8 files changed, 11046 insertions, 0 deletions
diff --git a/3rdParty/SCons/scons-3.0.1/engine/SCons/Node/Alias.py b/3rdParty/SCons/scons-3.0.1/engine/SCons/Node/Alias.py
new file mode 100644
index 0000000..a035816
--- /dev/null
+++ b/3rdParty/SCons/scons-3.0.1/engine/SCons/Node/Alias.py
@@ -0,0 +1,181 @@
+
+"""scons.Node.Alias
+
+Alias nodes.
+
+This creates a hash of global Aliases (dummy targets).
+
+"""
+
+#
+# __COPYRIGHT__
+#
+# 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 collections
+
+import SCons.Errors
+import SCons.Node
+import SCons.Util
+
+class AliasNameSpace(collections.UserDict):
+    def Alias(self, name, **kw):
+        if isinstance(name, SCons.Node.Alias.Alias):
+            return name
+        try:
+            a = self[name]
+        except KeyError:
+            a = SCons.Node.Alias.Alias(name, **kw)
+            self[name] = a
+        return a
+
+    def lookup(self, name, **kw):
+        try:
+            return self[name]
+        except KeyError:
+            return None
+
+class AliasNodeInfo(SCons.Node.NodeInfoBase):
+    __slots__ = ('csig',)
+    current_version_id = 2
+    field_list = ['csig']
+    def str_to_node(self, s):
+        return default_ans.Alias(s)
+
+    def __getstate__(self):
+        """
+        Return all fields that shall be pickled. Walk the slots in the class
+        hierarchy and add those to the state dictionary. If a '__dict__' slot is
+        available, copy all entries to the dictionary. Also include the version
+        id, which is fixed for all instances of a class.
+        """
+        state = getattr(self, '__dict__', {}).copy()
+        for obj in type(self).mro():
+            for name in getattr(obj,'__slots__',()):
+                if hasattr(self, name):
+                    state[name] = getattr(self, name)
+
+        state['_version_id'] = self.current_version_id
+        try:
+            del state['__weakref__']
+        except KeyError:
+            pass
+
+        return state
+
+    def __setstate__(self, state):
+        """
+        Restore the attributes from a pickled state.
+        """
+        # TODO check or discard version
+        del state['_version_id']
+        for key, value in state.items():
+            if key not in ('__weakref__',):
+                setattr(self, key, value)
+          
+
+class AliasBuildInfo(SCons.Node.BuildInfoBase):
+    __slots__ = ()
+    current_version_id = 2
+
+class Alias(SCons.Node.Node):
+
+    NodeInfo = AliasNodeInfo
+    BuildInfo = AliasBuildInfo
+
+    def __init__(self, name):
+        SCons.Node.Node.__init__(self)
+        self.name = name
+        self.changed_since_last_build = 1
+        self.store_info = 0
+        
+    def str_for_display(self):
+        return '"' + self.__str__() + '"'
+
+    def __str__(self):
+        return self.name
+
+    def make_ready(self):
+        self.get_csig()
+
+    really_build = SCons.Node.Node.build
+    is_up_to_date = SCons.Node.Node.children_are_up_to_date
+
+    def is_under(self, dir):
+        # Make Alias nodes get built regardless of
+        # what directory scons was run from. Alias nodes
+        # are outside the filesystem:
+        return 1
+
+    def get_contents(self):
+        """The contents of an alias is the concatenation
+        of the content signatures of all its sources."""
+        childsigs = [n.get_csig() for n in self.children()]
+        return ''.join(childsigs)
+
+    def sconsign(self):
+        """An Alias is not recorded in .sconsign files"""
+        pass
+
+    #
+    #
+    #
+
+    def build(self):
+        """A "builder" for aliases."""
+        pass
+
+    def convert(self):
+        try: del self.builder
+        except AttributeError: pass
+        self.reset_executor()
+        self.build = self.really_build
+
+    def get_csig(self):
+        """
+        Generate a node's content signature, the digested signature
+        of its content.
+
+        node - the node
+        cache - alternate node to use for the signature cache
+        returns - the content signature
+        """
+        try:
+            return self.ninfo.csig
+        except AttributeError:
+            pass
+
+        contents = self.get_contents()
+        csig = SCons.Util.MD5signature(contents)
+        self.get_ninfo().csig = csig
+        return csig
+
+default_ans = AliasNameSpace()
+
+SCons.Node.arg2nodes_lookups.append(default_ans.lookup)
+
+# Local Variables:
+# tab-width:4
+# indent-tabs-mode:nil
+# End:
+# vim: set expandtab tabstop=4 shiftwidth=4:
diff --git a/3rdParty/SCons/scons-3.0.1/engine/SCons/Node/AliasTests.py b/3rdParty/SCons/scons-3.0.1/engine/SCons/Node/AliasTests.py
new file mode 100644
index 0000000..8e31875
--- /dev/null
+++ b/3rdParty/SCons/scons-3.0.1/engine/SCons/Node/AliasTests.py
@@ -0,0 +1,131 @@
+#
+# __COPYRIGHT__
+#
+# 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 sys
+import unittest
+
+import TestUnit
+
+import SCons.Errors
+import SCons.Node.Alias
+
+class AliasTestCase(unittest.TestCase):
+
+    def test_AliasNameSpace(self):
+        """Test creating an Alias name space
+        """
+        ans = SCons.Node.Alias.AliasNameSpace()
+        assert ans is not None, ans
+
+    def test_ANS_Alias(self):
+        """Test the Alias() factory
+        """
+        ans = SCons.Node.Alias.AliasNameSpace()
+
+        a1 = ans.Alias('a1')
+        assert a1.name == 'a1', a1.name
+
+        a2 = ans.Alias('a1')
+        assert a1 is a2, (a1, a2)
+
+    def test_get_contents(self):
+        """Test the get_contents() method
+        """
+        class DummyNode(object):
+            def __init__(self, contents):
+                self.contents = contents
+            def get_csig(self):
+                return self.contents
+            def get_contents(self):
+                return self.contents
+
+        ans = SCons.Node.Alias.AliasNameSpace()
+
+        ans.Alias('a1')
+        a = ans.lookup('a1')
+
+        a.sources = [ DummyNode('one'), DummyNode('two'), DummyNode('three') ]
+
+        c = a.get_contents()
+        assert c == 'onetwothree', c
+
+    def test_lookup(self):
+        """Test the lookup() method
+        """
+        ans = SCons.Node.Alias.AliasNameSpace()
+
+        ans.Alias('a1')
+        a = ans.lookup('a1')
+        assert a.name == 'a1', a.name
+
+        a1 = ans.lookup('a1')
+        assert a is a1, a1
+
+        a = ans.lookup('a2')
+        assert a is None, a
+
+    def test_Alias(self):
+        """Test creating an Alias() object
+        """
+        a1 = SCons.Node.Alias.Alias('a')
+        assert a1.name == 'a', a1.name
+
+        a2 = SCons.Node.Alias.Alias('a')
+        assert a2.name == 'a', a2.name
+
+        assert not a1 is a2
+        assert a1.name == a2.name
+
+class AliasNodeInfoTestCase(unittest.TestCase):
+    def test___init__(self):
+        """Test AliasNodeInfo initialization"""
+        ans = SCons.Node.Alias.AliasNameSpace()
+        aaa = ans.Alias('aaa')
+        ni = SCons.Node.Alias.AliasNodeInfo()
+
+class AliasBuildInfoTestCase(unittest.TestCase):
+    def test___init__(self):
+        """Test AliasBuildInfo initialization"""
+        ans = SCons.Node.Alias.AliasNameSpace()
+        aaa = ans.Alias('aaa')
+        bi = SCons.Node.Alias.AliasBuildInfo()
+
+if __name__ == "__main__":
+    suite = unittest.TestSuite()
+    tclasses = [
+        AliasTestCase,
+        AliasBuildInfoTestCase,
+        AliasNodeInfoTestCase,
+    ]
+    for tclass in tclasses:
+        names = unittest.getTestCaseNames(tclass, 'test_')
+        suite.addTests(list(map(tclass, names)))
+    TestUnit.run(suite)
+
+# Local Variables:
+# tab-width:4
+# indent-tabs-mode:nil
+# End:
+# vim: set expandtab tabstop=4 shiftwidth=4:
diff --git a/3rdParty/SCons/scons-3.0.1/engine/SCons/Node/FS.py b/3rdParty/SCons/scons-3.0.1/engine/SCons/Node/FS.py
new file mode 100644
index 0000000..684f0d1
--- /dev/null
+++ b/3rdParty/SCons/scons-3.0.1/engine/SCons/Node/FS.py
@@ -0,0 +1,3545 @@
+"""scons.Node.FS
+
+File system nodes.
+
+These Nodes represent the canonical external objects that people think
+of when they think of building software: files and directories.
+
+This holds a "default_fs" variable that should be initialized with an FS
+that can be used by scripts or modules looking for the canonical default.
+
+"""
+
+#
+# __COPYRIGHT__
+#
+# 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.
+from __future__ import print_function
+
+__revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
+
+import fnmatch
+import os
+import re
+import shutil
+import stat
+import sys
+import time
+import codecs
+
+import SCons.Action
+import SCons.Debug
+from SCons.Debug import logInstanceCreation
+import SCons.Errors
+import SCons.Memoize
+import SCons.Node
+import SCons.Node.Alias
+import SCons.Subst
+import SCons.Util
+import SCons.Warnings
+
+from SCons.Debug import Trace
+
+print_duplicate = 0
+
+
+def sconsign_none(node):
+    raise NotImplementedError
+
+def sconsign_dir(node):
+    """Return the .sconsign file info for this directory,
+    creating it first if necessary."""
+    if not node._sconsign:
+        import SCons.SConsign
+        node._sconsign = SCons.SConsign.ForDirectory(node)
+    return node._sconsign
+
+_sconsign_map = {0 : sconsign_none,
+                 1 : sconsign_dir}
+
+class EntryProxyAttributeError(AttributeError):
+    """
+    An AttributeError subclass for recording and displaying the name
+    of the underlying Entry involved in an AttributeError exception.
+    """
+    def __init__(self, entry_proxy, attribute):
+        AttributeError.__init__(self)
+        self.entry_proxy = entry_proxy
+        self.attribute = attribute
+    def __str__(self):
+        entry = self.entry_proxy.get()
+        fmt = "%s instance %s has no attribute %s"
+        return fmt % (entry.__class__.__name__,
+                      repr(entry.name),
+                      repr(self.attribute))
+
+# The max_drift value:  by default, use a cached signature value for
+# any file that's been untouched for more than two days.
+default_max_drift = 2*24*60*60
+
+#
+# We stringify these file system Nodes a lot.  Turning a file system Node
+# into a string is non-trivial, because the final string representation
+# can depend on a lot of factors:  whether it's a derived target or not,
+# whether it's linked to a repository or source directory, and whether
+# there's duplication going on.  The normal technique for optimizing
+# calculations like this is to memoize (cache) the string value, so you
+# only have to do the calculation once.
+#
+# A number of the above factors, however, can be set after we've already
+# been asked to return a string for a Node, because a Repository() or
+# VariantDir() call or the like may not occur until later in SConscript
+# files.  So this variable controls whether we bother trying to save
+# string values for Nodes.  The wrapper interface can set this whenever
+# they're done mucking with Repository and VariantDir and the other stuff,
+# to let this module know it can start returning saved string values
+# for Nodes.
+#
+Save_Strings = None
+
+def save_strings(val):
+    global Save_Strings
+    Save_Strings = val
+
+#
+# Avoid unnecessary function calls by recording a Boolean value that
+# tells us whether or not os.path.splitdrive() actually does anything
+# on this system, and therefore whether we need to bother calling it
+# when looking up path names in various methods below.
+#
+
+do_splitdrive = None
+_my_splitdrive =None
+
+def initialize_do_splitdrive():
+    global do_splitdrive
+    global has_unc
+    drive, path = os.path.splitdrive('X:/foo')
+    has_unc = hasattr(os.path, 'splitunc')
+
+    do_splitdrive = not not drive or has_unc
+
+    global _my_splitdrive
+    if has_unc:
+        def splitdrive(p):
+            if p[1:2] == ':':
+                return p[:2], p[2:]
+            if p[0:2] == '//':
+                # Note that we leave a leading slash in the path
+                # because UNC paths are always absolute.
+                return '//', p[1:]
+            return '', p
+    else:
+        def splitdrive(p):
+            if p[1:2] == ':':
+                return p[:2], p[2:]
+            return '', p
+    _my_splitdrive = splitdrive
+
+    # Keep some commonly used values in global variables to skip to
+    # module look-up costs.
+    global OS_SEP
+    global UNC_PREFIX
+    global os_sep_is_slash
+
+    OS_SEP = os.sep
+    UNC_PREFIX = OS_SEP + OS_SEP
+    os_sep_is_slash = OS_SEP == '/'
+
+initialize_do_splitdrive()
+
+# Used to avoid invoking os.path.normpath if not necessary.
+needs_normpath_check = re.compile(
+    r'''
+      # We need to renormalize the path if it contains any consecutive
+      # '/' characters.
+      .*// |
+
+      # We need to renormalize the path if it contains a '..' directory.
+      # Note that we check for all the following cases:
+      #
+      #    a) The path is a single '..'
+      #    b) The path starts with '..'. E.g. '../' or '../moredirs'
+      #       but we not match '..abc/'.
+      #    c) The path ends with '..'. E.g. '/..' or 'dirs/..'
+      #    d) The path contains a '..' in the middle.
+      #       E.g. dirs/../moredirs
+
+      (.*/)?\.\.(?:/|$) |
+
+      # We need to renormalize the path if it contains a '.'
+      # directory, but NOT if it is a single '.'  '/' characters. We
+      # do not want to match a single '.' because this case is checked
+      # for explicitly since this is common enough case.
+      #
+      # Note that we check for all the following cases:
+      #
+      #    a) We don't match a single '.'
+      #    b) We match if the path starts with '.'. E.g. './' or
+      #       './moredirs' but we not match '.abc/'.
+      #    c) We match if the path ends with '.'. E.g. '/.' or
+      #    'dirs/.'
+      #    d) We match if the path contains a '.' in the middle.
+      #       E.g. dirs/./moredirs
+
+      \./|.*/\.(?:/|$)
+
+    ''',
+    re.VERBOSE
+    )
+needs_normpath_match = needs_normpath_check.match
+
+#
+# SCons.Action objects for interacting with the outside world.
+#
+# The Node.FS methods in this module should use these actions to
+# create and/or remove files and directories; they should *not* use
+# os.{link,symlink,unlink,mkdir}(), etc., directly.
+#
+# Using these SCons.Action objects ensures that descriptions of these
+# external activities are properly displayed, that the displays are
+# suppressed when the -s (silent) option is used, and (most importantly)
+# the actions are disabled when the the -n option is used, in which case
+# there should be *no* changes to the external file system(s)...
+#
+
+# For Now disable hard & softlinks for win32
+# PY3 supports them, but the rest of SCons is not ready for this
+# in some cases user permissions may be required.
+# TODO: See if theres a reasonable way to enable using links on win32/64
+
+if hasattr(os, 'link') and sys.platform != 'win32':
+    def _hardlink_func(fs, src, dst):
+        # If the source is a symlink, we can't just hard-link to it
+        # because a relative symlink may point somewhere completely
+        # different.  We must disambiguate the symlink and then
+        # hard-link the final destination file.
+        while fs.islink(src):
+            link = fs.readlink(src)
+            if not os.path.isabs(link):
+                src = link
+            else:
+                src = os.path.join(os.path.dirname(src), link)
+        fs.link(src, dst)
+else:
+    _hardlink_func = None
+
+if hasattr(os, 'symlink') and sys.platform != 'win32':
+    def _softlink_func(fs, src, dst):
+        fs.symlink(src, dst)
+else:
+    _softlink_func = None
+
+def _copy_func(fs, src, dest):
+    shutil.copy2(src, dest)
+    st = fs.stat(src)
+    fs.chmod(dest, stat.S_IMODE(st[stat.ST_MODE]) | stat.S_IWRITE)
+
+
+Valid_Duplicates = ['hard-soft-copy', 'soft-hard-copy',
+                    'hard-copy', 'soft-copy', 'copy']
+
+Link_Funcs = [] # contains the callables of the specified duplication style
+
+def set_duplicate(duplicate):
+    # Fill in the Link_Funcs list according to the argument
+    # (discarding those not available on the platform).
+
+    # Set up the dictionary that maps the argument names to the
+    # underlying implementations.  We do this inside this function,
+    # not in the top-level module code, so that we can remap os.link
+    # and os.symlink for testing purposes.
+    link_dict = {
+        'hard' : _hardlink_func,
+        'soft' : _softlink_func,
+        'copy' : _copy_func
+    }
+
+    if not duplicate in Valid_Duplicates:
+        raise SCons.Errors.InternalError("The argument of set_duplicate "
+                                           "should be in Valid_Duplicates")
+    global Link_Funcs
+    Link_Funcs = []
+    for func in duplicate.split('-'):
+        if link_dict[func]:
+            Link_Funcs.append(link_dict[func])
+
+def LinkFunc(target, source, env):
+    # Relative paths cause problems with symbolic links, so
+    # we use absolute paths, which may be a problem for people
+    # who want to move their soft-linked src-trees around. Those
+    # people should use the 'hard-copy' mode, softlinks cannot be
+    # used for that; at least I have no idea how ...
+    src = source[0].get_abspath()
+    dest = target[0].get_abspath()
+    dir, file = os.path.split(dest)
+    if dir and not target[0].fs.isdir(dir):
+        os.makedirs(dir)
+    if not Link_Funcs:
+        # Set a default order of link functions.
+        set_duplicate('hard-soft-copy')
+    fs = source[0].fs
+    # Now link the files with the previously specified order.
+    for func in Link_Funcs:
+        try:
+            func(fs, src, dest)
+            break
+        except (IOError, OSError):
+            # An OSError indicates something happened like a permissions
+            # problem or an attempt to symlink across file-system
+            # boundaries.  An IOError indicates something like the file
+            # not existing.  In either case, keeping trying additional
+            # functions in the list and only raise an error if the last
+            # one failed.
+            if func == Link_Funcs[-1]:
+                # exception of the last link method (copy) are fatal
+                raise
+    return 0
+
+Link = SCons.Action.Action(LinkFunc, None)
+def LocalString(target, source, env):
+    return 'Local copy of %s from %s' % (target[0], source[0])
+
+LocalCopy = SCons.Action.Action(LinkFunc, LocalString)
+
+def UnlinkFunc(target, source, env):
+    t = target[0]
+    t.fs.unlink(t.get_abspath())
+    return 0
+
+Unlink = SCons.Action.Action(UnlinkFunc, None)
+
+def MkdirFunc(target, source, env):
+    t = target[0]
+    if not t.exists():
+        t.fs.mkdir(t.get_abspath())
+    return 0
+
+Mkdir = SCons.Action.Action(MkdirFunc, None, presub=None)
+
+MkdirBuilder = None
+
+def get_MkdirBuilder():
+    global MkdirBuilder
+    if MkdirBuilder is None:
+        import SCons.Builder
+        import SCons.Defaults
+        # "env" will get filled in by Executor.get_build_env()
+        # calling SCons.Defaults.DefaultEnvironment() when necessary.
+        MkdirBuilder = SCons.Builder.Builder(action = Mkdir,
+                                             env = None,
+                                             explain = None,
+                                             is_explicit = None,
+                                             target_scanner = SCons.Defaults.DirEntryScanner,
+                                             name = "MkdirBuilder")
+    return MkdirBuilder
+
+class _Null(object):
+    pass
+
+_null = _Null()
+
+# Cygwin's os.path.normcase pretends it's on a case-sensitive filesystem.
+_is_cygwin = sys.platform == "cygwin"
+if os.path.normcase("TeSt") == os.path.normpath("TeSt") and not _is_cygwin:
+    def _my_normcase(x):
+        return x
+else:
+    def _my_normcase(x):
+        return x.upper()
+
+
+
+class DiskChecker(object):
+    def __init__(self, type, do, ignore):
+        self.type = type
+        self.do = do
+        self.ignore = ignore
+        self.func = do
+    def __call__(self, *args, **kw):
+        return self.func(*args, **kw)
+    def set(self, list):
+        if self.type in list:
+            self.func = self.do
+        else:
+            self.func = self.ignore
+
+def do_diskcheck_match(node, predicate, errorfmt):
+    result = predicate()
+    try:
+        # If calling the predicate() cached a None value from stat(),
+        # remove it so it doesn't interfere with later attempts to
+        # build this Node as we walk the DAG.  (This isn't a great way
+        # to do this, we're reaching into an interface that doesn't
+        # really belong to us, but it's all about performance, so
+        # for now we'll just document the dependency...)
+        if node._memo['stat'] is None:
+            del node._memo['stat']
+    except (AttributeError, KeyError):
+        pass
+    if result:
+        raise TypeError(errorfmt % node.get_abspath())
+
+def ignore_diskcheck_match(node, predicate, errorfmt):
+    pass
+
+
+
+diskcheck_match = DiskChecker('match', do_diskcheck_match, ignore_diskcheck_match)
+
+diskcheckers = [
+    diskcheck_match,
+]
+
+def set_diskcheck(list):
+    for dc in diskcheckers:
+        dc.set(list)
+
+def diskcheck_types():
+    return [dc.type for dc in diskcheckers]
+
+
+
+class EntryProxy(SCons.Util.Proxy):
+
+    __str__ = SCons.Util.Delegate('__str__')
+
+    # In PY3 if a class defines __eq__, then it must explicitly provide
+    # __hash__.  Since SCons.Util.Proxy provides __eq__ we need the following
+    # see: https://docs.python.org/3.1/reference/datamodel.html#object.__hash__
+    __hash__ = SCons.Util.Delegate('__hash__')
+
+    def __get_abspath(self):
+        entry = self.get()
+        return SCons.Subst.SpecialAttrWrapper(entry.get_abspath(),
+                                             entry.name + "_abspath")
+
+    def __get_filebase(self):
+        name = self.get().name
+        return SCons.Subst.SpecialAttrWrapper(SCons.Util.splitext(name)[0],
+                                             name + "_filebase")
+
+    def __get_suffix(self):
+        name = self.get().name
+        return SCons.Subst.SpecialAttrWrapper(SCons.Util.splitext(name)[1],
+                                             name + "_suffix")
+
+    def __get_file(self):
+        name = self.get().name
+        return SCons.Subst.SpecialAttrWrapper(name, name + "_file")
+
+    def __get_base_path(self):
+        """Return the file's directory and file name, with the
+        suffix stripped."""
+        entry = self.get()
+        return SCons.Subst.SpecialAttrWrapper(SCons.Util.splitext(entry.get_path())[0],
+                                             entry.name + "_base")
+
+    def __get_posix_path(self):
+        """Return the path with / as the path separator,
+        regardless of platform."""
+        if os_sep_is_slash:
+            return self
+        else:
+            entry = self.get()
+            r = entry.get_path().replace(OS_SEP, '/')
+            return SCons.Subst.SpecialAttrWrapper(r, entry.name + "_posix")
+
+    def __get_windows_path(self):
+        """Return the path with \ as the path separator,
+        regardless of platform."""
+        if OS_SEP == '\\':
+            return self
+        else:
+            entry = self.get()
+            r = entry.get_path().replace(OS_SEP, '\\')
+            return SCons.Subst.SpecialAttrWrapper(r, entry.name + "_windows")
+
+    def __get_srcnode(self):
+        return EntryProxy(self.get().srcnode())
+
+    def __get_srcdir(self):
+        """Returns the directory containing the source node linked to this
+        node via VariantDir(), or the directory of this node if not linked."""
+        return EntryProxy(self.get().srcnode().dir)
+
+    def __get_rsrcnode(self):
+        return EntryProxy(self.get().srcnode().rfile())
+
+    def __get_rsrcdir(self):
+        """Returns the directory containing the source node linked to this
+        node via VariantDir(), or the directory of this node if not linked."""
+        return EntryProxy(self.get().srcnode().rfile().dir)
+
+    def __get_dir(self):
+        return EntryProxy(self.get().dir)
+
+    dictSpecialAttrs = { "base"     : __get_base_path,
+                         "posix"    : __get_posix_path,
+                         "windows"  : __get_windows_path,
+                         "win32"    : __get_windows_path,
+                         "srcpath"  : __get_srcnode,
+                         "srcdir"   : __get_srcdir,
+                         "dir"      : __get_dir,
+                         "abspath"  : __get_abspath,
+                         "filebase" : __get_filebase,
+                         "suffix"   : __get_suffix,
+                         "file"     : __get_file,
+                         "rsrcpath" : __get_rsrcnode,
+                         "rsrcdir"  : __get_rsrcdir,
+                       }
+
+    def __getattr__(self, name):
+        # This is how we implement the "special" attributes
+        # such as base, posix, srcdir, etc.
+        try:
+            attr_function = self.dictSpecialAttrs[name]
+        except KeyError:
+            try:
+                attr = SCons.Util.Proxy.__getattr__(self, name)
+            except AttributeError as e:
+                # Raise our own AttributeError subclass with an
+                # overridden __str__() method that identifies the
+                # name of the entry that caused the exception.
+                raise EntryProxyAttributeError(self, name)
+            return attr
+        else:
+            return attr_function(self)
+
+
+class Base(SCons.Node.Node):
+    """A generic class for file system entries.  This class is for
+    when we don't know yet whether the entry being looked up is a file
+    or a directory.  Instances of this class can morph into either
+    Dir or File objects by a later, more precise lookup.
+
+    Note: this class does not define __cmp__ and __hash__ for
+    efficiency reasons.  SCons does a lot of comparing of
+    Node.FS.{Base,Entry,File,Dir} objects, so those operations must be
+    as fast as possible, which means we want to use Python's built-in
+    object identity comparisons.
+    """
+
+    __slots__ = ['name',
+                 'fs',
+                 '_abspath',
+                 '_labspath',
+                 '_path',
+                 '_tpath',
+                 '_path_elements',
+                 'dir',
+                 'cwd',
+                 'duplicate',
+                 '_local',
+                 'sbuilder',
+                 '_proxy',
+                 '_func_sconsign']
+
+    def __init__(self, name, directory, fs):
+        """Initialize a generic Node.FS.Base object.
+
+        Call the superclass initialization, take care of setting up
+        our relative and absolute paths, identify our parent
+        directory, and indicate that this node should use
+        signatures."""
+
+        if SCons.Debug.track_instances: logInstanceCreation(self, 'Node.FS.Base')
+        SCons.Node.Node.__init__(self)
+
+        # Filenames and paths are probably reused and are intern'ed to save some memory.
+        # Filename with extension as it was specified when the object was
+        # created; to obtain filesystem path, use Python str() function
+        self.name = SCons.Util.silent_intern(name)
+        self.fs = fs #: Reference to parent Node.FS object
+
+        assert directory, "A directory must be provided"
+
+        self._abspath = None
+        self._labspath = None
+        self._path = None
+        self._tpath = None
+        self._path_elements = None
+
+        self.dir = directory
+        self.cwd = None # will hold the SConscript directory for target nodes
+        self.duplicate = directory.duplicate
+        self.changed_since_last_build = 2
+        self._func_sconsign = 0
+        self._func_exists = 2
+        self._func_rexists = 2
+        self._func_get_contents = 0
+        self._func_target_from_source = 1
+        self.store_info = 1
+
+    def str_for_display(self):
+        return '"' + self.__str__() + '"'
+
+    def must_be_same(self, klass):
+        """
+        This node, which already existed, is being looked up as the
+        specified klass.  Raise an exception if it isn't.
+        """
+        if isinstance(self, klass) or klass is Entry:
+            return
+        raise TypeError("Tried to lookup %s '%s' as a %s." %\
+              (self.__class__.__name__, self.get_internal_path(), klass.__name__))
+
+    def get_dir(self):
+        return self.dir
+
+    def get_suffix(self):
+        return SCons.Util.splitext(self.name)[1]
+
+    def rfile(self):
+        return self
+
+    def __getattr__(self, attr):
+        """ Together with the node_bwcomp dict defined below,
+            this method provides a simple backward compatibility
+            layer for the Node attributes 'abspath', 'labspath',
+            'path', 'tpath', 'suffix' and 'path_elements'. These Node
+            attributes used to be directly available in v2.3 and earlier, but
+            have been replaced by getter methods that initialize the
+            single variables lazily when required, in order to save memory.
+            The redirection to the getters lets older Tools and
+            SConstruct continue to work without any additional changes,
+            fully transparent to the user.
+            Note, that __getattr__ is only called as fallback when the
+            requested attribute can't be found, so there should be no
+            speed performance penalty involved for standard builds.
+        """
+        if attr in node_bwcomp:
+            return node_bwcomp[attr](self)
+
+        raise AttributeError("%r object has no attribute %r" %
+                         (self.__class__, attr))
+
+    def __str__(self):
+        """A Node.FS.Base object's string representation is its path
+        name."""
+        global Save_Strings
+        if Save_Strings:
+            return self._save_str()
+        return self._get_str()
+
+    def __lt__(self, other):
+        """ less than operator used by sorting on py3"""
+        return str(self) < str(other)
+
+    @SCons.Memoize.CountMethodCall
+    def _save_str(self):
+        try:
+            return self._memo['_save_str']
+        except KeyError:
+            pass
+        result = SCons.Util.silent_intern(self._get_str())
+        self._memo['_save_str'] = result
+        return result
+
+    def _get_str(self):
+        global Save_Strings
+        if self.duplicate or self.is_derived():
+            return self.get_path()
+        srcnode = self.srcnode()
+        if srcnode.stat() is None and self.stat() is not None:
+            result = self.get_path()
+        else:
+            result = srcnode.get_path()
+        if not Save_Strings:
+            # We're not at the point where we're saving the string
+            # representations of FS Nodes (because we haven't finished
+            # reading the SConscript files and need to have str() return
+            # things relative to them).  That also means we can't yet
+            # cache values returned (or not returned) by stat(), since
+            # Python code in the SConscript files might still create
+            # or otherwise affect the on-disk file.  So get rid of the
+            # values that the underlying stat() method saved.
+            try: del self._memo['stat']
+            except KeyError: pass
+            if self is not srcnode:
+                try: del srcnode._memo['stat']
+                except KeyError: pass
+        return result
+
+    rstr = __str__
+
+    @SCons.Memoize.CountMethodCall
+    def stat(self):
+        try: return self._memo['stat']
+        except KeyError: pass
+        try: result = self.fs.stat(self.get_abspath())
+        except os.error: result = None
+        self._memo['stat'] = result
+        return result
+
+    def exists(self):
+        return SCons.Node._exists_map[self._func_exists](self)
+
+    def rexists(self):
+        return SCons.Node._rexists_map[self._func_rexists](self)
+
+    def getmtime(self):
+        st = self.stat()
+        if st: return st[stat.ST_MTIME]
+        else: return None
+
+    def getsize(self):
+        st = self.stat()
+        if st: return st[stat.ST_SIZE]
+        else: return None
+
+    def isdir(self):
+        st = self.stat()
+        return st is not None and stat.S_ISDIR(st[stat.ST_MODE])
+
+    def isfile(self):
+        st = self.stat()
+        return st is not None and stat.S_ISREG(st[stat.ST_MODE])
+
+    if hasattr(os, 'symlink'):
+        def islink(self):
+            try: st = self.fs.lstat(self.get_abspath())
+            except os.error: return 0
+            return stat.S_ISLNK(st[stat.ST_MODE])
+    else:
+        def islink(self):
+            return 0                    # no symlinks
+
+    def is_under(self, dir):
+        if self is dir:
+            return 1
+        else:
+            return self.dir.is_under(dir)
+
+    def set_local(self):
+        self._local = 1
+
+    def srcnode(self):
+        """If this node is in a build path, return the node
+        corresponding to its source file.  Otherwise, return
+        ourself.
+        """
+        srcdir_list = self.dir.srcdir_list()
+        if srcdir_list:
+            srcnode = srcdir_list[0].Entry(self.name)
+            srcnode.must_be_same(self.__class__)
+            return srcnode
+        return self
+
+    def get_path(self, dir=None):
+        """Return path relative to the current working directory of the
+        Node.FS.Base object that owns us."""
+        if not dir:
+            dir = self.fs.getcwd()
+        if self == dir:
+            return '.'
+        path_elems = self.get_path_elements()
+        pathname = ''
+        try: i = path_elems.index(dir)
+        except ValueError:
+            for p in path_elems[:-1]:
+                pathname += p.dirname
+        else:
+            for p in path_elems[i+1:-1]:
+                pathname += p.dirname
+        return pathname + path_elems[-1].name
+
+    def set_src_builder(self, builder):
+        """Set the source code builder for this node."""
+        self.sbuilder = builder
+        if not self.has_builder():
+            self.builder_set(builder)
+
+    def src_builder(self):
+        """Fetch the source code builder for this node.
+
+        If there isn't one, we cache the source code builder specified
+        for the directory (which in turn will cache the value from its
+        parent directory, and so on up to the file system root).
+        """
+        try:
+            scb = self.sbuilder
+        except AttributeError:
+            scb = self.dir.src_builder()
+            self.sbuilder = scb
+        return scb
+
+    def get_abspath(self):
+        """Get the absolute path of the file."""
+        return self.dir.entry_abspath(self.name)
+
+    def get_labspath(self):
+        """Get the absolute path of the file."""
+        return self.dir.entry_labspath(self.name)
+
+    def get_internal_path(self):
+        if self.dir._path == '.':
+            return self.name
+        else:
+            return self.dir.entry_path(self.name)
+
+    def get_tpath(self):
+        if self.dir._tpath == '.':
+            return self.name
+        else:
+            return self.dir.entry_tpath(self.name)
+
+    def get_path_elements(self):
+        return self.dir._path_elements + [self]
+
+    def for_signature(self):
+        # Return just our name.  Even an absolute path would not work,
+        # because that can change thanks to symlinks or remapped network
+        # paths.
+        return self.name
+
+    def get_subst_proxy(self):
+        try:
+            return self._proxy
+        except AttributeError:
+            ret = EntryProxy(self)
+            self._proxy = ret
+            return ret
+
+    def target_from_source(self, prefix, suffix, splitext=SCons.Util.splitext):
+        """
+
+        Generates a target entry that corresponds to this entry (usually
+        a source file) with the specified prefix and suffix.
+
+        Note that this method can be overridden dynamically for generated
+        files that need different behavior.  See Tool/swig.py for
+        an example.
+        """
+        return SCons.Node._target_from_source_map[self._func_target_from_source](self, prefix, suffix, splitext)
+
+    def _Rfindalldirs_key(self, pathlist):
+        return pathlist
+
+    @SCons.Memoize.CountDictCall(_Rfindalldirs_key)
+    def Rfindalldirs(self, pathlist):
+        """
+        Return all of the directories for a given path list, including
+        corresponding "backing" directories in any repositories.
+
+        The Node lookups are relative to this Node (typically a
+        directory), so memoizing result saves cycles from looking
+        up the same path for each target in a given directory.
+        """
+        try:
+            memo_dict = self._memo['Rfindalldirs']
+        except KeyError:
+            memo_dict = {}
+            self._memo['Rfindalldirs'] = memo_dict
+        else:
+            try:
+                return memo_dict[pathlist]
+            except KeyError:
+                pass
+
+        create_dir_relative_to_self = self.Dir
+        result = []
+        for path in pathlist:
+            if isinstance(path, SCons.Node.Node):
+                result.append(path)
+            else:
+                dir = create_dir_relative_to_self(path)
+                result.extend(dir.get_all_rdirs())
+
+        memo_dict[pathlist] = result
+
+        return result
+
+    def RDirs(self, pathlist):
+        """Search for a list of directories in the Repository list."""
+        cwd = self.cwd or self.fs._cwd
+        return cwd.Rfindalldirs(pathlist)
+
+    @SCons.Memoize.CountMethodCall
+    def rentry(self):
+        try:
+            return self._memo['rentry']
+        except KeyError:
+            pass
+        result = self
+        if not self.exists():
+            norm_name = _my_normcase(self.name)
+            for dir in self.dir.get_all_rdirs():
+                try:
+                    node = dir.entries[norm_name]
+                except KeyError:
+                    if dir.entry_exists_on_disk(self.name):
+                        result = dir.Entry(self.name)
+                        break
+        self._memo['rentry'] = result
+        return result
+
+    def _glob1(self, pattern, ondisk=True, source=False, strings=False):
+        return []
+
+# Dict that provides a simple backward compatibility
+# layer for the Node attributes 'abspath', 'labspath',
+# 'path', 'tpath' and 'path_elements'.
+# @see Base.__getattr__ above
+node_bwcomp = {'abspath' : Base.get_abspath,
+               'labspath' : Base.get_labspath,
+               'path' : Base.get_internal_path,
+               'tpath' : Base.get_tpath,
+               'path_elements' : Base.get_path_elements,
+               'suffix' : Base.get_suffix}
+
+class Entry(Base):
+    """This is the class for generic Node.FS entries--that is, things
+    that could be a File or a Dir, but we're just not sure yet.
+    Consequently, the methods in this class really exist just to
+    transform their associated object into the right class when the
+    time comes, and then call the same-named method in the transformed
+    class."""
+
+    __slots__ = ['scanner_paths',
+                 'cachedir_csig',
+                 'cachesig',
+                 'repositories',
+                 'srcdir',
+                 'entries',
+                 'searched',
+                 '_sconsign',
+                 'variant_dirs',
+                 'root',
+                 'dirname',
+                 'on_disk_entries',
+                 'released_target_info',
+                 'contentsig']
+
+    def __init__(self, name, directory, fs):
+        Base.__init__(self, name, directory, fs)
+        self._func_exists = 3
+        self._func_get_contents = 1
+
+    def diskcheck_match(self):
+        pass
+
+    def disambiguate(self, must_exist=None):
+        """
+        """
+        if self.isdir():
+            self.__class__ = Dir
+            self._morph()
+        elif self.isfile():
+            self.__class__ = File
+            self._morph()
+            self.clear()
+        else:
+            # There was nothing on-disk at this location, so look in
+            # the src directory.
+            #
+            # We can't just use self.srcnode() straight away because
+            # that would create an actual Node for this file in the src
+            # directory, and there might not be one.  Instead, use the
+            # dir_on_disk() method to see if there's something on-disk
+            # with that name, in which case we can go ahead and call
+            # self.srcnode() to create the right type of entry.
+            srcdir = self.dir.srcnode()
+            if srcdir != self.dir and \
+               srcdir.entry_exists_on_disk(self.name) and \
+               self.srcnode().isdir():
+                self.__class__ = Dir
+                self._morph()
+            elif must_exist:
+                msg = "No such file or directory: '%s'" % self.get_abspath()
+                raise SCons.Errors.UserError(msg)
+            else:
+                self.__class__ = File
+                self._morph()
+                self.clear()
+        return self
+
+    def rfile(self):
+        """We're a generic Entry, but the caller is actually looking for
+        a File at this point, so morph into one."""
+        self.__class__ = File
+        self._morph()
+        self.clear()
+        return File.rfile(self)
+
+    def scanner_key(self):
+        return self.get_suffix()
+
+    def get_contents(self):
+        """Fetch the contents of the entry.  Returns the exact binary
+        contents of the file."""
+        return SCons.Node._get_contents_map[self._func_get_contents](self)
+
+    def get_text_contents(self):
+        """Fetch the decoded text contents of a Unicode encoded Entry.
+
+        Since this should return the text contents from the file
+        system, we check to see into what sort of subclass we should
+        morph this Entry."""
+        try:
+            self = self.disambiguate(must_exist=1)
+        except SCons.Errors.UserError:
+            # There was nothing on disk with which to disambiguate
+            # this entry.  Leave it as an Entry, but return a null
+            # string so calls to get_text_contents() in emitters and
+            # the like (e.g. in qt.py) don't have to disambiguate by
+            # hand or catch the exception.
+            return ''
+        else:
+            return self.get_text_contents()
+
+    def must_be_same(self, klass):
+        """Called to make sure a Node is a Dir.  Since we're an
+        Entry, we can morph into one."""
+        if self.__class__ is not klass:
+            self.__class__ = klass
+            self._morph()
+            self.clear()
+
+    # The following methods can get called before the Taskmaster has
+    # had a chance to call disambiguate() directly to see if this Entry
+    # should really be a Dir or a File.  We therefore use these to call
+    # disambiguate() transparently (from our caller's point of view).
+    #
+    # Right now, this minimal set of methods has been derived by just
+    # looking at some of the methods that will obviously be called early
+    # in any of the various Taskmasters' calling sequences, and then
+    # empirically figuring out which additional methods are necessary
+    # to make various tests pass.
+
+    def exists(self):
+        return SCons.Node._exists_map[self._func_exists](self)
+
+    def rel_path(self, other):
+        d = self.disambiguate()
+        if d.__class__ is Entry:
+            raise Exception("rel_path() could not disambiguate File/Dir")
+        return d.rel_path(other)
+
+    def new_ninfo(self):
+        return self.disambiguate().new_ninfo()
+
+    def _glob1(self, pattern, ondisk=True, source=False, strings=False):
+        return self.disambiguate()._glob1(pattern, ondisk, source, strings)
+
+    def get_subst_proxy(self):
+        return self.disambiguate().get_subst_proxy()
+
+# This is for later so we can differentiate between Entry the class and Entry
+# the method of the FS class.
+_classEntry = Entry
+
+
+class LocalFS(object):
+
+    # This class implements an abstraction layer for operations involving
+    # a local file system.  Essentially, this wraps any function in
+    # the os, os.path or shutil modules that we use to actually go do
+    # anything with or to the local file system.
+    #
+    # Note that there's a very good chance we'll refactor this part of
+    # the architecture in some way as we really implement the interface(s)
+    # for remote file system Nodes.  For example, the right architecture
+    # might be to have this be a subclass instead of a base class.
+    # Nevertheless, we're using this as a first step in that direction.
+    #
+    # We're not using chdir() yet because the calling subclass method
+    # needs to use os.chdir() directly to avoid recursion.  Will we
+    # really need this one?
+    #def chdir(self, path):
+    #    return os.chdir(path)
+    def chmod(self, path, mode):
+        return os.chmod(path, mode)
+    def copy(self, src, dst):
+        return shutil.copy(src, dst)
+    def copy2(self, src, dst):
+        return shutil.copy2(src, dst)
+    def exists(self, path):
+        return os.path.exists(path)
+    def getmtime(self, path):
+        return os.path.getmtime(path)
+    def getsize(self, path):
+        return os.path.getsize(path)
+    def isdir(self, path):
+        return os.path.isdir(path)
+    def isfile(self, path):
+        return os.path.isfile(path)
+    def link(self, src, dst):
+        return os.link(src, dst)
+    def lstat(self, path):
+        return os.lstat(path)
+    def listdir(self, path):
+        return os.listdir(path)
+    def makedirs(self, path):
+        return os.makedirs(path)
+    def mkdir(self, path):
+        return os.mkdir(path)
+    def rename(self, old, new):
+        return os.rename(old, new)
+    def stat(self, path):
+        return os.stat(path)
+    def symlink(self, src, dst):
+        return os.symlink(src, dst)
+    def open(self, path):
+        return open(path)
+    def unlink(self, path):
+        return os.unlink(path)
+
+    if hasattr(os, 'symlink'):
+        def islink(self, path):
+            return os.path.islink(path)
+    else:
+        def islink(self, path):
+            return 0                    # no symlinks
+
+    if hasattr(os, 'readlink'):
+        def readlink(self, file):
+            return os.readlink(file)
+    else:
+        def readlink(self, file):
+            return ''
+
+
+class FS(LocalFS):
+
+    def __init__(self, path = None):
+        """Initialize the Node.FS subsystem.
+
+        The supplied path is the top of the source tree, where we
+        expect to find the top-level build file.  If no path is
+        supplied, the current directory is the default.
+
+        The path argument must be a valid absolute path.
+        """
+        if SCons.Debug.track_instances: logInstanceCreation(self, 'Node.FS')
+
+        self._memo = {}
+
+        self.Root = {}
+        self.SConstruct_dir = None
+        self.max_drift = default_max_drift
+
+        self.Top = None
+        if path is None:
+            self.pathTop = os.getcwd()
+        else:
+            self.pathTop = path
+        self.defaultDrive = _my_normcase(_my_splitdrive(self.pathTop)[0])
+
+        self.Top = self.Dir(self.pathTop)
+        self.Top._path = '.'
