Download arm sysroot as part of gclient hooks

build/install-arm-sysroot.py

+#!/usr/bin/env python
+# 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.
+
+# Script to install arm choot image for cross building of arm chrome on linux.
+# This script can be run manually but is more often run as part of gclient
+# hooks. When run from hooks this script should be a no-op on non-linux
+# platforms.
+
+# The sysroot image could be constructed from scratch based on the current
+# state or precise/arm but for consistency we currently use a pre-built root
+# image which was originally designed for building trusted NaCl code. The image
+# will normally need to be rebuilt every time chrome's build dependancies are
+# changed.
+
+import os
+import sys
+
+
+script_dir = os.path.dirname(os.path.abspath(__file__))
+
+
+def main(args):
+  if '--linux-only' in args:
+    # This argument is passed when run from the gclient hooks.
+    # In this case we return early on non-linux platforms
+    # or if GYP_DEFINES doesn't include target_arch=arm
+    if sys.platform != 'linux2':

[tony, 2012/12/07 01:01:42]

Please use sys.platform.startswith('linux'). See the note here:
http://docs.python.org/2/library/sys.html#sys.platform

[Sam Clegg, 2012/12/07 18:29:37]

Done.

+      return
+
+    if "target_arch=arm" not in os.environ.get('GYP_DEFINES', ''):

[tony, 2012/12/07 01:01:42]

Is it OK that this doesn't run when someone uses ~/.gyp/include.gypi or if they
pass -Dtarget_arch=arm to build/gyp_chromium directly?

It's OK with me, but you might want to make mention of this in your setup docs.

[Sam Clegg, 2012/12/07 18:29:37]

Such people will want to run install-arm-sysroot.py directly from time to time
(just like we all do for install-build-deps.sh).

Once all this stuff is nailed down (the recipe for
building chrome/arm/linux) that will certainly go in the
documentation, yes.

+      return 0
+
+  src_root = os.path.dirname(script_dir)
+  sysroot = os.path.join(src_root, 'arm-sysroot')
+  url_prefix = 'https://commondatastorage.googleapis.com/nativeclient-archive2/toolchain'
+  rev = 8001
+  url = "%s/%s/naclsdk_linux_arm-trusted.tgz" % (url_prefix, rev)
+
+  stamp = os.path.join(sysroot, ".stamp")
+  if os.path.exists(stamp):
+    with open(stamp) as s:
+      if s.read() == url:
+        print "ARM root image already up-to-date: %s" % sysroot
+        return 0
+
+  print "Installing ARM root image: %s" % sysroot
+  if not os.path.isdir(sysroot):
+    os.mkdir(sysroot)
+  tarball = os.path.join(sysroot, 'naclsdk_linux_arm-trusted.tgz')
+  rtn = os.system('curl -L "%s" -o "%s"' % (url, tarball))
+  if rtn:
+    return rtn
+  rtn = os.system('tar xf %s -C %s' % (tarball, sysroot))
+  if rtn:
+    return rtn
+  os.remove(tarball)
+  open(stamp, 'w').write(url)
+
+  return 0
+
+
+if __name__ == '__main__':
+  sys.exit(main(sys.argv[1:]))