Package SCons :: Package Node
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Source Code for Package SCons.Node

   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  # Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 The SCons Foundation 
  24  # 
  25  # Permission is hereby granted, free of charge, to any person obtaining 
  26  # a copy of this software and associated documentation files (the 
  27  # "Software"), to deal in the Software without restriction, including 
  28  # without limitation the rights to use, copy, modify, merge, publish, 
  29  # distribute, sublicense, and/or sell copies of the Software, and to 
  30  # permit persons to whom the Software is furnished to do so, subject to 
  31  # the following conditions: 
  32  # 
  33  # The above copyright notice and this permission notice shall be included 
  34  # in all copies or substantial portions of the Software. 
  35  # 
  36  # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY 
  37  # KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE 
  38  # WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 
  39  # NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE 
  40  # LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION 
  41  # OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION 
  42  # WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. 
  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   
57 -def classname(obj):
58 return str(obj.__class__).split('.')[-1]
59 60 # Node states 61 # 62 # These are in "priority" order, so that the maximum value for any 63 # child/dependency of a node represents the state of that node if 64 # it has no builder of its own. The canonical example is a file 65 # system directory, which is only up to date if all of its children 66 # were up to date. 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 # controls whether implicit dependencies are cached: 84 implicit_cache = 0 85 86 # controls whether implicit dep changes are ignored: 87 implicit_deps_unchanged = 0 88 89 # controls whether the cached implicit deps are ignored: 90 implicit_deps_changed = 0 91 92 # A variable that can be set to an interface-specific function be called 93 # to annotate a Node with information about its creation.
94 -def do_nothing(node): pass
95 96 Annotate = do_nothing 97 98 # Classes for signature info for Nodes. 99
100 -class NodeInfoBase(object):
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
108 - def __init__(self, node=None):
109 # Create an object attribute from the class attribute so it ends up 110 # in the pickled data in the .sconsign file. 111 self._version_id = self.current_version_id
112 - def update(self, node):
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())
128 - def convert(self, node, val):
129 pass
130 - def merge(self, other):
131 self.__dict__.update(other.__dict__)
132 - def format(self, field_list=None, names=0):
133 if field_list is None: 134 try: 135 field_list = self.field_list 136 except AttributeError: 137 field_list = sorted(self.__dict__.keys()) 138 fields = [] 139 for field in field_list: 140 try: 141 f = getattr(self, field) 142 except AttributeError: 143 f = None 144 f = str(f) 145 if names: 146 f = field + ': ' + f 147 fields.append(f) 148 return fields
149
150 -class BuildInfoBase(object):
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
161 - def __init__(self, node=None):
162 # Create an object attribute from the class attribute so it ends up 163 # in the pickled data in the .sconsign file. 164 self._version_id = self.current_version_id 165 self.bsourcesigs = [] 166 self.bdependsigs = [] 167 self.bimplicitsigs = [] 168 self.bactsig = None
169 - def merge(self, other):
170 self.__dict__.update(other.__dict__)
171
172 -class Node(object):
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
182 - class Attrs(object):
183 pass
184
185 - def __init__(self):
186 if __debug__: logInstanceCreation(self, 'Node.Node') 187 # Note that we no longer explicitly initialize a self.builder 188 # attribute to None here. That's because the self.builder 189 # attribute may be created on-the-fly later by a subclass (the 190 # canonical example being a builder to fetch a file from a 191 # source code system like CVS or Subversion). 192 193 # Each list of children that we maintain is accompanied by a 194 # dictionary used to look up quickly whether a node is already 195 # present in the list. Empirical tests showed that it was 196 # fastest to maintain them as side-by-side Node attributes in 197 # this way, instead of wrapping up each list+dictionary pair in 198 # a class. (Of course, we could always still do that in the 199 # future if we had a good reason to...). 200 self.sources = [] # source files used to build node 201 self.sources_set = set() 202 self._specific_sources = False 203 self.depends = [] # explicit dependencies (from Depends) 204 self.depends_set = set() 205 self.ignore = [] # dependencies to ignore 206 self.ignore_set = set() 207 self.prerequisites = SCons.Util.UniqueList() 208 self.implicit = None # implicit (scanned) dependencies (None means not scanned yet) 209 self.waiting_parents = set() 210 self.waiting_s_e = set() 211 self.ref_count = 0 212 self.wkids = None # Kids yet to walk, when it's an array 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() # Generic place to stick information about the Node. 222 self.side_effect = 0 # true iff this node is a side effect 223 self.side_effects = [] # the side effects of building this target 224 self.linked = 0 # is this node linked to the variant directory? 225 226 self.clear_memoized_values() 227 228 # Let the interface in which the build engine is embedded 229 # annotate this Node with its own info (like a description of 230 # what line in what file created the node, for example). 231 Annotate(self)
