1 """SCons.Node
2
3 The Node package for the SCons software construction utility.
4
5 This is, in many ways, the heart of SCons.
6
7 A Node is where we encapsulate all of the dependency information about
8 any thing that SCons can build, or about any thing which SCons can use
9 to build some other thing. The canonical "thing," of course, is a file,
10 but a Node can also represent something remote (like a web page) or
11 something completely abstract (like an Alias).
12
13 Each specific type of "thing" is specifically represented by a subclass
14 of the Node base class: Node.FS.File for files, Node.Alias for aliases,
15 etc. Dependency information is kept here in the base class, and
16 information specific to files/aliases/etc. is in the subclass. The
17 goal, if we've done this correctly, is that any type of "thing" should
18 be able to depend on any other type of "thing."
19
20 """
21
22
23
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42
43
44 __revision__ = "src/engine/SCons/Node/__init__.py 5357 2011/09/09 21:31:03 bdeegan"
45
46 import collections
47 import copy
48 from itertools import chain
49
50 from SCons.Debug import logInstanceCreation
51 import SCons.Executor
52 import SCons.Memoize
53 import SCons.Util
54
55 from SCons.Debug import Trace
56
58 return str(obj.__class__).split('.')[-1]
59
60
61
62
63
64
65
66
67 no_state = 0
68 pending = 1
69 executing = 2
70 up_to_date = 3
71 executed = 4
72 failed = 5
73
74 StateString = {
75 0 : "no_state",
76 1 : "pending",
77 2 : "executing",
78 3 : "up_to_date",
79 4 : "executed",
80 5 : "failed",
81 }
82
83
84 implicit_cache = 0
85
86
87 implicit_deps_unchanged = 0
88
89
90 implicit_deps_changed = 0
91
92
93
95
96 Annotate = do_nothing
97
98
99
101 """
102 The generic base class for signature information for a Node.
103
104 Node subclasses should subclass NodeInfoBase to provide their own
105 logic for dealing with their own Node-specific signature information.
106 """
107 current_version_id = 1
113 try:
114 field_list = self.field_list
115 except AttributeError:
116 return
117 for f in field_list:
118 try:
119 delattr(self, f)
120 except AttributeError:
121 pass
122 try:
123 func = getattr(node, 'get_' + f)
124 except AttributeError:
125 pass
126 else:
127 setattr(self, f, func())
131 self.__dict__.update(other.__dict__)
149
151 """
152 The generic base class for build information for a Node.
153
154 This is what gets stored in a .sconsign file for each target file.
155 It contains a NodeInfo instance for this node (signature information
156 that's specific to the type of Node) and direct attributes for the
157 generic build stuff we have to track: sources, explicit dependencies,
158 implicit dependencies, and action information.
159 """
160 current_version_id = 1
162
163
164 self._version_id = self.current_version_id
165 self.bsourcesigs = []
166 self.bdependsigs = []
167 self.bimplicitsigs = []
168 self.bactsig = None
170 self.__dict__.update(other.__dict__)
171
173 """The base Node class, for entities that we know how to
174 build, or use to build other Nodes.
175 """
176
177 if SCons.Memoize.use_memoizer:
178 __metaclass__ = SCons.Memoize.Memoized_Metaclass
179
180 memoizer_counters = []
181
184
186 if __debug__: logInstanceCreation(self, 'Node.Node')
187
188
189
190
191
192
193
194
195
196
197
198
199
200 self.sources = []
201 self.sources_set = set()
202 self._specific_sources = False
203 self.depends = []
204 self.depends_set = set()
205 self.ignore = []
206 self.ignore_set = set()
207 self.prerequisites = SCons.Util.UniqueList()
208 self.implicit = None
209 self.waiting_parents = set()
210 self.waiting_s_e = set()
211 self.ref_count = 0
212 self.wkids = None
213
214 self.env = None
215 self.state = no_state
216 self.precious = None
217 self.noclean = 0
218 self.nocache = 0
219 self.always_build = None
220 self.includes = None
221 self.attributes = self.Attrs()
222 self.side_effect = 0
223 self.side_effects = []
224 self.linked = 0
225
226 self.clear_memoized_values()
227
228
229
230
231 Annotate(self)
232
235
238
239 memoizer_counters.append(SCons.Memoize.CountValue('get_build_env'))
240
242 """Fetch the appropriate Environment to build this node.
