1. anatoly techtonik
  2. SCons

Source

SCons / src / engine / SCons / Node / __init__.py

The default branch has multiple heads

  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
"""SCons.Node

The Node package for the SCons software construction utility.

This is, in many ways, the heart of SCons.

A Node is where we encapsulate all of the dependency information about
any thing that SCons can build, or about any thing which SCons can use
to build some other thing.  The canonical "thing," of course, is a file,
but a Node can also represent something remote (like a web page) or
something completely abstract (like an Alias).

Each specific type of "thing" is specifically represented by a subclass
of the Node base class:  Node.FS.File for files, Node.Alias for aliases,
etc.  Dependency information is kept here in the base class, and
information specific to files/aliases/etc. is in the subclass.  The
goal, if we've done this correctly, is that any type of "thing" should
be able to depend on any other type of "thing."

"""

#
# Copyright (c) 2001, 2002 Steven Knight
#
# Permission is hereby granted, free of charge, to any person obtaining
# a copy of this software and associated documentation files (the
# "Software"), to deal in the Software without restriction, including
# without limitation the rights to use, copy, modify, merge, publish,
# distribute, sublicense, and/or sell copies of the Software, and to
# permit persons to whom the Software is furnished to do so, subject to
# the following conditions:
#
# The above copyright notice and this permission notice shall be included
# in all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
# KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
# WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
# LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
# OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
# WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
#

__revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"



import copy
import types

import SCons.Sig
import SCons.Util

# Node states
#
# These are in "priority" order, so that the maximum value for any
# child/dependency of a node represents the state of that node if
# it has no builder of its own.  The canonical example is a file
# system directory, which is only up to date if all of its children
# were up to date.
pending = 1
executing = 2
up_to_date = 3
executed = 4
failed = 5
stack = 6 # nodes that are in the current Taskmaster execution stack

# controls whether implicit depedencies are cached:
implicit_cache = 0

# controls whether implicit dep changes are ignored:
implicit_deps_unchanged = 0

# controls whether the cached implicit deps are ignored:
implicit_deps_changed = 0


class Node:
    """The base Node class, for entities that we know how to
    build, or use to build other Nodes.
    """

    class Attrs:
        pass

    def __init__(self):
        self.sources = []       # source files used to build node
        self.depends = []       # explicit dependencies (from Depends)
        self.implicit = None    # implicit (scanned) dependencies (None means not scanned yet)
        self.ignore = []        # dependencies to ignore
        self.parents = {}
        self.wkids = None       # Kids yet to walk, when it's an array
        self.builder = None
        self.source_scanner = None      # implicit scanner from scanner map
        self.target_scanner = None      # explicit scanner from this node's Builder
        self.env = None
        self.state = None
        self.precious = None
        self.found_includes = {}
        self.includes = None
        self.overrides = {}     # construction variable overrides for building this node
        self.attributes = self.Attrs() # Generic place to stick information about the Node.
        self.side_effect = 0 # true iff this node is a side effect
        self.side_effects = [] # the side effects of building this target

    def generate_build_env(self):
        return self.env.Override(self.overrides)

    def build(self):
        """Actually build the node.

        This method is called from multiple threads in a parallel build,
        so only do thread safe stuff here. Do thread unsafe stuff in
        built().
        """
        if not self.builder:
            return None
        action_list = self.builder.get_actions()
        if not action_list:
            return
        targets = self.builder.targets(self)
        env = self.generate_build_env()
        for action in action_list:
            stat = action(targets, self.sources, env)
            if stat:
                raise SCons.Errors.BuildError(node = self,
                                              errstr = "Error %d" % stat)

    def built(self):
        """Called just after this node is sucessfully built."""
        self.store_bsig()

        # Clear out the implicit dependency caches:
        # XXX this really should somehow be made more general and put
        #     under the control of the scanners.
        if self.source_scanner:
            self.found_includes = {}
            self.includes = None

            def get_parents(node, parent): return node.get_parents()
            def clear_cache(node, parent):
                node.implicit = None
                node.del_bsig()
            w = Walker(self, get_parents, ignore_cycle, clear_cache)
            while w.next(): pass

        # clear out the content signature, since the contents of this
        # node were presumably just changed:
        self.del_csig()

    def depends_on(self, nodes):
        """Does this node depend on any of 'nodes'?"""
        for node in nodes:
            if node in self.children():
                return 1

        return 0

    def builder_set(self, builder):
        self.builder = builder

    def builder_sig_adapter(self):
        """Create an adapter for calculating a builder's signature.