232
233 - def disambiguate(self, must_exist=None):
234 return self
235
236 - def get_suffix(self):
237 return ''
238 239 memoizer_counters.append(SCons.Memoize.CountValue('get_build_env')) 240
241 - def get_build_env(self):
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
252 - def get_build_scanner_path(self, scanner):
253 """Fetch the appropriate scanner path for this node.""" 254 return self.get_executor().get_build_scanner_path(scanner)
255
256 - def set_executor(self, executor):
257 """Set the action executor for this node.""" 258 self.executor = executor
259
260 - def get_executor(self, create=1):
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
281 - def executor_cleanup(self):
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
290 - def reset_executor(self):
291 "Remove cached executor; forces recompute when needed." 292 try: 293 delattr(self, 'executor') 294 except AttributeError: 295 pass
296
297 - def push_to_cache(self):
298 """Try to push a node into a cache 299 """ 300 pass
301
302 - def retrieve_from_cache(self):
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 # Taskmaster interface subsystem 315 # 316
317 - def make_ready(self):
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
327 - def prepare(self):
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
359 - def build(self, **kw):
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
377 - def built(self):
378 """Called just after this node is successfully built.""" 379 380 # Clear the implicit dependency caches of any Nodes 381 # waiting for this Node to be built. 382 for parent in self.waiting_parents: 383 parent.implicit = None 384 385 self.clear() 386 387 self.ninfo.update(self)
388
389 - def visited(self):
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 # Apparently this node doesn't need build info, so 396 # don't bother calculating or storing it. 397 pass 398 else: 399 self.ninfo.update(self) 400 self.store_info()
401 402 # 403 # 404 # 405
406 - def add_to_waiting_s_e(self, node):
407 self.waiting_s_e.add(node)
408
409 - def add_to_waiting_parents(self, node):
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
429 - def clear(self):
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 # The del_binfo() call here isn't necessary for normal execution, 435 # but is for interactive mode, where we might rebuild the same 436 # target and need to start from scratch. 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
447 - def clear_memoized_values(self):
448 self._memo = {}
449
450 - def builder_set(self, builder):
451 self.builder = builder 452 try: 453 del self.executor 454 except AttributeError: 455 pass
456
457 - def has_builder(self):
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 # There was no explicit builder for this Node, so initialize 472 # the self.builder attribute to None now. 473 b = self.builder = None 474 return b is not None
475
476 - def set_explicit(self, is_explicit):
477 self.is_explicit = is_explicit
478
479 - def has_explicit_builder(self):
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
492 - def get_builder(self, default_builder=None):
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
501 - def is_derived(self):
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
513 - def alter_targets(self):
514 """Return a list of alternate targets for this Node. 515 """ 516 return [], None
517
518 - def get_found_includes(self, env, scanner, path):
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
528 - def get_implicit_deps(self, env, scanner, path):
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 # Give the scanner a chance to select a more specific scanner 539 # for this Node. 540 #scanner = scanner.select(self) 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
557 - def get_env_scanner(self, env, kw={}):
558 return env.get_scanner(self.scanner_key())
559
560 - def get_target_scanner(self):
561 return self.builder.target_scanner
562
563 - def get_source_scanner(self, node):
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 # The builder didn't have an explicit scanner, so go look up 582 # a scanner from env['SCANNERS'] based on the node's scanner 583 # key (usually the file extension). 584 scanner = self.get_env_scanner(self.get_build_env()) 585 if scanner: 586 scanner = scanner.select(node) 587 return scanner
588
589 - def add_to_implicit(self, deps):
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
596 - def scan(self):