243 """
244 try:
245 return self._memo['get_build_env']
246 except KeyError:
247 pass
248 result = self.get_executor().get_build_env()
249 self._memo['get_build_env'] = result
250 return result
251
255
257 """Set the action executor for this node."""
258 self.executor = executor
259
261 """Fetch the action executor for this node. Create one if
262 there isn't already one, and requested to do so."""
263 try:
264 executor = self.executor
265 except AttributeError:
266 if not create:
267 raise
268 try:
269 act = self.builder.action
270 except AttributeError:
271 executor = SCons.Executor.Null(targets=[self])
272 else:
273 executor = SCons.Executor.Executor(act,
274 self.env or self.builder.env,
275 [self.builder.overrides],
276 [self],
277 self.sources)
278 self.executor = executor
279 return executor
280
282 """Let the executor clean up any cached information."""
283 try:
284 executor = self.get_executor(create=None)
285 except AttributeError:
286 pass
287 else:
288 executor.cleanup()
289
291 "Remove cached executor; forces recompute when needed."
292 try:
293 delattr(self, 'executor')
294 except AttributeError:
295 pass
296
298 """Try to push a node into a cache
299 """
300 pass
301
303 """Try to retrieve the node's content from a cache
304
305 This method is called from multiple threads in a parallel build,
306 so only do thread safe stuff here. Do thread unsafe stuff in
307 built().
308
309 Returns true iff the node was successfully retrieved.
310 """
311 return 0
312
313
314
315
316
318 """Get a Node ready for evaluation.
319
320 This is called before the Taskmaster decides if the Node is
321 up-to-date or not. Overriding this method allows for a Node
322 subclass to be disambiguated if necessary, or for an implicit
323 source builder to be attached.
324 """
325 pass
326
328 """Prepare for this Node to be built.
329
330 This is called after the Taskmaster has decided that the Node
331 is out-of-date and must be rebuilt, but before actually calling
332 the method to build the Node.
333
334 This default implementation checks that explicit or implicit
335 dependencies either exist or are derived, and initializes the
336 BuildInfo structure that will hold the information about how
337 this node is, uh, built.
338
339 (The existence of source files is checked separately by the
340 Executor, which aggregates checks for all of the targets built
341 by a specific action.)
342
343 Overriding this method allows for for a Node subclass to remove
344 the underlying file from the file system. Note that subclass
345 methods should call this base class method to get the child
346 check and the BuildInfo structure.
347 """
348 for d in self.depends:
349 if d.missing():
350 msg = "Explicit dependency `%s' not found, needed by target `%s'."
351 raise SCons.Errors.StopError(msg % (d, self))
352 if self.implicit is not None:
353 for i in self.implicit:
354 if i.missing():
355 msg = "Implicit dependency `%s' not found, needed by target `%s'."
356 raise SCons.Errors.StopError(msg % (i, self))
357 self.binfo = self.get_binfo()
358
360 """Actually build the node.
361
362 This is called by the Taskmaster after it's decided that the
363 Node is out-of-date and must be rebuilt, and after the prepare()
364 method has gotten everything, uh, prepared.
365
366 This method is called from multiple threads in a parallel build,
367 so only do thread safe stuff here. Do thread unsafe stuff
368 in built().
369
370 """
371 try:
372 self.get_executor()(self, **kw)
373 except SCons.Errors.BuildError, e:
374 e.node = self
375 raise
376
378 """Called just after this node is successfully built."""
379
380
381
382 for parent in self.waiting_parents:
383 parent.implicit = None
384
385 self.clear()
386
387 self.ninfo.update(self)
388
390 """Called just after this node has been visited (with or
391 without a build)."""
392 try:
393 binfo = self.binfo
394 except AttributeError:
395
396
397 pass
398 else:
399 self.ninfo.update(self)
400 self.store_info()
401
402
403
404
405
407 self.waiting_s_e.add(node)
408
410 """
411 Returns the number of nodes added to our waiting parents list:
412 1 if we add a unique waiting parent, 0 if not. (Note that the
413 returned values are intended to be used to increment a reference
414 count, so don't think you can "clean up" this function by using
415 True and False instead...)
416 """
417 wp = self.waiting_parents
418 if node in wp:
419 return 0
420 wp.add(node)
421 return 1
422
423 - def postprocess(self):
424 """Clean up anything we don't need to hang onto after we've
425 been built."""
