/
util.py
1488 lines (1152 loc) · 51 KB
/
util.py
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this file,
# You can obtain one at http://mozilla.org/MPL/2.0/.
# This file contains miscellaneous utility functions that don't belong anywhere
# in particular.
from __future__ import absolute_import, print_function, unicode_literals
import argparse
import collections
import ctypes
import difflib
import errno
import functools
import hashlib
import os
import pprint
import re
import stat
import subprocess
import sys
import time
from collections import (
OrderedDict,
)
from io import (BytesIO, StringIO)
import six
if sys.platform == 'win32':
_kernel32 = ctypes.windll.kernel32
_FILE_ATTRIBUTE_NOT_CONTENT_INDEXED = 0x2000
system_encoding = 'mbcs'
else:
system_encoding = 'utf-8'
def exec_(object, globals=None, locals=None):
"""Wrapper around the exec statement to avoid bogus errors like:
SyntaxError: unqualified exec is not allowed in function ...
it is a nested function.
or
SyntaxError: unqualified exec is not allowed in function ...
it contains a nested function with free variable
which happen with older versions of python 2.7.
"""
exec(object, globals, locals)
def hash_file(path, hasher=None):
"""Hashes a file specified by the path given and returns the hex digest."""
# If the default hashing function changes, this may invalidate
# lots of cached data. Don't change it lightly.
h = hasher or hashlib.sha1()
with open(path, 'rb') as fh:
while True:
data = fh.read(8192)
if not len(data):
break
h.update(data)
return h.hexdigest()
class EmptyValue(six.text_type):
"""A dummy type that behaves like an empty string and sequence.
This type exists in order to support
:py:class:`mozbuild.frontend.reader.EmptyConfig`. It should likely not be
used elsewhere.
"""
def __init__(self):
super(EmptyValue, self).__init__()
class ReadOnlyNamespace(object):
"""A class for objects with immutable attributes set at initialization."""
def __init__(self, **kwargs):
for k, v in six.iteritems(kwargs):
super(ReadOnlyNamespace, self).__setattr__(k, v)
def __delattr__(self, key):
raise Exception('Object does not support deletion.')
def __setattr__(self, key, value):
raise Exception('Object does not support assignment.')
def __ne__(self, other):
return not (self == other)
def __eq__(self, other):
return self is other or (
hasattr(other, '__dict__') and self.__dict__ == other.__dict__)
def __repr__(self):
return '<%s %r>' % (self.__class__.__name__, self.__dict__)
class ReadOnlyDict(dict):
"""A read-only dictionary."""
def __init__(self, *args, **kwargs):
dict.__init__(self, *args, **kwargs)
def __delitem__(self, key):
raise Exception('Object does not support deletion.')
def __setitem__(self, key, value):
raise Exception('Object does not support assignment.')
def update(self, *args, **kwargs):
raise Exception('Object does not support update.')
class undefined_default(object):
"""Represents an undefined argument value that isn't None."""
undefined = undefined_default()
class ReadOnlyDefaultDict(ReadOnlyDict):
"""A read-only dictionary that supports default values on retrieval."""
def __init__(self, default_factory, *args, **kwargs):
ReadOnlyDict.__init__(self, *args, **kwargs)
self._default_factory = default_factory
def __missing__(self, key):
value = self._default_factory()
dict.__setitem__(self, key, value)
return value
def ensureParentDir(path):
"""Ensures the directory parent to the given file exists."""
d = os.path.dirname(path)
if d and not os.path.exists(path):
try:
os.makedirs(d)
except OSError as error:
if error.errno != errno.EEXIST:
raise
def mkdir(path, not_indexed=False):
"""Ensure a directory exists.
If ``not_indexed`` is True, an attribute is set that disables content
indexing on the directory.