+        self.Top._tpath = '.'
+        self._cwd = self.Top
+
+        DirNodeInfo.fs = self
+        FileNodeInfo.fs = self
+
+    def set_SConstruct_dir(self, dir):
+        self.SConstruct_dir = dir
+
+    def get_max_drift(self):
+        return self.max_drift
+
+    def set_max_drift(self, max_drift):
+        self.max_drift = max_drift
+
+    def getcwd(self):
+        if hasattr(self, "_cwd"):
+            return self._cwd
+        else:
+            return "<no cwd>"
+
+    def chdir(self, dir, change_os_dir=0):
+        """Change the current working directory for lookups.
+        If change_os_dir is true, we will also change the "real" cwd
+        to match.
+        """
+        curr=self._cwd
+        try:
+            if dir is not None:
+                self._cwd = dir
+                if change_os_dir:
+                    os.chdir(dir.get_abspath())
+        except OSError:
+            self._cwd = curr
+            raise
+
+    def get_root(self, drive):
+        """
+        Returns the root directory for the specified drive, creating
+        it if necessary.
+        """
+        drive = _my_normcase(drive)
+        try:
+            return self.Root[drive]
+        except KeyError:
+            root = RootDir(drive, self)
+            self.Root[drive] = root
+            if not drive:
+                self.Root[self.defaultDrive] = root
+            elif drive == self.defaultDrive:
+                self.Root[''] = root
+            return root
+
+    def _lookup(self, p, directory, fsclass, create=1):
+        """
+        The generic entry point for Node lookup with user-supplied data.
+
+        This translates arbitrary input into a canonical Node.FS object
+        of the specified fsclass.  The general approach for strings is
+        to turn it into a fully normalized absolute path and then call
+        the root directory's lookup_abs() method for the heavy lifting.
+
+        If the path name begins with '#', it is unconditionally
+        interpreted relative to the top-level directory of this FS.  '#'
+        is treated as a synonym for the top-level SConstruct directory,
+        much like '~' is treated as a synonym for the user's home
+        directory in a UNIX shell.  So both '#foo' and '#/foo' refer
+        to the 'foo' subdirectory underneath the top-level SConstruct
+        directory.
+
+        If the path name is relative, then the path is looked up relative
+        to the specified directory, or the current directory (self._cwd,
+        typically the SConscript directory) if the specified directory
+        is None.
+        """
+        if isinstance(p, Base):
+            # It's already a Node.FS object.  Make sure it's the right
+            # class and return.
+            p.must_be_same(fsclass)
+            return p
+        # str(p) in case it's something like a proxy object
+        p = str(p)
+
+        if not os_sep_is_slash:
+            p = p.replace(OS_SEP, '/')
+
+        if p[0:1] == '#':
+            # There was an initial '#', so we strip it and override
+            # whatever directory they may have specified with the
+            # top-level SConstruct directory.
+            p = p[1:]
+            directory = self.Top
+
+            # There might be a drive letter following the
+            # '#'. Although it is not described in the SCons man page,
+            # the regression test suite explicitly tests for that
+            # syntax. It seems to mean the following thing:
+            #
+            #   Assuming the the SCons top dir is in C:/xxx/yyy,
+            #   '#X:/toto' means X:/xxx/yyy/toto.
+            #
+            # i.e. it assumes that the X: drive has a directory
+            # structure similar to the one found on drive C:.
+            if do_splitdrive:
+                drive, p = _my_splitdrive(p)
+                if drive:
+                    root = self.get_root(drive)
+                else:
+                    root = directory.root
+            else:
+                root = directory.root
+
+            # We can only strip trailing after splitting the drive
+            # since the drive might the UNC '//' prefix.
+            p = p.strip('/')
+
+            needs_normpath = needs_normpath_match(p)
+
+            # The path is relative to the top-level SCons directory.
+            if p in ('', '.'):
+                p = directory.get_labspath()
+            else:
+                p = directory.get_labspath() + '/' + p
+        else:
+            if do_splitdrive:
+                drive, p = _my_splitdrive(p)
+                if drive and not p:
+                    # This causes a naked drive letter to be treated
+                    # as a synonym for the root directory on that
+                    # drive.
+                    p = '/'
+            else:
+                drive = ''
+
+            # We can only strip trailing '/' since the drive might the
+            # UNC '//' prefix.
+            if p != '/':
+                p = p.rstrip('/')
+
+            needs_normpath = needs_normpath_match(p)
+
+            if p[0:1] == '/':
+                # Absolute path
+                root = self.get_root(drive)
+            else:
+                # This is a relative lookup or to the current directory
+                # (the path name is not absolute).  Add the string to the
+                # appropriate directory lookup path, after which the whole
+                # thing gets normalized.
+                if directory:
+                    if not isinstance(directory, Dir):
+                        directory = self.Dir(directory)
+                else:
+                    directory = self._cwd
+
+                if p in ('', '.'):
+                    p = directory.get_labspath()
+                else:
+                    p = directory.get_labspath() + '/' + p
+
+                if drive:
+                    root = self.get_root(drive)
+                else:
+                    root = directory.root
+
+        if needs_normpath is not None:
+            # Normalize a pathname. Will return the same result for
+            # equivalent paths.
+            #
+            # We take advantage of the fact that we have an absolute
+            # path here for sure. In addition, we know that the
+            # components of lookup path are separated by slashes at
+            # this point. Because of this, this code is about 2X
+            # faster than calling os.path.normpath() followed by
+            # replacing os.sep with '/' again.
+            ins = p.split('/')[1:]
+            outs = []
+            for d in ins:
+                if d == '..':
+                    try:
+                        outs.pop()
+                    except IndexError:
+                        pass
+                elif d not in ('', '.'):
+                    outs.append(d)
+            p = '/' + '/'.join(outs)
+
+        return root._lookup_abs(p, fsclass, create)
+
+    def Entry(self, name, directory = None, create = 1):
+        """Look up or create a generic Entry node with the specified name.
+        If the name is a relative path (begins with ./, ../, or a file
+        name), then it is looked up relative to the supplied directory
+        node, or to the top level directory of the FS (supplied at
+        construction time) if no directory is supplied.
+        """
+        return self._lookup(name, directory, Entry, create)
+
+    def File(self, name, directory = None, create = 1):
+        """Look up or create a File node with the specified name.  If
+        the name is a relative path (begins with ./, ../, or a file name),
+        then it is looked up relative to the supplied directory node,
+        or to the top level directory of the FS (supplied at construction
+        time) if no directory is supplied.
+
+        This method will raise TypeError if a directory is found at the
+        specified path.
+        """
+        return self._lookup(name, directory, File, create)
+
+    def Dir(self, name, directory = None, create = True):
+        """Look up or create a Dir node with the specified name.  If
+        the name is a relative path (begins with ./, ../, or a file name),
+        then it is looked up relative to the supplied directory node,
+        or to the top level directory of the FS (supplied at construction
+        time) if no directory is supplied.
+
+        This method will raise TypeError if a normal file is found at the
+        specified path.
+        """
+        return self._lookup(name, directory, Dir, create)
+
+    def VariantDir(self, variant_dir, src_dir, duplicate=1):
+        """Link the supplied variant directory to the source directory
+        for purposes of building files."""
+
+        if not isinstance(src_dir, SCons.Node.Node):
+            src_dir = self.Dir(src_dir)
+        if not isinstance(variant_dir, SCons.Node.Node):
+            variant_dir = self.Dir(variant_dir)
+        if src_dir.is_under(variant_dir):
+            raise SCons.Errors.UserError("Source directory cannot be under variant directory.")
+        if variant_dir.srcdir:
+            if variant_dir.srcdir == src_dir:
+                return # We already did this.
+            raise SCons.Errors.UserError("'%s' already has a source directory: '%s'."%(variant_dir, variant_dir.srcdir))
+        variant_dir.link(src_dir, duplicate)
+
+    def Repository(self, *dirs):
+        """Specify Repository directories to search."""
+        for d in dirs:
+            if not isinstance(d, SCons.Node.Node):
+                d = self.Dir(d)
+            self.Top.addRepository(d)
+    
+    def PyPackageDir(self, modulename):
+        """Locate the directory of a given python module name
+		
+        For example scons might resolve to
+        Windows: C:\Python27\Lib\site-packages\scons-2.5.1
+        Linux: /usr/lib/scons
+
+        This can be useful when we want to determine a toolpath based on a python module name"""
+
+        dirpath = ''
+        if sys.version_info[0] < 3 or (sys.version_info[0] == 3 and sys.version_info[1] in (0,1,2,3,4)):
+            # Python2 Code
+            import imp
+            splitname = modulename.split('.')
+            srchpths = sys.path
+            for item in splitname:
+                file, path, desc = imp.find_module(item, srchpths)
+                if file is not None:
+                    path = os.path.dirname(path)
+                srchpths = [path]
+            dirpath = path
+        else:
+            # Python3 Code
+            import importlib.util
+            modspec = importlib.util.find_spec(modulename)
+            dirpath = os.path.dirname(modspec.origin)
+        return self._lookup(dirpath, None, Dir, True)
+
+
+    def variant_dir_target_climb(self, orig, dir, tail):
+        """Create targets in corresponding variant directories
+
+        Climb the directory tree, and look up path names
+        relative to any linked variant directories we find.
+
+        Even though this loops and walks up the tree, we don't memoize
+        the return value because this is really only used to process
+        the command-line targets.
+        """
+        targets = []
+        message = None
+        fmt = "building associated VariantDir targets: %s"
+        start_dir = dir
+        while dir:
+            for bd in dir.variant_dirs:
+                if start_dir.is_under(bd):
+                    # If already in the build-dir location, don't reflect
+                    return [orig], fmt % str(orig)
+                p = os.path.join(bd._path, *tail)
+                targets.append(self.Entry(p))
+            tail = [dir.name] + tail
+            dir = dir.up()
+        if targets:
+            message = fmt % ' '.join(map(str, targets))
+        return targets, message
+
+    def Glob(self, pathname, ondisk=True, source=True, strings=False, exclude=None, cwd=None):
+        """
+        Globs
+
+        This is mainly a shim layer
+        """
+        if cwd is None:
+            cwd = self.getcwd()
+        return cwd.glob(pathname, ondisk, source, strings, exclude)
+
+class DirNodeInfo(SCons.Node.NodeInfoBase):
+    __slots__ = ()
+    # This should get reset by the FS initialization.
+    current_version_id = 2
+
+    fs = None
+
+    def str_to_node(self, s):
+        top = self.fs.Top
+        root = top.root
+        if do_splitdrive:
+            drive, s = _my_splitdrive(s)
+            if drive:
+                root = self.fs.get_root(drive)
+        if not os.path.isabs(s):
+            s = top.get_labspath() + '/' + s
+        return root._lookup_abs(s, Entry)
+
+class DirBuildInfo(SCons.Node.BuildInfoBase):
+    __slots__ = ()
+    current_version_id = 2
+
+glob_magic_check = re.compile('[*?[]')
+
+def has_glob_magic(s):
+    return glob_magic_check.search(s) is not None
+
+class Dir(Base):
+    """A class for directories in a file system.
+    """
+
+    __slots__ = ['scanner_paths',
+                 'cachedir_csig',
+                 'cachesig',
+                 'repositories',
+                 'srcdir',
+                 'entries',
+                 'searched',
+                 '_sconsign',
+                 'variant_dirs',
+                 'root',
+                 'dirname',
+                 'on_disk_entries',
+                 'released_target_info',
+                 'contentsig']
+
+    NodeInfo = DirNodeInfo
+    BuildInfo = DirBuildInfo
+
+    def __init__(self, name, directory, fs):
+        if SCons.Debug.track_instances: logInstanceCreation(self, 'Node.FS.Dir')
+        Base.__init__(self, name, directory, fs)
+        self._morph()
+
+    def _morph(self):
+        """Turn a file system Node (either a freshly initialized directory
+        object or a separate Entry object) into a proper directory object.
+
+        Set up this directory's entries and hook it into the file
+        system tree.  Specify that directories (this Node) don't use
+        signatures for calculating whether they're current.
+        """
+
+        self.repositories = []
+        self.srcdir = None
+
+        self.entries = {}
+        self.entries['.'] = self
+        self.entries['..'] = self.dir
+        self.cwd = self
+        self.searched = 0
+        self._sconsign = None
+        self.variant_dirs = []
+        self.root = self.dir.root
+        self.changed_since_last_build = 3
+        self._func_sconsign = 1
+        self._func_exists = 2
+        self._func_get_contents = 2
+
+        self._abspath = SCons.Util.silent_intern(self.dir.entry_abspath(self.name))
+        self._labspath = SCons.Util.silent_intern(self.dir.entry_labspath(self.name))
+        if self.dir._path == '.':
+            self._path = SCons.Util.silent_intern(self.name)
+        else:
+            self._path = SCons.Util.silent_intern(self.dir.entry_path(self.name))
+        if self.dir._tpath == '.':
+            self._tpath = SCons.Util.silent_intern(self.name)
+        else:
+            self._tpath = SCons.Util.silent_intern(self.dir.entry_tpath(self.name))
+        self._path_elements = self.dir._path_elements + [self]
+
+        # For directories, we make a difference between the directory
+        # 'name' and the directory 'dirname'. The 'name' attribute is
+        # used when we need to print the 'name' of the directory or
+        # when we it is used as the last part of a path. The 'dirname'
+        # is used when the directory is not the last element of the
+        # path. The main reason for making that distinction is that
+        # for RoorDir's the dirname can not be easily inferred from
+        # the name. For example, we have to add a '/' after a drive
+        # letter but not after a UNC path prefix ('//').
+        self.dirname = self.name + OS_SEP
+
+        # Don't just reset the executor, replace its action list,
+        # because it might have some pre-or post-actions that need to
+        # be preserved.
+        #
+        # But don't reset the executor if there is a non-null executor
+        # attached already. The existing executor might have other
+        # targets, in which case replacing the action list with a
+        # Mkdir action is a big mistake.
+        if not hasattr(self, 'executor'):
+            self.builder = get_MkdirBuilder()
+            self.get_executor().set_action_list(self.builder.action)
+        else:
+            # Prepend MkdirBuilder action to existing action list
+            l = self.get_executor().action_list
+            a = get_MkdirBuilder().action
+            l.insert(0, a)
+            self.get_executor().set_action_list(l)
+
+    def diskcheck_match(self):
+        diskcheck_match(self, self.isfile,
+                        "File %s found where directory expected.")
+
+    def __clearRepositoryCache(self, duplicate=None):
+        """Called when we change the repository(ies) for a directory.
+        This clears any cached information that is invalidated by changing
+        the repository."""
+
+        for node in list(self.entries.values()):
+            if node != self.dir:
+                if node != self and isinstance(node, Dir):
+                    node.__clearRepositoryCache(duplicate)
+                else:
+                    node.clear()
+                    try:
+                        del node._srcreps
+                    except AttributeError:
+                        pass
+                    if duplicate is not None:
+                        node.duplicate=duplicate
+
+    def __resetDuplicate(self, node):
+        if node != self:
+            node.duplicate = node.get_dir().duplicate
+
+    def Entry(self, name):
+        """
+        Looks up or creates an entry node named 'name' relative to
+        this directory.
+        """
+        return self.fs.Entry(name, self)
+
+    def Dir(self, name, create=True):
+        """
+        Looks up or creates a directory node named 'name' relative to
+        this directory.
+        """
+        return self.fs.Dir(name, self, create)
+
+    def File(self, name):
+        """
+        Looks up or creates a file node named 'name' relative to
+        this directory.
+        """
+        return self.fs.File(name, self)
+
+    def link(self, srcdir, duplicate):
+        """Set this directory as the variant directory for the
+        supplied source directory."""
+        self.srcdir = srcdir
+        self.duplicate = duplicate
+        self.__clearRepositoryCache(duplicate)
+        srcdir.variant_dirs.append(self)
+
+    def getRepositories(self):
+        """Returns a list of repositories for this directory.
+        """
+        if self.srcdir and not self.duplicate:
+            return self.srcdir.get_all_rdirs() + self.repositories
+        return self.repositories
+
+    @SCons.Memoize.CountMethodCall
+    def get_all_rdirs(self):
+        try:
+            return list(self._memo['get_all_rdirs'])
+        except KeyError:
+            pass
+
+        result = [self]
+        fname = '.'
+        dir = self
+        while dir:
+            for rep in dir.getRepositories():
+                result.append(rep.Dir(fname))
+            if fname == '.':
+                fname = dir.name
+            else:
+                fname = dir.name + OS_SEP + fname
+            dir = dir.up()
+
+        self._memo['get_all_rdirs'] = list(result)
+
+        return result
+
+    def addRepository(self, dir):
+        if dir != self and not dir in self.repositories:
+            self.repositories.append(dir)
+            dir._tpath = '.'
+            self.__clearRepositoryCache()
+
+    def up(self):
+        return self.dir
+
+    def _rel_path_key(self, other):
+        return str(other)
+
+    @SCons.Memoize.CountDictCall(_rel_path_key)
+    def rel_path(self, other):
+        """Return a path to "other" relative to this directory.
+        """
+
+        # This complicated and expensive method, which constructs relative
+        # paths between arbitrary Node.FS objects, is no longer used
+        # by SCons itself.  It was introduced to store dependency paths
+        # in .sconsign files relative to the target, but that ended up
+        # being significantly inefficient.
+        #
+        # We're continuing to support the method because some SConstruct
+        # files out there started using it when it was available, and
+        # we're all about backwards compatibility..
+
+        try:
+            memo_dict = self._memo['rel_path']
+        except KeyError:
+            memo_dict = {}
+            self._memo['rel_path'] = memo_dict
+        else:
+            try:
+                return memo_dict[other]
+            except KeyError:
+                pass
+
+        if self is other:
+            result = '.'
+
+        elif not other in self._path_elements:
+            try:
+                other_dir = other.get_dir()
+            except AttributeError:
+                result = str(other)
+            else:
+                if other_dir is None:
+                    result = other.name
+                else:
+                    dir_rel_path = self.rel_path(other_dir)
+                    if dir_rel_path == '.':
+                        result = other.name
+                    else:
+                        result = dir_rel_path + OS_SEP + other.name
+        else:
+            i = self._path_elements.index(other) + 1
+
+            path_elems = ['..'] * (len(self._path_elements) - i) \
+                         + [n.name for n in other._path_elements[i:]]
+
+            result = OS_SEP.join(path_elems)
+
+        memo_dict[other] = result
+
+        return result
+
+    def get_env_scanner(self, env, kw={}):
+        import SCons.Defaults
+        return SCons.Defaults.DirEntryScanner
+
+    def get_target_scanner(self):
+        import SCons.Defaults
+        return SCons.Defaults.DirEntryScanner
+
+    def get_found_includes(self, env, scanner, path):
+        """Return this directory's implicit dependencies.
+
+        We don't bother caching the results because the scan typically
+        shouldn't be requested more than once (as opposed to scanning
+        .h file contents, which can be requested as many times as the
+        files is #included by other files).
+        """
+        if not scanner:
+            return []
+        # Clear cached info for this Dir.  If we already visited this
+        # directory on our walk down the tree (because we didn't know at
+        # that point it was being used as the source for another Node)
+        # then we may have calculated build signature before realizing
+        # we had to scan the disk.  Now that we have to, though, we need
+        # to invalidate the old calculated signature so that any node
+        # dependent on our directory structure gets one that includes
+        # info about everything on disk.
+        self.clear()
+        return scanner(self, env, path)
+
+    #
+    # Taskmaster interface subsystem
+    #
+
+    def prepare(self):
+        pass
+
+    def build(self, **kw):
+        """A null "builder" for directories."""
+        global MkdirBuilder
+        if self.builder is not MkdirBuilder:
+            SCons.Node.Node.build(self, **kw)
+
+    #
+    #
+    #
+
+    def _create(self):
+        """Create this directory, silently and without worrying about
+        whether the builder is the default or not."""
+        listDirs = []
+        parent = self
+        while parent:
+            if parent.exists():
+                break
+            listDirs.append(parent)
+            p = parent.up()
+            if p is None:
+                # Don't use while: - else: for this condition because
+                # if so, then parent is None and has no .path attribute.
+                raise SCons.Errors.StopError(parent._path)
+            parent = p
+        listDirs.reverse()
+        for dirnode in listDirs:
+            try:
+                # Don't call dirnode.build(), call the base Node method
+                # directly because we definitely *must* create this
+                # directory.  The dirnode.build() method will suppress
+                # the build if it's the default builder.
+                SCons.Node.Node.build(dirnode)
+                dirnode.get_executor().nullify()
+                # The build() action may or may not have actually
+                # created the directory, depending on whether the -n
+                # option was used or not.  Delete the _exists and
+                # _rexists attributes so they can be reevaluated.
+                dirnode.clear()
+            except OSError:
+                pass
+
+    def multiple_side_effect_has_builder(self):
+        global MkdirBuilder
+        return self.builder is not MkdirBuilder and self.has_builder()
+
+    def alter_targets(self):
+        """Return any corresponding targets in a variant directory.
+        """
+        return self.fs.variant_dir_target_climb(self, self, [])
+
+    def scanner_key(self):
+        """A directory does not get scanned."""
+        return None
+
+    def get_text_contents(self):
+        """We already emit things in text, so just return the binary
+        version."""
+        return self.get_contents()
+
+    def get_contents(self):
+        """Return content signatures and names of all our children
+        separated by new-lines. Ensure that the nodes are sorted."""
+        return SCons.Node._get_contents_map[self._func_get_contents](self)
+
+    def get_csig(self):
+        """Compute the content signature for Directory nodes. In
+        general, this is not needed and the content signature is not
+        stored in the DirNodeInfo. However, if get_contents on a Dir
+        node is called which has a child directory, the child
+        directory should return the hash of its contents."""
+        contents = self.get_contents()
+        return SCons.Util.MD5signature(contents)
+
+    def do_duplicate(self, src):
+        pass
+
+    def is_up_to_date(self):
+        """If any child is not up-to-date, then this directory isn't,
+        either."""
+        if self.builder is not MkdirBuilder and not self.exists():
+            return 0
+        up_to_date = SCons.Node.up_to_date
+        for kid in self.children():
+            if kid.get_state() > up_to_date:
+                return 0
+        return 1
+
+    def rdir(self):
+        if not self.exists():
+            norm_name = _my_normcase(self.name)
+            for dir in self.dir.get_all_rdirs():
+                try: node = dir.entries[norm_name]
+                except KeyError: node = dir.dir_on_disk(self.name)
+                if node and node.exists() and \
+                    (isinstance(dir, Dir) or isinstance(dir, Entry)):
+                        return node
+        return self
+
+    def sconsign(self):
+        """Return the .sconsign file info for this directory. """
+        return _sconsign_map[self._func_sconsign](self)
+
+    def srcnode(self):
+        """Dir has a special need for srcnode()...if we
+        have a srcdir attribute set, then that *is* our srcnode."""
+        if self.srcdir:
+            return self.srcdir
+        return Base.srcnode(self)
+
+    def get_timestamp(self):
+        """Return the latest timestamp from among our children"""
+        stamp = 0
+        for kid in self.children():
+            if kid.get_timestamp() > stamp:
+                stamp = kid.get_timestamp()
+        return stamp
+
+    def get_abspath(self):
+        """Get the absolute path of the file."""
+        return self._abspath
+
+    def get_labspath(self):
+        """Get the absolute path of the file."""
+        return self._labspath
+
+    def get_internal_path(self):
+        return self._path
+
+    def get_tpath(self):
+        return self._tpath
+
+    def get_path_elements(self):
+        return self._path_elements
+
+    def entry_abspath(self, name):
+        return self._abspath + OS_SEP + name
+
+    def entry_labspath(self, name):
+        return self._labspath + '/' + name
+
+    def entry_path(self, name):
+        return self._path + OS_SEP + name
+
+    def entry_tpath(self, name):
+        return self._tpath + OS_SEP + name
+
+    def entry_exists_on_disk(self, name):
+        """ Searches through the file/dir entries of the current
+            directory, and returns True if a physical entry with the given
+            name could be found.
+
+            @see rentry_exists_on_disk
+        """
+        try:
+            d = self.on_disk_entries
+        except AttributeError:
+            d = {}
+            try:
+                entries = os.listdir(self._abspath)
+            except OSError:
+                pass
+            else:
+                for entry in map(_my_normcase, entries):
+                    d[entry] = True
+            self.on_disk_entries = d
+        if sys.platform == 'win32' or sys.platform == 'cygwin':
+            name = _my_normcase(name)
+            result = d.get(name)
+            if result is None:
+                # Belt-and-suspenders for Windows:  check directly for
+                # 8.3 file names that don't show up in os.listdir().
+                result = os.path.exists(self._abspath + OS_SEP + name)
+                d[name] = result
+            return result
+        else:
+            return name in d
+
+    def rentry_exists_on_disk(self, name):
+        """ Searches through the file/dir entries of the current
+            *and* all its remote directories (repos), and returns
+            True if a physical entry with the given name could be found.
+            The local directory (self) gets searched first, so
+            repositories take a lower precedence regarding the
+            searching order.
+
+            @see entry_exists_on_disk
+        """
+
+        rentry_exists = self.entry_exists_on_disk(name)
+        if not rentry_exists:
+            # Search through the repository folders
+            norm_name = _my_normcase(name)
+            for rdir in self.get_all_rdirs():
+                try:
+                    node = rdir.entries[norm_name]
+                    if node:
+                        rentry_exists = True
+                        break
+                except KeyError:
+                    if rdir.entry_exists_on_disk(name):
+                        rentry_exists = True
+                        break
+        return rentry_exists
+
+    @SCons.Memoize.CountMethodCall
+    def srcdir_list(self):
+        try:
+            return self._memo['srcdir_list']
+        except KeyError:
+            pass
+
+        result = []
+
+        dirname = '.'
+        dir = self
+        while dir:
+            if dir.srcdir:
+                result.append(dir.srcdir.Dir(dirname))
+            dirname = dir.name + OS_SEP + dirname
+            dir = dir.up()
+
+        self._memo['srcdir_list'] = result
+
+        return result
+
+    def srcdir_duplicate(self, name):
+        for dir in self.srcdir_list():
+            if self.is_under(dir):
+                # We shouldn't source from something in the build path;
+                # variant_dir is probably under src_dir, in which case
+                # we are reflecting.
+                break
+            if dir.entry_exists_on_disk(name):
+                srcnode = dir.Entry(name).disambiguate()
+                if self.duplicate:
+                    node = self.Entry(name).disambiguate()
+                    node.do_duplicate(srcnode)
+                    return node
+                else:
+                    return srcnode
+        return None
+
+    def _srcdir_find_file_key(self, filename):
+        return filename
+
+    @SCons.Memoize.CountDictCall(_srcdir_find_file_key)
+    def srcdir_find_file(self, filename):
+        try:
+            memo_dict = self._memo['srcdir_find_file']
+        except KeyError:
+            memo_dict = {}
+            self._memo['srcdir_find_file'] = memo_dict
+        else:
+            try:
+                return memo_dict[filename]
+            except KeyError:
+                pass
+
+        def func(node):
+            if (isinstance(node, File) or isinstance(node, Entry)) and \
+               (node.is_derived() or node.exists()):
+                    return node
+            return None
+
+        norm_name = _my_normcase(filename)
+
+        for rdir in self.get_all_rdirs():
+            try: node = rdir.entries[norm_name]
+            except KeyError: node = rdir.file_on_disk(filename)
+            else: node = func(node)
+            if node:
+                result = (node, self)
+                memo_dict[filename] = result
+                return result
+
+        for srcdir in self.srcdir_list():
+            for rdir in srcdir.get_all_rdirs():
+                try: node = rdir.entries[norm_name]
+                except KeyError: node = rdir.file_on_disk(filename)
+                else: node = func(node)
+                if node:
+                    result = (File(filename, self, self.fs), srcdir)
+                    memo_dict[filename] = result
+                    return result
+
+        result = (None, None)
+        memo_dict[filename] = result
+        return result
+
+    def dir_on_disk(self, name):
+        if self.entry_exists_on_disk(name):
+            try: return self.Dir(name)
+            except TypeError: pass
+        node = self.srcdir_duplicate(name)
+        if isinstance(node, File):
+            return None
+        return node
+
+    def file_on_disk(self, name):
+        if self.entry_exists_on_disk(name):
+            try: return self.File(name)
+            except TypeError: pass
+        node = self.srcdir_duplicate(name)
+        if isinstance(node, Dir):
+            return None
+        return node
+
+    def walk(self, func, arg):
+        """
+        Walk this directory tree by calling the specified function
+        for each directory in the tree.
+
+        This behaves like the os.path.walk() function, but for in-memory
+        Node.FS.Dir objects.  The function takes the same arguments as
+        the functions passed to os.path.walk():
+
+                func(arg, dirname, fnames)
+
+        Except that "dirname" will actually be the directory *Node*,
+        not the string.  The '.' and '..' entries are excluded from
+        fnames.  The fnames list may be modified in-place to filter the
+        subdirectories visited or otherwise impose a specific order.
+        The "arg" argument is always passed to func() and may be used
+        in any way (or ignored, passing None is common).
+        """
+        entries = self.entries
+        names = list(entries.keys())
+        names.remove('.')
+        names.remove('..')
+        func(arg, self, names)
+        for dirname in [n for n in names if isinstance(entries[n], Dir)]:
+            entries[dirname].walk(func, arg)
+
+    def glob(self, pathname, ondisk=True, source=False, strings=False, exclude=None):
+        """
+        Returns a list of Nodes (or strings) matching a specified
+        pathname pattern.
+
+        Pathname patterns follow UNIX shell semantics:  * matches
+        any-length strings of any characters, ? matches any character,
+        and [] can enclose lists or ranges of characters.  Matches do
+        not span directory separators.
+
+        The matches take into account Repositories, returning local
+        Nodes if a corresponding entry exists in a Repository (either
+        an in-memory Node or something on disk).
+
+        By defafult, the glob() function matches entries that exist
+        on-disk, in addition to in-memory Nodes.  Setting the "ondisk"
+        argument to False (or some other non-true value) causes the glob()
+        function to only match in-memory Nodes.  The default behavior is
+        to return both the on-disk and in-memory Nodes.
+
+        The "source" argument, when true, specifies that corresponding
+        source Nodes must be returned if you're globbing in a build
+        directory (initialized with VariantDir()).  The default behavior
+        is to return Nodes local to the VariantDir().
+
+        The "strings" argument, when true, returns the matches as strings,
+        not Nodes.  The strings are path names relative to this directory.
+
+        The "exclude" argument, if not None, must be a pattern or a list
+        of patterns following the same UNIX shell semantics.
+        Elements matching a least one pattern of this list will be excluded
+        from the result.
+
+        The underlying algorithm is adapted from the glob.glob() function
+        in the Python library (but heavily modified), and uses fnmatch()
+        under the covers.
+        """
+        dirname, basename = os.path.split(pathname)
+        if not dirname:
+            result = self._glob1(basename, ondisk, source, strings)
+        else:
+            if has_glob_magic(dirname):
+                list = self.glob(dirname, ondisk, source, False, exclude)
+            else:
+                list = [self.Dir(dirname, create=True)]
+            result = []
+            for dir in list:
+                r = dir._glob1(basename, ondisk, source, strings)
+                if strings:
+                    r = [os.path.join(str(dir), x) for x in r]
+                result.extend(r)
+        if exclude:
+            excludes = []
+            excludeList = SCons.Util.flatten(exclude)
+            for x in excludeList:
+                r = self.glob(x, ondisk, source, strings)
+                excludes.extend(r)
+            result = [x for x in result if not any(fnmatch.fnmatch(str(x), str(e)) for e in SCons.Util.flatten(excludes))]
+        return sorted(result, key=lambda a: str(a))
+
+    def _glob1(self, pattern, ondisk=True, source=False, strings=False):
+        """
+        Globs for and returns a list of entry names matching a single
+        pattern in this directory.
+
+        This searches any repositories and source directories for
+        corresponding entries and returns a Node (or string) relative
+        to the current directory if an entry is found anywhere.
+
+        TODO: handle pattern with no wildcard
+        """
+        search_dir_list = self.get_all_rdirs()
+        for srcdir in self.srcdir_list():
+            search_dir_list.extend(srcdir.get_all_rdirs())
+
+        selfEntry = self.Entry
+        names = []
+        for dir in search_dir_list:
+            # We use the .name attribute from the Node because the keys of
+            # the dir.entries dictionary are normalized (that is, all upper
+            # case) on case-insensitive systems like Windows.
+            node_names = [ v.name for k, v in dir.entries.items()
+                           if k not in ('.', '..') ]
+            names.extend(node_names)
+            if not strings:
+                # Make sure the working directory (self) actually has
+                # entries for all Nodes in repositories or variant dirs.
+                for name in node_names: selfEntry(name)
+            if ondisk:
+                try:
+                    disk_names = os.listdir(dir._abspath)
+                except os.error:
+                    continue
+                names.extend(disk_names)
+                if not strings:
+                    # We're going to return corresponding Nodes in
+                    # the local directory, so we need to make sure
+                    # those Nodes exist.  We only want to create
+                    # Nodes for the entries that will match the
+                    # specified pattern, though, which means we
+                    # need to filter the list here, even though
+                    # the overall list will also be filtered later,
+                    # after we exit this loop.
+                    if pattern[0] != '.':
+                        disk_names = [x for x in disk_names if x[0] != '.']
+                    disk_names = fnmatch.filter(disk_names, pattern)
+                    dirEntry = dir.Entry
+                    for name in disk_names:
+                        # Add './' before disk filename so that '#' at
+                        # beginning of filename isn't interpreted.
+                        name = './' + name
+                        node = dirEntry(name).disambiguate()
+                        n = selfEntry(name)
+                        if n.__class__ != node.__class__:
+                            n.__class__ = node.__class__
+                            n._morph()
+
+        names = set(names)
+        if pattern[0] != '.':
+            names = [x for x in names if x[0] != '.']
+        names = fnmatch.filter(names, pattern)
+
+        if strings:
+            return names
+
+        return [self.entries[_my_normcase(n)] for n in names]
+
+class RootDir(Dir):
+    """A class for the root directory of a file system.
+
+    This is the same as a Dir class, except that the path separator
+    ('/' or '\\') is actually part of the name, so we don't need to
+    add a separator when creating the path names of entries within
+    this directory.
+    """
+
+    __slots__ = ['_lookupDict']
+
+    def __init__(self, drive, fs):
+        if SCons.Debug.track_instances: logInstanceCreation(self, 'Node.FS.RootDir')
+        SCons.Node.Node.__init__(self)
+
+        # Handle all the types of drives:
+        if drive == '':
+            # No drive, regular UNIX root or Windows default drive.
+            name = OS_SEP
+            dirname = OS_SEP
+        elif drive == '//':
+            # UNC path
+            name = UNC_PREFIX
+            dirname = UNC_PREFIX
+        else:
+            # Windows drive letter
+            name = drive
+            dirname = drive + OS_SEP
+
+        # Filename with extension as it was specified when the object was
+        # created; to obtain filesystem path, use Python str() function
+        self.name = SCons.Util.silent_intern(name)
+        self.fs = fs #: Reference to parent Node.FS object
+
+        self._path_elements = [self]
+        self.dir = self
+        self._func_rexists = 2
+        self._func_target_from_source = 1
+        self.store_info = 1
+
+        # Now set our paths to what we really want them to be. The
+        # name should already contain any necessary separators, such
+        # as the initial drive letter (the name) plus the directory
+        # separator, except for the "lookup abspath," which does not
+        # have the drive letter.
+        self._abspath = dirname
+        self._labspath = ''
+        self._path = dirname
+        self._tpath = dirname
+        self.dirname = dirname
+
+        self._morph()
+
+        self.duplicate = 0
+        self._lookupDict = {}
+
+        self._lookupDict[''] = self
+        self._lookupDict['/'] = self
+        self.root = self
+        # The // entry is necessary because os.path.normpath()
+        # preserves double slashes at the beginning of a path on Posix
+        # platforms.
+        if not has_unc:
+            self._lookupDict['//'] = self
+
+    def _morph(self):
+        """Turn a file system Node (either a freshly initialized directory
+        object or a separate Entry object) into a proper directory object.
+
+        Set up this directory's entries and hook it into the file
+        system tree.  Specify that directories (this Node) don't use
+        signatures for calculating whether they're current.
+        """
+
+        self.repositories = []
+        self.srcdir = None
+
+        self.entries = {}
+        self.entries['.'] = self
+        self.entries['..'] = self.dir
+        self.cwd = self
+        self.searched = 0
+        self._sconsign = None
+        self.variant_dirs = []
+        self.changed_since_last_build = 3
+        self._func_sconsign = 1
+        self._func_exists = 2
+        self._func_get_contents = 2
+
+        # Don't just reset the executor, replace its action list,
+        # because it might have some pre-or post-actions that need to
+        # be preserved.
+        #
+        # But don't reset the executor if there is a non-null executor
+        # attached already. The existing executor might have other
+        # targets, in which case replacing the action list with a
+        # Mkdir action is a big mistake.
+        if not hasattr(self, 'executor'):
+            self.builder = get_MkdirBuilder()
+            self.get_executor().set_action_list(self.builder.action)
+        else:
+            # Prepend MkdirBuilder action to existing action list
+            l = self.get_executor().action_list
+            a = get_MkdirBuilder().action
+            l.insert(0, a)
+            self.get_executor().set_action_list(l)
+
+
+    def must_be_same(self, klass):
+        if klass is Dir:
+            return
+        Base.must_be_same(self, klass)
+
+    def _lookup_abs(self, p, klass, create=1):
+        """
+        Fast (?) lookup of a *normalized* absolute path.
+
+        This method is intended for use by internal lookups with
+        already-normalized path data.  For general-purpose lookups,
+        use the FS.Entry(), FS.Dir() or FS.File() methods.
+
+        The caller is responsible for making sure we're passed a
+        normalized absolute path; we merely let Python's dictionary look
+        up and return the One True Node.FS object for the path.
+
+        If a Node for the specified "p" doesn't already exist, and
+        "create" is specified, the Node may be created after recursive
+        invocation to find or create the parent directory or directories.
+        """
+        k = _my_normcase(p)
+        try:
+            result = self._lookupDict[k]
+        except KeyError:
+            if not create:
+                msg = "No such file or directory: '%s' in '%s' (and create is False)" % (p, str(self))
+                raise SCons.Errors.UserError(msg)
+            # There is no Node for this path name, and we're allowed
+            # to create it.
+            dir_name, file_name = p.rsplit('/',1)
+            dir_node = self._lookup_abs(dir_name, Dir)
+            result = klass(file_name, dir_node, self.fs)
+
+            # Double-check on disk (as configured) that the Node we
+            # created matches whatever is out there in the real world.
+            result.diskcheck_match()
+
+            self._lookupDict[k] = result
+            dir_node.entries[_my_normcase(file_name)] = result
+            dir_node.implicit = None
+        else:
+            # There is already a Node for this path name.  Allow it to
+            # complain if we were looking for an inappropriate type.
+            result.must_be_same(klass)
+        return result
+
+    def __str__(self):
+        return self._abspath
+
+    def entry_abspath(self, name):
+        return self._abspath + name
+
+    def entry_labspath(self, name):
+        return '/' + name
+
+    def entry_path(self, name):
+        return self._path + name
+
+    def entry_tpath(self, name):
+        return self._tpath + name
+
+    def is_under(self, dir):
+        if self is dir:
+            return 1
+        else:
+            return 0
+
+    def up(self):
+        return None
+
+    def get_dir(self):
+        return None
+
+    def src_builder(self):
+        return _null
+
+
+class FileNodeInfo(SCons.Node.NodeInfoBase):
+    __slots__ = ('csig', 'timestamp', 'size')
+    current_version_id = 2
+
+    field_list = ['csig', 'timestamp', 'size']
+
+    # This should get reset by the FS initialization.
+    fs = None
+
+    def str_to_node(self, s):
+        top = self.fs.Top
+        root = top.root
+        if do_splitdrive:
+            drive, s = _my_splitdrive(s)
+            if drive:
+                root = self.fs.get_root(drive)
+        if not os.path.isabs(s):
+            s = top.get_labspath() + '/' + s
+        return root._lookup_abs(s, Entry)
+
+    def __getstate__(self):
+        """
+        Return all fields that shall be pickled. Walk the slots in the class
+        hierarchy and add those to the state dictionary. If a '__dict__' slot is
+        available, copy all entries to the dictionary. Also include the version
+        id, which is fixed for all instances of a class.
+        """
+        state = getattr(self, '__dict__', {}).copy()
+        for obj in type(self).mro():
+            for name in getattr(obj,'__slots__',()):
+                if hasattr(self, name):
+                    state[name] = getattr(self, name)
+
+        state['_version_id'] = self.current_version_id
+        try:
+            del state['__weakref__']
+        except KeyError:
+            pass
+
+        return state
+
+    def __setstate__(self, state):
+        """
+        Restore the attributes from a pickled state.
+        """
+        # TODO check or discard version
+        del state['_version_id']
+        for key, value in state.items():
+            if key not in ('__weakref__',):
+                setattr(self, key, value)
+
+
+class FileBuildInfo(SCons.Node.BuildInfoBase):
+    __slots__ = ()
+    current_version_id = 2
+
+    def convert_to_sconsign(self):
+        """
+        Converts this FileBuildInfo object for writing to a .sconsign file
+
+        This replaces each Node in our various dependency lists with its
+        usual string representation: relative to the top-level SConstruct
+        directory, or an absolute path if it's outside.
+        """
+        if os_sep_is_slash:
+            node_to_str = str
+        else:
+            def node_to_str(n):
+                try:
+                    s = n.get_internal_path()
+                except AttributeError:
+                    s = str(n)
+                else:
+                    s = s.replace(OS_SEP, '/')
+                return s
+        for attr in ['bsources', 'bdepends', 'bimplicit']:
+            try:
+                val = getattr(self, attr)
+            except AttributeError:
+                pass
+            else:
+                setattr(self, attr, list(map(node_to_str, val)))
+
+    def convert_from_sconsign(self, dir, name):
+        """
+        Converts a newly-read FileBuildInfo object for in-SCons use
+
+        For normal up-to-date checking, we don't have any conversion to
+        perform--but we're leaving this method here to make that clear.
+        """
+        pass
+
+    def prepare_dependencies(self):
+        """
+        Prepares a FileBuildInfo object for explaining what changed
+
+        The bsources, bdepends and bimplicit lists have all been
+        stored on disk as paths relative to the top-level SConstruct
+        directory.  Convert the strings to actual Nodes (for use by the
+        --debug=explain code and --implicit-cache).
+        """
+        attrs = [
+            ('bsources', 'bsourcesigs'),
+            ('bdepends', 'bdependsigs'),
+            ('bimplicit', 'bimplicitsigs'),
+        ]
+        for (nattr, sattr) in attrs:
+            try:
+                strings = getattr(self, nattr)
+                nodeinfos = getattr(self, sattr)
+            except AttributeError:
+                continue
+            if strings is None or nodeinfos is None:
+                continue
+            nodes = []
+            for s, ni in zip(strings, nodeinfos):
+                if not isinstance(s, SCons.Node.Node):
+                    s = ni.str_to_node(s)
+                nodes.append(s)
+            setattr(self, nattr, nodes)
+
+    def format(self, names=0):
+        result = []
+        bkids = self.bsources + self.bdepends + self.bimplicit
+        bkidsigs = self.bsourcesigs + self.bdependsigs + self.bimplicitsigs
+        for bkid, bkidsig in zip(bkids, bkidsigs):
+            result.append(str(bkid) + ': ' +
+                          ' '.join(bkidsig.format(names=names)))
+        if not hasattr(self,'bact'):
+            self.bact = "none"
+        result.append('%s [%s]' % (self.bactsig, self.bact))
+        return '\n'.join(result)
+
+
+class File(Base):
+    """A class for files in a file system.
+    """
+
+    __slots__ = ['scanner_paths',
+                 'cachedir_csig',
+                 'cachesig',
+                 'repositories',
+                 'srcdir',
+                 'entries',
+                 'searched',
+                 '_sconsign',
+                 'variant_dirs',
+                 'root',
+                 'dirname',
+                 'on_disk_entries',
+                 'released_target_info',
+                 'contentsig']
+
+    NodeInfo = FileNodeInfo
+    BuildInfo = FileBuildInfo
+
+    md5_chunksize = 64
+
+    def diskcheck_match(self):
+        diskcheck_match(self, self.isdir,
+                        "Directory %s found where file expected.")
