Add GN bootstrap step to continuous integration

tools/gn/bootstrap/bootstrap.py

 #!/usr/bin/env python
 # 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.
 
 """Bootstraps gn.
 
 It is done by first building it manually in a temporary directory, then building
 it with its own BUILD.gn to the final destination.
 """
 
 import contextlib
 import errno
+import json
 import logging
 import optparse
 import os
 import shutil
 import subprocess
 import sys
 import tempfile
 
 BOOTSTRAP_DIR = os.path.dirname(os.path.abspath(__file__))
 GN_ROOT = os.path.dirname(BOOTSTRAP_DIR)
@@ skipping 25 matching lines @@
 
 
 def main(argv):
   parser = optparse.OptionParser(description=sys.modules[__name__].__doc__)
   parser.add_option('-d', '--debug', action='store_true',
                     help='Do a debug build. Defaults to release build.')
   parser.add_option('-o', '--output',
                     help='place output in PATH', metavar='PATH')
   parser.add_option('-s', '--no-rebuild', action='store_true',
                     help='Do not rebuild GN with GN.')
+  parser.add_option('--temp-build-dir', action='store_true',
+                    help='Build GN in temporary directory')
+  parser.add_option('--use-bundled-clang', action='store_true',
+                    help='Use bundled clang compiler (e.g. when host toolchain '
+                         'is too old to support C++11)')
   parser.add_option('-v', '--verbose', action='store_true',
                     help='Log more details')
+  parser.add_option('--json')
   options, args = parser.parse_args(argv)
 
   if args:
     parser.error('Unrecognized command line arguments: %s.' % ', '.join(args))
 
   logging.basicConfig(level=logging.DEBUG if options.verbose else logging.ERROR)
 
   if options.debug:
     build_rel = os.path.join('out', 'Debug')
   else:
     build_rel = os.path.join('out', 'Release')
-  build_root = os.path.join(SRC_ROOT, build_rel)
+
+  failures = []
 
   try:
     with scoped_tempdir() as tempdir:
       print 'Building gn manually in a temporary directory for bootstrapping...'
       build_gn_with_ninja_manually(tempdir, options)
       temp_gn = os.path.join(tempdir, 'gn')
+      if options.temp_build_dir:
+        build_root = os.path.join(tempdir, 'build_root')
+      else:
+        build_root = os.path.join(SRC_ROOT, build_rel)
       out_gn = os.path.join(build_root, 'gn')
 
       if options.no_rebuild:
         mkdir_p(build_root)
         shutil.copy2(temp_gn, out_gn)
       else:
-        print 'Building gn using itself to %s...' % build_rel
-        build_gn_with_gn(temp_gn, build_rel, options)
+        print 'Building gn using itself to %s...' % build_root
+        build_gn_with_gn(temp_gn, build_root, options)
 
       if options.output:
         # Preserve the executable permission bit.
         shutil.copy2(out_gn, options.output)
   except subprocess.CalledProcessError as e:
     print >> sys.stderr, str(e)
-    return 1
-  return 0
+    failures.append(str(e))
+
+  if options.json:
+    with open(options.json, 'w') as f:
+      json.dump(failures, f)
+  return 1 if failures else 0
 
 
 def build_gn_with_ninja_manually(tempdir, options):
   write_ninja(os.path.join(tempdir, 'build.ninja'), options)
   cmd = ['ninja', '-C', tempdir]
   if options.verbose:
     cmd.append('-v')
   cmd.append('gn')
   check_call(cmd)
 
 def write_ninja(path, options):
-  cc = os.environ.get('CC', '')
-  cxx = os.environ.get('CXX', '')
+  default_cc = ''
+  default_cxx = ''
+  if options.use_bundled_clang:
+    clang_dir = os.path.join(
+        SRC_ROOT, 'third_party', 'llvm-build', 'Release+Asserts', 'bin')
+    default_cc = os.path.join(clang_dir, 'clang')
+    default_cxx = os.path.join(clang_dir, 'clang++')
+  cc = os.environ.get('CC', default_cc)
+  cxx = os.environ.get('CXX', default_cxx)
   cflags = os.environ.get('CFLAGS', '').split()
   cflags_cc = os.environ.get('CXXFLAGS', '').split()
   ld = os.environ.get('LD', cxx)
   ldflags = os.environ.get('LDFLAGS', '').split()
   include_dirs = [SRC_ROOT]
   libs = []
 
   if is_posix:
     if options.debug:
       cflags.extend(['-O0', '-g'])
@@ skipping 102 matching lines @@
       'base/threading/simple_thread.cc',
       'base/threading/thread_checker_impl.cc',
       'base/threading/thread_collision_warner.cc',
       'base/threading/thread_id_name_manager.cc',
       'base/threading/thread_local_storage.cc',
       'base/threading/thread_restrictions.cc',
       'base/threading/worker_pool.cc',
       'base/time/time.cc',
       'base/timer/elapsed_timer.cc',
       'base/timer/timer.cc',
+      'base/trace_event/category_filter.cc',
+      'base/trace_event/trace_config.cc',
       'base/trace_event/trace_event_impl.cc',
       'base/trace_event/trace_event_impl_constants.cc',
       'base/trace_event/trace_event_memory.cc',
       'base/trace_event/trace_event_synthetic_delay.cc',
+      'base/trace_event/trace_options.cc',
       'base/tracked_objects.cc',
       'base/tracking_info.cc',
       'base/values.cc',
       'base/vlog.cc',
   ])
 
   if is_posix:
     static_libraries['base']['sources'].extend([
         'base/base_paths_posix.cc',
         'base/debug/debugger_posix.cc',
@@ skipping 164 matching lines @@
     cmd.append('-v')
   cmd.append('gn')
   check_call(cmd)
 
   if not options.debug:
     check_call(['strip', os.path.join(build_dir, 'gn')])
 
 
 if __name__ == '__main__':
   sys.exit(main(sys.argv[1:]))