"""
try:
os.makedirs(path)
except OSError as e:
if e.errno != errno.EEXIST:
raise
if not_indexed:
if sys.platform == 'win32':
if isinstance(path, six.string_types):
fn = _kernel32.SetFileAttributesW
else:
fn = _kernel32.SetFileAttributesA
fn(path, _FILE_ATTRIBUTE_NOT_CONTENT_INDEXED)
elif sys.platform == 'darwin':
with open(os.path.join(path, '.metadata_never_index'), 'a'):
pass
def simple_diff(filename, old_lines, new_lines):
"""Returns the diff between old_lines and new_lines, in unified diff form,
as a list of lines.
old_lines and new_lines are lists of non-newline terminated lines to
compare.
old_lines can be None, indicating a file creation.
new_lines can be None, indicating a file deletion.
"""
old_name = '/dev/null' if old_lines is None else filename
new_name = '/dev/null' if new_lines is None else filename
return difflib.unified_diff(old_lines or [], new_lines or [],
old_name, new_name, n=4, lineterm='')
class FileAvoidWrite(BytesIO):
"""File-like object that buffers output and only writes if content changed.
We create an instance from an existing filename. New content is written to
it. When we close the file object, if the content in the in-memory buffer
differs from what is on disk, then we write out the new content. Otherwise,
the original file is untouched.
Instances can optionally capture diffs of file changes. This feature is not
enabled by default because it a) doesn't make sense for binary files b)
could add unwanted overhead to calls.
Additionally, there is dry run mode where the file is not actually written
out, but reports whether the file was existing and would have been updated
still occur, as well as diff capture if requested.
"""
def __init__(self, filename, capture_diff=False, dry_run=False, readmode='rU'):
BytesIO.__init__(self)
self.name = filename
assert type(capture_diff) == bool
assert type(dry_run) == bool
assert 'r' in readmode
self._capture_diff = capture_diff
self._write_to_file = not dry_run
self.diff = None
self.mode = readmode
self._binary_mode = 'b' in readmode
def write(self, buf):
if isinstance(buf, six.text_type):
buf = buf.encode('utf-8')
BytesIO.write(self, buf)
def avoid_writing_to_file(self):
self._write_to_file = False
def close(self):
"""Stop accepting writes, compare file contents, and rewrite if needed.
Returns a tuple of bools indicating what action was performed:
(file existed, file updated)
If ``capture_diff`` was specified at construction time and the
underlying file was changed, ``.diff`` will be populated with the diff
of the result.
"""
if self._binary_mode or six.PY2:
# Use binary data under Python 2 because it can be written to files
# opened with either open(mode='w') or open(mode='wb') without raising
# unicode errors. Also use binary data if the caller explicitly asked for
# it.
buf = self.getvalue()
else:
# Use strings in Python 3 unless the caller explicitly asked for binary
# data.
buf = self.getvalue().decode('utf-8')
BytesIO.close(self)
existed = False
old_content = None
try:
existing = open(self.name, self.mode)
existed = True
except IOError:
pass
else:
try:
old_content = existing.read()
if old_content == buf:
return True, False
except IOError:
pass
finally:
existing.close()
if self._write_to_file:
ensureParentDir(self.name)
# Maintain 'b' if specified. 'U' only applies to modes starting with
# 'r', so it is dropped.
writemode = 'w'
if self._binary_mode:
writemode += 'b'
with open(self.name, writemode) as file:
file.write(buf)
self._generate_diff(buf, old_content)
return existed, True
def _generate_diff(self, new_content, old_content):
"""Generate a diff for the changed contents if `capture_diff` is True.
If the changed contents could not be decoded as utf-8 then generate a
placeholder message instead of a diff.
Args:
new_content: Str or bytes holding the new file contents.
old_content: Str or bytes holding the original file contents. Should be
None if no old content is being overwritten.