597 """Scan this node's dependents for implicit dependencies.""" 598 # Don't bother scanning non-derived files, because we don't 599 # care what their dependencies are. 600 # Don't scan again, if we already have scanned. 601 if self.implicit is not None: 602 return 603 self.implicit = [] 604 self.implicit_set = set() 605 self._children_reset() 606 if not self.has_builder(): 607 return 608 609 build_env = self.get_build_env() 610 executor = self.get_executor() 611 612 # Here's where we implement --implicit-cache. 613 if implicit_cache and not implicit_deps_changed: 614 implicit = self.get_stored_implicit() 615 if implicit is not None: 616 # We now add the implicit dependencies returned from the 617 # stored .sconsign entry to have already been converted 618 # to Nodes for us. (We used to run them through a 619 # source_factory function here.) 620 621 # Update all of the targets with them. This 622 # essentially short-circuits an N*M scan of the 623 # sources for each individual target, which is a hell 624 # of a lot more efficient. 625 for tgt in executor.get_all_targets(): 626 tgt.add_to_implicit(implicit) 627 628 if implicit_deps_unchanged or self.is_up_to_date(): 629 return 630 # one of this node's sources has changed, 631 # so we must recalculate the implicit deps for all targets 632 for tgt in executor.get_all_targets(): 633 tgt.implicit = [] 634 tgt.implicit_set = set() 635 636 # Have the executor scan the sources. 637 executor.scan_sources(self.builder.source_scanner) 638 639 # If there's a target scanner, have the executor scan the target 640 # node itself and associated targets that might be built. 641 scanner = self.get_target_scanner() 642 if scanner: 643 executor.scan_targets(scanner)
644
645 - def scanner_key(self):
646 return None
647
648 - def select_scanner(self, scanner):
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
658 - def env_set(self, env, safe=0):
659 if safe and self.env: 660 return 661 self.env = env
662 663 # 664 # SIGNATURE SUBSYSTEM 665 # 666 667 NodeInfo = NodeInfoBase 668 BuildInfo = BuildInfoBase 669
670 - def new_ninfo(self):
671 ninfo = self.NodeInfo(self) 672 return ninfo
673
674 - def get_ninfo(self):
675 try: 676 return self.ninfo 677 except AttributeError: 678 self.ninfo = self.new_ninfo() 679 return self.ninfo
680
681 - def new_binfo(self):
682 binfo = self.BuildInfo(self) 683 return binfo
684
685 - def get_binfo(self):
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
749 - def del_binfo(self):
750 """Delete the build info from this node.""" 751 try: 752 delattr(self, 'binfo') 753 except AttributeError: 754 pass
755
756 - def get_csig(self):
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
764 - def get_cachedir_csig(self):
765 return self.get_csig()
766
767 - def store_info(self):
768 """Make the build signature permanent (that is, store it in the 769 .sconsign file or equivalent).""" 770 pass
771
772 - def do_not_store_info(self):
773 pass
774
775 - def get_stored_info(self):
776 return None
777
778 - def get_stored_implicit(self):
779 """Fetch the stored implicit dependencies""" 780 return None
781 782 # 783 # 784 # 785
786 - def set_precious(self, precious = 1):
787 """Set the Node's precious value.""" 788 self.precious = precious
789
790 - def set_noclean(self, noclean = 1):
791 """Set the Node's noclean value.""" 792 # Make sure noclean is an integer so the --debug=stree 793 # output in Util.py can use it as an index. 794 self.noclean = noclean and 1 or 0
795
796 - def set_nocache(self, nocache = 1):
797 """Set the Node's nocache value.""" 798 # Make sure nocache is an integer so the --debug=stree 799 # output in Util.py can use it as an index. 800 self.nocache = nocache and 1 or 0
801
802 - def set_always_build(self, always_build = 1):
803 """Set the Node's always_build value.""" 804 self.always_build = always_build
805
806 - def exists(self):
807 """Does this node exists?""" 808 # All node exist by default: 809 return 1
810
811 - def rexists(self):
812 """Does this node exist locally or in a repositiory?""" 813 # There are no repositories by default: 814 return self.exists()
815
816 - def missing(self):
817 return not self.is_derived() and \ 818 not self.linked and \ 819 not self.rexists()
820
821 - def remove(self):
822 """Remove this Node: no-op by default.""" 823 return None
824
825 - def add_dependency(self, depend):
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
837 - def add_prerequisite(self, prerequisite):
838 """Adds prerequisites""" 839 self.prerequisites.extend(prerequisite) 840 self._children_reset()
841
842 - def add_ignore(self, depend):
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
854 - def add_source(self, source):
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
868 - def _add_child(self, collection, set, child):
869 """Adds 'child' to 'collection', first checking 'set' to see if it's 870 already present.""" 871 #if type(child) is not type([]): 872 # child = [child] 873 #for c in child: 874 # if not isinstance(c, Node): 875 # raise TypeError, c 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
885 - def set_specific_source(self, source):
886 self.add_source(source) 887 self._specific_sources = True
888
889 - def add_wkid(self, wkid):
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
894 - def _children_reset(self):
895 self.clear_memoized_values() 896 # We need to let the Executor clear out any calculated 897 # build info that it's cached so we can re-calculate it. 898 self.executor_cleanup()