        The underlying signature class will call get_contents()
        to fetch the signature of a builder, but the actual
        content of that signature depends on the node and the
        environment (for construction variable substitution),
        so this adapter provides the right glue between the two.
        """
        class Adapter:
            def __init__(self, node):
                self.node = node
            def get_contents(self):
                return self.node.builder.get_contents(self.node, self.node.sources, self.node.generate_build_env())
            def get_timestamp(self):
                return None
        return Adapter(self)

    def get_implicit_deps(self, env, scanner, target):
        """Return a list of implicit dependencies for this node"""
        return []

    def scan(self):
        """Scan this node's dependents for implicit dependencies."""
        # Don't bother scanning non-derived files, because we don't
        # care what their dependencies are.
        # Don't scan again, if we already have scanned.
        if not self.implicit is None:
            return
        self.implicit = []
        if not self.builder:
            return

        if implicit_cache and not implicit_deps_changed:
            implicit = self.get_stored_implicit()
            if implicit is not None:
                implicit = map(self.builder.source_factory, implicit)
                self._add_child(self.implicit, implicit)
                calc = SCons.Sig.default_calc
                if implicit_deps_unchanged or calc.current(self, calc.bsig(self)):
                    return
                else:
                    # one of this node's sources has changed, so
                    # we need to recalculate the implicit deps,
                    # and the bsig:
                    self.implicit = []
                    self.del_bsig()

        for child in self.children(scan=0):
            self._add_child(self.implicit,
                            child.get_implicit_deps(self.generate_build_env(),
                                                    child.source_scanner,
                                                    self))

        # scan this node itself for implicit dependencies
        self._add_child(self.implicit,
                        self.get_implicit_deps(self.generate_build_env(),
                                               self.target_scanner,
                                               self))

        if implicit_cache:
            self.store_implicit()

    def scanner_key(self):
        return None

    def env_set(self, env, safe=0):
        if safe and self.env:
            return
        self.env = env

    def calc_signature(self, calc):
        """
        Select and calculate the appropriate build signature for a node.

        self - the node
        calc - the signature calculation module
        returns - the signature

        This method does not store the signature in the node or
        in the .sconsign file.
        """

        if self.builder:
            if SCons.Sig.build_signature:
                if not hasattr(self, 'bsig'):
                    self.set_bsig(calc.bsig(self))
                return self.get_bsig()
            else:
                if not hasattr(self, 'csig'):
                    self.set_csig(calc.csig(self))
                return self.get_csig()
        elif not self.exists():
            return None
        else:
            if not hasattr(self, 'csig'):
                self.set_csig(calc.csig(self))
            return self.get_csig()

    def get_bsig(self):
        """Get the node's build signature (based on the signatures
        of its dependency files and build information)."""
        if not hasattr(self, 'bsig'):
            return None
        return self.bsig

    def set_bsig(self, bsig):
        """Set the node's build signature (based on the signatures
        of its dependency files and build information)."""
        self.bsig = bsig

    def store_bsig(self):
        """Make the build signature permanent (that is, store it in the
        .sconsign file or equivalent)."""
        pass

    def del_bsig(self):
        """Delete the bsig from this node."""
        if hasattr(self, 'bsig'):
            delattr(self, 'bsig')

    def get_csig(self):
        """Get the signature of the node's content."""
        if not hasattr(self, 'csig'):
            return None
        return self.csig

    def set_csig(self, csig):
        """Set the signature of the node's content."""
        self.csig = csig

    def store_csig(self):
        """Make the content signature permanent (that is, store it in the
        .sconsign file or equivalent)."""
        pass

    def del_csig(self):
        """Delete the csig from this node."""
        if hasattr(self, 'csig'):
            delattr(self, 'csig')

    def get_prevsiginfo(self):
        """Fetch the previous signature information from the
        .sconsign entry."""
        return None

    def get_timestamp(self):
        return 0

    def store_timestamp(self):
        """Make the timestamp permanent (that is, store it in the
        .sconsign file or equivalent)."""
        pass

    def store_implicit(self):
        """Make the implicit deps permanent (that is, store them in the
        .sconsign file or equivalent)."""
        pass

    def get_stored_implicit(self):
        """Fetch the stored implicit dependencies"""
        return None

    def set_precious(self, precious = 1):
        """Set the Node's precious value."""
        self.precious = precious

    def prepare(self):
        """Prepare for this Node to be created:  no-op by default."""
        pass

    def remove(self):
        """Remove this Node:  no-op by default."""
        return None