+
+    def __init__(self, name, directory, fs):
+        if SCons.Debug.track_instances: logInstanceCreation(self, 'Node.FS.File')
+        Base.__init__(self, name, directory, fs)
+        self._morph()
+
+    def Entry(self, name):
+        """Create an entry node named 'name' relative to
+        the directory of this file."""
+        return self.dir.Entry(name)
+
+    def Dir(self, name, create=True):
+        """Create a directory node named 'name' relative to
+        the directory of this file."""
+        return self.dir.Dir(name, create=create)
+
+    def Dirs(self, pathlist):
+        """Create a list of directories relative to the SConscript
+        directory of this file."""
+        return [self.Dir(p) for p in pathlist]
+
+    def File(self, name):
+        """Create a file node named 'name' relative to
+        the directory of this file."""
+        return self.dir.File(name)
+
+    def _morph(self):
+        """Turn a file system node into a File object."""
+        self.scanner_paths = {}
+        if not hasattr(self, '_local'):
+            self._local = 0
+        if not hasattr(self, 'released_target_info'):
+            self.released_target_info = False
+
+        self.store_info = 1
+        self._func_exists = 4
+        self._func_get_contents = 3
+
+        # Initialize this Node's decider function to decide_source() because
+        # every file is a source file until it has a Builder attached...
+        self.changed_since_last_build = 4
+
+        # If there was already a Builder set on this entry, then
+        # we need to make sure we call the target-decider function,
+        # not the source-decider.  Reaching in and doing this by hand
+        # is a little bogus.  We'd prefer to handle this by adding
+        # an Entry.builder_set() method that disambiguates like the
+        # other methods, but that starts running into problems with the
+        # fragile way we initialize Dir Nodes with their Mkdir builders,
+        # yet still allow them to be overridden by the user.  Since it's
+        # not clear right now how to fix that, stick with what works
+        # until it becomes clear...
+        if self.has_builder():
+            self.changed_since_last_build = 5
+
+    def scanner_key(self):
+        return self.get_suffix()
+
+    def get_contents(self):
+        return SCons.Node._get_contents_map[self._func_get_contents](self)
+
+    def get_text_contents(self):
+        """
+        This attempts to figure out what the encoding of the text is
+        based upon the BOM bytes, and then decodes the contents so that
+        it's a valid python string.
+        """
+        contents = self.get_contents()
+        # The behavior of various decode() methods and functions
+        # w.r.t. the initial BOM bytes is different for different
+        # encodings and/or Python versions.  ('utf-8' does not strip
+        # them, but has a 'utf-8-sig' which does; 'utf-16' seems to
+        # strip them; etc.)  Just sidestep all the complication by
+        # explicitly stripping the BOM before we decode().
+        if contents[:len(codecs.BOM_UTF8)] == codecs.BOM_UTF8:
+            return contents[len(codecs.BOM_UTF8):].decode('utf-8')
+        if contents[:len(codecs.BOM_UTF16_LE)] == codecs.BOM_UTF16_LE:
+            return contents[len(codecs.BOM_UTF16_LE):].decode('utf-16-le')
+        if contents[:len(codecs.BOM_UTF16_BE)] == codecs.BOM_UTF16_BE:
+            return contents[len(codecs.BOM_UTF16_BE):].decode('utf-16-be')
+        try:
+            return contents.decode('utf-8')
+        except UnicodeDecodeError as e:
+            try:
+                return contents.decode('latin-1')
+            except UnicodeDecodeError as e:
+                return contents.decode('utf-8', error='backslashreplace')
+
+
+    def get_content_hash(self):
+        """
+        Compute and return the MD5 hash for this file.
+        """
+        if not self.rexists():
+            return SCons.Util.MD5signature('')
+        fname = self.rfile().get_abspath()
+        try:
+            cs = SCons.Util.MD5filesignature(fname,
+                chunksize=SCons.Node.FS.File.md5_chunksize*1024)
+        except EnvironmentError as e:
+            if not e.filename:
+                e.filename = fname
+            raise
+        return cs
+
+    @SCons.Memoize.CountMethodCall
+    def get_size(self):
+        try:
+            return self._memo['get_size']
+        except KeyError:
+            pass
+
+        if self.rexists():
+            size = self.rfile().getsize()
+        else:
+            size = 0
+
+        self._memo['get_size'] = size
+
+        return size
+
+    @SCons.Memoize.CountMethodCall
+    def get_timestamp(self):
+        try:
+            return self._memo['get_timestamp']
+        except KeyError:
+            pass
+
+        if self.rexists():
+            timestamp = self.rfile().getmtime()
+        else:
+            timestamp = 0
+
+        self._memo['get_timestamp'] = timestamp
+
+        return timestamp
+
+    convert_copy_attrs = [
+        'bsources',
+        'bimplicit',
+        'bdepends',
+        'bact',
+        'bactsig',
+        'ninfo',
+    ]
+
+
+    convert_sig_attrs = [
+        'bsourcesigs',
+        'bimplicitsigs',
+        'bdependsigs',
+    ]
+
+    def convert_old_entry(self, old_entry):
+        # Convert a .sconsign entry from before the Big Signature
+        # Refactoring, doing what we can to convert its information
+        # to the new .sconsign entry format.
+        #
+        # The old format looked essentially like this:
+        #
+        #   BuildInfo
+        #       .ninfo (NodeInfo)
+        #           .bsig
+        #           .csig
+        #           .timestamp
+        #           .size
+        #       .bsources
+        #       .bsourcesigs ("signature" list)
+        #       .bdepends
+        #       .bdependsigs ("signature" list)
+        #       .bimplicit
+        #       .bimplicitsigs ("signature" list)
+        #       .bact
+        #       .bactsig
+        #
+        # The new format looks like this:
+        #
+        #   .ninfo (NodeInfo)
+        #       .bsig
+        #       .csig
+        #       .timestamp
+        #       .size
+        #   .binfo (BuildInfo)
+        #       .bsources
+        #       .bsourcesigs (NodeInfo list)
+        #           .bsig
+        #           .csig
+        #           .timestamp
+        #           .size
+        #       .bdepends
+        #       .bdependsigs (NodeInfo list)
+        #           .bsig
+        #           .csig
+        #           .timestamp
+        #           .size
+        #       .bimplicit
+        #       .bimplicitsigs (NodeInfo list)
+        #           .bsig
+        #           .csig
+        #           .timestamp
+        #           .size
+        #       .bact
+        #       .bactsig
+        #
+        # The basic idea of the new structure is that a NodeInfo always
+        # holds all available information about the state of a given Node
+        # at a certain point in time.  The various .b*sigs lists can just
+        # be a list of pointers to the .ninfo attributes of the different
+        # dependent nodes, without any copying of information until it's
+        # time to pickle it for writing out to a .sconsign file.
+        #
+        # The complicating issue is that the *old* format only stored one
+        # "signature" per dependency, based on however the *last* build
+        # was configured.  We don't know from just looking at it whether
+        # it was a build signature, a content signature, or a timestamp
+        # "signature".  Since we no longer use build signatures, the
+        # best we can do is look at the length and if it's thirty two,
+        # assume that it was (or might have been) a content signature.
+        # If it was actually a build signature, then it will cause a
+        # rebuild anyway when it doesn't match the new content signature,
+        # but that's probably the best we can do.
+        import SCons.SConsign
+        new_entry = SCons.SConsign.SConsignEntry()
+        new_entry.binfo = self.new_binfo()
+        binfo = new_entry.binfo
+        for attr in self.convert_copy_attrs:
+            try:
+                value = getattr(old_entry, attr)
+            except AttributeError:
+                continue
+            setattr(binfo, attr, value)
+            delattr(old_entry, attr)
+        for attr in self.convert_sig_attrs:
+            try:
+                sig_list = getattr(old_entry, attr)
+            except AttributeError:
+                continue
+            value = []
+            for sig in sig_list:
+                ninfo = self.new_ninfo()
+                if len(sig) == 32:
+                    ninfo.csig = sig
+                else:
+                    ninfo.timestamp = sig
+                value.append(ninfo)
+            setattr(binfo, attr, value)
+            delattr(old_entry, attr)
+        return new_entry
+
+    @SCons.Memoize.CountMethodCall
+    def get_stored_info(self):
+        try:
+            return self._memo['get_stored_info']
+        except KeyError:
+            pass
+
+        try:
+            sconsign_entry = self.dir.sconsign().get_entry(self.name)
+        except (KeyError, EnvironmentError):
+            import SCons.SConsign
+            sconsign_entry = SCons.SConsign.SConsignEntry()
+            sconsign_entry.binfo = self.new_binfo()
+            sconsign_entry.ninfo = self.new_ninfo()
+        else:
+            if isinstance(sconsign_entry, FileBuildInfo):
+                # This is a .sconsign file from before the Big Signature
+                # Refactoring; convert it as best we can.
+                sconsign_entry = self.convert_old_entry(sconsign_entry)
+            try:
+                delattr(sconsign_entry.ninfo, 'bsig')
+            except AttributeError:
+                pass
+
+        self._memo['get_stored_info'] = sconsign_entry
+
+        return sconsign_entry
+
+    def get_stored_implicit(self):
+        binfo = self.get_stored_info().binfo
+        binfo.prepare_dependencies()
+        try: return binfo.bimplicit
+        except AttributeError: return None
+
+    def rel_path(self, other):
+        return self.dir.rel_path(other)
+
+    def _get_found_includes_key(self, env, scanner, path):
+        return (id(env), id(scanner), path)
+
+    @SCons.Memoize.CountDictCall(_get_found_includes_key)
+    def get_found_includes(self, env, scanner, path):
+        """Return the included implicit dependencies in this file.
+        Cache results so we only scan the file once per path
+        regardless of how many times this information is requested.
+        """
+        memo_key = (id(env), id(scanner), path)
+        try:
+            memo_dict = self._memo['get_found_includes']
+        except KeyError:
+            memo_dict = {}
+            self._memo['get_found_includes'] = memo_dict
+        else:
+            try:
+                return memo_dict[memo_key]
+            except KeyError:
+                pass
+
+        if scanner:
+            result = [n.disambiguate() for n in scanner(self, env, path)]
+        else:
+            result = []
+
+        memo_dict[memo_key] = result
+
+        return result
+
+    def _createDir(self):
+        # ensure that the directories for this node are
+        # created.
+        self.dir._create()
+
+    def push_to_cache(self):
+        """Try to push the node into a cache
+        """
+        # This should get called before the Nodes' .built() method is
+        # called, which would clear the build signature if the file has
+        # a source scanner.
+        #
+        # We have to clear the local memoized values *before* we push
+        # the node to cache so that the memoization of the self.exists()
+        # return value doesn't interfere.
+        if self.nocache:
+            return
+        self.clear_memoized_values()
+        if self.exists():
+            self.get_build_env().get_CacheDir().push(self)
+
+    def retrieve_from_cache(self):
+        """Try to retrieve the node's content from a cache
+
+        This method is called from multiple threads in a parallel build,
+        so only do thread safe stuff here. Do thread unsafe stuff in
+        built().
+
+        Returns true if the node was successfully retrieved.
+        """
+        if self.nocache:
+            return None
+        if not self.is_derived():
+            return None
+        return self.get_build_env().get_CacheDir().retrieve(self)
+
+    def visited(self):
+        if self.exists() and self.executor is not None:
+            self.get_build_env().get_CacheDir().push_if_forced(self)
+
+        ninfo = self.get_ninfo()
+
+        csig = self.get_max_drift_csig()
+        if csig:
+            ninfo.csig = csig
+
+        ninfo.timestamp = self.get_timestamp()
+        ninfo.size      = self.get_size()
+
+        if not self.has_builder():
+            # This is a source file, but it might have been a target file
+            # in another build that included more of the DAG.  Copy
+            # any build information that's stored in the .sconsign file
+            # into our binfo object so it doesn't get lost.
+            old = self.get_stored_info()
+            self.get_binfo().merge(old.binfo)
+
+        SCons.Node.store_info_map[self.store_info](self)
+
+    def release_target_info(self):
+        """Called just after this node has been marked
+         up-to-date or was built completely.
+
+         This is where we try to release as many target node infos
+         as possible for clean builds and update runs, in order
+         to minimize the overall memory consumption.
+
+         We'd like to remove a lot more attributes like self.sources
+         and self.sources_set, but they might get used
+         in a next build step. For example, during configuration
+         the source files for a built E{*}.o file are used to figure out
+         which linker to use for the resulting Program (gcc vs. g++)!
+         That's why we check for the 'keep_targetinfo' attribute,
+         config Nodes and the Interactive mode just don't allow
+         an early release of most variables.
+
+         In the same manner, we can't simply remove the self.attributes
+         here. The smart linking relies on the shared flag, and some
+         parts of the java Tool use it to transport information
+         about nodes...
+
+         @see: built() and Node.release_target_info()
+         """
+        if (self.released_target_info or SCons.Node.interactive):
+            return
+
+        if not hasattr(self.attributes, 'keep_targetinfo'):
+            # Cache some required values, before releasing
+            # stuff like env, executor and builder...
+            self.changed(allowcache=True)
+            self.get_contents_sig()
+            self.get_build_env()
+            # Now purge unneeded stuff to free memory...
+            self.executor = None
+            self._memo.pop('rfile', None)
+            self.prerequisites = None
+            # Cleanup lists, but only if they're empty
+            if not len(self.ignore_set):
+                self.ignore_set = None
+            if not len(self.implicit_set):
+                self.implicit_set = None
+            if not len(self.depends_set):
+                self.depends_set = None
+            if not len(self.ignore):
+                self.ignore = None
+            if not len(self.depends):
+                self.depends = None
+            # Mark this node as done, we only have to release
+            # the memory once...
+            self.released_target_info = True
+
+    def find_src_builder(self):
+        if self.rexists():
+            return None
+        scb = self.dir.src_builder()
+        if scb is _null:
+            scb = None
+        if scb is not None:
+            try:
+                b = self.builder
+            except AttributeError:
+                b = None
+            if b is None:
+                self.builder_set(scb)
+        return scb
+
+    def has_src_builder(self):
+        """Return whether this Node has a source builder or not.
+
+        If this Node doesn't have an explicit source code builder, this
+        is where we figure out, on the fly, if there's a transparent
+        source code builder for it.
+
+        Note that if we found a source builder, we also set the
+        self.builder attribute, so that all of the methods that actually
+        *build* this file don't have to do anything different.
+        """
+        try:
+            scb = self.sbuilder
+        except AttributeError:
+            scb = self.sbuilder = self.find_src_builder()
+        return scb is not None
+
+    def alter_targets(self):
+        """Return any corresponding targets in a variant directory.
+        """
+        if self.is_derived():
+            return [], None
+        return self.fs.variant_dir_target_climb(self, self.dir, [self.name])
+
+    def _rmv_existing(self):
+        self.clear_memoized_values()
+        if SCons.Node.print_duplicate:
+            print("dup: removing existing target {}".format(self))
+        e = Unlink(self, [], None)
+        if isinstance(e, SCons.Errors.BuildError):
+            raise e
+
+    #
+    # Taskmaster interface subsystem
+    #
+
+    def make_ready(self):
+        self.has_src_builder()
+        self.get_binfo()
+
+    def prepare(self):
+        """Prepare for this file to be created."""
+        SCons.Node.Node.prepare(self)
+
+        if self.get_state() != SCons.Node.up_to_date:
+            if self.exists():
+                if self.is_derived() and not self.precious:
+                    self._rmv_existing()
+            else:
+                try:
+                    self._createDir()
+                except SCons.Errors.StopError as drive:
+                    raise SCons.Errors.StopError("No drive `{}' for target `{}'.".format(drive, self))
+
+    #
+    #
+    #
+
+    def remove(self):
+        """Remove this file."""
+        if self.exists() or self.islink():
+            self.fs.unlink(self.get_internal_path())
+            return 1
+        return None
+
+    def do_duplicate(self, src):
+        self._createDir()
+        if SCons.Node.print_duplicate:
+            print("dup: relinking variant '{}' from '{}'".format(self, src))
+        Unlink(self, None, None)
+        e = Link(self, src, None)
+        if isinstance(e, SCons.Errors.BuildError):
+            raise SCons.Errors.StopError("Cannot duplicate `{}' in `{}': {}.".format(src.get_internal_path(), self.dir._path, e.errstr))
+        self.linked = 1
+        # The Link() action may or may not have actually
+        # created the file, depending on whether the -n
+        # option was used or not.  Delete the _exists and
+        # _rexists attributes so they can be reevaluated.
+        self.clear()
+
+    @SCons.Memoize.CountMethodCall
+    def exists(self):
+        try:
+            return self._memo['exists']
+        except KeyError:
+            pass
+        result = SCons.Node._exists_map[self._func_exists](self)
+        self._memo['exists'] = result
+        return result
+
+    #
+    # SIGNATURE SUBSYSTEM
+    #
+
+    def get_max_drift_csig(self):
+        """
+        Returns the content signature currently stored for this node
+        if it's been unmodified longer than the max_drift value, or the
+        max_drift value is 0.  Returns None otherwise.
+        """
+        old = self.get_stored_info()
+        mtime = self.get_timestamp()
+
+        max_drift = self.fs.max_drift
+        if max_drift > 0:
+            if (time.time() - mtime) > max_drift:
+                try:
+                    n = old.ninfo
+                    if n.timestamp and n.csig and n.timestamp == mtime:
+                        return n.csig
+                except AttributeError:
+                    pass
+        elif max_drift == 0:
+            try:
+                return old.ninfo.csig
+            except AttributeError:
+                pass
+
+        return None
+
+    def get_csig(self):
+        """
+        Generate a node's content signature, the digested signature
+        of its content.
+
+        node - the node
+        cache - alternate node to use for the signature cache
+        returns - the content signature
+        """
+        ninfo = self.get_ninfo()
+        try:
+            return ninfo.csig
+        except AttributeError:
+            pass
+
+        csig = self.get_max_drift_csig()
+        if csig is None:
+
+            try:
+                if self.get_size() < SCons.Node.FS.File.md5_chunksize:
+                    contents = self.get_contents()
+                else:
+                    csig = self.get_content_hash()
+            except IOError:
+                # This can happen if there's actually a directory on-disk,
+                # which can be the case if they've disabled disk checks,
+                # or if an action with a File target actually happens to
+                # create a same-named directory by mistake.
+                csig = ''
+            else:
+                if not csig:
+                    csig = SCons.Util.MD5signature(contents)
+
+        ninfo.csig = csig
+
+        return csig
+
+    #
+    # DECISION SUBSYSTEM
+    #
+
+    def builder_set(self, builder):
+        SCons.Node.Node.builder_set(self, builder)
+        self.changed_since_last_build = 5
+
+    def built(self):
+        """Called just after this File node is successfully built.
+
+         Just like for 'release_target_info' we try to release
+         some more target node attributes in order to minimize the
+         overall memory consumption.
+
+         @see: release_target_info
+        """
+
+        SCons.Node.Node.built(self)
+
+        if (not SCons.Node.interactive and
+            not hasattr(self.attributes, 'keep_targetinfo')):
+            # Ensure that the build infos get computed and cached...
+            SCons.Node.store_info_map[self.store_info](self)
+            # ... then release some more variables.
+            self._specific_sources = False
+            self._labspath = None
+            self._save_str()
+            self.cwd = None
+
+            self.scanner_paths = None
+
+    def changed(self, node=None, allowcache=False):
+        """
+        Returns if the node is up-to-date with respect to the BuildInfo
+        stored last time it was built.
+
+        For File nodes this is basically a wrapper around Node.changed(),
+        but we allow the return value to get cached after the reference
+        to the Executor got released in release_target_info().
+
+        @see: Node.changed()
+        """
+        if node is None:
+            try:
+                return self._memo['changed']
+            except KeyError:
+                pass
+
+        has_changed = SCons.Node.Node.changed(self, node)
+        if allowcache:
+            self._memo['changed'] = has_changed
+        return has_changed
+
+    def changed_content(self, target, prev_ni):
+        cur_csig = self.get_csig()
+        try:
+            return cur_csig != prev_ni.csig
+        except AttributeError:
+            return 1
+
+    def changed_state(self, target, prev_ni):
+        return self.state != SCons.Node.up_to_date
+
+    def changed_timestamp_then_content(self, target, prev_ni):
+        if not self.changed_timestamp_match(target, prev_ni):
+            try:
+                self.get_ninfo().csig = prev_ni.csig
+            except AttributeError:
+                pass
+            return False
+        return self.changed_content(target, prev_ni)
+
+    def changed_timestamp_newer(self, target, prev_ni):
+        try:
+            return self.get_timestamp() > target.get_timestamp()
+        except AttributeError:
+            return 1
+
+    def changed_timestamp_match(self, target, prev_ni):
+        try:
+            return self.get_timestamp() != prev_ni.timestamp
+        except AttributeError:
+            return 1
+
+    def is_up_to_date(self):
+        T = 0
+        if T: Trace('is_up_to_date(%s):' % self)
+        if not self.exists():
+            if T: Trace(' not self.exists():')
+            # The file doesn't exist locally...
+            r = self.rfile()
+            if r != self:
+                # ...but there is one in a Repository...
+                if not self.changed(r):
+                    if T: Trace(' changed(%s):' % r)
+                    # ...and it's even up-to-date...
+                    if self._local:
+                        # ...and they'd like a local copy.
+                        e = LocalCopy(self, r, None)
+                        if isinstance(e, SCons.Errors.BuildError):
+                            raise
+                        SCons.Node.store_info_map[self.store_info](self)
+                    if T: Trace(' 1\n')
+                    return 1
+            self.changed()
+            if T: Trace(' None\n')
+            return None
+        else:
+            r = self.changed()
+            if T: Trace(' self.exists():  %s\n' % r)
+            return not r
+
+    @SCons.Memoize.CountMethodCall
+    def rfile(self):
+        try:
+            return self._memo['rfile']
+        except KeyError:
+            pass
+        result = self
+        if not self.exists():
+            norm_name = _my_normcase(self.name)
+            for dir in self.dir.get_all_rdirs():
+                try: node = dir.entries[norm_name]
+                except KeyError: node = dir.file_on_disk(self.name)
+                if node and node.exists() and \
+                   (isinstance(node, File) or isinstance(node, Entry) \
+                    or not node.is_derived()):
+                        result = node
+                        # Copy over our local attributes to the repository
+                        # Node so we identify shared object files in the
+                        # repository and don't assume they're static.
+                        #
+                        # This isn't perfect; the attribute would ideally
+                        # be attached to the object in the repository in
+                        # case it was built statically in the repository
+                        # and we changed it to shared locally, but that's
+                        # rarely the case and would only occur if you
+                        # intentionally used the same suffix for both
+                        # shared and static objects anyway.  So this
+                        # should work well in practice.
+                        result.attributes = self.attributes
+                        break
+        self._memo['rfile'] = result
+        return result
+
+    def rstr(self):
+        return str(self.rfile())
+
+    def get_cachedir_csig(self):
+        """
+        Fetch a Node's content signature for purposes of computing
+        another Node's cachesig.
+
+        This is a wrapper around the normal get_csig() method that handles
+        the somewhat obscure case of using CacheDir with the -n option.
+        Any files that don't exist would normally be "built" by fetching
+        them from the cache, but the normal get_csig() method will try
+        to open up the local file, which doesn't exist because the -n
+        option meant we didn't actually pull the file from cachedir.
+        But since the file *does* actually exist in the cachedir, we
+        can use its contents for the csig.
+        """
+        try:
+            return self.cachedir_csig
+        except AttributeError:
+            pass
+
+        cachedir, cachefile = self.get_build_env().get_CacheDir().cachepath(self)
+        if not self.exists() and cachefile and os.path.exists(cachefile):
+            self.cachedir_csig = SCons.Util.MD5filesignature(cachefile, \
+                SCons.Node.FS.File.md5_chunksize * 1024)
+        else:
+            self.cachedir_csig = self.get_csig()
+        return self.cachedir_csig
+
+    def get_contents_sig(self):
+        """
+        A helper method for get_cachedir_bsig.
+
+        It computes and returns the signature for this
+        node's contents.
+        """
+
+        try:
+            return self.contentsig
+        except AttributeError:
+            pass
+
+        executor = self.get_executor()
+
+        result = self.contentsig = SCons.Util.MD5signature(executor.get_contents())
+        return result
+
+    def get_cachedir_bsig(self):
+        """
+        Return the signature for a cached file, including
+        its children.
+
+        It adds the path of the cached file to the cache signature,
+        because multiple targets built by the same action will all
+        have the same build signature, and we have to differentiate
+        them somehow.
+        """
+        try:
+            return self.cachesig
+        except AttributeError:
+            pass
+
+        # Collect signatures for all children
+        children = self.children()
+        sigs = [n.get_cachedir_csig() for n in children]
+        # Append this node's signature...
+        sigs.append(self.get_contents_sig())
+        # ...and it's path
+        sigs.append(self.get_internal_path())
+        # Merge this all into a single signature
+        result = self.cachesig = SCons.Util.MD5collect(sigs)
+        return result
+
+default_fs = None
+
+def get_default_fs():
+    global default_fs
+    if not default_fs:
+        default_fs = FS()
+    return default_fs
+
+class FileFinder(object):
+    """
+    """
+
+    def __init__(self):
+        self._memo = {}
+
+    def filedir_lookup(self, p, fd=None):
+        """
+        A helper method for find_file() that looks up a directory for
+        a file we're trying to find.  This only creates the Dir Node if
+        it exists on-disk, since if the directory doesn't exist we know
+        we won't find any files in it...  :-)
+
+        It would be more compact to just use this as a nested function
+        with a default keyword argument (see the commented-out version
+        below), but that doesn't work unless you have nested scopes,
+        so we define it here just so this work under Python 1.5.2.
+        """
+        if fd is None:
+            fd = self.default_filedir
+        dir, name = os.path.split(fd)
+        drive, d = _my_splitdrive(dir)
+        if not name and d[:1] in ('/', OS_SEP):
+            #return p.fs.get_root(drive).dir_on_disk(name)
+            return p.fs.get_root(drive)
+        if dir:
+            p = self.filedir_lookup(p, dir)
+            if not p:
+                return None
+        norm_name = _my_normcase(name)
+        try:
+            node = p.entries[norm_name]
+        except KeyError:
+            return p.dir_on_disk(name)
+        if isinstance(node, Dir):
+            return node
+        if isinstance(node, Entry):
+            node.must_be_same(Dir)
+            return node
+        return None
+
+    def _find_file_key(self, filename, paths, verbose=None):
+        return (filename, paths)
+
+    @SCons.Memoize.CountDictCall(_find_file_key)
+    def find_file(self, filename, paths, verbose=None):
+        """
+        Find a node corresponding to either a derived file or a file that exists already.
+
+        Only the first file found is returned, and none is returned if no file is found.
+
+        filename: A filename to find
+        paths: A list of directory path *nodes* to search in.  Can be represented as a list, a tuple, or a callable that is called with no arguments and returns the list or tuple.
+
+        returns The node created from the found file.
+
+        """
+        memo_key = self._find_file_key(filename, paths)
+        try:
+            memo_dict = self._memo['find_file']
+        except KeyError:
+            memo_dict = {}
+            self._memo['find_file'] = memo_dict
+        else:
+            try:
+                return memo_dict[memo_key]
+            except KeyError:
+                pass
+
+        if verbose and not callable(verbose):
+            if not SCons.Util.is_String(verbose):
+                verbose = "find_file"
+            _verbose = u'  %s: ' % verbose
+            verbose = lambda s: sys.stdout.write(_verbose + s)
+
+        filedir, filename = os.path.split(filename)
+        if filedir:
+            self.default_filedir = filedir
+            paths = [_f for _f in map(self.filedir_lookup, paths) if _f]
+
+        result = None
+        for dir in paths:
+            if verbose:
+                verbose("looking for '%s' in '%s' ...\n" % (filename, dir))
+            node, d = dir.srcdir_find_file(filename)
+            if node:
+                if verbose:
+                    verbose("... FOUND '%s' in '%s'\n" % (filename, d))
+                result = node
+                break
+
+        memo_dict[memo_key] = result
+
+        return result
+
+find_file = FileFinder().find_file
+
+
+def invalidate_node_memos(targets):
+    """
+    Invalidate the memoized values of all Nodes (files or directories)
+    that are associated with the given entries. Has been added to
+    clear the cache of nodes affected by a direct execution of an
+    action (e.g.  Delete/Copy/Chmod). Existing Node caches become
+    inconsistent if the action is run through Execute().  The argument
+    `targets` can be a single Node object or filename, or a sequence
+    of Nodes/filenames.
+    """
+    from traceback import extract_stack
+
+    # First check if the cache really needs to be flushed. Only
+    # actions run in the SConscript with Execute() seem to be
+    # affected. XXX The way to check if Execute() is in the stacktrace
+    # is a very dirty hack and should be replaced by a more sensible
+    # solution.
+    for f in extract_stack():
+        if f[2] == 'Execute' and f[0][-14:] == 'Environment.py':
+            break
+    else:
+        # Dont have to invalidate, so return
+        return
+
+    if not SCons.Util.is_List(targets):
+        targets = [targets]
+
+    for entry in targets:
+        # If the target is a Node object, clear the cache. If it is a
+        # filename, look up potentially existing Node object first.
+        try:
+            entry.clear_memoized_values()
+        except AttributeError:
+            # Not a Node object, try to look up Node by filename.  XXX
+            # This creates Node objects even for those filenames which
+            # do not correspond to an existing Node object.
+            node = get_default_fs().Entry(entry)
+            if node:
+                node.clear_memoized_values()
+
+# Local Variables:
+# tab-width:4
+# indent-tabs-mode:nil
+# End:
+# vim: set expandtab tabstop=4 shiftwidth=4:
diff --git a/3rdParty/SCons/scons-3.0.1/engine/SCons/Node/FSTests.py b/3rdParty/SCons/scons-3.0.1/engine/SCons/Node/FSTests.py
new file mode 100644
index 0000000..273f809
--- /dev/null
+++ b/3rdParty/SCons/scons-3.0.1/engine/SCons/Node/FSTests.py
@@ -0,0 +1,3787 @@
+#
+# __COPYRIGHT__
+#
+# 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.
+#
+from __future__ import division, print_function
+
+__revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
+
+import SCons.compat
+
+import os
+import os.path
+import sys
+import time
+import unittest
+import shutil
+import stat
+
+from TestCmd import TestCmd
+import TestUnit
+
+import SCons.Errors
+import SCons.Node.FS
+import SCons.Util
+import SCons.Warnings
+
+built_it = None
+
+scanner_count = 0
+
+class Scanner(object):
+    def __init__(self, node=None):
+        global scanner_count
+        scanner_count = scanner_count + 1
+        self.hash = scanner_count
+        self.node = node
+    def path(self, env, dir, target=None, source=None):
+        return ()
+    def __call__(self, node, env, path):
+        return [self.node]
+    def __hash__(self):
+        return self.hash
+    def select(self, node):
+        return self
+    def recurse_nodes(self, nodes):
+        return nodes
+
+class Environment(object):
+    def __init__(self):
+        self.scanner = Scanner()
+    def Dictionary(self, *args):
+        return {}
+    def autogenerate(self, **kw):
+        return {}
+    def get_scanner(self, skey):
+        return self.scanner
+    def Override(self, overrides):
+        return self
+    def _update(self, dict):
+        pass
+
+class Action(object):
+    def __call__(self, targets, sources, env, **kw):
+        global built_it
+        if kw.get('execute', 1):
+            built_it = 1
+        return 0
+    def show(self, string):
+        pass
+    def get_contents(self, target, source, env):
+        return bytearray("",'utf-8')
+    def genstring(self, target, source, env):
+        return ""
+    def strfunction(self, targets, sources, env):
+        return ""
+    def get_implicit_deps(self, target, source, env):
+        return []
+
+class Builder(object):
+    def __init__(self, factory, action=Action()):
+        self.factory = factory
+        self.env = Environment()
+        self.overrides = {}
+        self.action = action
+        self.target_scanner = None
+        self.source_scanner = None
+
+    def targets(self, t):
+        return [t]
+
+    def source_factory(self, name):
+        return self.factory(name)
+
+class _tempdirTestCase(unittest.TestCase):
+    def setUp(self):
+        self.save_cwd = os.getcwd()
+        self.test = TestCmd(workdir='')
+        # FS doesn't like the cwd to be something other than its root.
+        os.chdir(self.test.workpath(""))
+        self.fs = SCons.Node.FS.FS()
+
+    def tearDown(self):
+        os.chdir(self.save_cwd)
+
+class VariantDirTestCase(unittest.TestCase):
+    def runTest(self):
+        """Test variant dir functionality"""
+        test=TestCmd(workdir='')
+
+        fs = SCons.Node.FS.FS()
+        f1 = fs.File('build/test1')
+        fs.VariantDir('build', 'src')
+        f2 = fs.File('build/test2')
+        d1 = fs.Dir('build')
+        assert f1.srcnode().get_internal_path() == os.path.normpath('src/test1'), f1.srcnode().get_internal_path()
+        assert f2.srcnode().get_internal_path() == os.path.normpath('src/test2'), f2.srcnode().get_internal_path()
+        assert d1.srcnode().get_internal_path() == 'src', d1.srcnode().get_internal_path()
+
+        fs = SCons.Node.FS.FS()
+        f1 = fs.File('build/test1')
+        fs.VariantDir('build', '.')
+        f2 = fs.File('build/test2')
+        d1 = fs.Dir('build')
+        assert f1.srcnode().get_internal_path() == 'test1', f1.srcnode().get_internal_path()
+        assert f2.srcnode().get_internal_path() == 'test2', f2.srcnode().get_internal_path()
+        assert d1.srcnode().get_internal_path() == '.', d1.srcnode().get_internal_path()
+
+        fs = SCons.Node.FS.FS()
+        fs.VariantDir('build/var1', 'src')
+        fs.VariantDir('build/var2', 'src')
+        f1 = fs.File('build/var1/test1')
+        f2 = fs.File('build/var2/test1')
+        assert f1.srcnode().get_internal_path() == os.path.normpath('src/test1'), f1.srcnode().get_internal_path()
+        assert f2.srcnode().get_internal_path() == os.path.normpath('src/test1'), f2.srcnode().get_internal_path()
+
+        fs = SCons.Node.FS.FS()
+        fs.VariantDir('../var1', 'src')
+        fs.VariantDir('../var2', 'src')
+        f1 = fs.File('../var1/test1')
+        f2 = fs.File('../var2/test1')
+        assert f1.srcnode().get_internal_path() == os.path.normpath('src/test1'), f1.srcnode().get_internal_path()
+        assert f2.srcnode().get_internal_path() == os.path.normpath('src/test1'), f2.srcnode().get_internal_path()
+
+        # Set up some files
+        test.subdir('work', ['work', 'src'])
+        test.subdir(['work', 'build'], ['work', 'build', 'var1'])
+        test.subdir(['work', 'build', 'var2'])
+        test.subdir('rep1', ['rep1', 'src'])
+        test.subdir(['rep1', 'build'], ['rep1', 'build', 'var1'])
+        test.subdir(['rep1', 'build', 'var2'])
+
+        # A source file in the source directory
+        test.write([ 'work', 'src', 'test.in' ], 'test.in')
+
+        # A source file in a subdir of the source directory
+        test.subdir([ 'work', 'src', 'new_dir' ])
+        test.write([ 'work', 'src', 'new_dir', 'test9.out' ], 'test9.out\n')
+
+        # A source file in the repository
+        test.write([ 'rep1', 'src', 'test2.in' ], 'test2.in')
+
+        # Some source files in the variant directory
+        test.write([ 'work', 'build', 'var2', 'test.in' ], 'test.old')
+        test.write([ 'work', 'build', 'var2', 'test2.in' ], 'test2.old')
+
+        # An old derived file in the variant directories
+        test.write([ 'work', 'build', 'var1', 'test.out' ], 'test.old')
+        test.write([ 'work', 'build', 'var2', 'test.out' ], 'test.old')
+
+        # And just in case we are weird, a derived file in the source
+        # dir.
+        test.write([ 'work', 'src', 'test.out' ], 'test.out.src')
+
+        # A derived file in the repository
+        test.write([ 'rep1', 'build', 'var1', 'test2.out' ], 'test2.out_rep')
+        test.write([ 'rep1', 'build', 'var2', 'test2.out' ], 'test2.out_rep')
+
+        os.chdir(test.workpath('work'))
+
+        fs = SCons.Node.FS.FS(test.workpath('work'))
+        fs.VariantDir('build/var1', 'src', duplicate=0)
+        fs.VariantDir('build/var2', 'src')
+        f1 = fs.File('build/var1/test.in')
+        f1out = fs.File('build/var1/test.out')
+        f1out.builder = 1
+        f1out_2 = fs.File('build/var1/test2.out')
+        f1out_2.builder = 1
+        f2 = fs.File('build/var2/test.in')
+        f2out = fs.File('build/var2/test.out')
+        f2out.builder = 1
+        f2out_2 = fs.File('build/var2/test2.out')
+        f2out_2.builder = 1
+        fs.Repository(test.workpath('rep1'))
+
+        assert f1.srcnode().get_internal_path() == os.path.normpath('src/test.in'),\
+               f1.srcnode().get_internal_path()
+        # str(node) returns source path for duplicate = 0
+        assert str(f1) == os.path.normpath('src/test.in'), str(f1)
+        # Build path does not exist
+        assert not f1.exists()
+        # ...but the actual file is not there...
+        assert not os.path.exists(f1.get_abspath())
+        # And duplicate=0 should also work just like a Repository
+        assert f1.rexists()
+        # rfile() should point to the source path
+        assert f1.rfile().get_internal_path() == os.path.normpath('src/test.in'),\
+               f1.rfile().get_internal_path()
+
+        assert f2.srcnode().get_internal_path() == os.path.normpath('src/test.in'),\
+               f2.srcnode().get_internal_path()
+        # str(node) returns build path for duplicate = 1
+        assert str(f2) == os.path.normpath('build/var2/test.in'), str(f2)
+        # Build path exists
+        assert f2.exists()
+        # ...and exists() should copy the file from src to build path
+        assert test.read(['work', 'build', 'var2', 'test.in']) == bytearray('test.in','utf-8'),\
+               test.read(['work', 'build', 'var2', 'test.in'])
+        # Since exists() is true, so should rexists() be
+        assert f2.rexists()
+
+        f3 = fs.File('build/var1/test2.in')
+        f4 = fs.File('build/var2/test2.in')
+
+        assert f3.srcnode().get_internal_path() == os.path.normpath('src/test2.in'),\
+               f3.srcnode().get_internal_path()
+        # str(node) returns source path for duplicate = 0
+        assert str(f3) == os.path.normpath('src/test2.in'), str(f3)
+        # Build path does not exist
+        assert not f3.exists()
+        # Source path does not either
+        assert not f3.srcnode().exists()
+        # But we do have a file in the Repository
+        assert f3.rexists()
+        # rfile() should point to the source path
+        assert f3.rfile().get_internal_path() == os.path.normpath(test.workpath('rep1/src/test2.in')),\
+               f3.rfile().get_internal_path()
+
+        assert f4.srcnode().get_internal_path() == os.path.normpath('src/test2.in'),\
+               f4.srcnode().get_internal_path()
+        # str(node) returns build path for duplicate = 1
+        assert str(f4) == os.path.normpath('build/var2/test2.in'), str(f4)
+        # Build path should exist
+        assert f4.exists()
+        # ...and copy over the file into the local build path
+        assert test.read(['work', 'build', 'var2', 'test2.in']) == bytearray('test2.in','utf-8')
+        # should exist in repository, since exists() is true
+        assert f4.rexists()
+        # rfile() should point to ourselves
+        assert f4.rfile().get_internal_path() == os.path.normpath('build/var2/test2.in'),\
+               f4.rfile().get_internal_path()
+
+        f5 = fs.File('build/var1/test.out')
+        f6 = fs.File('build/var2/test.out')
+
+        assert f5.exists()
+        # We should not copy the file from the source dir, since this is
+        # a derived file.
+        assert test.read(['work', 'build', 'var1', 'test.out']) == bytearray('test.old','utf-8')
+
+        assert f6.exists()
+        # We should not copy the file from the source dir, since this is
+        # a derived file.
+        assert test.read(['work', 'build', 'var2', 'test.out']) == bytearray('test.old','utf-8')
+
+        f7 = fs.File('build/var1/test2.out')
+        f8 = fs.File('build/var2/test2.out')
+
+        assert not f7.exists()
+        assert f7.rexists()
+        r = f7.rfile().get_internal_path()
+        expect = os.path.normpath(test.workpath('rep1/build/var1/test2.out'))
+        assert r == expect, (repr(r), repr(expect))
+
+        assert not f8.exists()
+        assert f8.rexists()
+        assert f8.rfile().get_internal_path() == os.path.normpath(test.workpath('rep1/build/var2/test2.out')),\
+               f8.rfile().get_internal_path()
+
+        # Verify the Mkdir and Link actions are called
+        d9 = fs.Dir('build/var2/new_dir')
+        f9 = fs.File('build/var2/new_dir/test9.out')
+
+        class MkdirAction(Action):
+            def __init__(self, dir_made):
+                self.dir_made = dir_made
+            def __call__(self, target, source, env, executor=None):
+                if executor:
+                    target = executor.get_all_targets()
+                    source = executor.get_all_sources()
+                self.dir_made.extend(target)
+
+        save_Link = SCons.Node.FS.Link
+        link_made = []
+        def link_func(target, source, env, link_made=link_made):
+            link_made.append(target)
+        SCons.Node.FS.Link = link_func
+
+        try:
+            dir_made = []
+            d9.builder = Builder(fs.Dir, action=MkdirAction(dir_made))
+            d9.reset_executor()
+            f9.exists()
+            expect = os.path.join('build', 'var2', 'new_dir')
+            assert dir_made[0].get_internal_path() == expect, dir_made[0].get_internal_path()
+            expect = os.path.join('build', 'var2', 'new_dir', 'test9.out')
+            assert link_made[0].get_internal_path() == expect, link_made[0].get_internal_path()
+            assert f9.linked
+        finally:
+            SCons.Node.FS.Link = save_Link
+
+        # Test for an interesting pathological case...we have a source
+        # file in a build path, but not in a source path.  This can
+        # happen if you switch from duplicate=1 to duplicate=0, then
+        # delete a source file.  At one time, this would cause exists()
+        # to return a 1 but get_contents() to throw.
+        test.write([ 'work', 'build', 'var1', 'asourcefile' ], 'stuff')
+        f10 = fs.File('build/var1/asourcefile')
+        assert f10.exists()
+        assert f10.get_contents() == bytearray('stuff','utf-8'), f10.get_contents()
+
+        f11 = fs.File('src/file11')
+        t, m = f11.alter_targets()
+        bdt = [n.get_internal_path() for n in t]
+        var1_file11 = os.path.normpath('build/var1/file11')
+        var2_file11 = os.path.normpath('build/var2/file11')
+        assert bdt == [var1_file11, var2_file11], bdt
+
+        f12 = fs.File('src/file12')
+        f12.builder = 1
+        bdt, m = f12.alter_targets()
+        assert bdt == [], [n.get_internal_path() for n in bdt]
+
+        d13 = fs.Dir('src/new_dir')
+        t, m = d13.alter_targets()
+        bdt = [n.get_internal_path() for n in t]
+        var1_new_dir = os.path.normpath('build/var1/new_dir')
+        var2_new_dir = os.path.normpath('build/var2/new_dir')
+        assert bdt == [var1_new_dir, var2_new_dir], bdt
+
+        # Test that an IOError trying to Link a src file
+        # into a VariantDir ends up throwing a StopError.
+        fIO = fs.File("build/var2/IOError")
+
+        save_Link = SCons.Node.FS.Link
+        def Link_IOError(target, source, env):
+            raise IOError(17, "Link_IOError")
+        SCons.Node.FS.Link = SCons.Action.Action(Link_IOError, None)
+
+        test.write(['work', 'src', 'IOError'], "work/src/IOError\n")
+
+        try:
+            exc_caught = 0
+            try:
+                fIO.exists()
+            except SCons.Errors.StopError:
+                exc_caught = 1
+            assert exc_caught, "Should have caught a StopError"
+
+        finally:
+            SCons.Node.FS.Link = save_Link
+
+        # Test to see if Link() works...