"""
if not self._capture_diff:
return
try:
if old_content is None:
old_lines = None
else:
if self._binary_mode:
# difflib doesn't work with bytes.
old_content = old_content.decode('utf-8')
old_lines = old_content.splitlines()
if self._binary_mode:
# difflib doesn't work with bytes.
new_content = new_content.decode('utf-8')
new_lines = new_content.splitlines()
self.diff = simple_diff(self.name, old_lines, new_lines)
# FileAvoidWrite isn't unicode/bytes safe. So, files with non-ascii
# content or opened and written in different modes may involve
# implicit conversion and this will make Python unhappy. Since
# diffing isn't a critical feature, we just ignore the failure.
# This can go away once FileAvoidWrite uses io.BytesIO and
# io.StringIO. But that will require a lot of work.
except (UnicodeDecodeError, UnicodeEncodeError):
self.diff = ['Binary or non-ascii file changed: %s' %
self.name]
def __enter__(self):
return self
def __exit__(self, type, value, traceback):
if not self.closed:
self.close()
def resolve_target_to_make(topobjdir, target):
r'''
Resolve `target` (a target, directory, or file) to a make target.
`topobjdir` is the object directory; all make targets will be
rooted at or below the top-level Makefile in this directory.
Returns a pair `(reldir, target)` where `reldir` is a directory
relative to `topobjdir` containing a Makefile and `target` is a
make target (possibly `None`).
A directory resolves to the nearest directory at or above
containing a Makefile, and target `None`.
A regular (non-Makefile) file resolves to the nearest directory at
or above the file containing a Makefile, and an appropriate
target.
A Makefile resolves to the nearest parent strictly above the
Makefile containing a different Makefile, and an appropriate
target.
'''
target = target.replace(os.sep, '/').lstrip('/')
abs_target = os.path.join(topobjdir, target)
# For directories, run |make -C dir|. If the directory does not
# contain a Makefile, check parents until we find one. At worst,
# this will terminate at the root.
if os.path.isdir(abs_target):
current = abs_target
while True:
make_path = os.path.join(current, 'Makefile')
if os.path.exists(make_path):
return (current[len(topobjdir) + 1:], None)
current = os.path.dirname(current)
# If it's not in a directory, this is probably a top-level make
# target. Treat it as such.
if '/' not in target:
return (None, target)
# We have a relative path within the tree. We look for a Makefile
# as far into the path as possible. Then, we compute the make
# target as relative to that directory.
reldir = os.path.dirname(target)
target = os.path.basename(target)
while True:
make_path = os.path.join(topobjdir, reldir, 'Makefile')
# We append to target every iteration, so the check below
# happens exactly once.
if target != 'Makefile' and os.path.exists(make_path):
return (reldir, target)
target = os.path.join(os.path.basename(reldir), target)
reldir = os.path.dirname(reldir)
class List(list):
"""A list specialized for moz.build environments.
We overload the assignment and append operations to require that the
appended thing is a list. This avoids bad surprises coming from appending
a string to a list, which would just add each letter of the string.
"""
def __init__(self, iterable=None, **kwargs):
if iterable is None:
iterable = []
if not isinstance(iterable, list):
raise ValueError('List can only be created from other list instances.')
self._kwargs = kwargs
return super(List, self).__init__(iterable)
def extend(self, l):
if not isinstance(l, list):
raise ValueError('List can only be extended with other list instances.')
return super(List, self).extend(l)
def __setitem__(self, key, val):
if isinstance(key, slice):
if not isinstance(val, list):
raise ValueError('List can only be sliced with other list '
'instances.')
if key.step:
raise ValueError('List cannot be sliced with a nonzero step '
'value')
# Python 2 and Python 3 do this differently for some reason.
if six.PY2:
return super(List, self).__setslice__(key.start, key.stop,
val)
else:
return super(List, self).__setitem__(key, val)
return super(List, self).__setitem__(key, val)
def __setslice__(self, i, j, sequence):
return self.__setitem__(slice(i, j), sequence)
def __add__(self, other):
# Allow None and EmptyValue is a special case because it makes undefined
# variable references in moz.build behave better.
other = [] if isinstance(other, (type(None), EmptyValue)) else other
if not isinstance(other, list):
raise ValueError('Only lists can be appended to lists.')