426 self.executor_cleanup()
427 self.waiting_parents = set()
428
430 """Completely clear a Node of all its cached state (so that it
431 can be re-evaluated by interfaces that do continuous integration
432 builds).
433 """
434
435
436
437 self.del_binfo()
438 self.clear_memoized_values()
439 self.ninfo = self.new_ninfo()
440 self.executor_cleanup()
441 try:
442 delattr(self, '_calculated_sig')
443 except AttributeError:
444 pass
445 self.includes = None
446
449
451 self.builder = builder
452 try:
453 del self.executor
454 except AttributeError:
455 pass
456
458 """Return whether this Node has a builder or not.
459
460 In Boolean tests, this turns out to be a *lot* more efficient
461 than simply examining the builder attribute directly ("if
462 node.builder: ..."). When the builder attribute is examined
463 directly, it ends up calling __getattr__ for both the __len__
464 and __nonzero__ attributes on instances of our Builder Proxy
465 class(es), generating a bazillion extra calls and slowing
466 things down immensely.
467 """
468 try:
469 b = self.builder
470 except AttributeError:
471
472
473 b = self.builder = None
474 return b is not None
475
477 self.is_explicit = is_explicit
478
480 """Return whether this Node has an explicit builder
481
482 This allows an internal Builder created by SCons to be marked
483 non-explicit, so that it can be overridden by an explicit
484 builder that the user supplies (the canonical example being
485 directories)."""
486 try:
487 return self.is_explicit
488 except AttributeError:
489 self.is_explicit = None
490 return self.is_explicit
491
493 """Return the set builder, or a specified default value"""
494 try:
495 return self.builder
496 except AttributeError:
497 return default_builder
498
499 multiple_side_effect_has_builder = has_builder
500
502 """
503 Returns true iff this node is derived (i.e. built).
504
505 This should return true only for nodes whose path should be in
506 the variant directory when duplicate=0 and should contribute their build
507 signatures when they are used as source files to other derived files. For
508 example: source with source builders are not derived in this sense,
509 and hence should not return true.
510 """
511 return self.has_builder() or self.side_effect
512
514 """Return a list of alternate targets for this Node.
515 """
516 return [], None
517
519 """Return the scanned include lines (implicit dependencies)
520 found in this node.
521
522 The default is no implicit dependencies. We expect this method
523 to be overridden by any subclass that can be scanned for
524 implicit dependencies.
525 """
526 return []
527
529 """Return a list of implicit dependencies for this node.
530
531 This method exists to handle recursive invocation of the scanner
532 on the implicit dependencies returned by the scanner, if the
533 scanner's recursive flag says that we should.
534 """
535 if not scanner:
536 return []
537
538
539
540
541
542 nodes = [self]
543 seen = {}
544 seen[self] = 1
545 deps = []
546 while nodes:
547 n = nodes.pop(0)
548 d = [x for x in n.get_found_includes(env, scanner, path) if x not in seen]
549 if d:
550 deps.extend(d)
551 for n in d:
552 seen[n] = 1
553 nodes.extend(scanner.recurse_nodes(d))
554
555 return deps
556
559
561 return self.builder.target_scanner
562
564 """Fetch the source scanner for the specified node
565
566 NOTE: "self" is the target being built, "node" is
567 the source file for which we want to fetch the scanner.
568
569 Implies self.has_builder() is true; again, expect to only be
570 called from locations where this is already verified.
571
572 This function may be called very often; it attempts to cache
573 the scanner found to improve performance.
574 """
575 scanner = None
576 try:
577 scanner = self.builder.source_scanner
578 except AttributeError:
579 pass
580 if not scanner:
581
582
583
584 scanner = self.get_env_scanner(self.get_build_env())
585 if scanner:
586 scanner = scanner.select(node)
587 return scanner
588
590 if not hasattr(self, 'implicit') or self.implicit is None:
591 self.implicit = []
592 self.implicit_set = set()
593 self._children_reset()
594 self._add_child(self.implicit, self.implicit_set, deps)
595
644
647
649 """Selects a scanner for this Node.
650
651 This is a separate method so it can be overridden by Node
652 subclasses (specifically, Node.FS.Dir) that *must* use their
653 own Scanner and don't select one the Scanner.Selector that's
654 configured for the target.