+        test.subdir('src','build')
+        test.write('src/foo', 'src/foo\n')
+        os.chmod(test.workpath('src/foo'), stat.S_IRUSR)
+        SCons.Node.FS.Link(fs.File(test.workpath('build/foo')),
+                           fs.File(test.workpath('src/foo')),
+                           None)
+        os.chmod(test.workpath('src/foo'), stat.S_IRUSR | stat.S_IWRITE)
+        st=os.stat(test.workpath('build/foo'))
+        assert (stat.S_IMODE(st[stat.ST_MODE]) & stat.S_IWRITE), \
+               stat.S_IMODE(st[stat.ST_MODE])
+
+        # This used to generate a UserError when we forbid the source
+        # directory from being outside the top-level SConstruct dir.
+        fs = SCons.Node.FS.FS()
+        fs.VariantDir('build', '/test/foo')
+
+        exc_caught = 0
+        try:
+            try:
+                fs = SCons.Node.FS.FS()
+                fs.VariantDir('build', 'build/src')
+            except SCons.Errors.UserError:
+                exc_caught = 1
+            assert exc_caught, "Should have caught a UserError."
+        finally:
+            test.unlink( "src/foo" )
+            test.unlink( "build/foo" )
+
+        fs = SCons.Node.FS.FS()
+        fs.VariantDir('build', 'src1')
+
+        # Calling the same VariantDir twice should work fine.
+        fs.VariantDir('build', 'src1')
+
+        # Trying to move a variant dir to a second source dir
+        # should blow up
+        try:
+            fs.VariantDir('build', 'src2')
+        except SCons.Errors.UserError:
+            pass
+        else:
+            assert 0, "Should have caught a UserError."
+
+        # Test against a former bug.  Make sure we can get a repository
+        # path for the variant directory itself!
+        fs=SCons.Node.FS.FS(test.workpath('work'))
+        test.subdir('work')
+        fs.VariantDir('build/var3', 'src', duplicate=0)
+        d1 = fs.Dir('build/var3')
+        r = d1.rdir()
+        assert r == d1, "%s != %s" % (r, d1)
+
+        # verify the link creation attempts in file_link()
+        class LinkSimulator (object):
+            """A class to intercept os.[sym]link() calls and track them."""
+
+            def __init__( self, duplicate, link, symlink, copy ) :
+                self.duplicate = duplicate
+                self.have = {}
+                self.have['hard'] = link
+                self.have['soft'] = symlink
+                self.have['copy'] = copy
+
+                self.links_to_be_called = []
+                for link in self.duplicate.split('-'):
+                    if self.have[link]:
+                        self.links_to_be_called.append(link)
+
+            def link_fail( self , src , dest ) :
+                next_link = self.links_to_be_called.pop(0)
+                assert next_link == "hard", \
+                       "Wrong link order: expected %s to be called "\
+                       "instead of hard" % next_link
+                raise OSError( "Simulating hard link creation error." )
+
+            def symlink_fail( self , src , dest ) :
+                next_link = self.links_to_be_called.pop(0)
+                assert next_link == "soft", \
+                       "Wrong link order: expected %s to be called "\
+                       "instead of soft" % next_link
+                raise OSError( "Simulating symlink creation error." )
+
+            def copy( self , src , dest ) :
+                next_link = self.links_to_be_called.pop(0)
+                assert next_link == "copy", \
+                       "Wrong link order: expected %s to be called "\
+                       "instead of copy" % next_link
+                # copy succeeds, but use the real copy
+                self.have['copy'](src, dest)
+        # end class LinkSimulator
+
+        try:
+            SCons.Node.FS.set_duplicate("no-link-order")
+            assert 0, "Expected exception when passing an invalid duplicate to set_duplicate"
+        except SCons.Errors.InternalError:
+            pass
+
+        for duplicate in SCons.Node.FS.Valid_Duplicates:
+            # save the real functions for later restoration
+            try:
+                real_link = os.link
+            except AttributeError:
+                real_link = None
+            try:
+                real_symlink = os.symlink
+            except AttributeError:
+                real_symlink = None
+
+            # Disable symlink and link for now in win32.
+            # We don't have a consistant plan to make these work as yet
+            # They are only supported with PY3
+            if sys.platform == 'win32':
+                real_symlink = None
+                real_link = None
+
+            real_copy = shutil.copy2
+
+            simulator = LinkSimulator(duplicate, real_link, real_symlink, real_copy)
+
+            # override the real functions with our simulation
+            os.link = simulator.link_fail
+            os.symlink = simulator.symlink_fail
+            shutil.copy2 = simulator.copy
+
+            try:
+
+                SCons.Node.FS.set_duplicate(duplicate)
+
+                src_foo = test.workpath('src', 'foo')
+                build_foo = test.workpath('build', 'foo')
+
+                test.write(src_foo, 'src/foo\n')
+                os.chmod(src_foo, stat.S_IRUSR)
+                try:
+                    SCons.Node.FS.Link(fs.File(build_foo),
+                                       fs.File(src_foo),
+                                       None)
+                finally:
+                    os.chmod(src_foo, stat.S_IRUSR | stat.S_IWRITE)
+                    test.unlink(src_foo)
+                    test.unlink(build_foo)
+
+            finally:
+                # restore the real functions
+                if real_link:
+                    os.link = real_link
+                else:
+                    delattr(os, 'link')
+                if real_symlink:
+                    os.symlink = real_symlink
+                else:
+                    delattr(os, 'symlink')
+                shutil.copy2 = real_copy
+
+        # Test VariantDir "reflection," where a same-named subdirectory
+        # exists underneath a variant_dir.
+        fs = SCons.Node.FS.FS()
+        fs.VariantDir('work/src/b1/b2', 'work/src')
+
+        dir_list = [
+                'work/src',
+                'work/src/b1',
+                'work/src/b1/b2',
+                'work/src/b1/b2/b1',
+                'work/src/b1/b2/b1/b2',
+                'work/src/b1/b2/b1/b2/b1',
+                'work/src/b1/b2/b1/b2/b1/b2',
+        ]
+
+        srcnode_map = {
+                'work/src/b1/b2' : 'work/src',
+                'work/src/b1/b2/f' : 'work/src/f',
+                'work/src/b1/b2/b1' : 'work/src/b1/',
+                'work/src/b1/b2/b1/f' : 'work/src/b1/f',
+                'work/src/b1/b2/b1/b2' : 'work/src/b1/b2',
+                'work/src/b1/b2/b1/b2/f' : 'work/src/b1/b2/f',
+                'work/src/b1/b2/b1/b2/b1' : 'work/src/b1/b2/b1',
+                'work/src/b1/b2/b1/b2/b1/f' : 'work/src/b1/b2/b1/f',
+                'work/src/b1/b2/b1/b2/b1/b2' : 'work/src/b1/b2/b1/b2',
+                'work/src/b1/b2/b1/b2/b1/b2/f' : 'work/src/b1/b2/b1/b2/f',
+        }
+
+        alter_map = {
+                'work/src' : 'work/src/b1/b2',
+                'work/src/f' : 'work/src/b1/b2/f',
+                'work/src/b1' : 'work/src/b1/b2/b1',
+                'work/src/b1/f' : 'work/src/b1/b2/b1/f',
+        }
+
+        errors = 0
+
+        for dir in dir_list:
+            dnode = fs.Dir(dir)
+            f = dir + '/f'
+            fnode = fs.File(dir + '/f')
+
+            dp = dnode.srcnode().get_internal_path()
+            expect = os.path.normpath(srcnode_map.get(dir, dir))
+            if dp != expect:
+                print("Dir `%s' srcnode() `%s' != expected `%s'" % (dir, dp, expect))
+                errors = errors + 1
+
+            fp = fnode.srcnode().get_internal_path()
+            expect = os.path.normpath(srcnode_map.get(f, f))
+            if fp != expect:
+                print("File `%s' srcnode() `%s' != expected `%s'" % (f, fp, expect))
+                errors = errors + 1
+
+        for dir in dir_list:
+            dnode = fs.Dir(dir)
+            f = dir + '/f'
+            fnode = fs.File(dir + '/f')
+
+            t, m = dnode.alter_targets()
+            tp = t[0].get_internal_path()
+            expect = os.path.normpath(alter_map.get(dir, dir))
+            if tp != expect:
+                print("Dir `%s' alter_targets() `%s' != expected `%s'" % (dir, tp, expect))
+                errors = errors + 1
+
+            t, m = fnode.alter_targets()
+            tp = t[0].get_internal_path()
+            expect = os.path.normpath(alter_map.get(f, f))
+            if tp != expect:
+                print("File `%s' alter_targets() `%s' != expected `%s'" % (f, tp, expect))
+                errors = errors + 1
+
+        self.failIf(errors)
+
+class BaseTestCase(_tempdirTestCase):
+    def test_stat(self):
+        """Test the Base.stat() method"""
+        test = self.test
+        test.write("e1", "e1\n")
+        fs = SCons.Node.FS.FS()
+
+        e1 = fs.Entry('e1')
+        s = e1.stat()
+        assert s is not None, s
+
+        e2 = fs.Entry('e2')
+        s = e2.stat()
+        assert s is None, s
+
+    def test_getmtime(self):
+        """Test the Base.getmtime() method"""
+        test = self.test
+        test.write("file", "file\n")
+        fs = SCons.Node.FS.FS()
+
+        file = fs.Entry('file')
+        assert file.getmtime()
+
+        file = fs.Entry('nonexistent')
+        mtime = file.getmtime()
+        assert mtime is None, mtime
+
+    def test_getsize(self):
+        """Test the Base.getsize() method"""
+        test = self.test
+        test.write("file", "file\n")
+        fs = SCons.Node.FS.FS()
+
+        file = fs.Entry('file')
+        size = file.getsize()
+        assert size == 5, size
+
+        file = fs.Entry('nonexistent')
+        size = file.getsize()
+        assert size is None, size
+
+    def test_isdir(self):
+        """Test the Base.isdir() method"""
+        test = self.test
+        test.subdir('dir')
+        test.write("file", "file\n")
+        fs = SCons.Node.FS.FS()
+
+        dir = fs.Entry('dir')
+        assert dir.isdir()
+
+        file = fs.Entry('file')
+        assert not file.isdir()
+
+        nonexistent = fs.Entry('nonexistent')
+        assert not nonexistent.isdir()
+
+    def test_isfile(self):
+        """Test the Base.isfile() method"""
+        test = self.test
+        test.subdir('dir')
+        test.write("file", "file\n")
+        fs = SCons.Node.FS.FS()
+
+        dir = fs.Entry('dir')
+        assert not dir.isfile()
+
+        file = fs.Entry('file')
+        assert file.isfile()
+
+        nonexistent = fs.Entry('nonexistent')
+        assert not nonexistent.isfile()
+
+    if sys.platform != 'win32' and hasattr(os, 'symlink'):
+        def test_islink(self):
+            """Test the Base.islink() method"""
+            test = self.test
+            test.subdir('dir')
+            test.write("file", "file\n")
+            test.symlink("symlink", "symlink")
+            fs = SCons.Node.FS.FS()
+
+            dir = fs.Entry('dir')
+            assert not dir.islink()
+
+            file = fs.Entry('file')
+            assert not file.islink()
+
+            symlink = fs.Entry('symlink')
+            assert symlink.islink()
+
+            nonexistent = fs.Entry('nonexistent')
+            assert not nonexistent.islink()
+
+class DirNodeInfoTestCase(_tempdirTestCase):
+    def test___init__(self):
+        """Test DirNodeInfo initialization"""
+        ddd = self.fs.Dir('ddd')
+        ni = SCons.Node.FS.DirNodeInfo()
+
+class DirBuildInfoTestCase(_tempdirTestCase):
+    def test___init__(self):
+        """Test DirBuildInfo initialization"""
+        ddd = self.fs.Dir('ddd')
+        bi = SCons.Node.FS.DirBuildInfo()
+
+class FileNodeInfoTestCase(_tempdirTestCase):
+    def test___init__(self):
+        """Test FileNodeInfo initialization"""
+        fff = self.fs.File('fff')
+        ni = SCons.Node.FS.FileNodeInfo()
+        assert isinstance(ni, SCons.Node.FS.FileNodeInfo)
+
+    def test_update(self):
+        """Test updating a File.NodeInfo with on-disk information"""
+        test = self.test
+        fff = self.fs.File('fff')
+
+        ni = SCons.Node.FS.FileNodeInfo()
+
+        test.write('fff', "fff\n")
+
+        st = os.stat('fff')
+
+        ni.update(fff)
+
+        assert hasattr(ni, 'timestamp')
+        assert hasattr(ni, 'size')
+
+        ni.timestamp = 0
+        ni.size = 0
+
+        ni.update(fff)
+
+        mtime = st[stat.ST_MTIME]
+        assert ni.timestamp == mtime, (ni.timestamp, mtime)
+        size = st[stat.ST_SIZE]
+        assert ni.size == size, (ni.size, size)
+
+        import time
+        time.sleep(2)
+
+        test.write('fff', "fff longer size, different time stamp\n")
+
+        st = os.stat('fff')
+
+        mtime = st[stat.ST_MTIME]
+        assert ni.timestamp != mtime, (ni.timestamp, mtime)
+        size = st[stat.ST_SIZE]
+        assert ni.size != size, (ni.size, size)
+
+class FileBuildInfoTestCase(_tempdirTestCase):
+    def test___init__(self):
+        """Test File.BuildInfo initialization"""
+        fff = self.fs.File('fff')
+        bi = SCons.Node.FS.FileBuildInfo()
+        assert bi, bi
+
+    def test_convert_to_sconsign(self):
+        """Test converting to .sconsign file format"""
+        fff = self.fs.File('fff')
+        bi = SCons.Node.FS.FileBuildInfo()
+        assert hasattr(bi, 'convert_to_sconsign')
+
+    def test_convert_from_sconsign(self):
+        """Test converting from .sconsign file format"""
+        fff = self.fs.File('fff')
+        bi = SCons.Node.FS.FileBuildInfo()
+        assert hasattr(bi, 'convert_from_sconsign')
+
+    def test_prepare_dependencies(self):
+        """Test that we have a prepare_dependencies() method"""
+        fff = self.fs.File('fff')
+        bi = SCons.Node.FS.FileBuildInfo()
+        bi.prepare_dependencies()
+
+    def test_format(self):
+        """Test the format() method"""
+        f1 = self.fs.File('f1')
+        bi1 = SCons.Node.FS.FileBuildInfo()
+
+        self.fs.File('n1')
+        self.fs.File('n2')
+        self.fs.File('n3')
+
+        s1sig = SCons.Node.FS.FileNodeInfo()
+        s1sig.csig = 1
+        d1sig = SCons.Node.FS.FileNodeInfo()
+        d1sig.timestamp = 2
+        i1sig = SCons.Node.FS.FileNodeInfo()
+        i1sig.size = 3
+
+        bi1.bsources = [self.fs.File('s1')]
+        bi1.bdepends = [self.fs.File('d1')]
+        bi1.bimplicit = [self.fs.File('i1')]
+        bi1.bsourcesigs = [s1sig]
+        bi1.bdependsigs = [d1sig]
+        bi1.bimplicitsigs = [i1sig]
+        bi1.bact = 'action'
+        bi1.bactsig = 'actionsig'
+
+        expect_lines = [
+            's1: 1 None None',
+            'd1: None 2 None',
+            'i1: None None 3',
+            'actionsig [action]',
+        ]
+
+        expect = '\n'.join(expect_lines)
+        format = bi1.format()
+        assert format == expect, (repr(expect), repr(format))
+
+class FSTestCase(_tempdirTestCase):
+    def test_needs_normpath(self):
+        """Test the needs_normpath Regular expression
+
+        This test case verifies that the regular expression used to
+        determine whether a path needs normalization works as
+        expected.
+        """
+        needs_normpath_match = SCons.Node.FS.needs_normpath_match
+
+        do_not_need_normpath = [
+            ".",
+            "/",
+            "/a",
+            "/aa",
+            "/a/",
+            "/aa/",
+            "/a/b",
+            "/aa/bb",
+            "/a/b/",
+            "/aa/bb/",
+
+            "",
+            "a",
+            "aa",
+            "a/",
+            "aa/",
+            "a/b",
+            "aa/bb",
+            "a/b/",
+            "aa/bb/",
+
+            "a.",
+            "a..",
+            "/a.",
+            "/a..",
+            "a./",
+            "a../",
+            "/a./",
+            "/a../",
+
+
+            ".a",
+            "..a",
+            "/.a",
+            "/..a",
+            ".a/",
+            "..a/",
+            "/.a/",
+            "/..a/",
+            ]
+        for p in do_not_need_normpath:
+            assert needs_normpath_match(p) is None, p
+
+        needs_normpath = [
+            "//",
+            "//a",
+            "//aa",
+            "//a/",
+            "//a/",
+            "/aa//",
+
+            "//a/b",
+            "//aa/bb",
+            "//a/b/",
+            "//aa/bb/",
+
+            "/a//b",
+            "/aa//bb",
+            "/a/b//",
+            "/aa/bb//",
+
+            "/a/b//",
+            "/aa/bb//",
+
+            "a//",
+            "aa//",
+            "a//b",
+            "aa//bb",
+            "a//b/",
+            "aa//bb/",
+            "a/b//",
+            "aa/bb//",
+
+            "..",
+            "/.",
+            "/..",
+            "./",
+            "../",
+            "/./",
+            "/../",
+
+            "a/.",
+            "a/..",
+            "./a",
+            "../a",
+            "a/./a",
+            "a/../a",
+            ]
+        for p in needs_normpath:
+            assert needs_normpath_match(p) is not None, p
+
+    def test_runTest(self):
+        """Test FS (file system) Node operations
+
+        This test case handles all of the file system node
+        tests in one environment, so we don't have to set up a
+        complicated directory structure for each test individually.
+        """
+        test = self.test
+
+        test.subdir('sub', ['sub', 'dir'])
+
+        wp = test.workpath('')
+        sub = test.workpath('sub', '')
+        sub_dir = test.workpath('sub', 'dir', '')
+        sub_dir_foo = test.workpath('sub', 'dir', 'foo', '')
+        sub_dir_foo_bar = test.workpath('sub', 'dir', 'foo', 'bar', '')
+        sub_foo = test.workpath('sub', 'foo', '')
+
+        os.chdir(sub_dir)
+
+        fs = SCons.Node.FS.FS()
+
+        e1 = fs.Entry('e1')
+        assert isinstance(e1, SCons.Node.FS.Entry)
+
+        d1 = fs.Dir('d1')
+        assert isinstance(d1, SCons.Node.FS.Dir)
+        assert d1.cwd is d1, d1
+
+        f1 = fs.File('f1', directory = d1)
+        assert isinstance(f1, SCons.Node.FS.File)
+
+        d1_f1 = os.path.join('d1', 'f1')
+        assert f1.get_internal_path() == d1_f1, "f1.path %s != %s" % (f1.get_internal_path(), d1_f1)
+        assert str(f1) == d1_f1, "str(f1) %s != %s" % (str(f1), d1_f1)
+
+        x1 = d1.File('x1')
+        assert isinstance(x1, SCons.Node.FS.File)
+        assert str(x1) == os.path.join('d1', 'x1')
+
+        x2 = d1.Dir('x2')
+        assert isinstance(x2, SCons.Node.FS.Dir)
+        assert str(x2) == os.path.join('d1', 'x2')
+
+        x3 = d1.Entry('x3')
+        assert isinstance(x3, SCons.Node.FS.Entry)
+        assert str(x3) == os.path.join('d1', 'x3')
+
+        assert d1.File(x1) == x1
+        assert d1.Dir(x2) == x2
+        assert d1.Entry(x3) == x3
+
+        x1.cwd = d1
+
+        x4 = x1.File('x4')
+        assert str(x4) == os.path.join('d1', 'x4')
+
+        x5 = x1.Dir('x5')
+        assert str(x5) == os.path.join('d1', 'x5')
+
+        x6 = x1.Entry('x6')
+        assert str(x6) == os.path.join('d1', 'x6')
+        x7 = x1.Entry('x7')
+        assert str(x7) == os.path.join('d1', 'x7')
+
+        assert x1.File(x4) == x4
+        assert x1.Dir(x5) == x5
+        assert x1.Entry(x6) == x6
+        assert x1.Entry(x7) == x7
+
+        assert x1.Entry(x5) == x5
+        try:
+            x1.File(x5)
+        except TypeError:
+            pass
+        else:
+            raise Exception("did not catch expected TypeError")
+
+        assert x1.Entry(x4) == x4
+        try:
+            x1.Dir(x4)
+        except TypeError:
+            pass
+        else:
+            raise Exception("did not catch expected TypeError")
+
+        x6 = x1.File(x6)
+        assert isinstance(x6, SCons.Node.FS.File)
+
+        x7 = x1.Dir(x7)
+        assert isinstance(x7, SCons.Node.FS.Dir)
+
+        seps = [os.sep]
+        if os.sep != '/':
+            seps = seps + ['/']
+
+        drive, path = os.path.splitdrive(os.getcwd())
+
+        def _do_Dir_test(lpath, path_, abspath_, up_path_, sep, fileSys=fs, drive=drive):
+            dir = fileSys.Dir(lpath.replace('/', sep))
+
+            if os.sep != '/':
+                path_ = path_.replace('/', os.sep)
+                abspath_ = abspath_.replace('/', os.sep)
+                up_path_ = up_path_.replace('/', os.sep)
+
+            def strip_slash(p, drive=drive):
+                if p[-1] == os.sep and len(p) > 1:
+                    p = p[:-1]
+                if p[0] == os.sep:
+                    p = drive + p
+                return p
+            path = strip_slash(path_)
+            abspath = strip_slash(abspath_)
+            up_path = strip_slash(up_path_)
+
+            name = abspath.split(os.sep)[-1]
+
+            if not name:
+                if drive:
+                    name = drive
+                else:
+                    name = os.sep
+
+            if dir.up() is None:
+                dir_up_path =  dir.get_internal_path()
+            else:
+                dir_up_path =  dir.up().get_internal_path()
+
+            assert dir.name == name, \
+                   "dir.name %s != expected name %s" % \
+                   (dir.name, name)
+            assert dir.get_internal_path() == path, \
+                   "dir.path %s != expected path %s" % \
+                   (dir.get_internal_path(), path)
+            assert str(dir) == path, \
+                   "str(dir) %s != expected path %s" % \
+                   (str(dir), path)
+            assert dir.get_abspath() == abspath, \
+                   "dir.abspath %s != expected absolute path %s" % \
+                   (dir.get_abspath(), abspath)
+            assert dir_up_path == up_path, \
+                   "dir.up().path %s != expected parent path %s" % \
+                   (dir_up_path, up_path)
+
+        for sep in seps:
+
+            def Dir_test(lpath, path_, abspath_, up_path_, sep=sep, func=_do_Dir_test):
+                return func(lpath, path_, abspath_, up_path_, sep)
+            
+            Dir_test('/',           '/',           '/',               '/')
+            Dir_test('',            './',          sub_dir,           sub)
+            Dir_test('foo',         'foo/',        sub_dir_foo,       './')
+            Dir_test('foo/bar',     'foo/bar/',    sub_dir_foo_bar,   'foo/')
+            Dir_test('/foo',        '/foo/',       '/foo/',           '/')
+            Dir_test('/foo/bar',    '/foo/bar/',   '/foo/bar/',       '/foo/')
+            Dir_test('..',          sub,           sub,               wp)
+            Dir_test('foo/..',      './',          sub_dir,           sub)
+            Dir_test('../foo',      sub_foo,       sub_foo,           sub)
+            Dir_test('.',           './',          sub_dir,           sub)
+            Dir_test('./.',         './',          sub_dir,           sub)
+            Dir_test('foo/./bar',   'foo/bar/',    sub_dir_foo_bar,   'foo/')
+            Dir_test('#../foo',     sub_foo,       sub_foo,           sub)
+            Dir_test('#/../foo',    sub_foo,       sub_foo,           sub)
+            Dir_test('#foo/bar',    'foo/bar/',    sub_dir_foo_bar,   'foo/')
+            Dir_test('#/foo/bar',   'foo/bar/',    sub_dir_foo_bar,   'foo/')
+            Dir_test('#',           './',          sub_dir,           sub)
+
+            try:
+                f2 = fs.File(sep.join(['f1', 'f2']), directory = d1)
+            except TypeError as x:
+                assert str(x) == ("Tried to lookup File '%s' as a Dir." %
+                                  d1_f1), x
+            except:
+                raise
+
+            try:
+                dir = fs.Dir(sep.join(['d1', 'f1']))
+            except TypeError as x:
+                assert str(x) == ("Tried to lookup File '%s' as a Dir." %
+                                  d1_f1), x
+            except:
+                raise
+
+            try:
+                f2 = fs.File('d1')
+            except TypeError as x:
+                assert str(x) == ("Tried to lookup Dir '%s' as a File." %
+                                  'd1'), x
+            except:
+                raise
+
+        # Test that just specifying the drive works to identify
+        # its root directory.
+        p = os.path.abspath(test.workpath('root_file'))
+        drive, path = os.path.splitdrive(p)
+        if drive:
+            # The assert below probably isn't correct for the general
+            # case, but it works for Windows, which covers a lot
+            # of ground...
+            dir = fs.Dir(drive)
+            assert str(dir) == drive + os.sep, str(dir)
+
+            # Make sure that lookups with and without the drive are
+            # equivalent.
+            p = os.path.abspath(test.workpath('some/file'))
+            drive, path = os.path.splitdrive(p)
+
+            e1 = fs.Entry(p)
+            e2 = fs.Entry(path)
+            assert e1 is e2, (e1, e2)
+            assert str(e1) is str(e2), (str(e1), str(e2))
+
+        # Test for a bug in 0.04 that did not like looking up
+        # dirs with a trailing slash on Windows.
+        d=fs.Dir('./')
+        assert d.get_internal_path() == '.', d.get_abspath()
+        d=fs.Dir('foo/')
+        assert d.get_internal_path() == 'foo', d.get_abspath()
+
+        # Test for sub-classing of node building.
+        global built_it
+
+        built_it = None
+        assert not built_it
+        d1.add_source([SCons.Node.Node()])    # XXX FAKE SUBCLASS ATTRIBUTE
+        d1.builder_set(Builder(fs.File))
+        d1.reset_executor()
+        d1.env_set(Environment())
+        d1.build()
+        assert built_it
+
+        built_it = None
+        assert not built_it
+        f1.add_source([SCons.Node.Node()])    # XXX FAKE SUBCLASS ATTRIBUTE
+        f1.builder_set(Builder(fs.File))
+        f1.reset_executor()
+        f1.env_set(Environment())
+        f1.build()
+        assert built_it
+
+        def match(path, expect):
+            expect = expect.replace('/', os.sep)
+            assert path == expect, "path %s != expected %s" % (path, expect)
+
+        e1 = fs.Entry("d1")
+        assert e1.__class__.__name__ == 'Dir'
+        match(e1.get_internal_path(), "d1")
+        match(e1.dir.get_internal_path(), ".")
+
+        e2 = fs.Entry("d1/f1")
+        assert e2.__class__.__name__ == 'File'
+        match(e2.get_internal_path(), "d1/f1")
+        match(e2.dir.get_internal_path(), "d1")
+
+        e3 = fs.Entry("e3")
+        assert e3.__class__.__name__ == 'Entry'
+        match(e3.get_internal_path(), "e3")
+        match(e3.dir.get_internal_path(), ".")
+
+        e4 = fs.Entry("d1/e4")
+        assert e4.__class__.__name__ == 'Entry'
+        match(e4.get_internal_path(), "d1/e4")
+        match(e4.dir.get_internal_path(), "d1")
+
+        e5 = fs.Entry("e3/e5")
+        assert e3.__class__.__name__ == 'Dir'
+        match(e3.get_internal_path(), "e3")
+        match(e3.dir.get_internal_path(), ".")
+        assert e5.__class__.__name__ == 'Entry'
+        match(e5.get_internal_path(), "e3/e5")
+        match(e5.dir.get_internal_path(), "e3")
+
+        e6 = fs.Dir("d1/e4")
+        assert e6 is e4
+        assert e4.__class__.__name__ == 'Dir'
+        match(e4.get_internal_path(), "d1/e4")
+        match(e4.dir.get_internal_path(), "d1")
+
+        e7 = fs.File("e3/e5")
+        assert e7 is e5
+        assert e5.__class__.__name__ == 'File'
+        match(e5.get_internal_path(), "e3/e5")
+        match(e5.dir.get_internal_path(), "e3")
+
+        fs.chdir(fs.Dir('subdir'))
+        f11 = fs.File("f11")
+        match(f11.get_internal_path(), "subdir/f11")
+        d12 = fs.Dir("d12")
+        e13 = fs.Entry("subdir/e13")
+        match(e13.get_internal_path(), "subdir/subdir/e13")
+        fs.chdir(fs.Dir('..'))
+
+        # Test scanning
+        f1.builder_set(Builder(fs.File))
+        f1.env_set(Environment())
+        xyz = fs.File("xyz")
+        f1.builder.target_scanner = Scanner(xyz)
+
+        f1.scan()
+        assert f1.implicit[0].get_internal_path() == "xyz"
+        f1.implicit = []
+        f1.scan()
+        assert f1.implicit == []
+        f1.implicit = None
+        f1.scan()
+        assert f1.implicit[0].get_internal_path() == "xyz"
+
+        # Test underlying scanning functionality in get_found_includes()
+        env = Environment()
+        f12 = fs.File("f12")
+        t1 = fs.File("t1")
+
+        deps = f12.get_found_includes(env, None, t1)
+        assert deps == [], deps
+
+        class MyScanner(Scanner):
+            call_count = 0
+            def __call__(self, node, env, path):
+                self.call_count = self.call_count + 1
+                return Scanner.__call__(self, node, env, path)
+        s = MyScanner(xyz)
+
+        deps = f12.get_found_includes(env, s, t1)
+        assert deps == [xyz], deps
+        assert s.call_count == 1, s.call_count
+
+        f12.built()
+
+        deps = f12.get_found_includes(env, s, t1)
+        assert deps == [xyz], deps
+        assert s.call_count == 2, s.call_count
+
+        env2 = Environment()
+
+        deps = f12.get_found_includes(env2, s, t1)
+        assert deps == [xyz], deps
+        assert s.call_count == 3, s.call_count
+
+
+
+        # Make sure we can scan this file even if the target isn't
+        # a file that has a scanner (it might be an Alias, e.g.).
+        class DummyNode(object):
+            pass
+
+        deps = f12.get_found_includes(env, s, DummyNode())
+        assert deps == [xyz], deps
+
+        # Test building a file whose directory is not there yet...
+        f1 = fs.File(test.workpath("foo/bar/baz/ack"))
+        assert not f1.dir.exists()
+        f1.prepare()
+        f1.build()
+        assert f1.dir.exists()
+
+        os.chdir('..')
+
+        # Test getcwd()
+        fs = SCons.Node.FS.FS()
+        assert str(fs.getcwd()) == ".", str(fs.getcwd())
+        fs.chdir(fs.Dir('subdir'))
+        # The cwd's path is always "."
+        assert str(fs.getcwd()) == ".", str(fs.getcwd())
+        assert fs.getcwd().get_internal_path() == 'subdir', fs.getcwd().get_internal_path()
+        fs.chdir(fs.Dir('../..'))
+        assert fs.getcwd().get_internal_path() == test.workdir, fs.getcwd().get_internal_path()
+
+        f1 = fs.File(test.workpath("do_i_exist"))
+        assert not f1.exists()
+        test.write("do_i_exist","\n")
+        assert not f1.exists(), "exists() call not cached"
+        f1.built()
+        assert f1.exists(), "exists() call caching not reset"
+        test.unlink("do_i_exist")
+        assert f1.exists()
+        f1.built()
+        assert not f1.exists()
+
+        # For some reason, in Windows, the \x1a character terminates
+        # the reading of files in text mode.  This tests that
+        # get_contents() returns the binary contents.
+        test.write("binary_file", "Foo\x1aBar")
+        f1 = fs.File(test.workpath("binary_file"))
+        assert f1.get_contents() == bytearray("Foo\x1aBar",'utf-8'), f1.get_contents()
+
+        # This tests to make sure we can decode UTF-8 text files.
+        test_string = u"Foo\x1aBar"
+        test.write("utf8_file", test_string.encode('utf-8'))
+        f1 = fs.File(test.workpath("utf8_file"))
+        assert eval('f1.get_text_contents() == u"Foo\x1aBar"'), \
+               f1.get_text_contents()
+
+        # Check for string which doesn't have BOM and isn't valid
+        # ASCII
+        test_string = b'Gan\xdfauge'
+        test.write('latin1_file', test_string)
+        f1 = fs.File(test.workpath("latin1_file"))
+        assert f1.get_text_contents() == test_string.decode('latin-1'), \
+               f1.get_text_contents()
+
+        def nonexistent(method, s):
+            try:
+                x = method(s, create = 0)
+            except SCons.Errors.UserError:
+                pass
+            else:
+                raise Exception("did not catch expected UserError")
+
+        nonexistent(fs.Entry, 'nonexistent')
+        nonexistent(fs.Entry, 'nonexistent/foo')
+
+        nonexistent(fs.File, 'nonexistent')
+        nonexistent(fs.File, 'nonexistent/foo')
+
+        nonexistent(fs.Dir, 'nonexistent')
+        nonexistent(fs.Dir, 'nonexistent/foo')
+
+        test.write("preserve_me", "\n")
+        assert os.path.exists(test.workpath("preserve_me"))
+        f1 = fs.File(test.workpath("preserve_me"))
+        f1.prepare()
+        assert os.path.exists(test.workpath("preserve_me"))
+
+        test.write("remove_me", "\n")
+        assert os.path.exists(test.workpath("remove_me"))
+        f1 = fs.File(test.workpath("remove_me"))
+        f1.builder = Builder(fs.File)
+        f1.env_set(Environment())
+        f1.prepare()
+        assert not os.path.exists(test.workpath("remove_me"))
+
+        e = fs.Entry('e_local')
+        assert not hasattr(e, '_local')
+        e.set_local()
+        assert e._local == 1
+        f = fs.File('e_local')
+        assert f._local == 1
+        f = fs.File('f_local')
+        assert f._local == 0
+
+        #XXX test_is_up_to_date() for directories
+
+        #XXX test_sconsign() for directories
+
+        #XXX test_set_signature() for directories
+
+        #XXX test_build() for directories
+
+        #XXX test_root()
+
+        # test Entry.get_contents()
+        e = fs.Entry('does_not_exist')
+        c = e.get_contents()
+        assert c == "", c
+        assert e.__class__ == SCons.Node.FS.Entry
+
+        test.write("file", "file\n")
+        try:
+            e = fs.Entry('file')
+            c = e.get_contents()
+            assert c == bytearray("file\n",'utf-8'), c
+            assert e.__class__ == SCons.Node.FS.File
+        finally:
+            test.unlink("file")
+
+        # test Entry.get_text_contents()
+        e = fs.Entry('does_not_exist')
+        c = e.get_text_contents()
+        assert c == "", c
+        assert e.__class__ == SCons.Node.FS.Entry
+
+        test.write("file", "file\n")
+        try:
+            e = fs.Entry('file')
+            c = e.get_text_contents()
+            assert c == "file\n", c
+            assert e.__class__ == SCons.Node.FS.File
+        finally:
+            test.unlink("file")
+
+        test.subdir("dir")
+        e = fs.Entry('dir')
+        c = e.get_contents()
+        assert c == "", c
+        assert e.__class__ == SCons.Node.FS.Dir
+
+        c = e.get_text_contents()
+        try:
+            eval('assert c == u"", c')
+        except SyntaxError:
+            assert c == ""
+
+        if sys.platform != 'win32' and hasattr(os, 'symlink'):
+            os.symlink('nonexistent', test.workpath('dangling_symlink'))
+            e = fs.Entry('dangling_symlink')
+            c = e.get_contents()
+            assert e.__class__ == SCons.Node.FS.Entry, e.__class__
+            assert c == "", c
+            c = e.get_text_contents()
+            try:
+                eval('assert c == u"", c')
+            except SyntaxError:
+                assert c == "", c
+
+        test.write("tstamp", "tstamp\n")
+        try:
+            # Okay, *this* manipulation accomodates Windows FAT file systems
+            # that only have two-second granularity on their timestamps.
+            # We round down the current time to the nearest even integer
+            # value, subtract two to make sure the timestamp is not "now,"
+            # and then convert it back to a float.
+            tstamp = float(int(time.time() // 2) * 2) - 2.0
+            os.utime(test.workpath("tstamp"), (tstamp - 2.0, tstamp))
+            f = fs.File("tstamp")
+            t = f.get_timestamp()
+            assert t == tstamp, "expected %f, got %f" % (tstamp, t)
+        finally:
+            test.unlink("tstamp")
+
+        test.subdir('tdir1')
+        d = fs.Dir('tdir1')
+        t = d.get_timestamp()
+        assert t == 0, "expected 0, got %s" % str(t)
+
+        test.subdir('tdir2')
+        f1 = test.workpath('tdir2', 'file1')
+        f2 = test.workpath('tdir2', 'file2')
+        test.write(f1, 'file1\n')
+        test.write(f2, 'file2\n')
+        current_time = float(int(time.time() // 2) * 2)
+        t1 = current_time - 4.0
+        t2 = current_time - 2.0
+        os.utime(f1, (t1 - 2.0, t1))
+        os.utime(f2, (t2 - 2.0, t2))
+        d = fs.Dir('tdir2')
+        fs.File(f1)
+        fs.File(f2)
+        t = d.get_timestamp()
+        assert t == t2, "expected %f, got %f" % (t2, t)
+
+        skey = fs.Entry('eee.x').scanner_key()
+        assert skey == '.x', skey
+        skey = fs.Entry('eee.xyz').scanner_key()
+        assert skey == '.xyz', skey
+
+        skey = fs.File('fff.x').scanner_key()
+        assert skey == '.x', skey
+        skey = fs.File('fff.xyz').scanner_key()
+        assert skey == '.xyz', skey
+
+        skey = fs.Dir('ddd.x').scanner_key()
+        assert skey is None, skey
+
+        test.write("i_am_not_a_directory", "\n")
+        try:
+            exc_caught = 0
+            try:
+                fs.Dir(test.workpath("i_am_not_a_directory"))
+            except TypeError:
+                exc_caught = 1
+            assert exc_caught, "Should have caught a TypeError"
+        finally:
+            test.unlink("i_am_not_a_directory")
+
+        exc_caught = 0
+        try:
+            fs.File(sub_dir)
+        except TypeError:
+            exc_caught = 1
+        assert exc_caught, "Should have caught a TypeError"
+
+        # XXX test_is_up_to_date()
+
+        d = fs.Dir('dir')
+        r = d.remove()
+        assert r is None, r
+
+        f = fs.File('does_not_exist')
+        r = f.remove()
+        assert r is None, r
+
+        test.write('exists', "exists\n")
+        f = fs.File('exists')
+        r = f.remove()
+        assert r, r
+        assert not os.path.exists(test.workpath('exists')), "exists was not removed"
+
+        if sys.platform != 'win32' and hasattr(os, 'symlink'):
+            symlink = test.workpath('symlink')
+            os.symlink(test.workpath('does_not_exist'), symlink)
+            assert os.path.islink(symlink)
+            f = fs.File('symlink')
+            r = f.remove()
+            assert r, r
+            assert not os.path.islink(symlink), "symlink was not removed"
+
+        test.write('can_not_remove', "can_not_remove\n")
+        test.writable(test.workpath('.'), 0)
+        fp = open(test.workpath('can_not_remove'))
+
+        f = fs.File('can_not_remove')
+        exc_caught = 0
+        try:
+            r = f.remove()
+        except OSError:
+            exc_caught = 1
+
+        fp.close()
+
+        assert exc_caught, "Should have caught an OSError, r = " + str(r)
+
+        f = fs.Entry('foo/bar/baz')
+        assert f.for_signature() == 'baz', f.for_signature()
+        assert f.get_string(0) == os.path.normpath('foo/bar/baz'), \
+               f.get_string(0)
+        assert f.get_string(1) == 'baz', f.get_string(1)
+
+    def test_drive_letters(self):
+        """Test drive-letter look-ups"""
+
+        test = self.test
+
+        test.subdir('sub', ['sub', 'dir'])
+
+        def drive_workpath(dirs, test=test):
+            x = test.workpath(*dirs)
+            drive, path = os.path.splitdrive(x)
+            return 'X:' + path
+
+        wp              = drive_workpath([''])
+
+        if wp[-1] in (os.sep, '/'):
+            tmp         = os.path.split(wp[:-1])[0]
+        else:
+            tmp         = os.path.split(wp)[0]
+
+        parent_tmp      = os.path.split(tmp)[0]
+        if parent_tmp == 'X:':
+            parent_tmp = 'X:' + os.sep
+
+        tmp_foo         = os.path.join(tmp, 'foo')
+
+        foo             = drive_workpath(['foo'])
+        foo_bar         = drive_workpath(['foo', 'bar'])
+        sub             = drive_workpath(['sub', ''])
+        sub_dir         = drive_workpath(['sub', 'dir', ''])
+        sub_dir_foo     = drive_workpath(['sub', 'dir', 'foo', ''])
+        sub_dir_foo_bar = drive_workpath(['sub', 'dir', 'foo', 'bar', ''])
+        sub_foo         = drive_workpath(['sub', 'foo', ''])
+
+        fs = SCons.Node.FS.FS()
+
+        seps = [os.sep]
+        if os.sep != '/':
+            seps = seps + ['/']
+
+        def _do_Dir_test(lpath, path_, up_path_, sep, fileSys=fs):
+            dir = fileSys.Dir(lpath.replace('/', sep))
+
+            if os.sep != '/':
+                path_ = path_.replace('/', os.sep)
+                up_path_ = up_path_.replace('/', os.sep)
+
+            def strip_slash(p):
+                if p[-1] == os.sep and len(p) > 3:
+                    p = p[:-1]
+                return p
+            path = strip_slash(path_)
+            up_path = strip_slash(up_path_)
+            name = path.split(os.sep)[-1]
+
+            assert dir.name == name, \
+                   "dir.name %s != expected name %s" % \
+                   (dir.name, name)
+            assert dir.get_internal_path() == path, \
+                   "dir.path %s != expected path %s" % \
+                   (dir.get_internal_path(), path)
+            assert str(dir) == path, \
+                   "str(dir) %s != expected path %s" % \
+                   (str(dir), path)
+            assert dir.up().get_internal_path() == up_path, \
+                   "dir.up().path %s != expected parent path %s" % \
+                   (dir.up().get_internal_path(), up_path)
+
+        save_os_path = os.path
+        save_os_sep = os.sep
+        try:
+            import ntpath
+            os.path = ntpath
+            os.sep = '\\'
+            SCons.Node.FS.initialize_do_splitdrive()
+
+            for sep in seps:
+
+                def Dir_test(lpath, path_, up_path_, sep=sep, func=_do_Dir_test):
+                    return func(lpath, path_, up_path_, sep)
+
+                Dir_test('#X:',         wp,             tmp)
+                Dir_test('X:foo',       foo,            wp)
+                Dir_test('X:foo/bar',   foo_bar,        foo)
+                Dir_test('X:/foo',      'X:/foo',       'X:/')
+                Dir_test('X:/foo/bar',  'X:/foo/bar/',  'X:/foo/')
+                Dir_test('X:..',        tmp,            parent_tmp)
+                Dir_test('X:foo/..',    wp,             tmp)
+                Dir_test('X:../foo',    tmp_foo,        tmp)
+                Dir_test('X:.',         wp,             tmp)
+                Dir_test('X:./.',       wp,             tmp)
+                Dir_test('X:foo/./bar', foo_bar,        foo)
+                Dir_test('#X:../foo',   tmp_foo,        tmp)
+                Dir_test('#X:/../foo',  tmp_foo,        tmp)
+                Dir_test('#X:foo/bar',  foo_bar,        foo)
+                Dir_test('#X:/foo/bar', foo_bar,        foo)
+                Dir_test('#X:/',        wp,             tmp)
+        finally:
+            os.path = save_os_path
+            os.sep = save_os_sep
+            SCons.Node.FS.initialize_do_splitdrive()
+
+    def test_unc_path(self):
+        """Test UNC path look-ups"""
+
+        test = self.test
+
+        test.subdir('sub', ['sub', 'dir'])
+
+        def strip_slash(p):
+            if p[-1] == os.sep and len(p) > 3:
+                p = p[:-1]
+            return p
+
+        def unc_workpath(dirs, test=test):
+            import ntpath
+            x = test.workpath(*dirs)
+            drive, path = ntpath.splitdrive(x)
+            unc, path = ntpath.splitunc(path)
+            path = strip_slash(path)
+            return '//' + path[1:]
+
+        wp              = unc_workpath([''])
+
+        if wp[-1] in (os.sep, '/'):
+            tmp         = os.path.split(wp[:-1])[0]
+        else:
+            tmp         = os.path.split(wp)[0]
+
+        parent_tmp      = os.path.split(tmp)[0]
+
+        tmp_foo         = os.path.join(tmp, 'foo')
+
+        foo             = unc_workpath(['foo'])
+        foo_bar         = unc_workpath(['foo', 'bar'])
+        sub             = unc_workpath(['sub', ''])
+        sub_dir         = unc_workpath(['sub', 'dir', ''])
+        sub_dir_foo     = unc_workpath(['sub', 'dir', 'foo', ''])
+        sub_dir_foo_bar = unc_workpath(['sub', 'dir', 'foo', 'bar', ''])
+        sub_foo         = unc_workpath(['sub', 'foo', ''])
+
+        fs = SCons.Node.FS.FS()
+
+        seps = [os.sep]
+        if os.sep != '/':
+            seps = seps + ['/']
+
+        def _do_Dir_test(lpath, path, up_path, sep, fileSys=fs):
+            dir = fileSys.Dir(lpath.replace('/', sep))
+
+            if os.sep != '/':
+                path = path.replace('/', os.sep)
+                up_path = up_path.replace('/', os.sep)
+
+            if path == os.sep + os.sep:
+                name = os.sep + os.sep
+            else:
+                name = path.split(os.sep)[-1]
+
+            if dir.up() is None:
+                dir_up_path =  dir.get_internal_path()
+            else:
+                dir_up_path =  dir.up().get_internal_path()
+
+            assert dir.name == name, \
+                   "dir.name %s != expected name %s" % \
+                   (dir.name, name)
+            assert dir.get_internal_path() == path, \
+                   "dir.path %s != expected path %s" % \
+                   (dir.get_internal_path(), path)
+            assert str(dir) == path, \
+                   "str(dir) %s != expected path %s" % \
+                   (str(dir), path)
+            assert dir_up_path == up_path, \
+                   "dir.up().path %s != expected parent path %s" % \
+                   (dir.up().get_internal_path(), up_path)
+
+        save_os_path = os.path
+        save_os_sep = os.sep
+        try:
+            import ntpath
+            os.path = ntpath
+            os.sep = '\\'
+            SCons.Node.FS.initialize_do_splitdrive()
+
+            for sep in seps:
+
+                def Dir_test(lpath, path_, up_path_, sep=sep, func=_do_Dir_test):
+                    return func(lpath, path_, up_path_, sep)
+
+                Dir_test('//foo',           '//foo',       '//')
+                Dir_test('//foo/bar',       '//foo/bar',   '//foo')
+                Dir_test('//',              '//',          '//')
+                Dir_test('//..',            '//',          '//')
+                Dir_test('//foo/..',        '//',          '//')
+                Dir_test('//../foo',        '//foo',       '//')
+                Dir_test('//.',             '//',          '//')
+                Dir_test('//./.',           '//',          '//')
+                Dir_test('//foo/./bar',     '//foo/bar',   '//foo')
+                Dir_test('//foo/../bar',    '//bar',       '//')
+                Dir_test('//foo/../../bar', '//bar',       '//')
+                Dir_test('//foo/bar/../..', '//',          '//')
+                Dir_test('#//',         wp,            tmp)
+                Dir_test('#//../foo',   tmp_foo,       tmp)
+                Dir_test('#//../foo',   tmp_foo,       tmp)
+                Dir_test('#//foo/bar',  foo_bar,       foo)
+                Dir_test('#//foo/bar',  foo_bar,       foo)
+                Dir_test('#//',         wp,            tmp)
+        finally:
+            os.path = save_os_path
+            os.sep = save_os_sep
+            SCons.Node.FS.initialize_do_splitdrive()
+
+    def test_target_from_source(self):
+        """Test the method for generating target nodes from sources"""
+        fs = self.fs
+
+        x = fs.File('x.c')
+        t = x.target_from_source('pre-', '-suf')
+        assert str(t) == 'pre-x-suf', str(t)
+        assert t.__class__ == SCons.Node.FS.Entry
+
+        y = fs.File('dir/y')
+        t = y.target_from_source('pre-', '-suf')
+        assert str(t) == os.path.join('dir', 'pre-y-suf'), str(t)
+        assert t.__class__ == SCons.Node.FS.Entry
+
+        z = fs.File('zz')
+        t = z.target_from_source('pre-', '-suf', lambda x: x[:-1])
+        assert str(t) == 'pre-z-suf', str(t)
+        assert t.__class__ == SCons.Node.FS.Entry
+
+        d = fs.Dir('ddd')
+        t = d.target_from_source('pre-', '-suf')
+        assert str(t) == 'pre-ddd-suf', str(t)
+        assert t.__class__ == SCons.Node.FS.Entry
+
+        e = fs.Entry('eee')
+        t = e.target_from_source('pre-', '-suf')
+        assert str(t) == 'pre-eee-suf', str(t)
+        assert t.__class__ == SCons.Node.FS.Entry
+
+    def test_same_name(self):
+        """Test that a local same-named file isn't found for a Dir lookup"""
+        test = self.test
+        fs = self.fs
+
+        test.subdir('subdir')
+        test.write(['subdir', 'build'], "subdir/build\n")
+
+        subdir = fs.Dir('subdir')
+        fs.chdir(subdir, change_os_dir=1)
+        self.fs._lookup('#build/file', subdir, SCons.Node.FS.File)
+
+    def test_above_root(self):
+        """Testing looking up a path above the root directory"""
+        test = self.test
+        fs = self.fs
+
+        d1 = fs.Dir('d1')
+        d2 = d1.Dir('d2')
+        dirs = os.path.normpath(d2.get_abspath()).split(os.sep)
+        above_path = os.path.join(*['..']*len(dirs) + ['above'])
+        above = d2.Dir(above_path)
+
+    def test_lookup_abs(self):
+        """Exercise the _lookup_abs function"""
+        test = self.test
+        fs = self.fs
+
+        root = fs.Dir('/')
+        d = root._lookup_abs('/tmp/foo-nonexistent/nonexistent-dir', SCons.Node.FS.Dir)
+        assert d.__class__ == SCons.Node.FS.Dir, str(d.__class__)
+
+    def test_lookup_uncpath(self):
+        """Testing looking up a UNC path on Windows"""
+        if sys.platform not in ('win32',):
+            return
+        test = self.test
+        fs = self.fs
+        path='//servername/C$/foo'
+        f = self.fs._lookup('//servername/C$/foo', fs.Dir('#'), SCons.Node.FS.File)
+        # before the fix in this commit, this returned 'C:\servername\C$\foo'
+        # Should be a normalized Windows UNC path as below.