new_list = self.__class__(self, **self._kwargs)
new_list.extend(other)
return new_list
def __iadd__(self, other):
other = [] if isinstance(other, (type(None), EmptyValue)) else other
if not isinstance(other, list):
raise ValueError('Only lists can be appended to lists.')
return super(List, self).__iadd__(other)
class UnsortedError(Exception):
def __init__(self, srtd, original):
assert len(srtd) == len(original)
self.sorted = srtd
self.original = original
for i, orig in enumerate(original):
s = srtd[i]
if orig != s:
self.i = i
break
def __str__(self):
s = StringIO()
s.write('An attempt was made to add an unsorted sequence to a list. ')
s.write('The incoming list is unsorted starting at element %d. ' %
self.i)
s.write('We expected "%s" but got "%s"' % (
self.sorted[self.i], self.original[self.i]))
return s.getvalue()
class StrictOrderingOnAppendList(List):
"""A list specialized for moz.build environments.
We overload the assignment and append operations to require that incoming
elements be ordered. This enforces cleaner style in moz.build files.
"""
@staticmethod
def ensure_sorted(l):
if isinstance(l, StrictOrderingOnAppendList):
return
def _first_element(e):
# If the list entry is a tuple, we sort based on the first element
# in the tuple.
return e[0] if isinstance(e, tuple) else e
srtd = sorted(l, key=lambda x: _first_element(x).lower())
if srtd != l:
raise UnsortedError(srtd, l)
def __init__(self, iterable=None, **kwargs):
if iterable is None:
iterable = []
StrictOrderingOnAppendList.ensure_sorted(iterable)
super(StrictOrderingOnAppendList, self).__init__(iterable, **kwargs)
def extend(self, l):
StrictOrderingOnAppendList.ensure_sorted(l)
return super(StrictOrderingOnAppendList, self).extend(l)
def __setitem__(self, key, val):
if isinstance(key, slice):
StrictOrderingOnAppendList.ensure_sorted(val)
return super(StrictOrderingOnAppendList, self).__setitem__(key, val)
def __add__(self, other):
StrictOrderingOnAppendList.ensure_sorted(other)
return super(StrictOrderingOnAppendList, self).__add__(other)
def __iadd__(self, other):
StrictOrderingOnAppendList.ensure_sorted(other)
return super(StrictOrderingOnAppendList, self).__iadd__(other)
class ImmutableStrictOrderingOnAppendList(StrictOrderingOnAppendList):
"""Like StrictOrderingOnAppendList, but not allowing mutations of the value.
"""
def append(self, elt):
raise Exception("cannot use append on this type")
def extend(self, iterable):
raise Exception("cannot use extend on this type")
def __setslice__(self, i, j, iterable):
raise Exception("cannot assign to slices on this type")
def __setitem__(self, i, elt):
raise Exception("cannot assign to indexes on this type")
def __iadd__(self, other):
raise Exception("cannot use += on this type")
class StrictOrderingOnAppendListWithAction(StrictOrderingOnAppendList):
"""An ordered list that accepts a callable to be applied to each item.
A callable (action) passed to the constructor is run on each item of input.
The result of running the callable on each item will be stored in place of
the original input, but the original item must be used to enforce sortedness.