655 """
656 return scanner.select(self)
657
659 if safe and self.env:
660 return
661 self.env = env
662
663
664
665
666
667 NodeInfo = NodeInfoBase
668 BuildInfo = BuildInfoBase
669
671 ninfo = self.NodeInfo(self)
672 return ninfo
673
675 try:
676 return self.ninfo
677 except AttributeError:
678 self.ninfo = self.new_ninfo()
679 return self.ninfo
680
682 binfo = self.BuildInfo(self)
683 return binfo
684
686 """
687 Fetch a node's build information.
688
689 node - the node whose sources will be collected
690 cache - alternate node to use for the signature cache
691 returns - the build signature
692
693 This no longer handles the recursive descent of the
694 node's children's signatures. We expect that they're
695 already built and updated by someone else, if that's
696 what's wanted.
697 """
698 try:
699 return self.binfo
700 except AttributeError:
701 pass
702
703 binfo = self.new_binfo()
704 self.binfo = binfo
705
706 executor = self.get_executor()
707 ignore_set = self.ignore_set
708
709 if self.has_builder():
710 binfo.bact = str(executor)
711 binfo.bactsig = SCons.Util.MD5signature(executor.get_contents())
712
713 if self._specific_sources:
714 sources = []
715 for s in self.sources:
716 if s not in ignore_set:
717 sources.append(s)
718 else:
719 sources = executor.get_unignored_sources(self, self.ignore)
720 seen = set()
721 bsources = []
722 bsourcesigs = []
723 for s in sources:
724 if not s in seen:
725 seen.add(s)
726 bsources.append(s)
727 bsourcesigs.append(s.get_ninfo())
728 binfo.bsources = bsources
729 binfo.bsourcesigs = bsourcesigs
730
731 depends = self.depends
732 dependsigs = []
733 for d in depends:
734 if d not in ignore_set:
735 dependsigs.append(d.get_ninfo())
736 binfo.bdepends = depends
737 binfo.bdependsigs = dependsigs
738
739 implicit = self.implicit or []
740 implicitsigs = []
741 for i in implicit:
742 if i not in ignore_set:
743 implicitsigs.append(i.get_ninfo())
744 binfo.bimplicit = implicit
745 binfo.bimplicitsigs = implicitsigs
746
747 return binfo
748
750 """Delete the build info from this node."""
751 try:
752 delattr(self, 'binfo')
753 except AttributeError:
754 pass
755
757 try:
758 return self.ninfo.csig
759 except AttributeError:
760 ninfo = self.get_ninfo()
761 ninfo.csig = SCons.Util.MD5signature(self.get_contents())
762 return self.ninfo.csig
763
766
768 """Make the build signature permanent (that is, store it in the
769 .sconsign file or equivalent)."""
770 pass
771
774
777
779 """Fetch the stored implicit dependencies"""
780 return None
781
782
783
784
785
787 """Set the Node's precious value."""
788 self.precious = precious
789
791 """Set the Node's noclean value."""
792
793
794 self.noclean = noclean and 1 or 0
795
797 """Set the Node's nocache value."""
798
799
800 self.nocache = nocache and 1 or 0
801
803 """Set the Node's always_build value."""
804 self.always_build = always_build
805
807 """Does this node exists?"""
808
809 return 1
810
812 """Does this node exist locally or in a repositiory?"""
813
814 return self.exists()
815
817 return not self.is_derived() and \
818 not self.linked and \
819 not self.rexists()
820
822 """Remove this Node: no-op by default."""
823 return None
824
826 """Adds dependencies."""
827 try:
828 self._add_child(self.depends, self.depends_set, depend)
829 except TypeError, e:
830 e = e.args[0]
831 if SCons.Util.is_List(e):
832 s = list(map(str, e))
833 else:
834 s = str(e)
835 raise SCons.Errors.UserError("attempted to add a non-Node dependency to %s:\n\t%s is a %s, not a Node" % (str(self), s, type(e)))
836
841
843 """Adds dependencies to ignore."""
844 try:
845 self._add_child(self.ignore, self.ignore_set, depend)
846 except TypeError, e:
847 e = e.args[0]
848 if SCons.Util.is_List(e):
849 s = list(map(str, e))
850 else:
851 s = str(e)
852 raise SCons.Errors.UserError("attempted to ignore a non-Node dependency of %s:\n\t%s is a %s, not a Node" % (str(self), s, type(e)))
853
855 """Adds sources."""