+        assert str(f) == r'\\servername\C$\foo', \
+        'UNC path %s got looked up as %s'%(path, f)
+ 
+    def test_unc_drive_letter(self):
+        """Test drive-letter lookup for windows UNC-style directories"""
+        if sys.platform not in ('win32',):
+            return
+        share = self.fs.Dir(r'\\SERVER\SHARE\Directory')
+        assert str(share) == r'\\SERVER\SHARE\Directory', str(share)
+
+    def test_UNC_dirs_2689(self):
+        """Test some UNC dirs that printed incorrectly and/or caused
+        infinite recursion errors prior to r5180 (SCons 2.1)."""
+        fs = self.fs
+        if sys.platform not in ('win32',):
+            return
+        p = fs.Dir(r"\\computername\sharename").get_abspath()
+        assert p == r"\\computername\sharename", p
+        p = fs.Dir(r"\\\computername\sharename").get_abspath()
+        assert p == r"\\computername\sharename", p
+
+    def test_rel_path(self):
+        """Test the rel_path() method"""
+        test = self.test
+        fs = self.fs
+
+        d1 = fs.Dir('d1')
+        d1_f = d1.File('f')
+        d1_d2 = d1.Dir('d2')
+        d1_d2_f = d1_d2.File('f')
+
+        d3 = fs.Dir('d3')
+        d3_f = d3.File('f')
+        d3_d4 = d3.Dir('d4')
+        d3_d4_f = d3_d4.File('f')
+
+        cases = [
+                d1,             d1,             '.',
+                d1,             d1_f,           'f',
+                d1,             d1_d2,          'd2',
+                d1,             d1_d2_f,        'd2/f',
+                d1,             d3,             '../d3',
+                d1,             d3_f,           '../d3/f',
+                d1,             d3_d4,          '../d3/d4',
+                d1,             d3_d4_f,        '../d3/d4/f',
+
+                d1_f,           d1,             '.',
+                d1_f,           d1_f,           'f',
+                d1_f,           d1_d2,          'd2',
+                d1_f,           d1_d2_f,        'd2/f',
+                d1_f,           d3,             '../d3',
+                d1_f,           d3_f,           '../d3/f',
+                d1_f,           d3_d4,          '../d3/d4',
+                d1_f,           d3_d4_f,        '../d3/d4/f',
+
+                d1_d2,          d1,             '..',
+                d1_d2,          d1_f,           '../f',
+                d1_d2,          d1_d2,          '.',
+                d1_d2,          d1_d2_f,        'f',
+                d1_d2,          d3,             '../../d3',
+                d1_d2,          d3_f,           '../../d3/f',
+                d1_d2,          d3_d4,          '../../d3/d4',
+                d1_d2,          d3_d4_f,        '../../d3/d4/f',
+
+                d1_d2_f,        d1,             '..',
+                d1_d2_f,        d1_f,           '../f',
+                d1_d2_f,        d1_d2,          '.',
+                d1_d2_f,        d1_d2_f,        'f',
+                d1_d2_f,        d3,             '../../d3',
+                d1_d2_f,        d3_f,           '../../d3/f',
+                d1_d2_f,        d3_d4,          '../../d3/d4',
+                d1_d2_f,        d3_d4_f,        '../../d3/d4/f',
+        ]
+
+        if sys.platform in ('win32',):
+            x_d1        = fs.Dir(r'X:\d1')
+            x_d1_d2     = x_d1.Dir('d2')
+            y_d1        = fs.Dir(r'Y:\d1')
+            y_d1_d2     = y_d1.Dir('d2')
+            y_d2        = fs.Dir(r'Y:\d2')
+
+            win32_cases = [
+                x_d1,           x_d1,           '.',
+                x_d1,           x_d1_d2,        'd2',
+                x_d1,           y_d1,           r'Y:\d1',
+                x_d1,           y_d1_d2,        r'Y:\d1\d2',
+                x_d1,           y_d2,           r'Y:\d2',
+            ]
+
+            cases.extend(win32_cases)
+
+        failed = 0
+        while cases:
+            dir, other, expect = cases[:3]
+            expect = os.path.normpath(expect)
+            del cases[:3]
+            result = dir.rel_path(other)
+            if result != expect:
+                if failed == 0: print()
+                fmt = "    dir_path(%(dir)s, %(other)s) => '%(result)s' did not match '%(expect)s'"
+                print(fmt % locals())
+                failed = failed + 1
+        assert failed == 0, "%d rel_path() cases failed" % failed
+
+    def test_proxy(self):
+        """Test a Node.FS object wrapped in a proxy instance"""
+        f1 = self.fs.File('fff')
+        class MyProxy(SCons.Util.Proxy):
+            __str__ = SCons.Util.Delegate('__str__')
+        p = MyProxy(f1)
+        f2 = self.fs.Entry(p)
+        assert f1 is f2, (f1, str(f1), f2, str(f2))
+
+
+
+class DirTestCase(_tempdirTestCase):
+
+    def test__morph(self):
+        """Test handling of actions when morphing an Entry into a Dir"""
+        test = self.test
+        e = self.fs.Entry('eee')
+        x = e.get_executor()
+        x.add_pre_action('pre')
+        x.add_post_action('post')
+        e.must_be_same(SCons.Node.FS.Dir)
+        a = x.get_action_list()
+        assert 'pre' in a, a
+        assert 'post' in a, a
+
+    def test_subclass(self):
+        """Test looking up subclass of Dir nodes"""
+        class DirSubclass(SCons.Node.FS.Dir):
+            pass
+        sd = self.fs._lookup('special_dir', None, DirSubclass, create=1)
+        sd.must_be_same(SCons.Node.FS.Dir)
+
+    def test_get_env_scanner(self):
+        """Test the Dir.get_env_scanner() method
+        """
+        import SCons.Defaults
+        d = self.fs.Dir('ddd')
+        s = d.get_env_scanner(Environment())
+        assert s is SCons.Defaults.DirEntryScanner, s
+
+    def test_get_target_scanner(self):
+        """Test the Dir.get_target_scanner() method
+        """
+        import SCons.Defaults
+        d = self.fs.Dir('ddd')
+        s = d.get_target_scanner()
+        assert s is SCons.Defaults.DirEntryScanner, s
+
+    def test_scan(self):
+        """Test scanning a directory for in-memory entries
+        """
+        fs = self.fs
+
+        dir = fs.Dir('ddd')
+        fs.File(os.path.join('ddd', 'f1'))
+        fs.File(os.path.join('ddd', 'f2'))
+        fs.File(os.path.join('ddd', 'f3'))
+        fs.Dir(os.path.join('ddd', 'd1'))
+        fs.Dir(os.path.join('ddd', 'd1', 'f4'))
+        fs.Dir(os.path.join('ddd', 'd1', 'f5'))
+        dir.scan()
+        kids = sorted([x.get_internal_path() for x in dir.children(None)])
+        assert kids == [os.path.join('ddd', 'd1'),
+                        os.path.join('ddd', 'f1'),
+                        os.path.join('ddd', 'f2'),
+                        os.path.join('ddd', 'f3')], kids
+
+    def test_get_contents(self):
+        """Test getting the contents for a directory.
+        """
+        test = self.test
+
+        test.subdir('d')
+        test.write(['d', 'g'], "67890\n")
+        test.write(['d', 'f'], "12345\n")
+        test.subdir(['d','sub'])
+        test.write(['d', 'sub','h'], "abcdef\n")
+        test.subdir(['d','empty'])
+
+        d = self.fs.Dir('d')
+        g = self.fs.File(os.path.join('d', 'g'))
+        f = self.fs.File(os.path.join('d', 'f'))
+        h = self.fs.File(os.path.join('d', 'sub', 'h'))
+        e = self.fs.Dir(os.path.join('d', 'empty'))
+        s = self.fs.Dir(os.path.join('d', 'sub'))
+
+        files = d.get_contents().split('\n')
+
+        assert e.get_contents() == '', e.get_contents()
+        assert e.get_text_contents() == '', e.get_text_contents()
+        assert e.get_csig()+" empty" == files[0], files
+        assert f.get_csig()+" f" == files[1], files
+        assert g.get_csig()+" g" == files[2], files
+        assert s.get_csig()+" sub" == files[3], files
+
+    def test_implicit_re_scans(self):
+        """Test that adding entries causes a directory to be re-scanned
+        """
+
+        fs = self.fs
+
+        dir = fs.Dir('ddd')
+
+        fs.File(os.path.join('ddd', 'f1'))
+        dir.scan()
+        kids = sorted([x.get_internal_path() for x in dir.children()])
+        assert kids == [os.path.join('ddd', 'f1')], kids
+
+        fs.File(os.path.join('ddd', 'f2'))
+        dir.scan()
+        kids = sorted([x.get_internal_path() for x in dir.children()])
+        assert kids == [os.path.join('ddd', 'f1'),
+                        os.path.join('ddd', 'f2')], kids
+
+    def test_entry_exists_on_disk(self):
+        """Test the Dir.entry_exists_on_disk() method
+        """
+        test = self.test
+
+        does_not_exist = self.fs.Dir('does_not_exist')
+        assert not does_not_exist.entry_exists_on_disk('foo')
+
+        test.subdir('d')
+        test.write(['d', 'exists'], "d/exists\n")
+        test.write(['d', 'Case-Insensitive'], "d/Case-Insensitive\n")
+
+        d = self.fs.Dir('d')
+        assert d.entry_exists_on_disk('exists')
+        assert not d.entry_exists_on_disk('does_not_exist')
+
+        if os.path.normcase("TeSt") != os.path.normpath("TeSt") or sys.platform == "cygwin":
+            assert d.entry_exists_on_disk('case-insensitive')
+
+    def test_rentry_exists_on_disk(self):
+        """Test the Dir.rentry_exists_on_disk() method
+        """
+        test = self.test
+
+        does_not_exist = self.fs.Dir('does_not_exist')
+        assert not does_not_exist.rentry_exists_on_disk('foo')
+
+        test.subdir('d')
+        test.write(['d', 'exists'], "d/exists\n")
+        test.write(['d', 'Case-Insensitive'], "d/Case-Insensitive\n")
+
+        test.subdir('r')
+        test.write(['r', 'rexists'], "r/rexists\n")
+
+        d = self.fs.Dir('d')
+        r = self.fs.Dir('r')
+        d.addRepository(r)
+        
+        assert d.rentry_exists_on_disk('exists')
+        assert d.rentry_exists_on_disk('rexists')
+        assert not d.rentry_exists_on_disk('does_not_exist')
+
+        if os.path.normcase("TeSt") != os.path.normpath("TeSt") or sys.platform == "cygwin":
+            assert d.rentry_exists_on_disk('case-insensitive')
+
+    def test_srcdir_list(self):
+        """Test the Dir.srcdir_list() method
+        """
+        src = self.fs.Dir('src')
+        bld = self.fs.Dir('bld')
+        sub1 = bld.Dir('sub')
+        sub2 = sub1.Dir('sub')
+        sub3 = sub2.Dir('sub')
+        self.fs.VariantDir(bld, src, duplicate=0)
+        self.fs.VariantDir(sub2, src, duplicate=0)
+
+        def check(result, expect):
+            result = list(map(str, result))
+            expect = list(map(os.path.normpath, expect))
+            assert result == expect, result
+
+        s = src.srcdir_list()
+        check(s, [])
+
+        s = bld.srcdir_list()
+        check(s, ['src'])
+
+        s = sub1.srcdir_list()
+        check(s, ['src/sub'])
+
+        s = sub2.srcdir_list()
+        check(s, ['src', 'src/sub/sub'])
+
+        s = sub3.srcdir_list()
+        check(s, ['src/sub', 'src/sub/sub/sub'])
+
+        self.fs.VariantDir('src/b1/b2', 'src')
+        b1 = src.Dir('b1')
+        b1_b2 = b1.Dir('b2')
+        b1_b2_b1 = b1_b2.Dir('b1')
+        b1_b2_b1_b2 = b1_b2_b1.Dir('b2')
+        b1_b2_b1_b2_sub = b1_b2_b1_b2.Dir('sub')
+
+        s = b1.srcdir_list()
+        check(s, [])
+
+        s = b1_b2.srcdir_list()
+        check(s, ['src'])
+
+        s = b1_b2_b1.srcdir_list()
+        check(s, ['src/b1'])
+
+        s = b1_b2_b1_b2.srcdir_list()
+        check(s, ['src/b1/b2'])
+
+        s = b1_b2_b1_b2_sub.srcdir_list()
+        check(s, ['src/b1/b2/sub'])
+
+    def test_srcdir_duplicate(self):
+        """Test the Dir.srcdir_duplicate() method
+        """
+        test = self.test
+
+        test.subdir('src0')
+        test.write(['src0', 'exists'], "src0/exists\n")
+
+        bld0 = self.fs.Dir('bld0')
+        src0 = self.fs.Dir('src0')
+        self.fs.VariantDir(bld0, src0, duplicate=0)
+
+        n = bld0.srcdir_duplicate('does_not_exist')
+        assert n is None, n
+        assert not os.path.exists(test.workpath('bld0', 'does_not_exist'))
+
+        n = bld0.srcdir_duplicate('exists')
+        assert str(n) == os.path.normpath('src0/exists'), str(n)
+        assert not os.path.exists(test.workpath('bld0', 'exists'))
+
+        test.subdir('src1')
+        test.write(['src1', 'exists'], "src0/exists\n")
+
+        bld1 = self.fs.Dir('bld1')
+        src1 = self.fs.Dir('src1')
+        self.fs.VariantDir(bld1, src1, duplicate=1)
+
+        n = bld1.srcdir_duplicate('does_not_exist')
+        assert n is None, n
+        assert not os.path.exists(test.workpath('bld1', 'does_not_exist'))
+
+        n = bld1.srcdir_duplicate('exists')
+        assert str(n) == os.path.normpath('bld1/exists'), str(n)
+        assert os.path.exists(test.workpath('bld1', 'exists'))
+
+    def test_srcdir_find_file(self):
+        """Test the Dir.srcdir_find_file() method
+        """
+        test = self.test
+
+        def return_true(node):
+            return 1
+
+        SCons.Node._is_derived_map[2] = return_true
+        SCons.Node._exists_map[5] = return_true
+        
+        test.subdir('src0')
+        test.write(['src0', 'on-disk-f1'], "src0/on-disk-f1\n")
+        test.write(['src0', 'on-disk-f2'], "src0/on-disk-f2\n")
+        test.write(['src0', 'on-disk-e1'], "src0/on-disk-e1\n")
+        test.write(['src0', 'on-disk-e2'], "src0/on-disk-e2\n")
+
+        bld0 = self.fs.Dir('bld0')
+        src0 = self.fs.Dir('src0')
+        self.fs.VariantDir(bld0, src0, duplicate=0)
+
+        derived_f = src0.File('derived-f')
+        derived_f._func_is_derived = 2
+        exists_f = src0.File('exists-f')
+        exists_f._func_exists = 5
+
+        derived_e = src0.Entry('derived-e')
+        derived_e._func_is_derived = 2
+        exists_e = src0.Entry('exists-e')
+        exists_e._func_exists = 5
+
+        def check(result, expect):
+            result = list(map(str, result))
+            expect = list(map(os.path.normpath, expect))
+            assert result == expect, result
+
+        # First check from the source directory.
+        n = src0.srcdir_find_file('does_not_exist')
+        assert n == (None, None), n
+
+        n = src0.srcdir_find_file('derived-f')
+        check(n, ['src0/derived-f', 'src0'])
+        n = src0.srcdir_find_file('exists-f')
+        check(n, ['src0/exists-f', 'src0'])
+        n = src0.srcdir_find_file('on-disk-f1')
+        check(n, ['src0/on-disk-f1', 'src0'])
+
+        n = src0.srcdir_find_file('derived-e')
+        check(n, ['src0/derived-e', 'src0'])
+        n = src0.srcdir_find_file('exists-e')
+        check(n, ['src0/exists-e', 'src0'])
+        n = src0.srcdir_find_file('on-disk-e1')
+        check(n, ['src0/on-disk-e1', 'src0'])
+
+        # Now check from the variant directory.
+        n = bld0.srcdir_find_file('does_not_exist')
+        assert n == (None, None), n
+
+        n = bld0.srcdir_find_file('derived-f')
+        check(n, ['src0/derived-f', 'bld0'])
+        n = bld0.srcdir_find_file('exists-f')
+        check(n, ['src0/exists-f', 'bld0'])
+        n = bld0.srcdir_find_file('on-disk-f2')
+        check(n, ['src0/on-disk-f2', 'bld0'])
+
+        n = bld0.srcdir_find_file('derived-e')
+        check(n, ['src0/derived-e', 'bld0'])
+        n = bld0.srcdir_find_file('exists-e')
+        check(n, ['src0/exists-e', 'bld0'])
+        n = bld0.srcdir_find_file('on-disk-e2')
+        check(n, ['src0/on-disk-e2', 'bld0'])
+
+        test.subdir('src1')
+        test.write(['src1', 'on-disk-f1'], "src1/on-disk-f1\n")
+        test.write(['src1', 'on-disk-f2'], "src1/on-disk-f2\n")
+        test.write(['src1', 'on-disk-e1'], "src1/on-disk-e1\n")
+        test.write(['src1', 'on-disk-e2'], "src1/on-disk-e2\n")
+
+        bld1 = self.fs.Dir('bld1')
+        src1 = self.fs.Dir('src1')
+        self.fs.VariantDir(bld1, src1, duplicate=1)
+
+        derived_f = src1.File('derived-f')
+        derived_f._func_is_derived = 2
+        exists_f = src1.File('exists-f')
+        exists_f._func_exists = 5
+
+        derived_e = src1.Entry('derived-e')
+        derived_e._func_is_derived = 2
+        exists_e = src1.Entry('exists-e')
+        exists_e._func_exists = 5
+
+        # First check from the source directory.
+        n = src1.srcdir_find_file('does_not_exist')
+        assert n == (None, None), n
+
+        n = src1.srcdir_find_file('derived-f')
+        check(n, ['src1/derived-f', 'src1'])
+        n = src1.srcdir_find_file('exists-f')
+        check(n, ['src1/exists-f', 'src1'])
+        n = src1.srcdir_find_file('on-disk-f1')
+        check(n, ['src1/on-disk-f1', 'src1'])
+
+        n = src1.srcdir_find_file('derived-e')
+        check(n, ['src1/derived-e', 'src1'])
+        n = src1.srcdir_find_file('exists-e')
+        check(n, ['src1/exists-e', 'src1'])
+        n = src1.srcdir_find_file('on-disk-e1')
+        check(n, ['src1/on-disk-e1', 'src1'])
+
+        # Now check from the variant directory.
+        n = bld1.srcdir_find_file('does_not_exist')
+        assert n == (None, None), n
+
+        n = bld1.srcdir_find_file('derived-f')
+        check(n, ['bld1/derived-f', 'src1'])
+        n = bld1.srcdir_find_file('exists-f')
+        check(n, ['bld1/exists-f', 'src1'])
+        n = bld1.srcdir_find_file('on-disk-f2')
+        check(n, ['bld1/on-disk-f2', 'bld1'])
+
+        n = bld1.srcdir_find_file('derived-e')
+        check(n, ['bld1/derived-e', 'src1'])
+        n = bld1.srcdir_find_file('exists-e')
+        check(n, ['bld1/exists-e', 'src1'])
+        n = bld1.srcdir_find_file('on-disk-e2')
+        check(n, ['bld1/on-disk-e2', 'bld1'])
+
+    def test_dir_on_disk(self):
+        """Test the Dir.dir_on_disk() method"""
+        self.test.subdir('sub', ['sub', 'exists'])
+        self.test.write(['sub', 'file'], "self/file\n")
+        sub = self.fs.Dir('sub')
+
+        r = sub.dir_on_disk('does_not_exist')
+        assert not r, r
+
+        r = sub.dir_on_disk('exists')
+        assert r, r
+
+        r = sub.dir_on_disk('file')
+        assert not r, r
+
+    def test_file_on_disk(self):
+        """Test the Dir.file_on_disk() method"""
+        self.test.subdir('sub', ['sub', 'dir'])
+        self.test.write(['sub', 'exists'], "self/exists\n")
+        sub = self.fs.Dir('sub')
+
+        r = sub.file_on_disk('does_not_exist')
+        assert not r, r
+
+        r = sub.file_on_disk('exists')
+        assert r, r
+
+        r = sub.file_on_disk('dir')
+        assert not r, r
+
+class EntryTestCase(_tempdirTestCase):
+    def test_runTest(self):
+        """Test methods specific to the Entry sub-class.
+        """
+        test = TestCmd(workdir='')
+        # FS doesn't like the cwd to be something other than its root.
+        os.chdir(test.workpath(""))
+
+        fs = SCons.Node.FS.FS()
+
+        e1 = fs.Entry('e1')
+        e1.rfile()
+        assert e1.__class__ is SCons.Node.FS.File, e1.__class__
+
+        test.subdir('e3d')
+        test.write('e3f', "e3f\n")
+
+        e3d = fs.Entry('e3d')
+        e3d.get_contents()
+        assert e3d.__class__ is SCons.Node.FS.Dir, e3d.__class__
+
+        e3f = fs.Entry('e3f')
+        e3f.get_contents()
+        assert e3f.__class__ is SCons.Node.FS.File, e3f.__class__
+
+        e3n = fs.Entry('e3n')
+        e3n.get_contents()
+        assert e3n.__class__ is SCons.Node.FS.Entry, e3n.__class__
+
+        test.subdir('e4d')
+        test.write('e4f', "e4f\n")
+
+        e4d = fs.Entry('e4d')
+        exists = e4d.exists()
+        assert e4d.__class__ is SCons.Node.FS.Dir, e4d.__class__
+        assert exists, "e4d does not exist?"
+
+        e4f = fs.Entry('e4f')
+        exists = e4f.exists()
+        assert e4f.__class__ is SCons.Node.FS.File, e4f.__class__
+        assert exists, "e4f does not exist?"
+
+        e4n = fs.Entry('e4n')
+        exists = e4n.exists()
+        assert e4n.__class__ is SCons.Node.FS.File, e4n.__class__
+        assert not exists, "e4n exists?"
+
+        class MyCalc(object):
+            def __init__(self, val):
+                self.max_drift = 0
+                class M(object):
+                    def __init__(self, val):
+                        self.val = val
+                    def collect(self, args):
+                        result = 0
+                        for a in args:
+                            result += a
+                        return result
+                    def signature(self, executor):
+                        return self.val + 222
+                self.module = M(val)
+
+        test.subdir('e5d')
+        test.write('e5f', "e5f\n")
+
+    def test_Entry_Entry_lookup(self):
+        """Test looking up an Entry within another Entry"""
+        self.fs.Entry('#topdir')
+        self.fs.Entry('#topdir/a/b/c')
+
+
+
+class FileTestCase(_tempdirTestCase):
+
+    def test_subclass(self):
+        """Test looking up subclass of File nodes"""
+        class FileSubclass(SCons.Node.FS.File):
+            pass
+        sd = self.fs._lookup('special_file', None, FileSubclass, create=1)
+        sd.must_be_same(SCons.Node.FS.File)
+
+    def test_Dirs(self):
+        """Test the File.Dirs() method"""
+        fff = self.fs.File('subdir/fff')
+        # This simulates that the SConscript file that defined
+        # fff is in subdir/.
+        fff.cwd = self.fs.Dir('subdir')
+        d1 = self.fs.Dir('subdir/d1')
+        d2 = self.fs.Dir('subdir/d2')
+        dirs = fff.Dirs(['d1', 'd2'])
+        assert dirs == [d1, d2], list(map(str, dirs))
+
+    def test_exists(self):
+        """Test the File.exists() method"""
+        fs = self.fs
+        test = self.test
+
+        src_f1 = fs.File('src/f1')
+        assert not src_f1.exists(), "%s apparently exists?" % src_f1
+
+        test.subdir('src')
+        test.write(['src', 'f1'], "src/f1\n")
+
+        assert not src_f1.exists(), "%s did not cache previous exists() value" % src_f1
+        src_f1.clear()
+        assert src_f1.exists(), "%s apparently does not exist?" % src_f1
+
+        test.subdir('build')
+        fs.VariantDir('build', 'src')
+        build_f1 = fs.File('build/f1')
+
+        assert build_f1.exists(), "%s did not realize that %s exists" % (build_f1, src_f1)
+        assert os.path.exists(build_f1.get_abspath()), "%s did not get duplicated on disk" % build_f1.get_abspath()
+
+        test.unlink(['src', 'f1'])
+        src_f1.clear()  # so the next exists() call will look on disk again
+
+        assert build_f1.exists(), "%s did not cache previous exists() value" % build_f1
+        build_f1.clear()
+        build_f1.linked = None
+        assert not build_f1.exists(), "%s did not realize that %s disappeared" % (build_f1, src_f1)
+        assert not os.path.exists(build_f1.get_abspath()), "%s did not get removed after %s was removed" % (build_f1, src_f1)
+
+
+
+class GlobTestCase(_tempdirTestCase):
+    def setUp(self):
+        _tempdirTestCase.setUp(self)
+
+        fs = SCons.Node.FS.FS()
+        self.fs = fs
+
+        # Make entries on disk that will not have Nodes, so we can verify
+        # the behavior of looking for things on disk.
+        self.test.write('disk-bbb', "disk-bbb\n")
+        self.test.write('disk-aaa', "disk-aaa\n")
+        self.test.write('disk-ccc', "disk-ccc\n")
+        self.test.write('#disk-hash', "#disk-hash\n")
+        self.test.subdir('disk-sub')
+        self.test.write(['disk-sub', 'disk-ddd'], "disk-sub/disk-ddd\n")
+        self.test.write(['disk-sub', 'disk-eee'], "disk-sub/disk-eee\n")
+        self.test.write(['disk-sub', 'disk-fff'], "disk-sub/disk-fff\n")
+
+        # Make some entries that have both Nodes and on-disk entries,
+        # so we can verify what we do with
+        self.test.write('both-aaa', "both-aaa\n")
+        self.test.write('both-bbb', "both-bbb\n")
+        self.test.write('both-ccc', "both-ccc\n")
+        self.test.write('#both-hash', "#both-hash\n")
+        self.test.subdir('both-sub1')
+        self.test.write(['both-sub1', 'both-ddd'], "both-sub1/both-ddd\n")
+        self.test.write(['both-sub1', 'both-eee'], "both-sub1/both-eee\n")
+        self.test.write(['both-sub1', 'both-fff'], "both-sub1/both-fff\n")
+        self.test.subdir('both-sub2')
+        self.test.write(['both-sub2', 'both-ddd'], "both-sub2/both-ddd\n")
+        self.test.write(['both-sub2', 'both-eee'], "both-sub2/both-eee\n")
+        self.test.write(['both-sub2', 'both-fff'], "both-sub2/both-fff\n")
+
+        self.both_aaa = fs.File('both-aaa')
+        self.both_bbb = fs.File('both-bbb')
+        self.both_ccc = fs.File('both-ccc')
+        self._both_hash = fs.File('./#both-hash')
+        self.both_sub1 = fs.Dir('both-sub1')
+        self.both_sub1_both_ddd = self.both_sub1.File('both-ddd')
+        self.both_sub1_both_eee = self.both_sub1.File('both-eee')
+        self.both_sub1_both_fff = self.both_sub1.File('both-fff')
+        self.both_sub2 = fs.Dir('both-sub2')
+        self.both_sub2_both_ddd = self.both_sub2.File('both-ddd')
+        self.both_sub2_both_eee = self.both_sub2.File('both-eee')
+        self.both_sub2_both_fff = self.both_sub2.File('both-fff')
+
+        # Make various Nodes (that don't have on-disk entries) so we
+        # can verify how we match them.
+        self.ggg = fs.File('ggg')
+        self.hhh = fs.File('hhh')
+        self.iii = fs.File('iii')
+        self._hash = fs.File('./#hash')
+        self.subdir1 = fs.Dir('subdir1')
+        self.subdir1_lll = self.subdir1.File('lll')
+        self.subdir1_jjj = self.subdir1.File('jjj')
+        self.subdir1_kkk = self.subdir1.File('kkk')
+        self.subdir2 = fs.Dir('subdir2')
+        self.subdir2_lll = self.subdir2.File('lll')
+        self.subdir2_kkk = self.subdir2.File('kkk')
+        self.subdir2_jjj = self.subdir2.File('jjj')
+        self.sub = fs.Dir('sub')
+        self.sub_dir3 = self.sub.Dir('dir3')
+        self.sub_dir3_kkk = self.sub_dir3.File('kkk')
+        self.sub_dir3_jjj = self.sub_dir3.File('jjj')
+        self.sub_dir3_lll = self.sub_dir3.File('lll')
+
+
+    def do_cases(self, cases, **kwargs):
+
+        # First, execute all of the cases with string=True and verify
+        # that we get the expected strings returned.  We do this first
+        # so the Glob() calls don't add Nodes to the self.fs file system
+        # hierarchy.
+
+        import copy
+        strings_kwargs = copy.copy(kwargs)
+        strings_kwargs['strings'] = True
+        for input, string_expect, node_expect in cases:
+            r = sorted(self.fs.Glob(input, **strings_kwargs))
+            assert r == string_expect, "Glob(%s, strings=True) expected %s, got %s" % (input, string_expect, r)
+
+        # Now execute all of the cases without string=True and look for
+        # the expected Nodes to be returned.  If we don't have a list of
+        # actual expected Nodes, that means we're expecting a search for
+        # on-disk-only files to have returned some newly-created nodes.
+        # Verify those by running the list through str() before comparing
+        # them with the expected list of strings.
+        for input, string_expect, node_expect in cases:
+            r = self.fs.Glob(input, **kwargs)
+            if node_expect:
+                r = sorted(r, key=lambda a: a.get_internal_path())
+                result = []
+                for n in node_expect:
+                    if isinstance(n, str):
+                        n = self.fs.Entry(n)
+                    result.append(n)
+                fmt = lambda n: "%s %s" % (repr(n), repr(str(n)))
+            else:
+                r = sorted(map(str, r))
+                result = string_expect
+                fmt = lambda n: n
+            if r != result:
+                import pprint
+                print("Glob(%s) expected:" % repr(input))
+                pprint.pprint(list(map(fmt, result)))
+                print("Glob(%s) got:" % repr(input))
+                pprint.pprint(list(map(fmt, r)))
+                self.fail()
+
+    def test_exact_match(self):
+        """Test globbing for exact Node matches"""
+        join = os.path.join
+
+        cases = (
+            ('ggg',         ['ggg'],                    [self.ggg]),
+
+            ('subdir1',     ['subdir1'],                [self.subdir1]),
+
+            ('subdir1/jjj', [join('subdir1', 'jjj')],   [self.subdir1_jjj]),
+
+            ('disk-aaa',    ['disk-aaa'],               None),
+
+            ('disk-sub',    ['disk-sub'],               None),
+
+            ('both-aaa',    ['both-aaa'],               []),
+        )
+
+        self.do_cases(cases)
+
+    def test_subdir_matches(self):
+        """Test globbing for exact Node matches in subdirectories"""
+        join = os.path.join
+
+        cases = (
+            ('*/jjj',
+             [join('subdir1', 'jjj'), join('subdir2', 'jjj')],
+             [self.subdir1_jjj, self.subdir2_jjj]),
+
+            ('*/disk-ddd',
+             [join('disk-sub', 'disk-ddd')],
+             None),
+        )
+
+        self.do_cases(cases)
+
+    def test_asterisk1(self):
+        """Test globbing for simple asterisk Node matches (1)"""
+        cases = (
+            ('h*',
+             ['hhh'],
+             [self.hhh]),
+
+            ('*',
+             ['#both-hash', '#hash',
+              'both-aaa', 'both-bbb', 'both-ccc',
+              'both-sub1', 'both-sub2',
+              'ggg', 'hhh', 'iii',
+              'sub', 'subdir1', 'subdir2'],
+             [self._both_hash, self._hash,
+              self.both_aaa, self.both_bbb, self.both_ccc, 'both-hash',
+              self.both_sub1, self.both_sub2,
+              self.ggg, 'hash', self.hhh, self.iii,
+              self.sub, self.subdir1, self.subdir2]),
+        )
+
+        self.do_cases(cases, ondisk=False)
+
+    def test_asterisk2(self):
+        """Test globbing for simple asterisk Node matches (2)"""
+        cases = (
+            ('disk-b*',
+             ['disk-bbb'],
+             None),
+
+            ('*',
+             ['#both-hash', '#disk-hash', '#hash',
+              'both-aaa', 'both-bbb', 'both-ccc',
+              'both-sub1', 'both-sub2',
+              'disk-aaa', 'disk-bbb', 'disk-ccc', 'disk-sub',
+              'ggg', 'hhh', 'iii',
+              'sub', 'subdir1', 'subdir2'],
+             ['./#both-hash', './#disk-hash', './#hash',
+              'both-aaa', 'both-bbb', 'both-ccc', 'both-hash',
+              'both-sub1', 'both-sub2',
+              'disk-aaa', 'disk-bbb', 'disk-ccc', 'disk-sub',
+              'ggg', 'hash', 'hhh', 'iii',
+              'sub', 'subdir1', 'subdir2']),
+        )
+
+        self.do_cases(cases)
+
+    def test_question_mark(self):
+        """Test globbing for simple question-mark Node matches"""
+        join = os.path.join
+
+        cases = (
+            ('ii?',
+             ['iii'],
+             [self.iii]),
+
+            ('both-sub?/both-eee',
+             [join('both-sub1', 'both-eee'), join('both-sub2', 'both-eee')],
+             [self.both_sub1_both_eee, self.both_sub2_both_eee]),
+
+            ('subdir?/jjj',
+             [join('subdir1', 'jjj'), join('subdir2', 'jjj')],
+             [self.subdir1_jjj, self.subdir2_jjj]),
+
+            ('disk-cc?',
+             ['disk-ccc'],
+             None),
+        )
+
+        self.do_cases(cases)
+
+    def test_does_not_exist(self):
+        """Test globbing for things that don't exist"""
+
+        cases = (
+            ('does_not_exist',  [], []),
+            ('no_subdir/*',     [], []),
+            ('subdir?/no_file', [], []),
+        )
+
+        self.do_cases(cases)
+
+    def test_subdir_asterisk(self):
+        """Test globbing for asterisk Node matches in subdirectories"""
+        join = os.path.join
+
+        cases = (
+            ('*/k*',
+             [join('subdir1', 'kkk'), join('subdir2', 'kkk')],
+             [self.subdir1_kkk, self.subdir2_kkk]),
+
+            ('both-sub?/*',
+             [join('both-sub1', 'both-ddd'),
+              join('both-sub1', 'both-eee'),
+              join('both-sub1', 'both-fff'),
+              join('both-sub2', 'both-ddd'),
+              join('both-sub2', 'both-eee'),
+              join('both-sub2', 'both-fff')],
+             [self.both_sub1_both_ddd,
+              self.both_sub1_both_eee,
+              self.both_sub1_both_fff,
+              self.both_sub2_both_ddd,
+              self.both_sub2_both_eee,
+              self.both_sub2_both_fff],
+             ),
+
+            ('subdir?/*',
+             [join('subdir1', 'jjj'),
+              join('subdir1', 'kkk'),
+              join('subdir1', 'lll'),
+              join('subdir2', 'jjj'),
+              join('subdir2', 'kkk'),
+              join('subdir2', 'lll')],
+             [self.subdir1_jjj, self.subdir1_kkk, self.subdir1_lll,
+              self.subdir2_jjj, self.subdir2_kkk, self.subdir2_lll]),
+
+            ('sub/*/*',
+             [join('sub', 'dir3', 'jjj'),
+              join('sub', 'dir3', 'kkk'),
+              join('sub', 'dir3', 'lll')],
+             [self.sub_dir3_jjj, self.sub_dir3_kkk, self.sub_dir3_lll]),
+
+            ('*/k*',
+             [join('subdir1', 'kkk'), join('subdir2', 'kkk')],
+             None),
+
+            ('subdir?/*',
+             [join('subdir1', 'jjj'),
+              join('subdir1', 'kkk'),
+              join('subdir1', 'lll'),
+              join('subdir2', 'jjj'),
+              join('subdir2', 'kkk'),
+              join('subdir2', 'lll')],
+             None),
+
+            ('sub/*/*',
+             [join('sub', 'dir3', 'jjj'),
+              join('sub', 'dir3', 'kkk'),
+              join('sub', 'dir3', 'lll')],
+             None),
+        )
+
+        self.do_cases(cases)
+
+    def test_subdir_question(self):
+        """Test globbing for question-mark Node matches in subdirectories"""
+        join = os.path.join
+
+        cases = (
+            ('*/?kk',
+             [join('subdir1', 'kkk'), join('subdir2', 'kkk')],
+             [self.subdir1_kkk, self.subdir2_kkk]),
+
+            ('subdir?/l?l',
+             [join('subdir1', 'lll'), join('subdir2', 'lll')],
+             [self.subdir1_lll, self.subdir2_lll]),
+
+            ('*/disk-?ff',
+             [join('disk-sub', 'disk-fff')],
+             None),
+
+            ('subdir?/l?l',
+             [join('subdir1', 'lll'), join('subdir2', 'lll')],
+             None),
+        )
+
+        self.do_cases(cases)
+
+    def test_sort(self):
+        """Test whether globbing sorts"""
+        join = os.path.join
+        # At least sometimes this should return out-of-order items
+        # if Glob doesn't sort.