"""
def __init__(self, iterable=(), action=None):
if not callable(action):
raise ValueError('A callable action is required to construct '
'a StrictOrderingOnAppendListWithAction')
self._action = action
if not isinstance(iterable, (tuple, list)):
raise ValueError(
'StrictOrderingOnAppendListWithAction can only be initialized '
'with another list')
iterable = [self._action(i) for i in iterable]
super(StrictOrderingOnAppendListWithAction, self).__init__(
iterable, action=action)
def extend(self, l):
if not isinstance(l, list):
raise ValueError(
'StrictOrderingOnAppendListWithAction can only be extended '
'with another list')
l = [self._action(i) for i in l]
return super(StrictOrderingOnAppendListWithAction, self).extend(l)
def __setitem__(self, key, val):
if isinstance(key, slice):
if not isinstance(val, list):
raise ValueError(
'StrictOrderingOnAppendListWithAction can only be sliced '
'with another list')
val = [self._action(item) for item in val]
return super(StrictOrderingOnAppendListWithAction, self).__setitem__(
key, val)
def __add__(self, other):
if not isinstance(other, list):
raise ValueError(
'StrictOrderingOnAppendListWithAction can only be added with '
'another list')
return super(StrictOrderingOnAppendListWithAction, self).__add__(other)
def __iadd__(self, other):
if not isinstance(other, list):
raise ValueError(
'StrictOrderingOnAppendListWithAction can only be added with '
'another list')
other = [self._action(i) for i in other]
return super(StrictOrderingOnAppendListWithAction, self).__iadd__(other)
class MozbuildDeletionError(Exception):
pass
def FlagsFactory(flags):
"""Returns a class which holds optional flags for an item in a list.
The flags are defined in the dict given as argument, where keys are
the flag names, and values the type used for the value of that flag.
The resulting class is used by the various <TypeName>WithFlagsFactory
functions below.
"""
assert isinstance(flags, dict)
assert all(isinstance(v, type) for v in flags.values())
class Flags(object):
__slots__ = flags.keys()
_flags = flags
def update(self, **kwargs):
for k, v in six.iteritems(kwargs):
setattr(self, k, v)
def __getattr__(self, name):
if name not in self.__slots__:
raise AttributeError("'%s' object has no attribute '%s'" %
(self.__class__.__name__, name))
try:
return object.__getattr__(self, name)
except AttributeError:
value = self._flags[name]()
self.__setattr__(name, value)
return value
def __setattr__(self, name, value):
if name not in self.__slots__:
raise AttributeError("'%s' object has no attribute '%s'" %
(self.__class__.__name__, name))
if not isinstance(value, self._flags[name]):
raise TypeError("'%s' attribute of class '%s' must be '%s'" %
(name, self.__class__.__name__,
self._flags[name].__name__))
return object.__setattr__(self, name, value)
def __delattr__(self, name):
raise MozbuildDeletionError('Unable to delete attributes for this object')
return Flags
class StrictOrderingOnAppendListWithFlags(StrictOrderingOnAppendList):
"""A list with flags specialized for moz.build environments.
Each subclass has a set of typed flags; this class lets us use `isinstance`
for natural testing.
"""
def StrictOrderingOnAppendListWithFlagsFactory(flags):
"""Returns a StrictOrderingOnAppendList-like object, with optional
flags on each item.
The flags are defined in the dict given as argument, where keys are
the flag names, and values the type used for the value of that flag.
Example:
FooList = StrictOrderingOnAppendListWithFlagsFactory({
'foo': bool, 'bar': unicode
})
foo = FooList(['a', 'b', 'c'])
foo['a'].foo = True
foo['b'].bar = 'bar'
"""
class StrictOrderingOnAppendListWithFlagsSpecialization(StrictOrderingOnAppendListWithFlags):
def __init__(self, iterable=None):
if iterable is None:
iterable = []
StrictOrderingOnAppendListWithFlags.__init__(self, iterable)
self._flags_type = FlagsFactory(flags)
self._flags = dict()
def __getitem__(self, name):
if name not in self._flags:
if name not in self:
raise KeyError("'%s'" % name)
self._flags[name] = self._flags_type()
return self._flags[name]
def __setitem__(self, name, value):
if not isinstance(name, slice):
raise TypeError("'%s' object does not support item assignment" %
self.__class__.__name__)
result = super(StrictOrderingOnAppendListWithFlagsSpecialization,
self).__setitem__(name, value)