856 if self._specific_sources:
857 return
858 try:
859 self._add_child(self.sources, self.sources_set, source)
860 except TypeError, e:
861 e = e.args[0]
862 if SCons.Util.is_List(e):
863 s = list(map(str, e))
864 else:
865 s = str(e)
866 raise SCons.Errors.UserError("attempted to add a non-Node as source of %s:\n\t%s is a %s, not a Node" % (str(self), s, type(e)))
867
869 """Adds 'child' to 'collection', first checking 'set' to see if it's
870 already present."""
871
872
873
874
875
876 added = None
877 for c in child:
878 if c not in set:
879 set.add(c)
880 collection.append(c)
881 added = 1
882 if added:
883 self._children_reset()
884
886 self.add_source(source)
887 self._specific_sources = True
888
890 """Add a node to the list of kids waiting to be evaluated"""
891 if self.wkids is not None:
892 self.wkids.append(wkid)
893
899
900 memoizer_counters.append(SCons.Memoize.CountValue('_children_get'))
901
903 try:
904 return self._memo['children_get']
905 except KeyError:
906 pass
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925 if self.ignore_set:
926 if self.implicit is None:
927 iter = chain(self.sources,self.depends)
928 else:
929 iter = chain(self.sources, self.depends, self.implicit)
930
931 children = []
932 for i in iter:
933 if i not in self.ignore_set:
934 children.append(i)
935 else:
936 if self.implicit is None:
937 children = self.sources + self.depends
938 else:
939 children = self.sources + self.depends + self.implicit
940
941 self._memo['children_get'] = children
942 return children
943
945 """Return a list of all the node's direct children."""
946 if scan:
947 self.scan()
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966 if self.implicit is None:
967 return self.sources + self.depends
968 else:
969 return self.sources + self.depends + self.implicit
970
972 """Return a list of the node's direct children, minus those
973 that are ignored by this node."""
974 if scan:
975 self.scan()
976 return self._children_get()
977
980
983
986
993
995 """
996
997 Must be overridden in a specific subclass to return True if this
998 Node (a dependency) has changed since the last time it was used
999 to build the specified target. prev_ni is this Node's state (for
1000 example, its file timestamp, length, maybe content signature)
1001 as of the last time the target was built.
1002
1003 Note that this method is called through the dependency, not the
1004 target, because a dependency Node must be able to use its own
1005 logic to decide if it changed. For example, File Nodes need to
1006 obey if we're configured to use timestamps, but Python Value Nodes
1007 never use timestamps and always use the content. If this method
1008 were called through the target, then each Node's implementation
1009 of this method would have to have more complicated logic to
1010 handle all the different Node types on which it might depend.
1011 """
1012 raise NotImplementedError
1013
1016
1018 """
1019 Returns if the node is up-to-date with respect to the BuildInfo
1020 stored last time it was built. The default behavior is to compare
1021 it against our own previously stored BuildInfo, but the stored
1022 BuildInfo from another Node (typically one in a Repository)
1023 can be used instead.
1024
1025 Note that we now *always* check every dependency. We used to
1026 short-circuit the check by returning as soon as we detected
1027 any difference, but we now rely on checking every dependency
1028 to make sure that any necessary Node information (for example,
1029 the content signature of an #included .h file) is updated.
1030 """
1031 t = 0
1032 if t: Trace('changed(%s [%s], %s)' % (self, classname(self), node))
1033 if node is None:
1034 node = self
1035
1036 result = False
1037
1038 bi = node.get_stored_info().binfo
1039 then = bi.bsourcesigs + bi.bdependsigs + bi.bimplicitsigs
1040 children = self.children()
1041
1042 diff = len(children) - len(then)
1043 if diff:
1044
1045
1046
1047
1048
1049 then.extend([None] * diff)
1050 if t: Trace(': old %s new %s' % (len(then), len(children)))
1051 result = True
1052
1053 for child, prev_ni in zip(children, then):
1054 if child.changed_since_last_build(self, prev_ni):
1055 if t: Trace(': %s changed' % child)
1056 result = True
1057
1058 contents = self.get_executor().get_contents()
1059 if self.has_builder():
1060 import SCons.Util
1061 newsig = SCons.Util.MD5signature(contents)
1062 if bi.bactsig != newsig:
1063 if t: Trace(': bactsig %s != newsig %s' % (bi.bactsig, newsig))
1064 result = True
1065
1066 if not result:
1067 if t: Trace(': up to date')
1068
1069 if t: Trace('\n')
1070
1071 return result
1072
1074 """Default check for whether the Node is current: unknown Node
1075 subtypes are always out of date, so they will always get built."""
