Clarify and update GN build flags docs.
[chromium-blink-merge.git] / build / landmine_utils.py
blob6d18b6d0f32d49309f3f498e779a5f2daf4b4eab
1 # Copyright 2013 The Chromium 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.
6 import functools
7 import logging
8 import os
9 import shlex
10 import sys
13 def 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
29 @memoize()
30 def IsWindows():
31 return sys.platform in ['win32', 'cygwin']
34 @memoize()
35 def IsLinux():
36 return sys.platform.startswith(('linux', 'freebsd', 'openbsd'))
39 @memoize()
40 def IsMac():
41 return sys.platform == 'darwin'
44 @memoize()
45 def 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', '')))
50 @memoize()
51 def gyp_generator_flags():
52 """Parses and returns GYP_GENERATOR_FLAGS env var as a dictionary."""
53 return dict(arg.split('=', 1)
54 for arg in shlex.split(os.environ.get('GYP_GENERATOR_FLAGS', '')))
56 @memoize()
57 def gyp_msvs_version():
58 return os.environ.get('GYP_MSVS_VERSION', '')
60 @memoize()
61 def distributor():
62 """
63 Returns a string which is the distributed build engine in use (if any).
64 Possible values: 'goma', 'ib', ''
65 """
66 if 'goma' in gyp_defines():
67 return 'goma'
68 elif IsWindows():
69 if 'CHROME_HEADLESS' in os.environ:
70 return 'ib' # use (win and !goma and headless) as approximation of ib
73 @memoize()
74 def platform():
75 """
76 Returns a string representing the platform this build is targetted for.
77 Possible values: 'win', 'mac', 'linux', 'ios', 'android'
78 """
79 if 'OS' in gyp_defines():
80 if 'android' in gyp_defines()['OS']:
81 return 'android'
82 else:
83 return gyp_defines()['OS']
84 elif IsWindows():
85 return 'win'
86 elif IsLinux():
87 return 'linux'
88 else:
89 return 'mac'
92 @memoize()
93 def builder():
94 """
95 Returns a string representing the build engine (not compiler) to use.
96 Possible values: 'make', 'ninja', 'xcode', 'msvs', 'scons'
97 """
98 if 'GYP_GENERATORS' in os.environ:
99 # for simplicity, only support the first explicit generator
100 generator = os.environ['GYP_GENERATORS'].split(',')[0]
101 if generator.endswith('-android'):
102 return generator.split('-')[0]
103 elif generator.endswith('-ninja'):
104 return 'ninja'
105 else:
106 return generator
107 else:
108 if platform() == 'android':
109 # Good enough for now? Do any android bots use make?
110 return 'ninja'
111 elif platform() == 'ios':
112 return 'xcode'
113 elif IsWindows():
114 return 'ninja'
115 elif IsLinux():
116 return 'ninja'
117 elif IsMac():
118 return 'ninja'
119 else:
120 assert False, 'Don\'t know what builder we\'re using!'