+        # It's not a very good test though since it depends on the
+        # order returned by glob, which might already be sorted.
+        g = self.fs.Glob('disk-sub/*', strings=True)
+        expect = [
+            os.path.join('disk-sub', 'disk-ddd'),
+            os.path.join('disk-sub', 'disk-eee'),
+            os.path.join('disk-sub', 'disk-fff'),
+        ]
+        assert g == expect, str(g) + " is not sorted, but should be!"
+
+        g = self.fs.Glob('disk-*', strings=True)
+        expect = [ 'disk-aaa', 'disk-bbb', 'disk-ccc', 'disk-sub' ]
+        assert g == expect, str(g) + " is not sorted, but should be!"
+
+
+class RepositoryTestCase(_tempdirTestCase):
+
+    def setUp(self):
+        _tempdirTestCase.setUp(self)
+
+        self.test.subdir('rep1', 'rep2', 'rep3', 'work')
+
+        self.rep1 = self.test.workpath('rep1')
+        self.rep2 = self.test.workpath('rep2')
+        self.rep3 = self.test.workpath('rep3')
+
+        os.chdir(self.test.workpath('work'))
+
+        self.fs = SCons.Node.FS.FS()
+        self.fs.Repository(self.rep1, self.rep2, self.rep3)
+
+    def test_getRepositories(self):
+        """Test the Dir.getRepositories() method"""
+        self.fs.Repository('foo')
+        self.fs.Repository(os.path.join('foo', 'bar'))
+        self.fs.Repository('bar/foo')
+        self.fs.Repository('bar')
+
+        expect = [
+            self.rep1,
+            self.rep2,
+            self.rep3,
+            'foo',
+            os.path.join('foo', 'bar'),
+            os.path.join('bar', 'foo'),
+            'bar'
+        ]
+
+        rep = self.fs.Dir('#').getRepositories()
+        r = [os.path.normpath(str(x)) for x in rep]
+        assert r == expect, r
+
+    def test_get_all_rdirs(self):
+        """Test the Dir.get_all_rdirs() method"""
+        self.fs.Repository('foo')
+        self.fs.Repository(os.path.join('foo', 'bar'))
+        self.fs.Repository('bar/foo')
+        self.fs.Repository('bar')
+
+        expect = [
+            '.',
+            self.rep1,
+            self.rep2,
+            self.rep3,
+            'foo',
+            os.path.join('foo', 'bar'),
+            os.path.join('bar', 'foo'),
+            'bar'
+        ]
+
+        rep = self.fs.Dir('#').get_all_rdirs()
+        r = [os.path.normpath(str(x)) for x in rep]
+        assert r == expect, r
+
+    def test_rentry(self):
+        """Test the Base.entry() method"""
+        return_true = lambda: 1
+        return_false = lambda: 0
+
+        d1 = self.fs.Dir('d1')
+        d2 = self.fs.Dir('d2')
+        d3 = self.fs.Dir('d3')
+
+        e1 = self.fs.Entry('e1')
+        e2 = self.fs.Entry('e2')
+        e3 = self.fs.Entry('e3')
+
+        f1 = self.fs.File('f1')
+        f2 = self.fs.File('f2')
+        f3 = self.fs.File('f3')
+
+        self.test.write([self.rep1, 'd2'], "")
+        self.test.subdir([self.rep2, 'd3'])
+        self.test.write([self.rep3, 'd3'], "")
+
+        self.test.write([self.rep1, 'e2'], "")
+        self.test.subdir([self.rep2, 'e3'])
+        self.test.write([self.rep3, 'e3'], "")
+
+        self.test.write([self.rep1, 'f2'], "")
+        self.test.subdir([self.rep2, 'f3'])
+        self.test.write([self.rep3, 'f3'], "")
+
+        r = d1.rentry()
+        assert r is d1, r
+
+        r = d2.rentry()
+        assert not r is d2, r
+        r = str(r)
+        assert r == os.path.join(self.rep1, 'd2'), r
+
+        r = d3.rentry()
+        assert not r is d3, r
+        r = str(r)
+        assert r == os.path.join(self.rep2, 'd3'), r
+
+        r = e1.rentry()
+        assert r is e1, r
+
+        r = e2.rentry()
+        assert not r is e2, r
+        r = str(r)
+        assert r == os.path.join(self.rep1, 'e2'), r
+
+        r = e3.rentry()
+        assert not r is e3, r
+        r = str(r)
+        assert r == os.path.join(self.rep2, 'e3'), r
+
+        r = f1.rentry()
+        assert r is f1, r
+
+        r = f2.rentry()
+        assert not r is f2, r
+        r = str(r)
+        assert r == os.path.join(self.rep1, 'f2'), r
+
+        r = f3.rentry()
+        assert not r is f3, r
+        r = str(r)
+        assert r == os.path.join(self.rep2, 'f3'), r
+
+    def test_rdir(self):
+        """Test the Dir.rdir() method"""
+        def return_true(obj):
+            return 1
+        def return_false(obj):
+            return 0
+        SCons.Node._exists_map[5] = return_true
+        SCons.Node._exists_map[6] = return_false
+        SCons.Node._is_derived_map[2] = return_true
+        SCons.Node._is_derived_map[3] = return_false
+
+        d1 = self.fs.Dir('d1')
+        d2 = self.fs.Dir('d2')
+        d3 = self.fs.Dir('d3')
+
+        self.test.subdir([self.rep1, 'd2'])
+        self.test.write([self.rep2, 'd3'], "")
+        self.test.subdir([self.rep3, 'd3'])
+
+        r = d1.rdir()
+        assert r is d1, r
+
+        r = d2.rdir()
+        assert not r is d2, r
+        r = str(r)
+        assert r == os.path.join(self.rep1, 'd2'), r
+
+        r = d3.rdir()
+        assert not r is d3, r
+        r = str(r)
+        assert r == os.path.join(self.rep3, 'd3'), r
+
+        e1 = self.fs.Dir('e1')
+        e1._func_exists = 6
+        e2 = self.fs.Dir('e2')
+        e2._func_exists = 6
+
+        # Make sure we match entries in repositories,
+        # regardless of whether they're derived or not.
+
+        re1 = self.fs.Entry(os.path.join(self.rep1, 'e1'))
+        re1._func_exists = 5
+        re1._func_is_derived = 2
+        re2 = self.fs.Entry(os.path.join(self.rep2, 'e2'))
+        re2._func_exists = 5
+        re2._func_is_derived = 3
+
+        r = e1.rdir()
+        assert r is re1, r
+
+        r = e2.rdir()
+        assert r is re2, r
+
+    def test_rfile(self):
+        """Test the File.rfile() method"""
+        def return_true(obj):
+            return 1
+        def return_false(obj):
+            return 0
+        SCons.Node._exists_map[5] = return_true
+        SCons.Node._exists_map[6] = return_false
+        SCons.Node._is_derived_map[2] = return_true
+        SCons.Node._is_derived_map[3] = return_false
+
+        f1 = self.fs.File('f1')
+        f2 = self.fs.File('f2')
+        f3 = self.fs.File('f3')
+
+        self.test.write([self.rep1, 'f2'], "")
+        self.test.subdir([self.rep2, 'f3'])
+        self.test.write([self.rep3, 'f3'], "")
+
+        r = f1.rfile()
+        assert r is f1, r
+
+        r = f2.rfile()
+        assert not r is f2, r
+        r = str(r)
+        assert r == os.path.join(self.rep1, 'f2'), r
+
+        r = f3.rfile()
+        assert not r is f3, r
+        r = f3.rstr()
+        assert r == os.path.join(self.rep3, 'f3'), r
+
+        e1 = self.fs.File('e1')
+        e1._func_exists = 6
+        e2 = self.fs.File('e2')
+        e2._func_exists = 6
+
+        # Make sure we match entries in repositories,
+        # regardless of whether they're derived or not.
+
+        re1 = self.fs.Entry(os.path.join(self.rep1, 'e1'))
+        re1._func_exists = 5
+        re1._func_is_derived = 2
+        re2 = self.fs.Entry(os.path.join(self.rep2, 'e2'))
+        re2._func_exists = 5
+        re2._func_is_derived = 3
+
+        r = e1.rfile()
+        assert r is re1, r
+
+        r = e2.rfile()
+        assert r is re2, r
+
+    def test_Rfindalldirs(self):
+        """Test the Rfindalldirs() methods"""
+        fs = self.fs
+        test = self.test
+
+        d1 = fs.Dir('d1')
+        d2 = fs.Dir('d2')
+        rep1_d1 = fs.Dir(test.workpath('rep1', 'd1'))
+        rep2_d1 = fs.Dir(test.workpath('rep2', 'd1'))
+        rep3_d1 = fs.Dir(test.workpath('rep3', 'd1'))
+        sub = fs.Dir('sub')
+        sub_d1 = sub.Dir('d1')
+        rep1_sub_d1 = fs.Dir(test.workpath('rep1', 'sub', 'd1'))
+        rep2_sub_d1 = fs.Dir(test.workpath('rep2', 'sub', 'd1'))
+        rep3_sub_d1 = fs.Dir(test.workpath('rep3', 'sub', 'd1'))
+
+        r = fs.Top.Rfindalldirs((d1,))
+        assert r == [d1], list(map(str, r))
+
+        r = fs.Top.Rfindalldirs((d1, d2))
+        assert r == [d1, d2], list(map(str, r))
+
+        r = fs.Top.Rfindalldirs(('d1',))
+        assert r == [d1, rep1_d1, rep2_d1, rep3_d1], list(map(str, r))
+
+        r = fs.Top.Rfindalldirs(('#d1',))
+        assert r == [d1, rep1_d1, rep2_d1, rep3_d1], list(map(str, r))
+
+        r = sub.Rfindalldirs(('d1',))
+        assert r == [sub_d1, rep1_sub_d1, rep2_sub_d1, rep3_sub_d1], list(map(str, r))
+
+        r = sub.Rfindalldirs(('#d1',))
+        assert r == [d1, rep1_d1, rep2_d1, rep3_d1], list(map(str, r))
+
+        r = fs.Top.Rfindalldirs(('d1', d2))
+        assert r == [d1, rep1_d1, rep2_d1, rep3_d1, d2], list(map(str, r))
+
+    def test_rexists(self):
+        """Test the Entry.rexists() method"""
+        fs = self.fs
+        test = self.test
+
+        test.write([self.rep1, 'f2'], "")
+        test.write([self.rep2, "i_exist"], "\n")
+        test.write(["work", "i_exist_too"], "\n")
+
+        fs.VariantDir('build', '.')
+
+        f = fs.File(test.workpath("work", "i_do_not_exist"))
+        assert not f.rexists()
+
+        f = fs.File(test.workpath("work", "i_exist"))
+        assert f.rexists()
+
+        f = fs.File(test.workpath("work", "i_exist_too"))
+        assert f.rexists()
+
+        f1 = fs.File(os.path.join('build', 'f1'))
+        assert not f1.rexists()
+
+        f2 = fs.File(os.path.join('build', 'f2'))
+        assert f2.rexists()
+
+    def test_FAT_timestamps(self):
+        """Test repository timestamps on FAT file systems"""
+        fs = self.fs
+        test = self.test
+
+        test.write(["rep2", "tstamp"], "tstamp\n")
+        try:
+            # Okay, *this* manipulation accomodates Windows FAT file systems
+            # that only have two-second granularity on their timestamps.
+            # We round down the current time to the nearest even integer
+            # value, subtract two to make sure the timestamp is not "now,"
+            # and then convert it back to a float.
+            tstamp = float(int(time.time() // 2) * 2) - 2.0
+            os.utime(test.workpath("rep2", "tstamp"), (tstamp - 2.0, tstamp))
+            f = fs.File("tstamp")
+            t = f.get_timestamp()
+            assert t == tstamp, "expected %f, got %f" % (tstamp, t)
+        finally:
+            test.unlink(["rep2", "tstamp"])
+
+    def test_get_contents(self):
+        """Ensure get_contents() returns binary contents from Repositories"""
+        fs = self.fs
+        test = self.test
+
+        test.write(["rep3", "contents"], "Con\x1aTents\n")
+        try:
+            c = fs.File("contents").get_contents()
+            assert c == bytearray("Con\x1aTents\n",'utf-8'), "got '%s'" % c
+        finally:
+            test.unlink(["rep3", "contents"])
+
+    def test_get_text_contents(self):
+        """Ensure get_text_contents() returns text contents from
+        Repositories"""
+        fs = self.fs
+        test = self.test
+
+        # Use a test string that has a file terminator in it to make
+        # sure we read the entire file, regardless of its contents.
+        try:
+            eval('test_string = u"Con\x1aTents\n"')
+        except SyntaxError:
+            import collections
+            class FakeUnicodeString(collections.UserString):
+                def encode(self, encoding):
+                    return str(self)
+            test_string = FakeUnicodeString("Con\x1aTents\n")
+
+
+        # Test with ASCII.
+        test.write(["rep3", "contents"], test_string.encode('ascii'))
+        try:
+            c = fs.File("contents").get_text_contents()
+            assert test_string == c, "got %s" % repr(c)
+        finally:
+            test.unlink(["rep3", "contents"])
+
+        # Test with utf-8
+        test.write(["rep3", "contents"], test_string.encode('utf-8'))
+        try:
+            c = fs.File("contents").get_text_contents()
+            assert test_string == c, "got %s" % repr(c)
+        finally:
+            test.unlink(["rep3", "contents"])
+
+        # Test with utf-16
+        test.write(["rep3", "contents"], test_string.encode('utf-16'))
+        try:
+            c = fs.File("contents").get_text_contents()
+            assert test_string == c, "got %s" % repr(c)
+        finally:
+            test.unlink(["rep3", "contents"])
+
+    #def test_is_up_to_date(self):
+
+
+
+class find_fileTestCase(unittest.TestCase):
+    def runTest(self):
+        """Testing find_file function"""
+        test = TestCmd(workdir = '')
+        test.write('./foo', 'Some file\n')
+        test.write('./foo2', 'Another file\n')
+        test.subdir('same')
+        test.subdir('bar')
+        test.write(['bar', 'on_disk'], 'Another file\n')
+        test.write(['bar', 'same'], 'bar/same\n')
+
+        fs = SCons.Node.FS.FS(test.workpath(""))
+        # FS doesn't like the cwd to be something other than its root.
+        os.chdir(test.workpath(""))
+
+        node_derived = fs.File(test.workpath('bar/baz'))
+        node_derived.builder_set(1) # Any non-zero value.
+        node_pseudo = fs.File(test.workpath('pseudo'))
+        node_pseudo.set_src_builder(1) # Any non-zero value.
+
+        paths = tuple(map(fs.Dir, ['.', 'same', './bar']))
+        nodes = [SCons.Node.FS.find_file('foo', paths)]
+        nodes.append(SCons.Node.FS.find_file('baz', paths))
+        nodes.append(SCons.Node.FS.find_file('pseudo', paths))
+        nodes.append(SCons.Node.FS.find_file('same', paths))
+
+        file_names = list(map(str, nodes))
+        file_names = list(map(os.path.normpath, file_names))
+        expect = ['./foo', './bar/baz', './pseudo', './bar/same']
+        expect = list(map(os.path.normpath, expect))
+        assert file_names == expect, file_names
+
+        # Make sure we don't blow up if there's already a File in place
+        # of a directory that we'd otherwise try to search.  If this
+        # is broken, we'll see an exception like "Tried to lookup File
+        # 'bar/baz' as a Dir.
+        SCons.Node.FS.find_file('baz/no_file_here', paths)
+
+        import io
+        save_sys_stdout = sys.stdout
+
+        try:
+            sio = io.StringIO()
+            sys.stdout = sio
+            SCons.Node.FS.find_file('foo2', paths, verbose="xyz")
+            expect = "  xyz: looking for 'foo2' in '.' ...\n" + \
+                     "  xyz: ... FOUND 'foo2' in '.'\n"
+            c = sio.getvalue()
+            assert c == expect, c
+
+            sio = io.StringIO()
+            sys.stdout = sio
+            SCons.Node.FS.find_file('baz2', paths, verbose=1)
+            expect = "  find_file: looking for 'baz2' in '.' ...\n" + \
+                     "  find_file: looking for 'baz2' in 'same' ...\n" + \
+                     "  find_file: looking for 'baz2' in 'bar' ...\n"
+            c = sio.getvalue()
+            assert c == expect, c
+
+            sio = io.StringIO()
+            sys.stdout = sio
+            SCons.Node.FS.find_file('on_disk', paths, verbose=1)
+            expect = "  find_file: looking for 'on_disk' in '.' ...\n" + \
+                     "  find_file: looking for 'on_disk' in 'same' ...\n" + \
+                     "  find_file: looking for 'on_disk' in 'bar' ...\n" + \
+                     "  find_file: ... FOUND 'on_disk' in 'bar'\n"
+            c = sio.getvalue()
+            assert c == expect, c
+        finally:
+            sys.stdout = save_sys_stdout
+
+class StringDirTestCase(unittest.TestCase):
+    def runTest(self):
+        """Test using a string as the second argument of
+        File() and Dir()"""
+
+        test = TestCmd(workdir = '')
+        test.subdir('sub')
+        fs = SCons.Node.FS.FS(test.workpath(''))
+
+        d = fs.Dir('sub', '.')
+        assert str(d) == 'sub', str(d)
+        assert d.exists()
+        f = fs.File('file', 'sub')
+        assert str(f) == os.path.join('sub', 'file')
+        assert not f.exists()
+
+class stored_infoTestCase(unittest.TestCase):
+    def runTest(self):
+        """Test how we store build information"""
+        test = TestCmd(workdir = '')
+        test.subdir('sub')
+        fs = SCons.Node.FS.FS(test.workpath(''))
+
+        d = fs.Dir('sub')
+        f = fs.File('file1', d)
+        bi = f.get_stored_info()
+        assert hasattr(bi, 'ninfo')
+
+        class MySConsign(object):
+            class Null(object):
+                def __init__(self):
+                    self.xyzzy = 7
+            def get_entry(self, name):
+                return self.Null()
+            
+        def test_sconsign(node):
+            return MySConsign()
+
+        f = fs.File('file2', d)
+        SCons.Node.FS._sconsign_map[2] = test_sconsign
+        f.dir._func_sconsign = 2
+        bi = f.get_stored_info()
+        assert bi.xyzzy == 7, bi
+
+class has_src_builderTestCase(unittest.TestCase):
+    def runTest(self):
+        """Test the has_src_builder() method"""
+        test = TestCmd(workdir = '')
+        fs = SCons.Node.FS.FS(test.workpath(''))
+        os.chdir(test.workpath(''))
+        test.subdir('sub1')
+
+        sub1 = fs.Dir('sub1', '.')
+        f1 = fs.File('f1', sub1)
+        f2 = fs.File('f2', sub1)
+        f3 = fs.File('f3', sub1)
+
+        h = f1.has_src_builder()
+        assert not h, h
+        h = f1.has_builder()
+        assert not h, h
+
+        b1 = Builder(fs.File)
+        sub1.set_src_builder(b1)
+
+        test.write(['sub1', 'f2'], "sub1/f2\n")
+        h = f1.has_src_builder()        # cached from previous call
+        assert not h, h
+        h = f1.has_builder()            # cached from previous call
+        assert not h, h
+        h = f2.has_src_builder()
+        assert not h, h
+        h = f2.has_builder()
+        assert not h, h
+        h = f3.has_src_builder()
+        assert h, h
+        h = f3.has_builder()
+        assert h, h
+        assert f3.builder is b1, f3.builder
+
+class prepareTestCase(unittest.TestCase):
+    def runTest(self):
+        """Test the prepare() method"""
+
+        class MyFile(SCons.Node.FS.File):
+            def _createDir(self, update=None):
+                raise SCons.Errors.StopError
+            def exists(self):
+                return None
+
+        fs = SCons.Node.FS.FS()
+        file = MyFile('foo', fs.Dir('.'), fs)
+
+        exc_caught = 0
+        try:
+            file.prepare()
+        except SCons.Errors.StopError:
+            exc_caught = 1
+        assert exc_caught, "Should have caught a StopError."
+
+        class MkdirAction(Action):
+            def __init__(self, dir_made):
+                self.dir_made = dir_made
+            def __call__(self, target, source, env, executor=None):
+                if executor:
+                    target = executor.get_all_targets()
+                    source = executor.get_all_sources()
+                self.dir_made.extend(target)
+
+        dir_made = []
+        new_dir = fs.Dir("new_dir")
+        new_dir.builder = Builder(fs.Dir, action=MkdirAction(dir_made))
+        new_dir.reset_executor()
+        xyz = fs.File(os.path.join("new_dir", "xyz"))
+
+        xyz.set_state(SCons.Node.up_to_date)
+        xyz.prepare()
+        assert dir_made == [], dir_made
+
+        xyz.set_state(0)
+        xyz.prepare()
+        assert dir_made[0].get_internal_path() == "new_dir", dir_made[0]
+
+        dir = fs.Dir("dir")
+        dir.prepare()
+
+
+
+class SConstruct_dirTestCase(unittest.TestCase):
+    def runTest(self):
+        """Test setting the SConstruct directory"""
+
+        fs = SCons.Node.FS.FS()
+        fs.set_SConstruct_dir(fs.Dir('xxx'))
+        assert fs.SConstruct_dir.get_internal_path() == 'xxx'
+
+
+
+class CacheDirTestCase(unittest.TestCase):
+
+    def test_get_cachedir_csig(self):
+        fs = SCons.Node.FS.FS()
+
+        f9 = fs.File('f9')
+        r = f9.get_cachedir_csig()
+        assert r == 'd41d8cd98f00b204e9800998ecf8427e', r
+
+
+
+class clearTestCase(unittest.TestCase):
+    def runTest(self):
+        """Test clearing FS nodes of cached data."""
+        fs = SCons.Node.FS.FS()
+        test = TestCmd(workdir='')
+
+        e = fs.Entry('e')
+        assert not e.exists()
+        assert not e.rexists()
+        assert str(e) == 'e', str(d)
+        e.clear()
+        assert not e.exists()
+        assert not e.rexists()
+        assert str(e) == 'e', str(d)
+
+        d = fs.Dir(test.workpath('d'))
+        test.subdir('d')
+        assert d.exists()
+        assert d.rexists()
+        assert str(d) == test.workpath('d'), str(d)
+        fs.rename(test.workpath('d'), test.workpath('gone'))
+        # Verify caching is active
+        assert d.exists(), 'caching not active'
+        assert d.rexists()
+        assert str(d) == test.workpath('d'), str(d)
+        # Now verify clear() resets the cache
+        d.clear()
+        assert not d.exists()      
+        assert not d.rexists()
+        assert str(d) == test.workpath('d'), str(d)
+        
+        f = fs.File(test.workpath('f'))
+        test.write(test.workpath('f'), 'file f')
+        assert f.exists()
+        assert f.rexists()
+        assert str(f) == test.workpath('f'), str(f)
+        # Verify caching is active
+        test.unlink(test.workpath('f'))
+        assert f.exists()
+        assert f.rexists()
+        assert str(f) == test.workpath('f'), str(f)
+        # Now verify clear() resets the cache
+        f.clear()
+        assert not f.exists()
+        assert not f.rexists()
+        assert str(f) == test.workpath('f'), str(f)
+
+
+
+class disambiguateTestCase(unittest.TestCase):
+    def runTest(self):
+        """Test calling the disambiguate() method."""
+        test = TestCmd(workdir='')
+
+        fs = SCons.Node.FS.FS()
+
+        ddd = fs.Dir('ddd')
+        d = ddd.disambiguate()
+        assert d is ddd, d
+
+        fff = fs.File('fff')
+        f = fff.disambiguate()
+        assert f is fff, f
+
+        test.subdir('edir')
+        test.write('efile', "efile\n")
+
+        edir = fs.Entry(test.workpath('edir'))
+        d = edir.disambiguate()
+        assert d.__class__ is ddd.__class__, d.__class__
+
+        efile = fs.Entry(test.workpath('efile'))
+        f = efile.disambiguate()
+        assert f.__class__ is fff.__class__, f.__class__
+
+        test.subdir('build')
+        test.subdir(['build', 'bdir'])
+        test.write(['build', 'bfile'], "build/bfile\n")
+
+        test.subdir('src')
+        test.write(['src', 'bdir'], "src/bdir\n")
+        test.subdir(['src', 'bfile'])
+
+        test.subdir(['src', 'edir'])
+        test.write(['src', 'efile'], "src/efile\n")
+
+        fs.VariantDir(test.workpath('build'), test.workpath('src'))
+
+        build_bdir = fs.Entry(test.workpath('build/bdir'))
+        d = build_bdir.disambiguate()
+        assert d is build_bdir, d
+        assert d.__class__ is ddd.__class__, d.__class__
+
+        build_bfile = fs.Entry(test.workpath('build/bfile'))
+        f = build_bfile.disambiguate()
+        assert f is build_bfile, f
+        assert f.__class__ is fff.__class__, f.__class__
+
+        build_edir = fs.Entry(test.workpath('build/edir'))
+        d = build_edir.disambiguate()
+        assert d.__class__ is ddd.__class__, d.__class__
+
+        build_efile = fs.Entry(test.workpath('build/efile'))
+        f = build_efile.disambiguate()
+        assert f.__class__ is fff.__class__, f.__class__
+
+        build_nonexistant = fs.Entry(test.workpath('build/nonexistant'))
+        f = build_nonexistant.disambiguate()
+        assert f.__class__ is fff.__class__, f.__class__
+
+class postprocessTestCase(unittest.TestCase):
+    def runTest(self):
+        """Test calling the postprocess() method."""
+        fs = SCons.Node.FS.FS()
+
+        e = fs.Entry('e')
+        e.postprocess()
+
+        d = fs.Dir('d')
+        d.postprocess()
+
+        f = fs.File('f')
+        f.postprocess()
+
+
+
+class SpecialAttrTestCase(unittest.TestCase):
+    def runTest(self):
+        """Test special attributes of file nodes."""
+        test=TestCmd(workdir='')
+        fs = SCons.Node.FS.FS(test.workpath('work'))
+
+        f = fs.Entry('foo/bar/baz.blat').get_subst_proxy()
+
+        s = str(f.dir)
+        assert s == os.path.normpath('foo/bar'), s
+        assert f.dir.is_literal(), f.dir
+        for_sig = f.dir.for_signature()
+        assert for_sig == 'bar', for_sig
+
+        s = str(f.file)
+        assert s == 'baz.blat', s
+        assert f.file.is_literal(), f.file
+        for_sig = f.file.for_signature()
+        assert for_sig == 'baz.blat_file', for_sig
+
+        s = str(f.base)
+        assert s == os.path.normpath('foo/bar/baz'), s
+        assert f.base.is_literal(), f.base
+        for_sig = f.base.for_signature()
+        assert for_sig == 'baz.blat_base', for_sig
+
+        s = str(f.filebase)
+        assert s == 'baz', s
+        assert f.filebase.is_literal(), f.filebase
+        for_sig = f.filebase.for_signature()
+        assert for_sig == 'baz.blat_filebase', for_sig
+
+        s = str(f.suffix)
+        assert s == '.blat', s
+        assert f.suffix.is_literal(), f.suffix
+        for_sig = f.suffix.for_signature()
+        assert for_sig == 'baz.blat_suffix', for_sig
+
+        s = str(f.get_abspath())
+        assert s == test.workpath('work', 'foo', 'bar', 'baz.blat'), s
+        assert f.abspath.is_literal(), f.abspath
+        for_sig = f.abspath.for_signature()
+        assert for_sig == 'baz.blat_abspath', for_sig
+
+        s = str(f.posix)
+        assert s == 'foo/bar/baz.blat', s
+        assert f.posix.is_literal(), f.posix
+        if f.posix != f:
+            for_sig = f.posix.for_signature()
+            assert for_sig == 'baz.blat_posix', for_sig
+
+        s = str(f.windows)
+        assert s == 'foo\\bar\\baz.blat', repr(s)
+        assert f.windows.is_literal(), f.windows
+        if f.windows != f:
+            for_sig = f.windows.for_signature()
+            assert for_sig == 'baz.blat_windows', for_sig
+
+        # Deprecated synonym for the .windows suffix.
+        s = str(f.win32)
+        assert s == 'foo\\bar\\baz.blat', repr(s)
+        assert f.win32.is_literal(), f.win32
+        if f.win32 != f:
+            for_sig = f.win32.for_signature()
+            assert for_sig == 'baz.blat_windows', for_sig
+
+        # And now, combinations!!!
+        s = str(f.srcpath.base)
+        assert s == os.path.normpath('foo/bar/baz'), s
+        s = str(f.srcpath.dir)
+        assert s == str(f.srcdir), s
+        s = str(f.srcpath.posix)
+        assert s == 'foo/bar/baz.blat', s
+        s = str(f.srcpath.windows)
+        assert s == 'foo\\bar\\baz.blat', s
+        s = str(f.srcpath.win32)
+        assert s == 'foo\\bar\\baz.blat', s
+
+        # Test what happens with VariantDir()
+        fs.VariantDir('foo', 'baz')
+
+        s = str(f.srcpath)
+        assert s == os.path.normpath('baz/bar/baz.blat'), s
+        assert f.srcpath.is_literal(), f.srcpath
+        g = f.srcpath.get()
+        assert isinstance(g, SCons.Node.FS.File), g.__class__
+
+        s = str(f.srcdir)
+        assert s == os.path.normpath('baz/bar'), s
+        assert f.srcdir.is_literal(), f.srcdir
+        g = f.srcdir.get()
+        assert isinstance(g, SCons.Node.FS.Dir), g.__class__
+
+        # And now what happens with VariantDir() + Repository()
+        fs.Repository(test.workpath('repository'))
+
+        f = fs.Entry('foo/sub/file.suffix').get_subst_proxy()
+        test.subdir('repository',
+                    ['repository', 'baz'],
+                    ['repository', 'baz', 'sub'])
+
+        rd = test.workpath('repository', 'baz', 'sub')
+        rf = test.workpath('repository', 'baz', 'sub', 'file.suffix')
+        test.write(rf, "\n")
+
+        s = str(f.srcpath)
+        assert s == os.path.normpath('baz/sub/file.suffix'), s
+        assert f.srcpath.is_literal(), f.srcpath
+        g = f.srcpath.get()
+        # Gets disambiguated to SCons.Node.FS.File by get_subst_proxy().
+        assert isinstance(g, SCons.Node.FS.File), g.__class__
+
+        s = str(f.srcdir)
+        assert s == os.path.normpath('baz/sub'), s
+        assert f.srcdir.is_literal(), f.srcdir
+        g = f.srcdir.get()
+        assert isinstance(g, SCons.Node.FS.Dir), g.__class__
+
+        s = str(f.rsrcpath)
+        assert s == rf, s
+        assert f.rsrcpath.is_literal(), f.rsrcpath
+        g = f.rsrcpath.get()
+        assert isinstance(g, SCons.Node.FS.File), g.__class__
+
+        s = str(f.rsrcdir)
+        assert s == rd, s
+        assert f.rsrcdir.is_literal(), f.rsrcdir
+        g = f.rsrcdir.get()
+        assert isinstance(g, SCons.Node.FS.Dir), g.__class__
+
+        # Check that attempts to access non-existent attributes of the
+        # subst proxy generate the right exceptions and messages.
+        caught = None
+        try:
+            fs.Dir('ddd').get_subst_proxy().no_such_attr
+        except AttributeError as e:
+            assert str(e) == "Dir instance 'ddd' has no attribute 'no_such_attr'", e
+            caught = 1
+        assert caught, "did not catch expected AttributeError"
+
+        caught = None
+        try:
+            fs.Entry('eee').get_subst_proxy().no_such_attr
+        except AttributeError as e:
+            # Gets disambiguated to File instance by get_subst_proxy().
+            assert str(e) == "File instance 'eee' has no attribute 'no_such_attr'", e
+            caught = 1
+        assert caught, "did not catch expected AttributeError"
+
+        caught = None
+        try:
+            fs.File('fff').get_subst_proxy().no_such_attr
+        except AttributeError as e:
+            assert str(e) == "File instance 'fff' has no attribute 'no_such_attr'", e
+            caught = 1
+        assert caught, "did not catch expected AttributeError"
+
+
+
+class SaveStringsTestCase(unittest.TestCase):
+    def runTest(self):
+        """Test caching string values of nodes."""
+        test=TestCmd(workdir='')
+
+        def setup(fs):
+            fs.Dir('src')
+            fs.Dir('d0')
+            fs.Dir('d1')
+
+            d0_f = fs.File('d0/f')
+            d1_f = fs.File('d1/f')
+            d0_b = fs.File('d0/b')
+            d1_b = fs.File('d1/b')
+            d1_f.duplicate = 1
+            d1_b.duplicate = 1
+            d0_b.builder = 1
+            d1_b.builder = 1
+
+            return [d0_f, d1_f, d0_b, d1_b]
+
+        def modify(nodes):
+            d0_f, d1_f, d0_b, d1_b = nodes
+            d1_f.duplicate = 0
+            d1_b.duplicate = 0
+            d0_b.builder = 0
+            d1_b.builder = 0
+
+        fs1 = SCons.Node.FS.FS(test.workpath('fs1'))
+        nodes = setup(fs1)
+        fs1.VariantDir('d0', 'src', duplicate=0)
+        fs1.VariantDir('d1', 'src', duplicate=1)
+
+        s = list(map(str, nodes))
+        expect = list(map(os.path.normpath, ['src/f', 'd1/f', 'd0/b', 'd1/b']))
+        assert s == expect, s
+
+        modify(nodes)
+
+        s = list(map(str, nodes))
+        expect = list(map(os.path.normpath, ['src/f', 'src/f', 'd0/b', 'd1/b']))
+        assert s == expect, s
+
+        SCons.Node.FS.save_strings(1)
+        fs2 = SCons.Node.FS.FS(test.workpath('fs2'))
+        nodes = setup(fs2)
+        fs2.VariantDir('d0', 'src', duplicate=0)
+        fs2.VariantDir('d1', 'src', duplicate=1)
+
+        s = list(map(str, nodes))
+        expect = list(map(os.path.normpath, ['src/f', 'd1/f', 'd0/b', 'd1/b']))
+        assert s == expect, s
+
+        modify(nodes)
+
+        s = list(map(str, nodes))
+        expect = list(map(os.path.normpath, ['src/f', 'd1/f', 'd0/b', 'd1/b']))
+        assert s == expect, 'node str() not cached: %s'%s
+
+
+class AbsolutePathTestCase(unittest.TestCase):
+    def test_root_lookup_equivalence(self):
+        """Test looking up /fff vs. fff in the / directory"""
+        test=TestCmd(workdir='')
+
+        fs = SCons.Node.FS.FS('/')
+
+        save_cwd = os.getcwd()
+        try:
+            os.chdir('/')
+            fff1 = fs.File('fff')
+            fff2 = fs.File('/fff')
+            assert fff1 is fff2, "fff and /fff returned different Nodes!"
+        finally:
+            os.chdir(save_cwd)
+
+
+
+if __name__ == "__main__":
+    suite = unittest.TestSuite()
+    suite.addTest(VariantDirTestCase())
+    suite.addTest(find_fileTestCase())
+    suite.addTest(StringDirTestCase())
+    suite.addTest(stored_infoTestCase())
+    suite.addTest(has_src_builderTestCase())
+    suite.addTest(prepareTestCase())
+    suite.addTest(SConstruct_dirTestCase())
+    suite.addTest(clearTestCase())
+    suite.addTest(disambiguateTestCase())
+    suite.addTest(postprocessTestCase())
+    suite.addTest(SpecialAttrTestCase())
+    suite.addTest(SaveStringsTestCase())
+    tclasses = [
+        AbsolutePathTestCase,
+        BaseTestCase,
+        CacheDirTestCase,
+        DirTestCase,
+        DirBuildInfoTestCase,
+        DirNodeInfoTestCase,
+        EntryTestCase,
+        FileTestCase,
+        FileBuildInfoTestCase,
+        FileNodeInfoTestCase,
+        FSTestCase,
+        GlobTestCase,
+        RepositoryTestCase,
+    ]
+    for tclass in tclasses:
+        names = unittest.getTestCaseNames(tclass, 'test_')
+        suite.addTests(list(map(tclass, names)))
+    TestUnit.run(suite)
+
+# Local Variables:
+# tab-width:4
+# indent-tabs-mode:nil
+# End:
+# vim: set expandtab tabstop=4 shiftwidth=4:
diff --git a/3rdParty/SCons/scons-3.0.1/engine/SCons/Node/NodeTests.py b/3rdParty/SCons/scons-3.0.1/engine/SCons/Node/NodeTests.py
new file mode 100644
index 0000000..3802f8c
--- /dev/null
+++ b/3rdParty/SCons/scons-3.0.1/engine/SCons/Node/NodeTests.py
@@ -0,0 +1,1366 @@
+#
+# __COPYRIGHT__
+#
+# 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 SCons.compat
+
+import collections
+import os
+import re
+import sys
+import unittest
+
+import TestUnit
+
+import SCons.Errors
+import SCons.Node
+import SCons.Util
+
+
+
+built_it = None
+built_target =  None
+built_source =  None
+cycle_detected = None
+built_order = 0
+
+def _actionAppend(a1, a2):
+    all = []
+    for curr_a in [a1, a2]:
+        if isinstance(curr_a, MyAction):
+            all.append(curr_a)
+        elif isinstance(curr_a, MyListAction):
+            all.extend(curr_a.list)
+        elif isinstance(curr_a, list):
+            all.extend(curr_a)
+        else:
+            raise Exception('Cannot Combine Actions')
+    return MyListAction(all)
+
+class MyActionBase(object):
+    def __add__(self, other):
+        return _actionAppend(self, other)
+
+    def __radd__(self, other):
+        return _actionAppend(other, self)
+
+class MyAction(MyActionBase):
+    def __init__(self):
+        self.order = 0
+
+    def __call__(self, target, source, env, executor=None):
+        global built_it, built_target, built_source, built_args, built_order
+        if executor:
+            target = executor.get_all_targets()
+            source = executor.get_all_sources()
+        built_it = 1
+        built_target = target
+        built_source = source
+        built_args = env
+        built_order = built_order + 1
+        self.order = built_order
+        return 0
+
+    def get_implicit_deps(self, target, source, env):
+        return []
+
+class MyExecutor(object):
+    def __init__(self, env=None, targets=[], sources=[]):
+        self.env = env
+        self.targets = targets
+        self.sources = sources
+    def get_build_env(self):
+        return self.env
+    def get_build_scanner_path(self, scanner):
+        return 'executor would call %s' % scanner
+    def cleanup(self):
+        self.cleaned_up = 1
+    def scan_targets(self, scanner):
+        if not scanner:
+            return
+        d = scanner(self.targets)
+        for t in self.targets:
+            t.implicit.extend(d)
+    def scan_sources(self, scanner):
+        if not scanner:
+            return
+        d = scanner(self.sources)
+        for t in self.targets:
+            t.implicit.extend(d)
+
+class MyListAction(MyActionBase):
+    def __init__(self, list):
+        self.list = list
+    def __call__(self, target, source, env):
+        for A in self.list:
+            A(target, source, env)
+
+class Environment(object):
+    def __init__(self, **kw):
+        self._dict = {}
+        self._dict.update(kw)
+    def __getitem__(self, key):
+        return self._dict[key]
+    def get(self, key, default = None):
+        return self._dict.get(key, default)
+    def Dictionary(self, *args):
+        return {}
+    def Override(self, overrides):
+        d = self._dict.copy()
+        d.update(overrides)
+        return Environment(**d)
+    def _update(self, dict):
+        self._dict.update(dict)
+    def get_factory(self, factory):
+        return factory or MyNode
+    def get_scanner(self, scanner_key):
+        try:
+            return self._dict['SCANNERS'][0]
+        except:
+            pass
+
+        return []
+
+class Builder(object):
+    def __init__(self, env=None, is_explicit=1):
+        if env is None: env = Environment()
+        self.env = env
+        self.overrides = {}
+        self.action = MyAction()
+        self.source_factory = MyNode
+        self.is_explicit = is_explicit
+        self.target_scanner = None
+        self.source_scanner = None
+    def targets(self, t):
+        return [t]
+    def get_actions(self):
+        return [self.action]
+    def get_contents(self, target, source, env):
+        return 7
+
+class NoneBuilder(Builder):
+    def execute(self, target, source, env):
+        Builder.execute(self, target, source, env)
+        return None
+
+class ListBuilder(Builder):
+    def __init__(self, *nodes):
+        Builder.__init__(self)
+        self.nodes = nodes
+    def execute(self, target, source, env):
+        if hasattr(self, 'status'):
+            return self.status
+        for n in self.nodes:
+            n.prepare()
+        target = self.nodes[0]
+        self.status = Builder.execute(self, target, source, env)
+
+class FailBuilder(object):
+    def execute(self, target, source, env):
+        return 1
+
+class ExceptBuilder(object):
+    def execute(self, target, source, env):
+        raise SCons.Errors.BuildError
+
+class ExceptBuilder2(object):
+    def execute(self, target, source, env):
+        raise Exception("foo")
+
+class Scanner(object):
+    called = None
+    def __call__(self, node):
+        self.called = 1
+        return node.GetTag('found_includes')
+    def path(self, env, dir=None, target=None, source=None, kw={}):
+        return ()
+    def select(self, node):
+        return self
+    def recurse_nodes(self, nodes):
+        return nodes
+
+class MyNode(SCons.Node.Node):
+    """The base Node class contains a number of do-nothing methods that
+    we expect to be overridden by real, functional Node subclasses.  So
+    simulate a real, functional Node subclass.
+    """
+    def __init__(self, name):
+        SCons.Node.Node.__init__(self)
+        self.name = name
+        self.Tag('found_includes', [])
+    def __str__(self):
+        return self.name
+    def get_found_includes(self, env, scanner, target):
+        return scanner(self)
+
+class Calculator(object):
+    def __init__(self, val):
+        self.max_drift = 0
+        class M(object):
+            def __init__(self, val):
+                self.val = val
+            def signature(self, args):
+                return self.val
+            def collect(self, args):
+                result = self.val
+                for a in args:
+                    result += a
+                return result
+        self.module = M(val)
+
+
+
+class NodeInfoBaseTestCase(unittest.TestCase):
+    # The abstract class NodeInfoBase has not enough default slots to perform
+    # the merge and format test (arbitrary attributes do not work). Do it with a
+    # derived class that does provide the slots.
+
+    def test_merge(self):
+        """Test merging NodeInfoBase attributes"""
+
+        class TestNodeInfo(SCons.Node.NodeInfoBase):
+            __slots__ = ('a1', 'a2', 'a3')
+
+        ni1 = TestNodeInfo()
+        ni2 = TestNodeInfo()
+
+        ni1.a1 = 1
+        ni1.a2 = 2
+
+        ni2.a2 = 222
+        ni2.a3 = 333
+
+        ni1.merge(ni2)
+        assert ni1.a1 == 1, ni1.a1
+        assert ni1.a2 == 222, ni1.a2
+        assert ni1.a3 == 333, ni1.a3
+
+    def test_update(self):
+        """Test the update() method"""
+        ni = SCons.Node.NodeInfoBase()
+        ni.update(SCons.Node.Node())
+
+    def test_format(self):
+        """Test the NodeInfoBase.format() method"""
+
+        class TestNodeInfo(SCons.Node.NodeInfoBase):
+            __slots__ = ('xxx', 'yyy', 'zzz')
+
+        ni1 = TestNodeInfo()
+        ni1.xxx = 'x'
+        ni1.yyy = 'y'
+        ni1.zzz = 'z'
+
+        f = ni1.format()
+        assert f == ['x', 'y', 'z'], f
+ 
+        field_list = ['xxx', 'zzz', 'aaa']
+
+        f = ni1.format(field_list)
+        assert f == ['x', 'z', 'None'], f
+
+
+
+class BuildInfoBaseTestCase(unittest.TestCase):
+
+    def test___init__(self):
+        """Test BuildInfoBase initialization"""
+        n = SCons.Node.Node()
+        bi = SCons.Node.BuildInfoBase()
+        assert bi
+
+    def test_merge(self):
+        """Test merging BuildInfoBase attributes"""
+        n1 = SCons.Node.Node()
+        bi1 = SCons.Node.BuildInfoBase()
+        n2 = SCons.Node.Node()
+        bi2 = SCons.Node.BuildInfoBase()
+
+        bi1.bsources = 1
+        bi1.bdepends = 2
+
+        bi2.bdepends = 222
+        bi2.bact = 333
+
+        bi1.merge(bi2)
+        assert bi1.bsources == 1, bi1.bsources
+        assert bi1.bdepends == 222, bi1.bdepends
+        assert bi1.bact == 333, bi1.bact
+
+
+class NodeTestCase(unittest.TestCase):
+
+    def test_build(self):
+        """Test building a node
+        """
+        global built_it, built_order
+
+        # Make sure it doesn't blow up if no builder is set.