1076 return None
1077
1079 """Alternate check for whether the Node is current: If all of
1080 our children were up-to-date, then this Node was up-to-date, too.
1081
1082 The SCons.Node.Alias and SCons.Node.Python.Value subclasses
1083 rebind their current() method to this method."""
1084
1085 self.binfo = self.get_binfo()
1086 if self.always_build:
1087 return None
1088 state = 0
1089 for kid in self.children(None):
1090 s = kid.get_state()
1091 if s and (not state or s > state):
1092 state = s
1093 return (state == 0 or state == SCons.Node.up_to_date)
1094
1096 """Always pass the string representation of a Node to
1097 the command interpreter literally."""
1098 return 1
1099
1101 """
1102 Return a text representation, suitable for displaying to the
1103 user, of the include tree for the sources of this node.
1104 """
1105 if self.is_derived() and self.env:
1106 env = self.get_build_env()
1107 for s in self.sources:
1108 scanner = self.get_source_scanner(s)
1109 if scanner:
1110 path = self.get_build_scanner_path(scanner)
1111 else:
1112 path = None
1113 def f(node, env=env, scanner=scanner, path=path):
1114 return node.get_found_includes(env, scanner, path)
1115 return SCons.Util.render_tree(s, f, 1)
1116 else:
1117 return None
1118
1120 """
1121 Return an absolute path to the Node. This will return simply
1122 str(Node) by default, but for Node types that have a concept of
1123 relative path, this might return something different.
1124 """
1125 return str(self)
1126
1128 """
1129 Return a string representation of the Node that will always
1130 be the same for this particular Node, no matter what. This
1131 is by contrast to the __str__() method, which might, for
1132 instance, return a relative path for a file Node. The purpose
1133 of this method is to generate a value to be used in signature
1134 calculation for the command line used to build a target, and
1135 we use this method instead of str() to avoid unnecessary
1136 rebuilds. This method does not need to return something that
1137 would actually work in a command line; it can return any kind of
1138 nonsense, so long as it does not change.
1139 """
1140 return str(self)
1141
1143 """This is a convenience function designed primarily to be
1144 used in command generators (i.e., CommandGeneratorActions or
1145 Environment variables that are callable), which are called
1146 with a for_signature argument that is nonzero if the command
1147 generator is being called to generate a signature for the
1148 command line, which determines if we should rebuild or not.
1149
1150 Such command generators should use this method in preference
1151 to str(Node) when converting a Node to a string, passing
1152 in the for_signature parameter, such that we will call
1153 Node.for_signature() or str(Node) properly, depending on whether
1154 we are calculating a signature or actually constructing a
1155 command line."""
1156 if for_signature:
1157 return self.for_signature()
1158 return str(self)
1159
1161 """
1162 This method is expected to return an object that will function
1163 exactly like this Node, except that it implements any additional
1164 special features that we would like to be in effect for
1165 Environment variable substitution. The principle use is that
1166 some Nodes would like to implement a __getattr__() method,
1167 but putting that in the Node type itself has a tendency to kill
1168 performance. We instead put it in a proxy and return it from
1169 this method. It is legal for this method to return self
1170 if no new functionality is needed for Environment substitution.