899 900 memoizer_counters.append(SCons.Memoize.CountValue('_children_get')) 901
902 - def _children_get(self):
903 try: 904 return self._memo['children_get'] 905 except KeyError: 906 pass 907 908 # The return list may contain duplicate Nodes, especially in 909 # source trees where there are a lot of repeated #includes 910 # of a tangle of .h files. Profiling shows, however, that 911 # eliminating the duplicates with a brute-force approach that 912 # preserves the order (that is, something like: 913 # 914 # u = [] 915 # for n in list: 916 # if n not in u: 917 # u.append(n)" 918 # 919 # takes more cycles than just letting the underlying methods 920 # hand back cached values if a Node's information is requested 921 # multiple times. (Other methods of removing duplicates, like 922 # using dictionary keys, lose the order, and the only ordered 923 # dictionary patterns I found all ended up using "not in" 924 # internally anyway...) 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
944 - def all_children(self, scan=1):
945 """Return a list of all the node's direct children.""" 946 if scan: 947 self.scan() 948 949 # The return list may contain duplicate Nodes, especially in 950 # source trees where there are a lot of repeated #includes 951 # of a tangle of .h files. Profiling shows, however, that 952 # eliminating the duplicates with a brute-force approach that 953 # preserves the order (that is, something like: 954 # 955 # u = [] 956 # for n in list: 957 # if n not in u: 958 # u.append(n)" 959 # 960 # takes more cycles than just letting the underlying methods 961 # hand back cached values if a Node's information is requested 962 # multiple times. (Other methods of removing duplicates, like 963 # using dictionary keys, lose the order, and the only ordered 964 # dictionary patterns I found all ended up using "not in" 965 # internally anyway...) 966 if self.implicit is None: 967 return self.sources + self.depends 968 else: 969 return self.sources + self.depends + self.implicit
970
971 - def children(self, scan=1):
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
978 - def set_state(self, state):
979 self.state = state
980
981 - def get_state(self):
982 return self.state
983
984 - def state_has_changed(self, target, prev_ni):
985 return (self.state != SCons.Node.up_to_date)
986
987 - def get_env(self):
988 env = self.env 989 if not env: 990 import SCons.Defaults 991 env = SCons.Defaults.DefaultEnvironment() 992 return env
993
994 - def changed_since_last_build(self, target, prev_ni):
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
1014 - def Decider(self, function):
1015 SCons.Util.AddMethod(self, function, 'changed_since_last_build')
1016
1017 - def changed(self, node=None):
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 # The old and new dependency lists are different lengths. 1045 # This always indicates that the Node must be rebuilt. 1046 # We also extend the old dependency list with enough None 1047 # entries to equal the new dependency list, for the benefit 1048 # of the loop below that updates node information. 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
1073 - def is_up_to_date(self):
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
1078 - def children_are_up_to_date(self):
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 # Allow the children to calculate their signatures. 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
1095 - def is_literal(self):
1096 """Always pass the string representation of a Node to 1097 the command interpreter literally.""" 1098 return 1
1099
1100 - def render_include_tree(self):
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
1119 - def get_abspath(self):
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
1127 - def for_signature(self):
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
1142 - def get_string(self, for_signature):
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
1160 - def get_subst_proxy(self):
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
1174 - def explain(self):
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 # The sources and dependencies we'll want to report are all stored 1203 # as relative paths to this target's directory, but we want to 1204 # report them relative to the top-level SConstruct directory, 1205 # so we only print them after running them through this lambda 1206 # to turn them into the right relative Node and then return 1207 # its string. 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
1256 -class NodeList(collections.UserList):
1257 - def __str__(self):
1258 return str(list(map(str, self.data)))
1259
1260 -def get_children(node, parent): return node.children()
1261 -def ignore_cycle(node, stack): pass
1262 -def do_nothing(node, parent): pass
1263
1264 -class Walker(object):
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 = {} # used to efficiently detect and avoid cycles 1287 self.history[node] = None
1288
1289 - def get_next(self):
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
1319 - def is_done(self):
1320 return not self.stack
1321 1322 1323 arg2nodes_lookups = [] 1324 1325 # Local Variables: 1326 # tab-width:4 1327 # indent-tabs-mode:nil 1328 # End: 1329 # vim: set expandtab tabstop=4 shiftwidth=4: 1330