+        node = MyNode("www")
+        node.build()
+        assert built_it is None
+        node.build(extra_kw_argument = 1)
+        assert built_it is None
+
+        node = MyNode("xxx")
+        node.builder_set(Builder())
+        node.env_set(Environment())
+        node.path = "xxx"
+        node.sources = ["yyy", "zzz"]
+        node.build()
+        assert built_it
+        assert built_target == [node], built_target
+        assert built_source == ["yyy", "zzz"], built_source
+
+        built_it = None
+        node = MyNode("qqq")
+        node.builder_set(NoneBuilder())
+        node.env_set(Environment())
+        node.path = "qqq"
+        node.sources = ["rrr", "sss"]
+        node.builder.overrides = { "foo" : 1, "bar" : 2 }
+        node.build()
+        assert built_it
+        assert built_target == [node], built_target
+        assert built_source == ["rrr", "sss"], built_source
+        assert built_args["foo"] == 1, built_args
+        assert built_args["bar"] == 2, built_args
+
+        fff = MyNode("fff")
+        ggg = MyNode("ggg")
+        lb = ListBuilder(fff, ggg)
+        e = Environment()
+        fff.builder_set(lb)
+        fff.env_set(e)
+        fff.path = "fff"
+        ggg.builder_set(lb)
+        ggg.env_set(e)
+        ggg.path = "ggg"
+        fff.sources = ["hhh", "iii"]
+        ggg.sources = ["hhh", "iii"]
+        built_it = None
+        fff.build()
+        assert built_it
+        assert built_target == [fff], built_target
+        assert built_source == ["hhh", "iii"], built_source
+        built_it = None
+        ggg.build()
+        assert built_it
+        assert built_target == [ggg], built_target
+        assert built_source == ["hhh", "iii"], built_source
+
+        built_it = None
+        jjj = MyNode("jjj")
+        b = Builder()
+        jjj.builder_set(b)
+        # NOTE:  No env_set()!  We should pull the environment from the builder.
+        b.env = Environment()
+        b.overrides = { "on" : 3, "off" : 4 }
+        e.builder = b
+        jjj.build()
+        assert built_it
+        assert built_target[0] == jjj, built_target[0]
+        assert built_source == [], built_source
+        assert built_args["on"] == 3, built_args
+        assert built_args["off"] == 4, built_args
+
+    def test_get_build_scanner_path(self):
+        """Test the get_build_scanner_path() method"""
+        n = SCons.Node.Node()
+        x = MyExecutor()
+        n.set_executor(x)
+        p = n.get_build_scanner_path('fake_scanner')
+        assert p == "executor would call fake_scanner", p
+
+    def test_get_executor(self):
+        """Test the get_executor() method"""
+        n = SCons.Node.Node()
+
+        try:
+            n.get_executor(0)
+        except AttributeError:
+            pass
+        else:
+            self.fail("did not catch expected AttributeError")
+
+        class Builder(object):
+            action = 'act'
+            env = 'env1'
+            overrides = {}
+
+        n = SCons.Node.Node()
+        n.builder_set(Builder())
+        x = n.get_executor()
+        assert x.env == 'env1', x.env
+
+        n = SCons.Node.Node()
+        n.builder_set(Builder())
+        n.env_set('env2')
+        x = n.get_executor()
+        assert x.env == 'env2', x.env
+
+    def test_set_executor(self):
+        """Test the set_executor() method"""
+        n = SCons.Node.Node()
+        n.set_executor(1)
+        assert n.executor == 1, n.executor
+
+    def test_executor_cleanup(self):
+        """Test letting the executor cleanup its cache"""
+        n = SCons.Node.Node()
+        x = MyExecutor()
+        n.set_executor(x)
+        n.executor_cleanup()
+        assert x.cleaned_up
+
+    def test_reset_executor(self):
+        """Test the reset_executor() method"""
+        n = SCons.Node.Node()
+        n.set_executor(1)
+        assert n.executor == 1, n.executor
+        n.reset_executor()
+        assert not hasattr(n, 'executor'), "unexpected executor attribute"
+
+    def test_built(self):
+        """Test the built() method"""
+        class SubNodeInfo(SCons.Node.NodeInfoBase):
+            __slots__ = ('updated',)
+            def update(self, node):
+                self.updated = 1
+        class SubNode(SCons.Node.Node):
+            def clear(self):
+                self.cleared = 1
+
+        n = SubNode()
+        n.ninfo = SubNodeInfo()
+        n.built()
+        assert n.cleared, n.cleared
+        assert n.ninfo.updated, n.ninfo.cleared
+
+    def test_push_to_cache(self):
+        """Test the base push_to_cache() method"""
+        n = SCons.Node.Node()
+        r = n.push_to_cache()
+        assert r is None, r
+
+    def test_retrieve_from_cache(self):
+        """Test the base retrieve_from_cache() method"""
+        n = SCons.Node.Node()
+        r = n.retrieve_from_cache()
+        assert r == 0, r
+
+    def test_visited(self):
+        """Test the base visited() method
+
+        Just make sure it's there and we can call it.
+        """
+        n = SCons.Node.Node()
+        n.visited()
+
+    def test_builder_set(self):
+        """Test setting a Node's Builder
+        """
+        node = SCons.Node.Node()
+        b = Builder()
+        node.builder_set(b)
+        assert node.builder == b
+
+    def test_has_builder(self):
+        """Test the has_builder() method
+        """
+        n1 = SCons.Node.Node()
+        assert n1.has_builder() == 0
+        n1.builder_set(Builder())
+        assert n1.has_builder() == 1
+
+    def test_has_explicit_builder(self):
+        """Test the has_explicit_builder() method
+        """
+        n1 = SCons.Node.Node()
+        assert not n1.has_explicit_builder()
+        n1.set_explicit(1)
+        assert n1.has_explicit_builder()
+        n1.set_explicit(None)
+        assert not n1.has_explicit_builder()
+
+    def test_get_builder(self):
+        """Test the get_builder() method"""
+        n1 = SCons.Node.Node()
+        b = n1.get_builder()
+        assert b is None, b
+        b = n1.get_builder(777)
+        assert b == 777, b
+        n1.builder_set(888)
+        b = n1.get_builder()
+        assert b == 888, b
+        b = n1.get_builder(999)
+        assert b == 888, b
+
+    def test_multiple_side_effect_has_builder(self):
+        """Test the multiple_side_effect_has_builder() method
+        """
+        n1 = SCons.Node.Node()
+        assert n1.multiple_side_effect_has_builder() == 0
+        n1.builder_set(Builder())
+        assert n1.multiple_side_effect_has_builder() == 1
+
+    def test_is_derived(self):
+        """Test the is_derived() method
+        """
+        n1 = SCons.Node.Node()
+        n2 = SCons.Node.Node()
+        n3 = SCons.Node.Node()
+
+        n2.builder_set(Builder())
+        n3.side_effect = 1
+
+        assert n1.is_derived() == 0
+        assert n2.is_derived() == 1
+        assert n3.is_derived() == 1
+
+    def test_alter_targets(self):
+        """Test the alter_targets() method
+        """
+        n = SCons.Node.Node()
+        t, m = n.alter_targets()
+        assert t == [], t
+        assert m is None, m
+
+    def test_is_up_to_date(self):
+        """Test the default is_up_to_date() method
+        """
+        node = SCons.Node.Node()
+        assert node.is_up_to_date() is None
+
+    def test_children_are_up_to_date(self):
+        """Test the children_are_up_to_date() method used by subclasses
+        """
+        n1 = SCons.Node.Node()
+        n2 = SCons.Node.Node()
+
+        n1.add_source([n2])
+        assert n1.children_are_up_to_date(), "expected up to date"
+        n2.set_state(SCons.Node.executed)
+        assert not n1.children_are_up_to_date(), "expected not up to date"
+        n2.set_state(SCons.Node.up_to_date)
+        assert n1.children_are_up_to_date(), "expected up to date"
+        n1.always_build = 1
+        assert not n1.children_are_up_to_date(), "expected not up to date"
+
+    def test_env_set(self):
+        """Test setting a Node's Environment
+        """
+        node = SCons.Node.Node()
+        e = Environment()
+        node.env_set(e)
+        assert node.env == e
+
+    def test_get_actions(self):
+        """Test fetching a Node's action list
+        """
+        node = SCons.Node.Node()
+        node.builder_set(Builder())
+        a = node.builder.get_actions()
+        assert isinstance(a[0], MyAction), a[0]
+
+    def test_get_csig(self):
+        """Test generic content signature calculation
+        """
+        
+        class TestNodeInfo(SCons.Node.NodeInfoBase):
+            __slots__ = ('csig',)
+        try:
+            SCons.Node.Node.NodeInfo = TestNodeInfo
+            def my_contents(obj):
+                return 444
+            SCons.Node._get_contents_map[4] = my_contents
+            node = SCons.Node.Node()
+            node._func_get_contents = 4
+            result = node.get_csig()
+            assert result == '550a141f12de6341fba65b0ad0433500', result
+        finally:
+            SCons.Node.Node.NodeInfo = SCons.Node.NodeInfoBase
+
+    def test_get_cachedir_csig(self):
+        """Test content signature calculation for CacheDir
+        """
+        class TestNodeInfo(SCons.Node.NodeInfoBase):
+            __slots__ = ('csig',)
+        try:
+            SCons.Node.Node.NodeInfo = TestNodeInfo
+            def my_contents(obj):
+                return 555
+            SCons.Node._get_contents_map[4] = my_contents
+            node = SCons.Node.Node()
+            node._func_get_contents = 4
+            result = node.get_cachedir_csig()
+            assert result == '15de21c670ae7c3f6f3f1f37029303c9', result
+        finally:
+            SCons.Node.Node.NodeInfo = SCons.Node.NodeInfoBase
+
+    def test_get_binfo(self):
+        """Test fetching/creating a build information structure
+        """
+        class TestNodeInfo(SCons.Node.NodeInfoBase):
+            __slots__ = ('csig',)
+        SCons.Node.Node.NodeInfo = TestNodeInfo
+        node = SCons.Node.Node()
+ 
+        binfo = node.get_binfo()
+        assert isinstance(binfo, SCons.Node.BuildInfoBase), binfo
+
+        node = SCons.Node.Node()
+        d = SCons.Node.Node()
+        ninfo = d.get_ninfo()
+        assert isinstance(ninfo, SCons.Node.NodeInfoBase), ninfo
+        i = SCons.Node.Node()
+        ninfo = i.get_ninfo()
+        assert isinstance(ninfo, SCons.Node.NodeInfoBase), ninfo
+        node.depends = [d]
+        node.implicit = [i]
+
+        binfo = node.get_binfo()
+        assert isinstance(binfo, SCons.Node.BuildInfoBase), binfo
+        assert hasattr(binfo, 'bsources')
+        assert hasattr(binfo, 'bsourcesigs')
+        assert binfo.bdepends == [d]
+        assert hasattr(binfo, 'bdependsigs')
+        assert binfo.bimplicit == [i]
+        assert hasattr(binfo, 'bimplicitsigs')
+
+    def test_explain(self):
+        """Test explaining why a Node must be rebuilt
+        """
+        class testNode(SCons.Node.Node):
+            def __str__(self): return 'xyzzy'
+        node = testNode()
+        node.exists = lambda: None
+        # Can't do this with new-style classes (python bug #1066490)
+        #node.__str__ = lambda: 'xyzzy'
+        result = node.explain()
+        assert result == "building `xyzzy' because it doesn't exist\n", result
+
+        class testNode2(SCons.Node.Node):
+            def __str__(self): return 'null_binfo'
+        class FS(object):
+            pass
+        node = testNode2()
+        node.fs = FS()
+        node.fs.Top = SCons.Node.Node()
+        result = node.explain()
+        assert result is None, result
+
+        def get_null_info():
+            class Null_SConsignEntry(object):
+                class Null_BuildInfo(object):
+                    def prepare_dependencies(self):
+                        pass
+                binfo = Null_BuildInfo()
+            return Null_SConsignEntry()
+
+        node.get_stored_info = get_null_info
+        #see above: node.__str__ = lambda: 'null_binfo'
+        result = node.explain()
+        assert result == "Cannot explain why `null_binfo' is being rebuilt: No previous build information found\n", result
+
+        # XXX additional tests for the guts of the functionality some day
+
+    #def test_del_binfo(self):
+    #    """Test deleting the build information from a Node
+    #    """
+    #    node = SCons.Node.Node()
+    #    node.binfo = None
+    #    node.del_binfo()
+    #    assert not hasattr(node, 'binfo'), node
+
+    def test_store_info(self):
+        """Test calling the method to store build information
+        """
+        node = SCons.Node.Node()
+        SCons.Node.store_info_map[node.store_info](node)
+
+    def test_get_stored_info(self):
+        """Test calling the method to fetch stored build information
+        """
+        node = SCons.Node.Node()
+        result = node.get_stored_info()
+        assert result is None, result
+
+    def test_set_always_build(self):
+        """Test setting a Node's always_build value
+        """
+        node = SCons.Node.Node()
+        node.set_always_build()
+        assert node.always_build
+        node.set_always_build(3)
+        assert node.always_build == 3
+
+    def test_set_noclean(self):
+        """Test setting a Node's noclean value
+        """
+        node = SCons.Node.Node()
+        node.set_noclean()
+        assert node.noclean == 1, node.noclean
+        node.set_noclean(7)
+        assert node.noclean == 1, node.noclean
+        node.set_noclean(0)
+        assert node.noclean == 0, node.noclean
+        node.set_noclean(None)
+        assert node.noclean == 0, node.noclean
+
+    def test_set_precious(self):
+        """Test setting a Node's precious value
+        """
+        node = SCons.Node.Node()
+        node.set_precious()
+        assert node.precious
+        node.set_precious(7)
+        assert node.precious == 7
+
+    def test_set_pseudo(self):
+        """Test setting a Node's pseudo value
+        """
+        node = SCons.Node.Node()
+        node.set_pseudo()
+        assert node.pseudo
+        node.set_pseudo(False)
+        assert not node.pseudo
+
+    def test_exists(self):
+        """Test evaluating whether a Node exists.
+        """
+        node = SCons.Node.Node()
+        e = node.exists()
+        assert e == 1, e
+
+    def test_exists(self):
+        """Test evaluating whether a Node exists locally or in a repository.
+        """
+        node = SCons.Node.Node()
+        e = node.rexists()
+        assert e == 1, e
+
+        class MyNode(SCons.Node.Node):
+            def exists(self):
+                return 'xyz'
+
+        node = MyNode()
+        e = node.rexists()
+        assert e == 'xyz', e
+
+    def test_prepare(self):
+        """Test preparing a node to be built
+
+        By extension, this also tests the missing() method.
+        """
+        node = SCons.Node.Node()
+
+        n1 = SCons.Node.Node()
+        n1.builder_set(Builder())
+        node.implicit = []
+        node.implicit_set = set()
+        node._add_child(node.implicit, node.implicit_set, [n1])
+
+        node.prepare()  # should not throw an exception
+
+        n2 = SCons.Node.Node()
+        n2.linked = 1
+        node.implicit = []
+        node.implicit_set = set()
+        node._add_child(node.implicit, node.implicit_set, [n2])
+
+        node.prepare()  # should not throw an exception
+
+        n3 = SCons.Node.Node()
+        node.implicit = []
+        node.implicit_set = set()
+        node._add_child(node.implicit, node.implicit_set, [n3])
+
+        node.prepare()  # should not throw an exception
+
+        class MyNode(SCons.Node.Node):
+            def rexists(self):
+                return None
+        n4 = MyNode()
+        node.implicit = []
+        node.implicit_set = set()
+        node._add_child(node.implicit, node.implicit_set, [n4])
+        exc_caught = 0
+        try:
+            node.prepare()
+        except SCons.Errors.StopError:
+            exc_caught = 1
+        assert exc_caught, "did not catch expected StopError"
+
+    def test_add_dependency(self):
+        """Test adding dependencies to a Node's list.
+        """
+        node = SCons.Node.Node()
+        assert node.depends == []
+
+        zero = SCons.Node.Node()
+
+        one = SCons.Node.Node()
+        two = SCons.Node.Node()
+        three = SCons.Node.Node()
+        four = SCons.Node.Node()
+        five = SCons.Node.Node()
+        six = SCons.Node.Node()
+
+        node.add_dependency([zero])
+        assert node.depends == [zero]
+        node.add_dependency([one])
+        assert node.depends == [zero, one]
+        node.add_dependency([two, three])
+        assert node.depends == [zero, one, two, three]
+        node.add_dependency([three, four, one])
+        assert node.depends == [zero, one, two, three, four]
+
+        try:
+            node.add_depends([[five, six]])
+        except:
+            pass
+        else:
+            raise Exception("did not catch expected exception")
+        assert node.depends == [zero, one, two, three, four]
+
+
+    def test_add_source(self):
+        """Test adding sources to a Node's list.
+        """
+        node = SCons.Node.Node()
+        assert node.sources == []
+
+        zero = SCons.Node.Node()
+        one = SCons.Node.Node()
+        two = SCons.Node.Node()
+        three = SCons.Node.Node()
+        four = SCons.Node.Node()
+        five = SCons.Node.Node()
+        six = SCons.Node.Node()
+
+        node.add_source([zero])
+        assert node.sources == [zero]
+        node.add_source([one])
+        assert node.sources == [zero, one]
+        node.add_source([two, three])
+        assert node.sources == [zero, one, two, three]
+        node.add_source([three, four, one])
+        assert node.sources == [zero, one, two, three, four]
+
+        try:
+            node.add_source([[five, six]])
+        except:
+            pass
+        else:
+            raise Exception("did not catch expected exception")
+        assert node.sources == [zero, one, two, three, four], node.sources
+
+    def test_add_ignore(self):
+        """Test adding files whose dependencies should be ignored.
+        """
+        node = SCons.Node.Node()
+        assert node.ignore == []
+
+        zero = SCons.Node.Node()
+        one = SCons.Node.Node()
+        two = SCons.Node.Node()
+        three = SCons.Node.Node()
+        four = SCons.Node.Node()
+        five = SCons.Node.Node()
+        six = SCons.Node.Node()
+
+        node.add_ignore([zero])
+        assert node.ignore == [zero]
+        node.add_ignore([one])
+        assert node.ignore == [zero, one]
+        node.add_ignore([two, three])
+        assert node.ignore == [zero, one, two, three]
+        node.add_ignore([three, four, one])
+        assert node.ignore == [zero, one, two, three, four]
+
+        try:
+            node.add_ignore([[five, six]])
+        except:
+            pass
+        else:
+            raise Exception("did not catch expected exception")
+        assert node.ignore == [zero, one, two, three, four]
+
+    def test_get_found_includes(self):
+        """Test the default get_found_includes() method
+        """
+        node = SCons.Node.Node()
+        target = SCons.Node.Node()
+        e = Environment()
+        deps = node.get_found_includes(e, None, target)
+        assert deps == [], deps
+
+    def test_get_implicit_deps(self):
+        """Test get_implicit_deps()
+        """
+        node = MyNode("nnn")
+        target = MyNode("ttt")
+        env = Environment()
+
+        # No scanner at all returns []
+        deps = node.get_implicit_deps(env, None, target)
+        assert deps == [], deps
+
+        s = Scanner()
+        d1 = MyNode("d1")
+        d2 = MyNode("d2")
+        node.Tag('found_includes', [d1, d2])
+
+        # Simple return of the found includes
+        deps = node.get_implicit_deps(env, s, s.path)
+        assert deps == [d1, d2], deps
+
+        # By default, our fake scanner recurses
+        e = MyNode("eee")
+        f = MyNode("fff")
+        g = MyNode("ggg")
+        d1.Tag('found_includes', [e, f])
+        d2.Tag('found_includes', [e, f])
+        f.Tag('found_includes', [g])
+        deps = node.get_implicit_deps(env, s, s.path)
+        assert deps == [d1, d2, e, f, g], list(map(str, deps))
+
+        # Recursive scanning eliminates duplicates
+        e.Tag('found_includes', [f])
+        deps = node.get_implicit_deps(env, s, s.path)
+        assert deps == [d1, d2, e, f, g], list(map(str, deps))
+
+        # Scanner method can select specific nodes to recurse
+        def no_fff(nodes):
+            return [n for n in nodes if str(n)[0] != 'f']
+        s.recurse_nodes = no_fff
+        deps = node.get_implicit_deps(env, s, s.path)
+        assert deps == [d1, d2, e, f], list(map(str, deps))
+
+        # Scanner method can short-circuit recursing entirely
+        s.recurse_nodes = lambda nodes: []
+        deps = node.get_implicit_deps(env, s, s.path)
+        assert deps == [d1, d2], list(map(str, deps))
+
+    def test_get_env_scanner(self):
+        """Test fetching the environment scanner for a Node
+        """
+        node = SCons.Node.Node()
+        scanner = Scanner()
+        env = Environment(SCANNERS = [scanner])
+        s = node.get_env_scanner(env)
+        assert s == scanner, s
+        s = node.get_env_scanner(env, {'X':1})
+        assert s == scanner, s
+
+    def test_get_target_scanner(self):
+        """Test fetching the target scanner for a Node
+        """
+        s = Scanner()
+        b = Builder()
+        b.target_scanner = s
+        n = SCons.Node.Node()
+        n.builder = b
+        x = n.get_target_scanner()
+        assert x is s, x
+
+    def test_get_source_scanner(self):
+        """Test fetching the source scanner for a Node
+        """
+        target = SCons.Node.Node()
+        source = SCons.Node.Node()
+        s = target.get_source_scanner(source)
+        assert isinstance(s, SCons.Util.Null), s
+
+        ts1 = Scanner()
+        ts2 = Scanner()
+        ts3 = Scanner()
+
+        class Builder1(Builder):
+            def __call__(self, source):
+                r = SCons.Node.Node()
+                r.builder = self
+                return [r]
+        class Builder2(Builder1):
+            def __init__(self, scanner):
+                self.source_scanner = scanner
+
+        builder = Builder2(ts1)
+
+        targets = builder([source])
+        s = targets[0].get_source_scanner(source)
+        assert s is ts1, s
+
+        target.builder_set(Builder2(ts1))
+        target.builder.source_scanner = ts2
+        s = target.get_source_scanner(source)
+        assert s is ts2, s
+
+        builder = Builder1(env=Environment(SCANNERS = [ts3]))
+
+        targets = builder([source])
+
+        s = targets[0].get_source_scanner(source)
+        assert s is ts3, s
+
+
+    def test_scan(self):
+        """Test Scanner functionality
+        """
+        env = Environment()
+        node = MyNode("nnn")
+        node.builder = Builder()
+        node.env_set(env)
+        x = MyExecutor(env, [node])
+
+        s = Scanner()
+        d = MyNode("ddd")
+        node.Tag('found_includes', [d])
+
+        node.builder.target_scanner = s
+        assert node.implicit is None
+
+        node.scan()
+        assert s.called
+        assert node.implicit == [d], node.implicit
+
+        # Check that scanning a node with some stored implicit
+        # dependencies resets internal attributes appropriately
+        # if the stored dependencies need recalculation.
+        class StoredNode(MyNode):
+            def get_stored_implicit(self):
+                return [MyNode('implicit1'), MyNode('implicit2')]
+
+        save_implicit_cache = SCons.Node.implicit_cache
+        save_implicit_deps_changed = SCons.Node.implicit_deps_changed
+        save_implicit_deps_unchanged = SCons.Node.implicit_deps_unchanged
+        SCons.Node.implicit_cache = 1
+        SCons.Node.implicit_deps_changed = None
+        SCons.Node.implicit_deps_unchanged = None
+        try:
+            sn = StoredNode("eee")
+            sn.builder_set(Builder())
+            sn.builder.target_scanner = s
+
+            sn.scan()
+
+            assert sn.implicit == [], sn.implicit
+            assert sn.children() == [], sn.children()
+
+        finally:
+            SCons.Node.implicit_cache = save_implicit_cache
+            SCons.Node.implicit_deps_changed = save_implicit_deps_changed
+            SCons.Node.implicit_deps_unchanged = save_implicit_deps_unchanged
+
+    def test_scanner_key(self):
+        """Test that a scanner_key() method exists"""
+        assert SCons.Node.Node().scanner_key() is None
+
+    def test_children(self):
+        """Test fetching the non-ignored "children" of a Node.
+        """
+        node = SCons.Node.Node()
+        n1 = SCons.Node.Node()
+        n2 = SCons.Node.Node()
+        n3 = SCons.Node.Node()
+        n4 = SCons.Node.Node()
+        n5 = SCons.Node.Node()
+        n6 = SCons.Node.Node()
+        n7 = SCons.Node.Node()
+        n8 = SCons.Node.Node()
+        n9 = SCons.Node.Node()
+        n10 = SCons.Node.Node()
+        n11 = SCons.Node.Node()
+        n12 = SCons.Node.Node()
+
+        node.add_source([n1, n2, n3])
+        node.add_dependency([n4, n5, n6])
+        node.implicit = []
+        node.implicit_set = set()
+        node._add_child(node.implicit, node.implicit_set, [n7, n8, n9])
+        node._add_child(node.implicit, node.implicit_set, [n10, n11, n12])
+        node.add_ignore([n2, n5, n8, n11])
+
+        kids = node.children()
+        for kid in [n1, n3, n4, n6, n7, n9, n10, n12]:
+            assert kid in kids, kid
+        for kid in [n2, n5, n8, n11]:
+            assert not kid in kids, kid
+
+    def test_all_children(self):
+        """Test fetching all the "children" of a Node.
+        """
+        node = SCons.Node.Node()
+        n1 = SCons.Node.Node()
+        n2 = SCons.Node.Node()
+        n3 = SCons.Node.Node()
+        n4 = SCons.Node.Node()
+        n5 = SCons.Node.Node()
+        n6 = SCons.Node.Node()
+        n7 = SCons.Node.Node()
+        n8 = SCons.Node.Node()
+        n9 = SCons.Node.Node()
+        n10 = SCons.Node.Node()
+        n11 = SCons.Node.Node()
+        n12 = SCons.Node.Node()
+
+        node.add_source([n1, n2, n3])
+        node.add_dependency([n4, n5, n6])
+        node.implicit = []
+        node.implicit_set = set()
+        node._add_child(node.implicit, node.implicit_set, [n7, n8, n9])
+        node._add_child(node.implicit, node.implicit_set, [n10, n11, n12])
+        node.add_ignore([n2, n5, n8, n11])
+
+        kids = node.all_children()
+        for kid in [n1, n2, n3, n4, n5, n6, n7, n8, n9, n10, n11, n12]:
+            assert kid in kids, kid
+
+    def test_state(self):
+        """Test setting and getting the state of a node
+        """
+        node = SCons.Node.Node()
+        assert node.get_state() == SCons.Node.no_state
+        node.set_state(SCons.Node.executing)
+        assert node.get_state() == SCons.Node.executing
+        assert SCons.Node.pending < SCons.Node.executing
+        assert SCons.Node.executing < SCons.Node.up_to_date
+        assert SCons.Node.up_to_date < SCons.Node.executed
+        assert SCons.Node.executed < SCons.Node.failed
+
+    def test_walker(self):
+        """Test walking a Node tree.
+        """
+
+        n1 = MyNode("n1")
+
+        nw = SCons.Node.Walker(n1)
+        assert not nw.is_done()
+        assert nw.get_next().name ==  "n1"
+        assert nw.is_done()
+        assert nw.get_next() is None
+
+        n2 = MyNode("n2")
+        n3 = MyNode("n3")
+        n1.add_source([n2, n3])
+
+        nw = SCons.Node.Walker(n1)
+        n = nw.get_next()
+        assert n.name ==  "n2", n.name
+        n = nw.get_next()
+        assert n.name ==  "n3", n.name
+        n = nw.get_next()
+        assert n.name ==  "n1", n.name
+        n = nw.get_next()
+        assert n is None, n
+
+        n4 = MyNode("n4")
+        n5 = MyNode("n5")
+        n6 = MyNode("n6")
+        n7 = MyNode("n7")
+        n2.add_source([n4, n5])
+        n3.add_dependency([n6, n7])
+
+        nw = SCons.Node.Walker(n1)
+        assert nw.get_next().name ==  "n4"
+        assert nw.get_next().name ==  "n5"
+        assert n2 in nw.history
+        assert nw.get_next().name ==  "n2"
+        assert nw.get_next().name ==  "n6"
+        assert nw.get_next().name ==  "n7"
+        assert n3 in nw.history
+        assert nw.get_next().name ==  "n3"
+        assert n1 in nw.history
+        assert nw.get_next().name ==  "n1"
+        assert nw.get_next() is None
+
+        n8 = MyNode("n8")
+        n8.add_dependency([n3])
+        n7.add_dependency([n8])
+
+        def cycle(node, stack):
+            global cycle_detected
+            cycle_detected = 1
+
+        global cycle_detected
+
+        nw = SCons.Node.Walker(n3, cycle_func = cycle)
+        n = nw.get_next()
+        assert n.name == "n6", n.name
+        n = nw.get_next()
+        assert n.name == "n8", n.name
+        assert cycle_detected
+        cycle_detected = None
+        n = nw.get_next()
+        assert n.name == "n7", n.name
+        n = nw.get_next()
+        assert nw.get_next() is None
+
+    def test_abspath(self):
+        """Test the get_abspath() method."""
+        n = MyNode("foo")
+        assert n.get_abspath() == str(n), n.get_abspath()
+
+    def test_for_signature(self):
+        """Test the for_signature() method."""
+        n = MyNode("foo")
+        assert n.for_signature() == str(n), n.get_abspath()
+
+    def test_get_string(self):
+        """Test the get_string() method."""
+        class TestNode(MyNode):
+            def __init__(self, name, sig):
+                MyNode.__init__(self, name)
+                self.sig = sig
+
+            def for_signature(self):
+                return self.sig
+
+        n = TestNode("foo", "bar")
+        assert n.get_string(0) == "foo", n.get_string(0)
+        assert n.get_string(1) == "bar", n.get_string(1)
+
+    def test_literal(self):
+        """Test the is_literal() function."""
+        n=SCons.Node.Node()
+        assert n.is_literal()
+
+    def test_Annotate(self):
+        """Test using an interface-specific Annotate function."""
+        def my_annotate(node, self=self):
+            node.Tag('annotation', self.node_string)
+
+        save_Annotate = SCons.Node.Annotate
+        SCons.Node.Annotate = my_annotate
+
+        try:
+            self.node_string = '#1'
+            n = SCons.Node.Node()
+            a = n.GetTag('annotation')
+            assert a == '#1', a
+
+            self.node_string = '#2'
+            n = SCons.Node.Node()
+            a = n.GetTag('annotation')
+            assert a == '#2', a
+        finally:
+            SCons.Node.Annotate = save_Annotate
+
+    def test_clear(self):
+        """Test clearing all cached state information."""
+        n = SCons.Node.Node()
+
+        n.set_state(3)
+        n.binfo = 'xyz'
+        n.includes = 'testincludes'
+        n.Tag('found_includes', {'testkey':'testvalue'})
+        n.implicit = 'testimplicit'
+
+        x = MyExecutor()
+        n.set_executor(x)
+
+        n.clear()
+
+        assert n.includes is None, n.includes
+        assert x.cleaned_up
+
+    def test_get_subst_proxy(self):
+        """Test the get_subst_proxy method."""
+        n = MyNode("test")
+
+        assert n.get_subst_proxy() == n, n.get_subst_proxy()
+
+    def test_new_binfo(self):
+        """Test the new_binfo() method"""
+        n = SCons.Node.Node()
+        result = n.new_binfo()
+        assert isinstance(result, SCons.Node.BuildInfoBase), result
+
+    def test_get_suffix(self):
+        """Test the base Node get_suffix() method"""
+        n = SCons.Node.Node()
+        s = n.get_suffix()
+        assert s == '', s
+
+    def test_postprocess(self):
+        """Test calling the base Node postprocess() method"""
+        n = SCons.Node.Node()
+        n.waiting_parents = set( ['foo','bar'] )
+
+        n.postprocess()
+        assert n.waiting_parents == set(), n.waiting_parents
+
+    def test_add_to_waiting_parents(self):
+        """Test the add_to_waiting_parents() method"""
+        n1 = SCons.Node.Node()
+        n2 = SCons.Node.Node()
+        assert n1.waiting_parents == set(), n1.waiting_parents
+        r = n1.add_to_waiting_parents(n2)
+        assert r == 1, r
+        assert n1.waiting_parents == set((n2,)), n1.waiting_parents
+        r = n1.add_to_waiting_parents(n2)
+        assert r == 0, r
+
+
+class NodeListTestCase(unittest.TestCase):
+    def test___str__(self):
+        """Test"""
+        n1 = MyNode("n1")
+        n2 = MyNode("n2")
+        n3 = MyNode("n3")
+        nl = SCons.Node.NodeList([n3, n2, n1])
+
+        l = [1]
+        ul = collections.UserList([2])
+        s = str(nl)
+        assert s == "['n3', 'n2', 'n1']", s
+
+        r = repr(nl)
+        r = re.sub('at (0[xX])?[0-9a-fA-F]+', 'at 0x', r)
+        # Don't care about ancestry: just leaf value of MyNode
+        r = re.sub('<.*?\.MyNode', '<MyNode', r)
+        # New-style classes report as "object"; classic classes report
+        # as "instance"...
+        r = re.sub("object", "instance", r)
+        l = ", ".join(["<MyNode instance at 0x>"]*3)
+        assert r == '[%s]' % l, r
+
+
+
+if __name__ == "__main__":
+    suite = unittest.TestSuite()
+    tclasses = [ BuildInfoBaseTestCase,
+                 NodeInfoBaseTestCase,
+                 NodeTestCase,
+                 NodeListTestCase ]
+    for tclass in tclasses:
+        names = unittest.getTestCaseNames(tclass, 'test_')
+        suite.addTests(list(map(tclass, names)))
+    TestUnit.run(suite)
+
+# Local Variables:
+# tab-width:4
+# indent-tabs-mode:nil
+# End:
+# vim: set expandtab tabstop=4 shiftwidth=4:
diff --git a/3rdParty/SCons/scons-3.0.1/engine/SCons/Node/Python.py b/3rdParty/SCons/scons-3.0.1/engine/SCons/Node/Python.py
new file mode 100644
index 0000000..8c47c97
--- /dev/null
+++ b/3rdParty/SCons/scons-3.0.1/engine/SCons/Node/Python.py
@@ -0,0 +1,171 @@
+"""scons.Node.Python
+
+Python nodes.
+
+"""
+
+#
+# __COPYRIGHT__
+#
+# 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 SCons.Node
+
+class ValueNodeInfo(SCons.Node.NodeInfoBase):
+    __slots__ = ('csig',)
+    current_version_id = 2
+
+    field_list = ['csig']
+
+    def str_to_node(self, s):
+        return Value(s)
+
+    def __getstate__(self):
+        """
+        Return all fields that shall be pickled. Walk the slots in the class
+        hierarchy and add those to the state dictionary. If a '__dict__' slot is
+        available, copy all entries to the dictionary. Also include the version
+        id, which is fixed for all instances of a class.
+        """
+        state = getattr(self, '__dict__', {}).copy()
+        for obj in type(self).mro():
+            for name in getattr(obj,'__slots__',()):
+                if hasattr(self, name):
+                    state[name] = getattr(self, name)
+
+        state['_version_id'] = self.current_version_id
+        try:
+            del state['__weakref__']
+        except KeyError:
+            pass
+
+        return state
+
+    def __setstate__(self, state):
+        """
+        Restore the attributes from a pickled state.
+        """
+        # TODO check or discard version
+        del state['_version_id']
+        for key, value in state.items():
+            if key not in ('__weakref__',):
+                setattr(self, key, value)
+
+
+class ValueBuildInfo(SCons.Node.BuildInfoBase):
+    __slots__ = ()
+    current_version_id = 2
+
+class Value(SCons.Node.Node):
+    """A class for Python variables, typically passed on the command line
+    or generated by a script, but not from a file or some other source.
+    """
+
+    NodeInfo = ValueNodeInfo
+    BuildInfo = ValueBuildInfo
+
+    def __init__(self, value, built_value=None):
+        SCons.Node.Node.__init__(self)
+        self.value = value
+        self.changed_since_last_build = 6
+        self.store_info = 0
+        if built_value is not None:
+            self.built_value = built_value
+
+    def str_for_display(self):
+        return repr(self.value)
+
+    def __str__(self):
+        return str(self.value)
+
+    def make_ready(self):
+        self.get_csig()
+
+    def build(self, **kw):
+        if not hasattr(self, 'built_value'):
+            SCons.Node.Node.build(self, **kw)
+
+    is_up_to_date = SCons.Node.Node.children_are_up_to_date
+
+    def is_under(self, dir):
+        # Make Value nodes get built regardless of
+        # what directory scons was run from. Value nodes
+        # are outside the filesystem:
+        return 1
+
+    def write(self, built_value):
+        """Set the value of the node."""
+        self.built_value = built_value
+
+    def read(self):
+        """Return the value. If necessary, the value is built."""
+        self.build()
+        if not hasattr(self, 'built_value'):
+            self.built_value = self.value
+        return self.built_value
+
+    def get_text_contents(self):
+        """By the assumption that the node.built_value is a
+        deterministic product of the sources, the contents of a Value
+        are the concatenation of all the contents of its sources.  As
+        the value need not be built when get_contents() is called, we
+        cannot use the actual node.built_value."""
+        ###TODO: something reasonable about universal newlines
+        contents = str(self.value)
+        for kid in self.children(None):
+            contents = contents + kid.get_contents().decode()
+        return contents
+
+    def get_contents(self):
+        text_contents = self.get_text_contents()
+        try:
+            return text_contents.encode()
+        except UnicodeDecodeError:
+            # Already encoded as python2 str are bytes
+            return text_contents
+
+
+    def changed_since_last_build(self, target, prev_ni):
+        cur_csig = self.get_csig()
+        try:
+            return cur_csig != prev_ni.csig
+        except AttributeError:
+            return 1
+
+    def get_csig(self, calc=None):
+        """Because we're a Python value node and don't have a real
+        timestamp, we get to ignore the calculator and just use the
+        value contents."""
+        try:
+            return self.ninfo.csig
+        except AttributeError:
+            pass
+        contents = self.get_contents()
+        self.get_ninfo().csig = contents
+        return contents
+
+# Local Variables:
+# tab-width:4
+# indent-tabs-mode:nil
+# End:
+# vim: set expandtab tabstop=4 shiftwidth=4:
diff --git a/3rdParty/SCons/scons-3.0.1/engine/SCons/Node/PythonTests.py b/3rdParty/SCons/scons-3.0.1/engine/SCons/Node/PythonTests.py
new file mode 100644
index 0000000..346542b
--- /dev/null
+++ b/3rdParty/SCons/scons-3.0.1/engine/SCons/Node/PythonTests.py
@@ -0,0 +1,131 @@
+#
+# __COPYRIGHT__
+#
+# 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 sys
+import unittest
+
+import TestUnit
+
+import SCons.Errors
+import SCons.Node.Python
+
+class ValueTestCase(unittest.TestCase):
+
+    def test_Value(self):
+        """Test creating a Value() object
+        """
+        v1 = SCons.Node.Python.Value('a')
+        assert v1.value == 'a', v1.value
+
+        value2 = 'a'
+        v2 = SCons.Node.Python.Value(value2)
+        assert v2.value == value2, v2.value
+        assert v2.value is value2, v2.value
+
+        assert not v1 is v2
+        assert v1.value == v2.value
+
+        v3 = SCons.Node.Python.Value('c', 'cb')
+        assert v3.built_value == 'cb'
+
+    def test_build(self):
+        """Test "building" a Value Node
+        """
+        class fake_executor(object):
+            def __call__(self, node):
+                node.write('faked')
+
+        v1 = SCons.Node.Python.Value('b', 'built')
+        v1.executor = fake_executor()
+        v1.build()
+        assert v1.built_value == 'built', v1.built_value
+
+        v2 = SCons.Node.Python.Value('b')
+        v2.executor = fake_executor()
+        v2.build()
+        assert v2.built_value == 'faked', v2.built_value
+
+    def test_read(self):
+        """Test the Value.read() method
+        """
+        v1 = SCons.Node.Python.Value('a')
+        x = v1.read()
+        assert x == 'a', x
+
+    def test_write(self):
+        """Test the Value.write() method
+        """
+        v1 = SCons.Node.Python.Value('a')
+        assert v1.value == 'a', v1.value
+        assert not hasattr(v1, 'built_value')
+
+        v1.write('new')
+        assert v1.value == 'a', v1.value
+        assert v1.built_value == 'new', v1.built_value
+
+    def test_get_csig(self):
+        """Test calculating the content signature of a Value() object
+        """
+        v1 = SCons.Node.Python.Value('aaa')
+        csig = v1.get_csig(None)
+        assert csig.decode() == 'aaa', csig
+
+        v2 = SCons.Node.Python.Value(7)
+        csig = v2.get_csig(None)
+        assert csig.decode() == '7', csig
+
+        v3 = SCons.Node.Python.Value(None)
+        csig = v3.get_csig(None)
+        assert csig.decode() == 'None', csig
+
+class ValueNodeInfoTestCase(unittest.TestCase):
+    def test___init__(self):
+        """Test ValueNodeInfo initialization"""
+        vvv = SCons.Node.Python.Value('vvv')
+        ni = SCons.Node.Python.ValueNodeInfo()
+
+class ValueBuildInfoTestCase(unittest.TestCase):
+    def test___init__(self):
+        """Test ValueBuildInfo initialization"""
+        vvv = SCons.Node.Python.Value('vvv')
+        bi = SCons.Node.Python.ValueBuildInfo()
+
+if __name__ == "__main__":
+    suite = unittest.TestSuite()
+    tclasses = [
+        ValueTestCase,
+        ValueBuildInfoTestCase,
+        ValueNodeInfoTestCase,
+    ]
+    for tclass in tclasses:
+        names = unittest.getTestCaseNames(tclass, 'test_')
+        suite.addTests(list(map(tclass, names)))
+    TestUnit.run(suite)
+
+# Local Variables:
+# tab-width:4
+# indent-tabs-mode:nil
+# End:
+# vim: set expandtab tabstop=4 shiftwidth=4:
diff --git a/3rdParty/SCons/scons-3.0.1/engine/SCons/Node/__init__.py b/3rdParty/SCons/scons-3.0.1/engine/SCons/Node/__init__.py
new file mode 100644
index 0000000..e186752
--- /dev/null
+++ b/3rdParty/SCons/scons-3.0.1/engine/SCons/Node/__init__.py
@@ -0,0 +1,1734 @@
+"""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."
+
+"""
+
+from __future__ import print_function
+
+#
+# __COPYRIGHT__
+#
+# 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 collections
+import copy
+from itertools import chain
+
+import SCons.Debug
+from SCons.Debug import logInstanceCreation
+import SCons.Executor
+import SCons.Memoize
+import SCons.Util
+
+from SCons.Debug import Trace
+
+from SCons.compat import with_metaclass, NoSlotsPyPy
+
+print_duplicate = 0
+
+def classname(obj):
+    return str(obj.__class__).split('.')[-1]
+
+# Set to false if we're doing a dry run. There's more than one of these
+# little treats
+do_store_info = True
+
+# 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.