# We may have removed items.
for k in set(self._flags.keys()) - set(self):
del self._flags[k]
if isinstance(value, StrictOrderingOnAppendListWithFlags):
self._update_flags(value)
return result
def _update_flags(self, other):
if self._flags_type._flags != other._flags_type._flags:
raise ValueError('Expected a list of strings with flags like %s, not like %s' %
(self._flags_type._flags, other._flags_type._flags))
intersection = set(self._flags.keys()) & set(other._flags.keys())
if intersection:
raise ValueError(
'Cannot update flags: both lists of strings with flags configure %s' %
intersection
)
self._flags.update(other._flags)
def extend(self, l):
result = super(StrictOrderingOnAppendListWithFlagsSpecialization,
self).extend(l)
if isinstance(l, StrictOrderingOnAppendListWithFlags):
self._update_flags(l)
return result
def __add__(self, other):
result = super(StrictOrderingOnAppendListWithFlagsSpecialization,
self).__add__(other)
if isinstance(other, StrictOrderingOnAppendListWithFlags):
# Result has flags from other but not from self, since
# internally we duplicate self and then extend with other, and
# only extend knows about flags. Since we don't allow updating
# when the set of flag keys intersect, which we instance we pass
# to _update_flags here matters. This needs to be correct but
# is an implementation detail.
result._update_flags(self)
return result
def __iadd__(self, other):
result = super(StrictOrderingOnAppendListWithFlagsSpecialization,
self).__iadd__(other)
if isinstance(other, StrictOrderingOnAppendListWithFlags):
self._update_flags(other)
return result
return StrictOrderingOnAppendListWithFlagsSpecialization
class HierarchicalStringList(object):
"""A hierarchy of lists of strings.
Each instance of this object contains a list of strings, which can be set or
appended to. A sub-level of the hierarchy is also an instance of this class,
can be added by appending to an attribute instead.
For example, the moz.build variable EXPORTS is an instance of this class. We
can do:
EXPORTS += ['foo.h']
EXPORTS.mozilla.dom += ['bar.h']
In this case, we have 3 instances (EXPORTS, EXPORTS.mozilla, and
EXPORTS.mozilla.dom), and the first and last each have one element in their
list.
"""
__slots__ = ('_strings', '_children')
def __init__(self):
# Please change ContextDerivedTypedHierarchicalStringList in context.py
# if you make changes here.
self._strings = StrictOrderingOnAppendList()
self._children = {}
class StringListAdaptor(collections.Sequence):
def __init__(self, hsl):
self._hsl = hsl
def __getitem__(self, index):
return self._hsl._strings[index]
def __len__(self):
return len(self._hsl._strings)
def walk(self):
"""Walk over all HierarchicalStringLists in the hierarchy.
This is a generator of (path, sequence).
The path is '' for the root level and '/'-delimited strings for
any descendants. The sequence is a read-only sequence of the
strings contained at that level.
"""
if self._strings:
path_to_here = ''
yield path_to_here, self.StringListAdaptor(self)
for k, l in sorted(self._children.items()):
for p, v in l.walk():
path_to_there = '%s/%s' % (k, p)
yield path_to_there.strip('/'), v
def __setattr__(self, name, value):
if name in self.__slots__:
return object.__setattr__(self, name, value)
# __setattr__ can be called with a list when a simple assignment is
# used:
#
# EXPORTS.foo = ['file.h']
#
# In this case, we need to overwrite foo's current list of strings.
#
# However, __setattr__ is also called with a HierarchicalStringList
# to try to actually set the attribute. We want to ignore this case,
# since we don't actually create an attribute called 'foo', but just add
# it to our list of children (using _get_exportvariable()).
self._set_exportvariable(name, value)
def __getattr__(self, name):
if name.startswith('__'):
return object.__getattr__(self, name)
return self._get_exportvariable(name)
def __delattr__(self, name):
raise MozbuildDeletionError('Unable to delete attributes for this object')
def __iadd__(self, other):
if isinstance(other, HierarchicalStringList):
self._strings += other._strings
for c in other._children:
self[c] += other[c]
else:
self._check_list(other)
self._strings += other
return self
def __getitem__(self, name):
return self._get_exportvariable(name)
def __setitem__(self, name, value):
self._set_exportvariable(name, value)
def _get_exportvariable(self, name):
