files.  When a crx
     # is added or removed from the list, the chrome/browser/resources/
     # default_apps/external_extensions.json file must also be updated.
     'default_apps_list': [
       'browser/resources/default_apps/external_extensions.json',
       'browser/resources/default_apps/gmail.crx',
@@ skipping 1180 matching lines @@
             'target_conditions': [
               ['_toolset=="target"', {
                 'cflags_cc': [
                   # The codesourcery arm-2009q3 toolchain warns at that the ABI
                   # has changed whenever it encounters a varargs function. This
                   # silences those warnings, as they are not helpful and
                   # clutter legitimate warnings.
                   '-Wno-abi',
                 ],
                 'conditions': [
-                  ['arm_thumb==1 and android_webview_build==0', {
+                  ['arm_arch!=""', {
+                    'cflags': [
+                      '-march=<(arm_arch)',
+                    ],
+                  }],
+                  ['arm_tune!=""', {
+                    'cflags': [
+                      '-mtune=<(arm_tune)',
+                    ],
+                  }],
+                  ['arm_fpu!=""', {
+                    'cflags': [
+                      '-mfpu=<(arm_fpu)',
+                    ],
+                  }],
+                  ['arm_float_abi!=""', {
+                    'cflags': [
+                      '-mfloat-abi=<(arm_float_abi)',
+                    ],
+                  }],
+                  ['arm_thumb==1', {
                     'cflags': [
                     '-mthumb',
                     ]
                   }],
-                  ['armv7==1 and android_webview_build==0', {
-                    'cflags': [
-                      '-march=armv7-a',
-                      '-mtune=cortex-a8',
-                      '-mfloat-abi=<(arm_float_abi)',
-                    ],
-                    'conditions': [
-                      ['arm_neon==1', {
-                        'cflags': [ '-mfpu=neon', ],
-                      }, {
-                        'cflags': [ '-mfpu=<(arm_fpu)', ],
-                      }],
-                    ],
-                  }],
                   ['OS=="android"', {
                     # Most of the following flags are derived from what Android
                     # uses by default when building for arm, reference for which
                     # can be found in the following file in the Android NDK:
                     # toolchains/arm-linux-androideabi-4.4.3/setup.mk
                     'cflags': [
                       # The tree-sra optimization (scalar replacement for
                       # aggregates enabling subsequent optimizations) leads to
                       # invalid code generation when using the Android NDK's
                       # compiler (r5-r7). This can be verified using
                       # TestWebKitAPI's WTF.Checked_int8_t test.
                       '-fno-tree-sra',
                       '-fuse-ld=gold',
                       '-Wno-psabi',
                     ],
                     # Android now supports .relro sections properly.
                     # NOTE: While these flags enable the generation of .relro
                     # sections, the generated libraries can still be loaded on
                     # older Android platform versions.
                     'ldflags': [
                         '-Wl,-z,relro',
                         '-Wl,-z,now',
                         '-fuse-ld=gold',
                     ],
                     'conditions': [
-                      ['arm_thumb==1 and android_webview_build==0', {
+                      ['arm_thumb==1', {
                         'cflags': [ '-mthumb-interwork' ],
                       }],
-                      ['armv7==0 and android_webview_build==0', {
-                        # Flags suitable for Android emulator

[Torne, 2013/04/11 13:04:22]

This block doesn't seem to have a replacement..

[Fredrik Öhrn, 2013/04/11 13:42:19]

It's replaced by the arm_version==5 block on line 1600.
The defines are redundant, they are compiler builtins.

-                        'cflags': [
-                          '-march=armv5te',
-                          '-mtune=xscale',
-                          '-msoft-float',
-                        ],
-                        'defines': [
-                          '__ARM_ARCH_5__',
-                          '__ARM_ARCH_5T__',
-                          '__ARM_ARCH_5E__',
-                          '__ARM_ARCH_5TE__',
-                        ],
-                      }],
                       ['profiling==1', {
                         'cflags': [
                           '-marm', # Probably reduntant, but recommend by "perf" docs.
                           '-mapcs-frame', # Seems required by -fno-omit-frame-pointer.
                         ],
                       }],
                       ['clang==1', {
                         'cflags!': [
                           # Clang does not support the following options.
                           '-mthumb-interwork',
@@ skipping 1360 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',
   },
 }