    def add_dependency(self, depend):
        """Adds dependencies. The depend argument must be a list."""
        self._add_child(self.depends, depend)

    def add_ignore(self, depend):
        """Adds dependencies to ignore. The depend argument must be a list."""
        self._add_child(self.ignore, depend)

    def add_source(self, source):
        """Adds sources. The source argument must be a list."""
        self._add_child(self.sources, source)

    def _add_child(self, collection, child):
        """Adds 'child' to 'collection'. The 'child' argument must be a list"""
        if type(child) is not type([]):
            raise TypeError("child must be a list")
        child = filter(lambda x, s=collection: x not in s, child)
        if child:
            collection.extend(child)

        for c in child:
            c.parents[self] = 1

    def add_wkid(self, wkid):
        """Add a node to the list of kids waiting to be evaluated"""
        if self.wkids != None:
            self.wkids.append(wkid)

    def children(self, scan=1):
        """Return a list of the node's direct children, minus those
        that are ignored by this node."""
        return filter(lambda x, i=self.ignore: x not in i,
                      self.all_children(scan))

    def all_children(self, scan=1):
        """Return a list of all the node's direct children."""
        #XXX Need to remove duplicates from this
        if scan:
            self.scan()
        if self.implicit is None:
            return self.sources + self.depends
        else:
            return self.sources + self.depends + self.implicit

    def get_parents(self):
        return self.parents.keys()

    def set_state(self, state):
        self.state = state

    def get_state(self):
        return self.state

    def current(self):
        return None

    def rfile(self):
        return self

    def rstr(self):
        return str(self)

    def is_literal(self):
        """Always pass the string representation of a Node to
        the command interpreter literally."""
        return 1

def get_children(node, parent): return node.children()
def ignore_cycle(node, stack): pass
def do_nothing(node, parent): pass

class Walker:
    """An iterator for walking a Node tree.

    This is depth-first, children are visited before the parent.
    The Walker object can be initialized with any node, and
    returns the next node on the descent with each next() call.
    'kids_func' is an optional function that will be called to
    get the children of a node instead of calling 'children'.
    'cycle_func' is an optional function that will be called
    when a cycle is detected.

    This class does not get caught in node cycles caused, for example,
    by C header file include loops.
    """
    def __init__(self, node, kids_func=get_children,
                             cycle_func=ignore_cycle,
                             eval_func=do_nothing):
        self.kids_func = kids_func
        self.cycle_func = cycle_func
        self.eval_func = eval_func
        node.wkids = copy.copy(kids_func(node, None))
        self.stack = [node]
        self.history = {} # used to efficiently detect and avoid cycles
        self.history[node] = None

    def next(self):
        """Return the next node for this walk of the tree.

        This function is intentionally iterative, not recursive,
        to sidestep any issues of stack size limitations.
        """

        while self.stack:
            if self.stack[-1].wkids:
                node = self.stack[-1].wkids.pop(0)
                if not self.stack[-1].wkids:
                    self.stack[-1].wkids = None
                if self.history.has_key(node):
                    self.cycle_func(node, self.stack)
                else:
                    node.wkids = copy.copy(self.kids_func(node, self.stack[-1]))
                    self.stack.append(node)
                    self.history[node] = None
            else:
                node = self.stack.pop()
                del self.history[node]
                if node:
                    if self.stack:
                        parent = self.stack[-1]
                    else:
                        parent = None
                    self.eval_func(node, parent)
                return node

    def is_done(self):
        return not self.stack


arg2nodes_lookups = []

def arg2nodes(args, node_factory=None, lookup_list=arg2nodes_lookups):
    """This function converts a string or list into a list of Node
    instances.  It accepts the following inputs:
        - A single string,
        - A single Node instance,
        - A list containing either strings or Node instances.
    In all cases, strings are converted to Node instances, and the
    function returns a list of Node instances."""

    if not args:
        return []
    if not SCons.Util.is_List(args):
        args = [args]

    nodes = []
    for v in args:
        if SCons.Util.is_String(v):
            n = None
            for l in lookup_list:
                n = l(v)
                if not n is None:
                    break
            if not n is None:
                if SCons.Util.is_String(n) and node_factory:
                    n = node_factory(n)
                nodes.append(n)
            elif node_factory:
                nodes.append(node_factory(v))
        # Do we enforce the following restriction?  Maybe, but it
        # would also restrict what we can do to allow people to
        # use the engine with alternate Node implementations...
        #elif not issubclass(v.__class__, Node):
        #    raise TypeError
        else:
            nodes.append(v)

    return nodes