1171 """
1172 return self
1173
1175 if not self.exists():
1176 return "building `%s' because it doesn't exist\n" % self
1177
1178 if self.always_build:
1179 return "rebuilding `%s' because AlwaysBuild() is specified\n" % self
1180
1181 old = self.get_stored_info()
1182 if old is None:
1183 return None
1184
1185 old = old.binfo
1186 old.prepare_dependencies()
1187
1188 try:
1189 old_bkids = old.bsources + old.bdepends + old.bimplicit
1190 old_bkidsigs = old.bsourcesigs + old.bdependsigs + old.bimplicitsigs
1191 except AttributeError:
1192 return "Cannot explain why `%s' is being rebuilt: No previous build information found\n" % self
1193
1194 new = self.get_binfo()
1195
1196 new_bkids = new.bsources + new.bdepends + new.bimplicit
1197 new_bkidsigs = new.bsourcesigs + new.bdependsigs + new.bimplicitsigs
1198
1199 osig = dict(zip(old_bkids, old_bkidsigs))
1200 nsig = dict(zip(new_bkids, new_bkidsigs))
1201
1202
1203
1204
1205
1206
1207
1208 def stringify( s, E=self.dir.Entry ) :
1209 if hasattr( s, 'dir' ) :
1210 return str(E(s))
1211 return str(s)
1212
1213 lines = []
1214
1215 removed = [x for x in old_bkids if not x in new_bkids]
1216 if removed:
1217 removed = list(map(stringify, removed))
1218 fmt = "`%s' is no longer a dependency\n"
1219 lines.extend([fmt % s for s in removed])
1220
1221 for k in new_bkids:
1222 if not k in old_bkids:
1223 lines.append("`%s' is a new dependency\n" % stringify(k))
1224 elif k.changed_since_last_build(self, osig[k]):
1225 lines.append("`%s' changed\n" % stringify(k))
1226
1227 if len(lines) == 0 and old_bkids != new_bkids:
1228 lines.append("the dependency order changed:\n" +
1229 "%sold: %s\n" % (' '*15, list(map(stringify, old_bkids))) +
1230 "%snew: %s\n" % (' '*15, list(map(stringify, new_bkids))))
1231
1232 if len(lines) == 0:
1233 def fmt_with_title(title, strlines):
1234 lines = strlines.split('\n')
1235 sep = '\n' + ' '*(15 + len(title))
1236 return ' '*15 + title + sep.join(lines) + '\n'
1237 if old.bactsig != new.bactsig:
1238 if old.bact == new.bact:
1239 lines.append("the contents of the build action changed\n" +
1240 fmt_with_title('action: ', new.bact))
1241 else:
1242 lines.append("the build action changed:\n" +
1243 fmt_with_title('old: ', old.bact) +
1244 fmt_with_title('new: ', new.bact))
1245
1246 if len(lines) == 0:
1247 return "rebuilding `%s' for unknown reasons\n" % self
1248
1249 preamble = "rebuilding `%s' because" % self
1250 if len(lines) == 1:
1251 return "%s %s" % (preamble, lines[0])
1252 else:
1253 lines = ["%s:\n" % preamble] + lines
1254 return ( ' '*11).join(lines)
1255
1258 return str(list(map(str, self.data)))
1259
1263
1265 """An iterator for walking a Node tree.
1266
1267 This is depth-first, children are visited before the parent.
1268 The Walker object can be initialized with any node, and
1269 returns the next node on the descent with each get_next() call.
1270 'kids_func' is an optional function that will be called to
1271 get the children of a node instead of calling 'children'.
1272 'cycle_func' is an optional function that will be called
1273 when a cycle is detected.
1274
1275 This class does not get caught in node cycles caused, for example,
1276 by C header file include loops.
1277 """
1278 - def __init__(self, node, kids_func=get_children,
1279 cycle_func=ignore_cycle,
1280 eval_func=do_nothing):
1281 self.kids_func = kids_func
1282 self.cycle_func = cycle_func
1283 self.eval_func = eval_func
1284 node.wkids = copy.copy(kids_func(node, None))
1285 self.stack = [node]
1286 self.history = {}
1287 self.history[node] = None
1288
1290 """Return the next node for this walk of the tree.
1291
1292 This function is intentionally iterative, not recursive,
1293 to sidestep any issues of stack size limitations.
1294 """
1295
1296 while self.stack:
1297 if self.stack[-1].wkids:
1298 node = self.stack[-1].wkids.pop(0)
1299 if not self.stack[-1].wkids:
1300 self.stack[-1].wkids = None
1301 if node in self.history:
1302 self.cycle_func(node, self.stack)
1303 else:
1304 node.wkids = copy.copy(self.kids_func(node, self.stack[-1]))
1305 self.stack.append(node)
1306 self.history[node] = None
1307 else:
1308 node = self.stack.pop()
1309 del self.history[node]
1310 if node:
1311 if self.stack:
1312 parent = self.stack[-1]
1313 else:
1314 parent = None
1315 self.eval_func(node, parent)
1316 return node
1317 return None
1318
1320 return not self.stack
1321
1322
1323 arg2nodes_lookups = []
1324
1325
1326
1327
1328
1329
1330