Run GN as part of runhooks.

build/gyp_chromium

 #!/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.
 
 # This script is wrapper for Chromium that adds some support for how GYP
 # is invoked by Chromium beyond what can be done in the gclient hooks.
 
 import glob
@@ skipping 60 matching lines @@
 
   # Always include common.gypi.
   AddInclude(os.path.join(script_dir, 'common.gypi'))
 
   # Optionally add supplemental .gypi files if present.
   supplements = glob.glob(os.path.join(chrome_src, '*', 'supplement.gypi'))
   for supplement in supplements:
     AddInclude(supplement)
 
   return result
 

[M-A Ruel, 2013/11/14 23:23:36]

2 lines between file level symbols

+def RunGN():
+  """Runs GN, returning True if it succeeded, printing an error and returning
+  false if not."""
+  # The binaries in platform-specific subdirectories in src/tools/gn/bin.
+  # We assume this file is in one subdirectory of the source root.
+  source_root = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))

[M-A Ruel, 2013/11/14 23:23:36]

It's highly preferable to create a global variable, e.g.
SRC_DIR = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
at the module level otherwise any os.chdir() call will invalidate the code here.

+  gnpath = source_root + '/tools/gn/bin/'
+  if sys.platform == 'win32':
+    gnpath += 'win/gn.exe'
+  elif sys.platform.startswith('linux'):
+    gnpath += 'linux/gn'
+  elif sys.platform == 'darwin':
+    gnpath += 'mac/gn'
+  else:
+    print 'Unknown platform for GN: ', sys.platform
+    return False
+
+  print 'Generating gyp files from GN...'
+
+  # Need to pass both the source root (the bots don't run this command from
+  # within the source tree) as well as set the is_gyp value so the BUILD files
+  # to know they're being run under GYP.
+  args = [gnpath, 'gyp', '-q', '--root=' + chrome_src, '--args=is_gyp=true']
+  return subprocess.call(args) == 0
+

[M-A Ruel, 2013/11/14 23:23:36]

2 lines

 if __name__ == '__main__':
   args = sys.argv[1:]
 
   # Use the Psyco JIT if available.
   if psyco:
     psyco.profile()
     print "Enabled Psyco JIT."
 
+  if not RunGN():
+    sys.exit(1)
+
   # Fall back on hermetic python if we happen to get run under cygwin.
   # TODO(bradnelson): take this out once this issue is fixed:
   #    http://code.google.com/p/gyp/issues/detail?id=177
   if sys.platform == 'cygwin':
     python_dir = os.path.join(chrome_src, 'third_party', 'python_26')
     env = os.environ.copy()
     env['PATH'] = python_dir + os.pathsep + env.get('PATH', '')
     p = subprocess.Popen(
        [os.path.join(python_dir, 'python.exe')] + sys.argv,
        env=env, shell=False)
@@ skipping 50 matching lines @@
   # to enfore syntax checking.
   syntax_check = os.environ.get('CHROMIUM_GYP_SYNTAX_CHECK')
   if syntax_check and int(syntax_check):
     args.append('--check')
 
   print 'Updating projects from gyp files...'
   sys.stdout.flush()
 
   # Off we go...
   sys.exit(gyp.main(args))