| # Copyright 2013 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. | 
 |  | 
 |  | 
 | import functools | 
 | import logging | 
 | import os | 
 | import shlex | 
 | import sys | 
 |  | 
 |  | 
 | def memoize(default=None): | 
 |   """This decorator caches the return value of a parameterless pure function""" | 
 |   def memoizer(func): | 
 |     val = [] | 
 |     @functools.wraps(func) | 
 |     def inner(): | 
 |       if not val: | 
 |         ret = func() | 
 |         val.append(ret if ret is not None else default) | 
 |         if logging.getLogger().isEnabledFor(logging.INFO): | 
 |           print '%s -> %r' % (func.__name__, val[0]) | 
 |       return val[0] | 
 |     return inner | 
 |   return memoizer | 
 |  | 
 |  | 
 | @memoize() | 
 | def IsWindows(): | 
 |   return sys.platform in ['win32', 'cygwin'] | 
 |  | 
 |  | 
 | @memoize() | 
 | def IsLinux(): | 
 |   return sys.platform.startswith(('linux', 'freebsd', 'openbsd')) | 
 |  | 
 |  | 
 | @memoize() | 
 | def IsMac(): | 
 |   return sys.platform == 'darwin' | 
 |  | 
 |  | 
 | @memoize() | 
 | def gyp_defines(): | 
 |   """Parses and returns GYP_DEFINES env var as a dictionary.""" | 
 |   return dict(arg.split('=', 1) | 
 |       for arg in shlex.split(os.environ.get('GYP_DEFINES', ''))) | 
 |  | 
 | @memoize() | 
 | def gyp_generator_flags(): | 
 |   """Parses and returns GYP_GENERATOR_FLAGS env var as a dictionary.""" | 
 |   return dict(arg.split('=', 1) | 
 |       for arg in shlex.split(os.environ.get('GYP_GENERATOR_FLAGS', ''))) | 
 |  | 
 | @memoize() | 
 | def gyp_msvs_version(): | 
 |   return os.environ.get('GYP_MSVS_VERSION', '') | 
 |  | 
 | @memoize() | 
 | def distributor(): | 
 |   """ | 
 |   Returns a string which is the distributed build engine in use (if any). | 
 |   Possible values: 'goma', 'ib', '' | 
 |   """ | 
 |   if 'goma' in gyp_defines(): | 
 |     return 'goma' | 
 |   elif IsWindows(): | 
 |     if 'CHROME_HEADLESS' in os.environ: | 
 |       return 'ib' # use (win and !goma and headless) as approximation of ib | 
 |  | 
 |  | 
 | @memoize() | 
 | def platform(): | 
 |   """ | 
 |   Returns a string representing the platform this build is targetted for. | 
 |   Possible values: 'win', 'mac', 'linux', 'ios', 'android' | 
 |   """ | 
 |   if 'OS' in gyp_defines(): | 
 |     if 'android' in gyp_defines()['OS']: | 
 |       return 'android' | 
 |     else: | 
 |       return gyp_defines()['OS'] | 
 |   elif IsWindows(): | 
 |     return 'win' | 
 |   elif IsLinux(): | 
 |     return 'linux' | 
 |   else: | 
 |     return 'mac' | 
 |  | 
 |  | 
 | @memoize() | 
 | def builder(): | 
 |   """ | 
 |   Returns a string representing the build engine (not compiler) to use. | 
 |   Possible values: 'make', 'ninja', 'xcode', 'msvs', 'scons' | 
 |   """ | 
 |   if 'GYP_GENERATORS' in os.environ: | 
 |     # for simplicity, only support the first explicit generator | 
 |     generator = os.environ['GYP_GENERATORS'].split(',')[0] | 
 |     if generator.endswith('-android'): | 
 |       return generator.split('-')[0] | 
 |     elif generator.endswith('-ninja'): | 
 |       return 'ninja' | 
 |     else: | 
 |       return generator | 
 |   else: | 
 |     if platform() == 'android': | 
 |       # Good enough for now? Do any android bots use make? | 
 |       return 'ninja' | 
 |     elif platform() == 'ios': | 
 |       return 'xcode' | 
 |     elif IsWindows(): | 
 |       return 'ninja' | 
 |     elif IsLinux(): | 
 |       return 'ninja' | 
 |     elif IsMac(): | 
 |       return 'ninja' | 
 |     else: | 
 |       assert False, 'Don\'t know what builder we\'re using!' |