1# Copyright 2014 the V8 project authors. All rights reserved.
2# Use of this source code is governed by a BSD-style license that can be
3# found in the LICENSE file.
4
5
6import functools
7import logging
8import os
9import shlex
10import sys
11
12
13def memoize(default=None):
14  """This decorator caches the return value of a parameterless pure function"""
15  def memoizer(func):
16    val = []
17    @functools.wraps(func)
18    def inner():
19      if not val:
20        ret = func()
21        val.append(ret if ret is not None else default)
22        if logging.getLogger().isEnabledFor(logging.INFO):
23          print '%s -> %r' % (func.__name__, val[0])
24      return val[0]
25    return inner
26  return memoizer
27
28
29@memoize()
30def IsWindows():
31  return sys.platform in ['win32', 'cygwin']
32
33
34@memoize()
35def IsLinux():
36  return sys.platform.startswith(('linux', 'freebsd'))
37
38
39@memoize()
40def IsMac():
41  return sys.platform == 'darwin'
42
43
44@memoize()
45def gyp_defines():
46  """Parses and returns GYP_DEFINES env var as a dictionary."""
47  return dict(arg.split('=', 1)
48      for arg in shlex.split(os.environ.get('GYP_DEFINES', '')))
49
50@memoize()
51def gyp_msvs_version():
52  return os.environ.get('GYP_MSVS_VERSION', '')
53
54@memoize()
55def distributor():
56  """
57  Returns a string which is the distributed build engine in use (if any).
58  Possible values: 'goma', 'ib', ''
59  """
60  if 'goma' in gyp_defines():
61    return 'goma'
62  elif IsWindows():
63    if 'CHROME_HEADLESS' in os.environ:
64      return 'ib' # use (win and !goma and headless) as approximation of ib
65
66
67@memoize()
68def platform():
69  """
70  Returns a string representing the platform this build is targetted for.
71  Possible values: 'win', 'mac', 'linux', 'ios', 'android'
72  """
73  if 'OS' in gyp_defines():
74    if 'android' in gyp_defines()['OS']:
75      return 'android'
76    else:
77      return gyp_defines()['OS']
78  elif IsWindows():
79    return 'win'
80  elif IsLinux():
81    return 'linux'
82  else:
83    return 'mac'
84
85
86@memoize()
87def builder():
88  """
89  Returns a string representing the build engine (not compiler) to use.
90  Possible values: 'make', 'ninja', 'xcode', 'msvs', 'scons'
91  """
92  if 'GYP_GENERATORS' in os.environ:
93    # for simplicity, only support the first explicit generator
94    generator = os.environ['GYP_GENERATORS'].split(',')[0]
95    if generator.endswith('-android'):
96      return generator.split('-')[0]
97    elif generator.endswith('-ninja'):
98      return 'ninja'
99    else:
100      return generator
101  else:
102    if platform() == 'android':
103      # Good enough for now? Do any android bots use make?
104      return 'make'
105    elif platform() == 'ios':
106      return 'xcode'
107    elif IsWindows():
108      return 'msvs'
109    elif IsLinux():
110      return 'make'
111    elif IsMac():
112      return 'xcode'
113    else:
114      assert False, 'Don\'t know what builder we\'re using!'
115