# Please change ContextDerivedTypedHierarchicalStringList in context.py
# if you make changes here.
child = self._children.get(name)
if not child:
child = self._children[name] = HierarchicalStringList()
return child
def _set_exportvariable(self, name, value):
if name in self._children:
if value is self._get_exportvariable(name):
return
raise KeyError('global_ns', 'reassign',
'<some variable>.%s' % name)
exports = self._get_exportvariable(name)
exports._check_list(value)
exports._strings += value
def _check_list(self, value):
if not isinstance(value, list):
raise ValueError('Expected a list of strings, not %s' % type(value))
for v in value:
if not isinstance(v, six.string_types):
raise ValueError(
'Expected a list of strings, not an element of %s' % type(v))
class LockFile(object):
"""LockFile is used by the lock_file method to hold the lock.
This object should not be used directly, but only through
the lock_file method below.
"""
def __init__(self, lockfile):
self.lockfile = lockfile
def __del__(self):
while True:
try:
os.remove(self.lockfile)
break
except OSError as e:
if e.errno == errno.EACCES:
# Another process probably has the file open, we'll retry.
# Just a short sleep since we want to drop the lock ASAP
# (but we need to let some other process close the file
# first).
time.sleep(0.1)
else:
# Re-raise unknown errors
raise
def lock_file(lockfile, max_wait=600):
"""Create and hold a lockfile of the given name, with the given timeout.
To release the lock, delete the returned object.
"""
# FUTURE This function and object could be written as a context manager.
while True:
try:
fd = os.open(lockfile, os.O_EXCL | os.O_RDWR | os.O_CREAT)
# We created the lockfile, so we're the owner
break
except OSError as e:
if (e.errno == errno.EEXIST or
(sys.platform == "win32" and e.errno == errno.EACCES)):
pass
else:
# Should not occur
raise
try:
# The lock file exists, try to stat it to get its age
# and read its contents to report the owner PID
f = open(lockfile, 'r')
s = os.stat(lockfile)
except EnvironmentError as e:
if e.errno == errno.ENOENT or e.errno == errno.EACCES:
# We didn't create the lockfile, so it did exist, but it's
# gone now. Just try again
continue
raise Exception('{0} exists but stat() failed: {1}'.format(
lockfile, e.strerror))
# We didn't create the lockfile and it's still there, check
# its age
now = int(time.time())
if now - s[stat.ST_MTIME] > max_wait:
pid = f.readline().rstrip()
raise Exception('{0} has been locked for more than '
'{1} seconds (PID {2})'.format(lockfile, max_wait, pid))
# It's not been locked too long, wait a while and retry
f.close()
time.sleep(1)
# if we get here. we have the lockfile. Convert the os.open file
# descriptor into a Python file object and record our PID in it
f = os.fdopen(fd, 'w')
f.write('{0}\n'.format(os.getpid()))
f.close()
return LockFile(lockfile)
class OrderedDefaultDict(OrderedDict):
'''A combination of OrderedDict and defaultdict.'''
def __init__(self, default_factory, *args, **kwargs):
OrderedDict.__init__(self, *args, **kwargs)
self._default_factory = default_factory
def __missing__(self, key):
value = self[key] = self._default_factory()
return value
class KeyedDefaultDict(dict):
'''Like a defaultdict, but the default_factory function takes the key as
argument'''
def __init__(self, default_factory, *args, **kwargs):
dict.__init__(self, *args, **kwargs)
self._default_factory = default_factory
def __missing__(self, key):
value = self._default_factory(key)
dict.__setitem__(self, key, value)
return value
class ReadOnlyKeyedDefaultDict(KeyedDefaultDict, ReadOnlyDict):
'''Like KeyedDefaultDict, but read-only.'''
class memoize(dict):
'''A decorator to memoize the results of function calls depending
on its arguments.
Both functions and instance methods are handled, although in the
instance method case, the results are cache in the instance itself.
'''