+no_state = 0
+pending = 1
+executing = 2
+up_to_date = 3
+executed = 4
+failed = 5
+
+StateString = {
+    0 : "no_state",
+    1 : "pending",
+    2 : "executing",
+    3 : "up_to_date",
+    4 : "executed",
+    5 : "failed",
+}
+
+# controls whether implicit dependencies 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
+
+# A variable that can be set to an interface-specific function be called
+# to annotate a Node with information about its creation.
+def do_nothing(node): pass
+
+Annotate = do_nothing
+
+# Gets set to 'True' if we're running in interactive mode. Is
+# currently used to release parts of a target's info during
+# clean builds and update runs (see release_target_info).
+interactive = False
+
+def is_derived_none(node):
+    raise NotImplementedError
+
+def is_derived_node(node):
+    """
+        Returns true if this node is derived (i.e. built).
+    """
+    return node.has_builder() or node.side_effect
+
+_is_derived_map = {0 : is_derived_none,
+                   1 : is_derived_node}
+
+def exists_none(node):
+    raise NotImplementedError
+
+def exists_always(node):
+    return 1
+
+def exists_base(node):
+    return node.stat() is not None
+
+def exists_entry(node):
+    """Return if the Entry exists.  Check the file system to see
+    what we should turn into first.  Assume a file if there's no
+    directory."""
+    node.disambiguate()
+    return _exists_map[node._func_exists](node)
+
+def exists_file(node):
+    # Duplicate from source path if we are set up to do this.
+    if node.duplicate and not node.is_derived() and not node.linked:
+        src = node.srcnode()
+        if src is not node:
+            # At this point, src is meant to be copied in a variant directory.
+            src = src.rfile()
+            if src.get_abspath() != node.get_abspath():
+                if src.exists():
+                    node.do_duplicate(src)
+                    # Can't return 1 here because the duplication might
+                    # not actually occur if the -n option is being used.
+                else:
+                    # The source file does not exist.  Make sure no old
+                    # copy remains in the variant directory.
+                    if print_duplicate:
+                        print("dup: no src for %s, unlinking old variant copy"%self)
+                    if exists_base(node) or node.islink():
+                        node.fs.unlink(node.get_internal_path())
+                    # Return None explicitly because the Base.exists() call
+                    # above will have cached its value if the file existed.
+                    return None
+    return exists_base(node)
+
+_exists_map = {0 : exists_none,
+               1 : exists_always,
+               2 : exists_base,
+               3 : exists_entry,
+               4 : exists_file}
+
+
+def rexists_none(node):
+    raise NotImplementedError
+
+def rexists_node(node):
+    return node.exists()
+
+def rexists_base(node):
+    return node.rfile().exists()
+
+_rexists_map = {0 : rexists_none,
+                1 : rexists_node,
+                2 : rexists_base}
+
+def get_contents_none(node):
+    raise NotImplementedError
+
+def get_contents_entry(node):
+    """Fetch the contents of the entry.  Returns the exact binary
+    contents of the file."""
+    try:
+        node = node.disambiguate(must_exist=1)
+    except SCons.Errors.UserError:
+        # There was nothing on disk with which to disambiguate
+        # this entry.  Leave it as an Entry, but return a null
+        # string so calls to get_contents() in emitters and the
+        # like (e.g. in qt.py) don't have to disambiguate by hand
+        # or catch the exception.
+        return ''
+    else:
+        return _get_contents_map[node._func_get_contents](node)
+
+def get_contents_dir(node):
+    """Return content signatures and names of all our children
+    separated by new-lines. Ensure that the nodes are sorted."""
+    contents = []
+    for n in sorted(node.children(), key=lambda t: t.name):
+        contents.append('%s %s\n' % (n.get_csig(), n.name))
+    return ''.join(contents)
+
+def get_contents_file(node):
+    if not node.rexists():
+        return b''
+    fname = node.rfile().get_abspath()
+    try:
+        with open(fname, "rb") as fp:
+            contents = fp.read()
+    except EnvironmentError as e:
+        if not e.filename:
+            e.filename = fname
+        raise
+    return contents
+
+_get_contents_map = {0 : get_contents_none,
+                     1 : get_contents_entry,
+                     2 : get_contents_dir,
+                     3 : get_contents_file}
+
+def target_from_source_none(node, prefix, suffix, splitext):
+    raise NotImplementedError
+
+def target_from_source_base(node, prefix, suffix, splitext):
+    return node.dir.Entry(prefix + splitext(node.name)[0] + suffix)
+
+_target_from_source_map = {0 : target_from_source_none,
+                           1 : target_from_source_base}
+
+#
+# The new decider subsystem for Nodes
+#
+# We would set and overwrite the changed_since_last_build function
+# before, but for being able to use slots (less memory!) we now have
+# a dictionary of the different decider functions. Then in the Node
+# subclasses we simply store the index to the decider that should be
+# used by it.
+#
+
+#
+# First, the single decider functions
+#
+def changed_since_last_build_node(node, target, prev_ni):
+    """
+
+    Must be overridden in a specific subclass to return True if this
+    Node (a dependency) has changed since the last time it was used
+    to build the specified target.  prev_ni is this Node's state (for
+    example, its file timestamp, length, maybe content signature)
+    as of the last time the target was built.
+
+    Note that this method is called through the dependency, not the
+    target, because a dependency Node must be able to use its own
+    logic to decide if it changed.  For example, File Nodes need to
+    obey if we're configured to use timestamps, but Python Value Nodes
+    never use timestamps and always use the content.  If this method
+    were called through the target, then each Node's implementation
+    of this method would have to have more complicated logic to
+    handle all the different Node types on which it might depend.
+    """
+    raise NotImplementedError
+
+def changed_since_last_build_alias(node, target, prev_ni):
+    cur_csig = node.get_csig()
+    try:
+        return cur_csig != prev_ni.csig
+    except AttributeError:
+        return 1
+
+def changed_since_last_build_entry(node, target, prev_ni):
+    node.disambiguate()
+    return _decider_map[node.changed_since_last_build](node, target, prev_ni)
+
+def changed_since_last_build_state_changed(node, target, prev_ni):
+    return (node.state != SCons.Node.up_to_date)
+
+def decide_source(node, target, prev_ni):
+    return target.get_build_env().decide_source(node, target, prev_ni)
+
+def decide_target(node, target, prev_ni):
+    return target.get_build_env().decide_target(node, target, prev_ni)
+
+def changed_since_last_build_python(node, target, prev_ni):
+    cur_csig = node.get_csig()
+    try:
+        return cur_csig != prev_ni.csig
+    except AttributeError:
+        return 1
+
+
+#
+# Now, the mapping from indices to decider functions
+#
+_decider_map = {0 : changed_since_last_build_node,
+               1 : changed_since_last_build_alias,
+               2 : changed_since_last_build_entry,
+               3 : changed_since_last_build_state_changed,
+               4 : decide_source,
+               5 : decide_target,
+               6 : changed_since_last_build_python}
+
+do_store_info = True
+
+#
+# The new store_info subsystem for Nodes
+#
+# We would set and overwrite the store_info function
+# before, but for being able to use slots (less memory!) we now have
+# a dictionary of the different functions. Then in the Node
+# subclasses we simply store the index to the info method that should be
+# used by it.
+#
+
+#
+# First, the single info functions
+#
+
+def store_info_pass(node):
+    pass
+
+def store_info_file(node):
+    # Merge our build information into the already-stored entry.
+    # This accommodates "chained builds" where a file that's a target
+    # in one build (SConstruct file) is a source in a different build.
+    # See test/chained-build.py for the use case.
+    if do_store_info:
+        node.dir.sconsign().store_info(node.name, node)
+
+
+store_info_map = {0 : store_info_pass,
+                  1 : store_info_file}
+
+# Classes for signature info for Nodes.
+
+class NodeInfoBase(object):
+    """
+    The generic base class for signature information for a Node.
+
+    Node subclasses should subclass NodeInfoBase to provide their own
+    logic for dealing with their own Node-specific signature information.
+    """
+    __slots__ = ('__weakref__',)
+    current_version_id = 2
+
+    def update(self, node):
+        try:
+            field_list = self.field_list
+        except AttributeError:
+            return
+        for f in field_list:
+            try:
+                delattr(self, f)
+            except AttributeError:
+                pass
+            try:
+                func = getattr(node, 'get_' + f)
+            except AttributeError:
+                pass
+            else:
+                setattr(self, f, func())
+
+    def convert(self, node, val):
+        pass
+
+    def merge(self, other):
+        """
+        Merge the fields of another object into this object. Already existing
+        information is overwritten by the other instance's data.
+        WARNING: If a '__dict__' slot is added, it should be updated instead of
+        replaced.
+        """
+        state = other.__getstate__()
+        self.__setstate__(state)
+    def format(self, field_list=None, names=0):
+        if field_list is None:
+            try:
+                field_list = self.field_list
+            except AttributeError:
+                field_list = list(getattr(self, '__dict__', {}).keys())
+                for obj in type(self).mro():
+                    for slot in getattr(obj, '__slots__', ()):
+                        if slot not in ('__weakref__', '__dict__'):
+                            field_list.append(slot)
+                field_list.sort()
+        fields = []
+        for field in field_list:
+            try:
+                f = getattr(self, field)
+            except AttributeError:
+                f = None
+            f = str(f)
+            if names:
+                f = field + ': ' + f
+            fields.append(f)
+        return fields
+
+    def __getstate__(self):
+        """
+        Return all fields that shall be pickled. Walk the slots in the class
+        hierarchy and add those to the state dictionary. If a '__dict__' slot is
+        available, copy all entries to the dictionary. Also include the version
+        id, which is fixed for all instances of a class.
+        """
+        state = getattr(self, '__dict__', {}).copy()
+        for obj in type(self).mro():
+            for name in getattr(obj,'__slots__',()):
+                if hasattr(self, name):
+                    state[name] = getattr(self, name)
+
+        state['_version_id'] = self.current_version_id
+        try:
+            del state['__weakref__']
+        except KeyError:
+            pass
+        return state
+
+    def __setstate__(self, state):
+        """
+        Restore the attributes from a pickled state. The version is discarded.
+        """
+        # TODO check or discard version
+        del state['_version_id']
+
+        for key, value in state.items():
+            if key not in ('__weakref__',):
+                setattr(self, key, value)
+
+
+class BuildInfoBase(object):
+    """
+    The generic base class for build information for a Node.
+
+    This is what gets stored in a .sconsign file for each target file.
+    It contains a NodeInfo instance for this node (signature information
+    that's specific to the type of Node) and direct attributes for the
+    generic build stuff we have to track:  sources, explicit dependencies,
+    implicit dependencies, and action information.
+    """
+    __slots__ = ("bsourcesigs", "bdependsigs", "bimplicitsigs", "bactsig",
+                 "bsources", "bdepends", "bact", "bimplicit", "__weakref__")
+    current_version_id = 2
+
+    def __init__(self):
+        # Create an object attribute from the class attribute so it ends up
+        # in the pickled data in the .sconsign file.
+        self.bsourcesigs = []
+        self.bdependsigs = []
+        self.bimplicitsigs = []
+        self.bactsig = None
+
+    def merge(self, other):
+        """
+        Merge the fields of another object into this object. Already existing
+        information is overwritten by the other instance's data.
+        WARNING: If a '__dict__' slot is added, it should be updated instead of
+        replaced.
+        """
+        state = other.__getstate__()
+        self.__setstate__(state)
+
+    def __getstate__(self):
+        """
+        Return all fields that shall be pickled. Walk the slots in the class
+        hierarchy and add those to the state dictionary. If a '__dict__' slot is
+        available, copy all entries to the dictionary. Also include the version
+        id, which is fixed for all instances of a class.
+        """
+        state = getattr(self, '__dict__', {}).copy()
+        for obj in type(self).mro():
+            for name in getattr(obj,'__slots__',()):
+                if hasattr(self, name):
+                    state[name] = getattr(self, name)
+
+        state['_version_id'] = self.current_version_id
+        try:
+            del state['__weakref__']
+        except KeyError:
+            pass
+        return state
+
+    def __setstate__(self, state):
+        """
+        Restore the attributes from a pickled state.
+        """
+        # TODO check or discard version
+        del state['_version_id']
+        for key, value in state.items():
+            if key not in ('__weakref__',):
+                setattr(self, key, value)
+
+
+class Node(object, with_metaclass(NoSlotsPyPy)):
+    """The base Node class, for entities that we know how to
+    build, or use to build other Nodes.
+    """
+
+    __slots__ = ['sources',
+                 'sources_set',
+                 '_specific_sources',
+                 'depends',
+                 'depends_set',
+                 'ignore',
+                 'ignore_set',
+                 'prerequisites',
+                 'implicit',
+                 'waiting_parents',
+                 'waiting_s_e',
+                 'ref_count',
+                 'wkids',
+                 'env',
+                 'state',
+                 'precious',
+                 'noclean',
+                 'nocache',
+                 'cached',
+                 'always_build',
+                 'includes',
+                 'attributes',
+                 'side_effect',
+                 'side_effects',
+                 'linked',
+                 '_memo',
+                 'executor',
+                 'binfo',
+                 'ninfo',
+                 'builder',
+                 'is_explicit',
+                 'implicit_set',
+                 'changed_since_last_build',
+                 'store_info',
+                 'pseudo',
+                 '_tags',
+                 '_func_is_derived',
+                 '_func_exists',
+                 '_func_rexists',
+                 '_func_get_contents',
+                 '_func_target_from_source']
+
+    class Attrs(object):
+        __slots__ = ('shared', '__dict__')
+
+
+    def __init__(self):
+        if SCons.Debug.track_instances: logInstanceCreation(self, 'Node.Node')
+        # Note that we no longer explicitly initialize a self.builder
+        # attribute to None here.  That's because the self.builder
+        # attribute may be created on-the-fly later by a subclass (the
+        # canonical example being a builder to fetch a file from a
+        # source code system like CVS or Subversion).
+
+        # Each list of children that we maintain is accompanied by a
+        # dictionary used to look up quickly whether a node is already
+        # present in the list.  Empirical tests showed that it was
+        # fastest to maintain them as side-by-side Node attributes in
+        # this way, instead of wrapping up each list+dictionary pair in
+        # a class.  (Of course, we could always still do that in the
+        # future if we had a good reason to...).
+        self.sources = []       # source files used to build node
+        self.sources_set = set()
+        self._specific_sources = False
+        self.depends = []       # explicit dependencies (from Depends)
+        self.depends_set = set()
+        self.ignore = []        # dependencies to ignore
+        self.ignore_set = set()
+        self.prerequisites = None
+        self.implicit = None    # implicit (scanned) dependencies (None means not scanned yet)
+        self.waiting_parents = set()
+        self.waiting_s_e = set()
+        self.ref_count = 0
+        self.wkids = None       # Kids yet to walk, when it's an array
+
+        self.env = None
+        self.state = no_state
+        self.precious = None
+        self.pseudo = False
+        self.noclean = 0
+        self.nocache = 0
+        self.cached = 0 # is this node pulled from cache?
+        self.always_build = None
+        self.includes = None
+        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
+        self.linked = 0 # is this node linked to the variant directory?
+        self.changed_since_last_build = 0
+        self.store_info = 0
+        self._tags = None
+        self._func_is_derived = 1
+        self._func_exists = 1
+        self._func_rexists = 1
+        self._func_get_contents = 0
+        self._func_target_from_source = 0
+
+        self.clear_memoized_values()
+
+        # Let the interface in which the build engine is embedded
+        # annotate this Node with its own info (like a description of
+        # what line in what file created the node, for example).
+        Annotate(self)
+
+    def disambiguate(self, must_exist=None):
+        return self
+
+    def get_suffix(self):
+        return ''
+
+    @SCons.Memoize.CountMethodCall
+    def get_build_env(self):
+        """Fetch the appropriate Environment to build this node.
+        """
+        try:
+            return self._memo['get_build_env']
+        except KeyError:
+            pass
+        result = self.get_executor().get_build_env()
+        self._memo['get_build_env'] = result
+        return result
+
+    def get_build_scanner_path(self, scanner):
+        """Fetch the appropriate scanner path for this node."""
+        return self.get_executor().get_build_scanner_path(scanner)
+
+    def set_executor(self, executor):
+        """Set the action executor for this node."""
+        self.executor = executor
+
+    def get_executor(self, create=1):
+        """Fetch the action executor for this node.  Create one if
+        there isn't already one, and requested to do so."""
+        try:
+            executor = self.executor
+        except AttributeError:
+            if not create:
+                raise
+            try:
+                act = self.builder.action
+            except AttributeError:
+                executor = SCons.Executor.Null(targets=[self])
+            else:
+                executor = SCons.Executor.Executor(act,
+                                                   self.env or self.builder.env,
+                                                   [self.builder.overrides],
+                                                   [self],
+                                                   self.sources)
+            self.executor = executor
+        return executor
+
+    def executor_cleanup(self):
+        """Let the executor clean up any cached information."""
+        try:
+            executor = self.get_executor(create=None)
+        except AttributeError:
+            pass
+        else:
+            if executor is not None:
+                executor.cleanup()
+
+    def reset_executor(self):
+        "Remove cached executor; forces recompute when needed."
+        try:
+            delattr(self, 'executor')
+        except AttributeError:
+            pass
+
+    def push_to_cache(self):
+        """Try to push a node into a cache
+        """
+        pass
+
+    def retrieve_from_cache(self):
+        """Try to retrieve the node's content from a cache
+
+        This method is called from multiple threads in a parallel build,
+        so only do thread safe stuff here. Do thread unsafe stuff in
+        built().
+
+        Returns true if the node was successfully retrieved.
+        """
+        return 0
+
+    #
+    # Taskmaster interface subsystem
+    #
+
+    def make_ready(self):
+        """Get a Node ready for evaluation.
+
+        This is called before the Taskmaster decides if the Node is
+        up-to-date or not.  Overriding this method allows for a Node
+        subclass to be disambiguated if necessary, or for an implicit
+        source builder to be attached.
+        """
+        pass
+
+    def prepare(self):
+        """Prepare for this Node to be built.
+
+        This is called after the Taskmaster has decided that the Node
+        is out-of-date and must be rebuilt, but before actually calling
+        the method to build the Node.
+
+        This default implementation checks that explicit or implicit
+        dependencies either exist or are derived, and initializes the
+        BuildInfo structure that will hold the information about how
+        this node is, uh, built.
+
+        (The existence of source files is checked separately by the
+        Executor, which aggregates checks for all of the targets built
+        by a specific action.)
+
+        Overriding this method allows for for a Node subclass to remove
+        the underlying file from the file system.  Note that subclass
+        methods should call this base class method to get the child
+        check and the BuildInfo structure.
+        """
+        if self.depends is not None:
+            for d in self.depends:
+                if d.missing():
+                    msg = "Explicit dependency `%s' not found, needed by target `%s'."
+                    raise SCons.Errors.StopError(msg % (d, self))
+        if self.implicit is not None:
+            for i in self.implicit:
+                if i.missing():
+                    msg = "Implicit dependency `%s' not found, needed by target `%s'."
+                    raise SCons.Errors.StopError(msg % (i, self))
+        self.binfo = self.get_binfo()
+
+    def build(self, **kw):
+        """Actually build the node.
+
+        This is called by the Taskmaster after it's decided that the
+        Node is out-of-date and must be rebuilt, and after the prepare()
+        method has gotten everything, uh, prepared.
+
+        This method is called from multiple threads in a parallel build,
+        so only do thread safe stuff here. Do thread unsafe stuff
+        in built().
+
+        """
+        try:
+            self.get_executor()(self, **kw)
+        except SCons.Errors.BuildError as e:
+            e.node = self
+            raise
+
+    def built(self):
+        """Called just after this node is successfully built."""
+
+        # Clear the implicit dependency caches of any Nodes
+        # waiting for this Node to be built.
+        for parent in self.waiting_parents:
+            parent.implicit = None
+
+        self.clear()
+
+        if self.pseudo:
+            if self.exists():
+                raise SCons.Errors.UserError("Pseudo target " + str(self) + " must not exist")
+        else:
+            if not self.exists() and do_store_info:
+                SCons.Warnings.warn(SCons.Warnings.TargetNotBuiltWarning,
+                                    "Cannot find target " + str(self) + " after building")
+        self.ninfo.update(self)
+
+    def visited(self):
+        """Called just after this node has been visited (with or
+        without a build)."""
+        try:
+            binfo = self.binfo
+        except AttributeError:
+            # Apparently this node doesn't need build info, so
+            # don't bother calculating or storing it.
+            pass
+        else:
+            self.ninfo.update(self)
+            SCons.Node.store_info_map[self.store_info](self)
+
+    def release_target_info(self):
+        """Called just after this node has been marked
+         up-to-date or was built completely.
+
+         This is where we try to release as many target node infos
+         as possible for clean builds and update runs, in order
+         to minimize the overall memory consumption.
+
+         By purging attributes that aren't needed any longer after
+         a Node (=File) got built, we don't have to care that much how
+         many KBytes a Node actually requires...as long as we free
+         the memory shortly afterwards.
+
+         @see: built() and File.release_target_info()
+         """
+        pass
+
+    #
+    #
+    #
+
+    def add_to_waiting_s_e(self, node):
+        self.waiting_s_e.add(node)
+
+    def add_to_waiting_parents(self, node):
+        """
+        Returns the number of nodes added to our waiting parents list:
+        1 if we add a unique waiting parent, 0 if not.  (Note that the
+        returned values are intended to be used to increment a reference
+        count, so don't think you can "clean up" this function by using
+        True and False instead...)
+        """
+        wp = self.waiting_parents
+        if node in wp:
+            return 0
+        wp.add(node)
+        return 1
+
+    def postprocess(self):
+        """Clean up anything we don't need to hang onto after we've
+        been built."""
+        self.executor_cleanup()
+        self.waiting_parents = set()
+
+    def clear(self):
+        """Completely clear a Node of all its cached state (so that it
+        can be re-evaluated by interfaces that do continuous integration
+        builds).
+        """
+        # The del_binfo() call here isn't necessary for normal execution,
+        # but is for interactive mode, where we might rebuild the same
+        # target and need to start from scratch.
+        self.del_binfo()
+        self.clear_memoized_values()
+        self.ninfo = self.new_ninfo()
+        self.executor_cleanup()
+        try:
+            delattr(self, '_calculated_sig')
+        except AttributeError:
+            pass
+        self.includes = None
+
+    def clear_memoized_values(self):
+        self._memo = {}
+
+    def builder_set(self, builder):
+        self.builder = builder
+        try:
+            del self.executor
+        except AttributeError:
+            pass
+
+    def has_builder(self):
+        """Return whether this Node has a builder or not.
+
+        In Boolean tests, this turns out to be a *lot* more efficient
+        than simply examining the builder attribute directly ("if
+        node.builder: ..."). When the builder attribute is examined
+        directly, it ends up calling __getattr__ for both the __len__
+        and __nonzero__ attributes on instances of our Builder Proxy
+        class(es), generating a bazillion extra calls and slowing
+        things down immensely.
+        """
+        try:
+            b = self.builder
+        except AttributeError:
+            # There was no explicit builder for this Node, so initialize
+            # the self.builder attribute to None now.
+            b = self.builder = None
+        return b is not None
+
+    def set_explicit(self, is_explicit):
+        self.is_explicit = is_explicit
+
+    def has_explicit_builder(self):
+        """Return whether this Node has an explicit builder
+
+        This allows an internal Builder created by SCons to be marked
+        non-explicit, so that it can be overridden by an explicit
+        builder that the user supplies (the canonical example being
+        directories)."""
+        try:
+            return self.is_explicit
+        except AttributeError:
+            self.is_explicit = None
+            return self.is_explicit
+
+    def get_builder(self, default_builder=None):
+        """Return the set builder, or a specified default value"""
+        try:
+            return self.builder
+        except AttributeError:
+            return default_builder
+
+    multiple_side_effect_has_builder = has_builder
+
+    def is_derived(self):
+        """
+        Returns true if this node is derived (i.e. built).
+
+        This should return true only for nodes whose path should be in
+        the variant directory when duplicate=0 and should contribute their build
+        signatures when they are used as source files to other derived files. For
+        example: source with source builders are not derived in this sense,
+        and hence should not return true.
+        """
+        return _is_derived_map[self._func_is_derived](self)
+
+    def alter_targets(self):
+        """Return a list of alternate targets for this Node.
+        """
+        return [], None
+
+    def get_found_includes(self, env, scanner, path):
+        """Return the scanned include lines (implicit dependencies)
+        found in this node.
+
+        The default is no implicit dependencies.  We expect this method
+        to be overridden by any subclass that can be scanned for
+        implicit dependencies.
+        """
+        return []
+
+    def get_implicit_deps(self, env, initial_scanner, path_func, kw = {}):
+        """Return a list of implicit dependencies for this node.
+
+        This method exists to handle recursive invocation of the scanner
+        on the implicit dependencies returned by the scanner, if the
+        scanner's recursive flag says that we should.
+        """
+        nodes = [self]
+        seen = set(nodes)
+        dependencies = []
+        path_memo = {}
+
+        root_node_scanner = self._get_scanner(env, initial_scanner, None, kw)
+
+        while nodes:
+            node = nodes.pop(0)
+
+            scanner = node._get_scanner(env, initial_scanner, root_node_scanner, kw)
+            if not scanner:
+                continue
+
+            try:
+                path = path_memo[scanner]
+            except KeyError:
+                path = path_func(scanner)
+                path_memo[scanner] = path
+
+            included_deps = [x for x in node.get_found_includes(env, scanner, path) if x not in seen]
+            if included_deps:
+                dependencies.extend(included_deps)
+                seen.update(included_deps)
+                nodes.extend(scanner.recurse_nodes(included_deps))
+
+        return dependencies
+
+    def _get_scanner(self, env, initial_scanner, root_node_scanner, kw):
+        if initial_scanner:
+            # handle explicit scanner case
+            scanner = initial_scanner.select(self)
+        else:
+            # handle implicit scanner case
+            scanner = self.get_env_scanner(env, kw)
+            if scanner:
+                scanner = scanner.select(self)
+
+        if not scanner:
+            # no scanner could be found for the given node's scanner key;
+            # thus, make an attempt at using a default.
+            scanner = root_node_scanner
+
+        return scanner
+
+    def get_env_scanner(self, env, kw={}):
+        return env.get_scanner(self.scanner_key())
+
+    def get_target_scanner(self):
+        return self.builder.target_scanner
+
+    def get_source_scanner(self, node):
+        """Fetch the source scanner for the specified node
+
+        NOTE:  "self" is the target being built, "node" is
+        the source file for which we want to fetch the scanner.
+
+        Implies self.has_builder() is true; again, expect to only be
+        called from locations where this is already verified.
+
+        This function may be called very often; it attempts to cache
+        the scanner found to improve performance.
+        """
+        scanner = None
+        try:
+            scanner = self.builder.source_scanner
+        except AttributeError:
+            pass
+        if not scanner:
+            # The builder didn't have an explicit scanner, so go look up
+            # a scanner from env['SCANNERS'] based on the node's scanner
+            # key (usually the file extension).
+            scanner = self.get_env_scanner(self.get_build_env())
+        if scanner:
+            scanner = scanner.select(node)
+        return scanner
+
+    def add_to_implicit(self, deps):
+        if not hasattr(self, 'implicit') or self.implicit is None:
+            self.implicit = []
+            self.implicit_set = set()
+            self._children_reset()
+        self._add_child(self.implicit, self.implicit_set, deps)
+
+    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 self.implicit is not None:
+            return
+        self.implicit = []
+        self.implicit_set = set()
+        self._children_reset()
+        if not self.has_builder():
+            return
+
+        build_env = self.get_build_env()
+        executor = self.get_executor()
+
+        # Here's where we implement --implicit-cache.
+        if implicit_cache and not implicit_deps_changed:
+            implicit = self.get_stored_implicit()
+            if implicit is not None:
+                # We now add the implicit dependencies returned from the
+                # stored .sconsign entry to have already been converted
+                # to Nodes for us.  (We used to run them through a
+                # source_factory function here.)
+
+                # Update all of the targets with them.  This
+                # essentially short-circuits an N*M scan of the
+                # sources for each individual target, which is a hell
+                # of a lot more efficient.
+                for tgt in executor.get_all_targets():
+                    tgt.add_to_implicit(implicit)
+
+                if implicit_deps_unchanged or self.is_up_to_date():
+                    return
+                # one of this node's sources has changed,
+                # so we must recalculate the implicit deps for all targets
+                for tgt in executor.get_all_targets():
+                    tgt.implicit = []
+                    tgt.implicit_set = set()
+
+        # Have the executor scan the sources.
+        executor.scan_sources(self.builder.source_scanner)
+
+        # If there's a target scanner, have the executor scan the target
+        # node itself and associated targets that might be built.
+        scanner = self.get_target_scanner()
+        if scanner:
+            executor.scan_targets(scanner)
+
+    def scanner_key(self):
+        return None
+
+    def select_scanner(self, scanner):
+        """Selects a scanner for this Node.
+
+        This is a separate method so it can be overridden by Node
+        subclasses (specifically, Node.FS.Dir) that *must* use their
+        own Scanner and don't select one the Scanner.Selector that's
+        configured for the target.
+        """
+        return scanner.select(self)
+
+    def env_set(self, env, safe=0):
+        if safe and self.env:
+            return
+        self.env = env
+
+    #
+    # SIGNATURE SUBSYSTEM
+    #
+
+    NodeInfo = NodeInfoBase
+    BuildInfo = BuildInfoBase
+
+    def new_ninfo(self):
+        ninfo = self.NodeInfo()
+        return ninfo
+
+    def get_ninfo(self):
+        try:
+            return self.ninfo
+        except AttributeError:
+            self.ninfo = self.new_ninfo()
+            return self.ninfo
+
+    def new_binfo(self):
+        binfo = self.BuildInfo()
+        return binfo
+
+    def get_binfo(self):
+        """
+        Fetch a node's build information.
+
+        node - the node whose sources will be collected
+        cache - alternate node to use for the signature cache
+        returns - the build signature
+
+        This no longer handles the recursive descent of the
+        node's children's signatures.  We expect that they're
+        already built and updated by someone else, if that's
+        what's wanted.
+        """
+        try:
+            return self.binfo
+        except AttributeError:
+            pass
+
+        binfo = self.new_binfo()
+        self.binfo = binfo
+
+        executor = self.get_executor()
+        ignore_set = self.ignore_set
+
+        if self.has_builder():
+            binfo.bact = str(executor)
+            binfo.bactsig = SCons.Util.MD5signature(executor.get_contents())
+
+        if self._specific_sources:
+            sources = [ s for s in self.sources if not s in ignore_set]
+
+        else:
+            sources = executor.get_unignored_sources(self, self.ignore)
+
+        seen = set()
+        binfo.bsources = [s for s in sources if s not in seen and not seen.add(s)]
+        binfo.bsourcesigs = [s.get_ninfo() for s in binfo.bsources]
+
+
+        binfo.bdepends = self.depends
+        binfo.bdependsigs = [d.get_ninfo() for d in self.depends if d not in ignore_set]
+
+        binfo.bimplicit = self.implicit or []
+        binfo.bimplicitsigs = [i.get_ninfo() for i in binfo.bimplicit if i not in ignore_set]
+
+
+        return binfo
+
+    def del_binfo(self):
+        """Delete the build info from this node."""
+        try:
+            delattr(self, 'binfo')
+        except AttributeError:
+            pass
+
+    def get_csig(self):
+        try:
+            return self.ninfo.csig
+        except AttributeError:
+            ninfo = self.get_ninfo()
+            ninfo.csig = SCons.Util.MD5signature(self.get_contents())
+            return self.ninfo.csig
+
+    def get_cachedir_csig(self):
+        return self.get_csig()
+
+    def get_stored_info(self):
+        return None
+
+    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 set_pseudo(self, pseudo = True):
+        """Set the Node's precious value."""
+        self.pseudo = pseudo
+
+    def set_noclean(self, noclean = 1):
+        """Set the Node's noclean value."""
+        # Make sure noclean is an integer so the --debug=stree
+        # output in Util.py can use it as an index.
+        self.noclean = noclean and 1 or 0
+
+    def set_nocache(self, nocache = 1):
+        """Set the Node's nocache value."""
+        # Make sure nocache is an integer so the --debug=stree
+        # output in Util.py can use it as an index.
+        self.nocache = nocache and 1 or 0
+
+    def set_always_build(self, always_build = 1):
+        """Set the Node's always_build value."""
+        self.always_build = always_build
+
+    def exists(self):
+        """Does this node exists?"""
+        return _exists_map[self._func_exists](self)
+
+    def rexists(self):
+        """Does this node exist locally or in a repositiory?"""
+        # There are no repositories by default:
+        return _rexists_map[self._func_rexists](self)
+
+    def get_contents(self):
+        """Fetch the contents of the entry."""
+        return _get_contents_map[self._func_get_contents](self)
+
+    def missing(self):
+        return not self.is_derived() and \
+               not self.linked and \
+               not self.rexists()
+
+    def remove(self):
+        """Remove this Node:  no-op by default."""
+        return None
+
+    def add_dependency(self, depend):
+        """Adds dependencies."""
+        try:
+            self._add_child(self.depends, self.depends_set, depend)
+        except TypeError as e:
+            e = e.args[0]
+            if SCons.Util.is_List(e):
+                s = list(map(str, e))
+            else:
+                s = str(e)
+            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)))
+
+    def add_prerequisite(self, prerequisite):
+        """Adds prerequisites"""
+        if self.prerequisites is None:
+            self.prerequisites = SCons.Util.UniqueList()
+        self.prerequisites.extend(prerequisite)
+        self._children_reset()
+
+    def add_ignore(self, depend):
+        """Adds dependencies to ignore."""
+        try:
+            self._add_child(self.ignore, self.ignore_set, depend)
+        except TypeError as e:
+            e = e.args[0]
+            if SCons.Util.is_List(e):
+                s = list(map(str, e))
+            else:
+                s = str(e)
+            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)))
+
+    def add_source(self, source):
+        """Adds sources."""
+        if self._specific_sources:
+            return
+        try:
+            self._add_child(self.sources, self.sources_set, source)
+        except TypeError as e:
+            e = e.args[0]
+            if SCons.Util.is_List(e):
+                s = list(map(str, e))
+            else:
+                s = str(e)
+            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)))
+
+    def _add_child(self, collection, set, child):
+        """Adds 'child' to 'collection', first checking 'set' to see if it's
+        already present."""
+        added = None
+        for c in child:
+            if c not in set:
+                set.add(c)
+                collection.append(c)
+                added = 1
+        if added:
+            self._children_reset()
+
+    def set_specific_source(self, source):
+        self.add_source(source)
+        self._specific_sources = True
+
+    def add_wkid(self, wkid):
+        """Add a node to the list of kids waiting to be evaluated"""
+        if self.wkids is not None:
+            self.wkids.append(wkid)
+
+    def _children_reset(self):
+        self.clear_memoized_values()
+        # We need to let the Executor clear out any calculated
+        # build info that it's cached so we can re-calculate it.
+        self.executor_cleanup()
+
+    @SCons.Memoize.CountMethodCall
+    def _children_get(self):
+        try:
+            return self._memo['_children_get']
+        except KeyError:
+            pass
+
+        # The return list may contain duplicate Nodes, especially in
+        # source trees where there are a lot of repeated #includes
+        # of a tangle of .h files.  Profiling shows, however, that
+        # eliminating the duplicates with a brute-force approach that
+        # preserves the order (that is, something like:
+        #
+        #       u = []
+        #       for n in list:
+        #           if n not in u:
+        #               u.append(n)"
+        #
+        # takes more cycles than just letting the underlying methods
+        # hand back cached values if a Node's information is requested
+        # multiple times.  (Other methods of removing duplicates, like
+        # using dictionary keys, lose the order, and the only ordered
+        # dictionary patterns I found all ended up using "not in"
+        # internally anyway...)
+        if self.ignore_set:
+            iter = chain.from_iterable([_f for _f in [self.sources, self.depends, self.implicit] if _f])
+
+            children = []
+            for i in iter:
+                if i not in self.ignore_set:
+                    children.append(i)
+        else:
+            children = self.all_children(scan=0)
+
+        self._memo['_children_get'] = children
+        return children
+
+    def all_children(self, scan=1):
+        """Return a list of all the node's direct children."""
+        if scan:
+            self.scan()
+
+        # The return list may contain duplicate Nodes, especially in
+        # source trees where there are a lot of repeated #includes
+        # of a tangle of .h files.  Profiling shows, however, that
+        # eliminating the duplicates with a brute-force approach that
+        # preserves the order (that is, something like:
+        #
+        #       u = []
+        #       for n in list:
+        #           if n not in u:
+        #               u.append(n)"
+        #
+        # takes more cycles than just letting the underlying methods
+        # hand back cached values if a Node's information is requested
+        # multiple times.  (Other methods of removing duplicates, like
+        # using dictionary keys, lose the order, and the only ordered
+        # dictionary patterns I found all ended up using "not in"
+        # internally anyway...)
+        return list(chain.from_iterable([_f for _f in [self.sources, self.depends, self.implicit] if _f]))
+
+    def children(self, scan=1):
+        """Return a list of the node's direct children, minus those
+        that are ignored by this node."""
+        if scan:
+            self.scan()
+        return self._children_get()
+
+    def set_state(self, state):
+        self.state = state
+
+    def get_state(self):
+        return self.state
+
+    def get_env(self):
+        env = self.env
+        if not env:
+            import SCons.Defaults
+            env = SCons.Defaults.DefaultEnvironment()
+        return env
+
+    def Decider(self, function):
+        foundkey = None
+        for k, v in _decider_map.items():
+            if v == function:
+                foundkey = k
+                break
+        if not foundkey:
+            foundkey = len(_decider_map)
+            _decider_map[foundkey] = function
+        self.changed_since_last_build = foundkey
+
+    def Tag(self, key, value):
+        """ Add a user-defined tag. """
+        if not self._tags:
+            self._tags = {}
+        self._tags[key] = value
+
+    def GetTag(self, key):
+        """ Return a user-defined tag. """
+        if not self._tags:
+            return None
+        return self._tags.get(key, None)
+
+    def changed(self, node=None, allowcache=False):
+        """
+        Returns if the node is up-to-date with respect to the BuildInfo
+        stored last time it was built.  The default behavior is to compare
+        it against our own previously stored BuildInfo, but the stored
+        BuildInfo from another Node (typically one in a Repository)
+        can be used instead.
+
+        Note that we now *always* check every dependency.  We used to
+        short-circuit the check by returning as soon as we detected
+        any difference, but we now rely on checking every dependency
+        to make sure that any necessary Node information (for example,
+        the content signature of an #included .h file) is updated.
+
+        The allowcache option was added for supporting the early
+        release of the executor/builder structures, right after
+        a File target was built. When set to true, the return
+        value of this changed method gets cached for File nodes.
+        Like this, the executor isn't needed any longer for subsequent
+        calls to changed().
+
+        @see: FS.File.changed(), FS.File.release_target_info()
+        """
+        t = 0
+        if t: Trace('changed(%s [%s], %s)' % (self, classname(self), node))
+        if node is None:
+            node = self
+
+        result = False
+
+        bi = node.get_stored_info().binfo
+        then = bi.bsourcesigs + bi.bdependsigs + bi.bimplicitsigs
+        children = self.children()
+
+        diff = len(children) - len(then)
+        if diff:
+            # The old and new dependency lists are different lengths.
+            # This always indicates that the Node must be rebuilt.
+            # We also extend the old dependency list with enough None
+            # entries to equal the new dependency list, for the benefit
+            # of the loop below that updates node information.
+            then.extend([None] * diff)
+            if t: Trace(': old %s new %s' % (len(then), len(children)))
+            result = True
+
+        for child, prev_ni in zip(children, then):
+            if _decider_map[child.changed_since_last_build](child, self, prev_ni):
+                if t: Trace(': %s changed' % child)
+                result = True
+
+        contents = self.get_executor().get_contents()
+        if self.has_builder():
+            import SCons.Util
+            newsig = SCons.Util.MD5signature(contents)
+            if bi.bactsig != newsig:
+                if t: Trace(': bactsig %s != newsig %s' % (bi.bactsig, newsig))
+                result = True
+
+        if not result:
+            if t: Trace(': up to date')
+
+        if t: Trace('\n')
+
+        return result
+
+    def is_up_to_date(self):
+        """Default check for whether the Node is current: unknown Node
+        subtypes are always out of date, so they will always get built."""
+        return None
+
+    def children_are_up_to_date(self):
+        """Alternate check for whether the Node is current:  If all of
+        our children were up-to-date, then this Node was up-to-date, too.
+
+        The SCons.Node.Alias and SCons.Node.Python.Value subclasses
+        rebind their current() method to this method."""
+        # Allow the children to calculate their signatures.
+        self.binfo = self.get_binfo()
+        if self.always_build:
+            return None
+        state = 0
+        for kid in self.children(None):
+            s = kid.get_state()
+            if s and (not state or s > state):
+                state = s
+        return (state == 0 or state == SCons.Node.up_to_date)
+
+    def is_literal(self):
+        """Always pass the string representation of a Node to
+        the command interpreter literally."""
+        return 1
+
+    def render_include_tree(self):
+        """
+        Return a text representation, suitable for displaying to the
+        user, of the include tree for the sources of this node.
+        """
+        if self.is_derived():
+            env = self.get_build_env()
+            if env:
+                for s in self.sources:
+                    scanner = self.get_source_scanner(s)
+                    if scanner:
+                        path = self.get_build_scanner_path(scanner)
+                    else:
+                        path = None
+                    def f(node, env=env, scanner=scanner, path=path):
+                        return node.get_found_includes(env, scanner, path)
+                    return SCons.Util.render_tree(s, f, 1)
+        else:
+            return None
+
+    def get_abspath(self):
+        """
+        Return an absolute path to the Node.  This will return simply
+        str(Node) by default, but for Node types that have a concept of
+        relative path, this might return something different.
+        """
+        return str(self)
+
+    def for_signature(self):
+        """
+        Return a string representation of the Node that will always
+        be the same for this particular Node, no matter what.  This
+        is by contrast to the __str__() method, which might, for
+        instance, return a relative path for a file Node.  The purpose
+        of this method is to generate a value to be used in signature
+        calculation for the command line used to build a target, and
+        we use this method instead of str() to avoid unnecessary
+        rebuilds.  This method does not need to return something that
+        would actually work in a command line; it can return any kind of
+        nonsense, so long as it does not change.
+        """
+        return str(self)
+
+    def get_string(self, for_signature):
+        """This is a convenience function designed primarily to be
+        used in command generators (i.e., CommandGeneratorActions or
+        Environment variables that are callable), which are called
+        with a for_signature argument that is nonzero if the command
+        generator is being called to generate a signature for the
+        command line, which determines if we should rebuild or not.
+
+        Such command generators should use this method in preference
+        to str(Node) when converting a Node to a string, passing
+        in the for_signature parameter, such that we will call
+        Node.for_signature() or str(Node) properly, depending on whether
+        we are calculating a signature or actually constructing a
+        command line."""
+        if for_signature:
+            return self.for_signature()
+        return str(self)
+
+    def get_subst_proxy(self):
+        """
+        This method is expected to return an object that will function
+        exactly like this Node, except that it implements any additional
+        special features that we would like to be in effect for
+        Environment variable substitution.  The principle use is that
+        some Nodes would like to implement a __getattr__() method,
+        but putting that in the Node type itself has a tendency to kill
+        performance.  We instead put it in a proxy and return it from
+        this method.  It is legal for this method to return self
+        if no new functionality is needed for Environment substitution.
+        """
+        return self
+
+    def explain(self):
+        if not self.exists():
+            return "building `%s' because it doesn't exist\n" % self
+
+        if self.always_build:
+            return "rebuilding `%s' because AlwaysBuild() is specified\n" % self
+
+        old = self.get_stored_info()
+        if old is None:
+            return None
+
+        old = old.binfo
+        old.prepare_dependencies()
+
+        try:
+            old_bkids    = old.bsources    + old.bdepends    + old.bimplicit
+            old_bkidsigs = old.bsourcesigs + old.bdependsigs + old.bimplicitsigs
+        except AttributeError:
+            return "Cannot explain why `%s' is being rebuilt: No previous build information found\n" % self
+
+        new = self.get_binfo()
+
+        new_bkids    = new.bsources    + new.bdepends    + new.bimplicit
+        new_bkidsigs = new.bsourcesigs + new.bdependsigs + new.bimplicitsigs
+
+        osig = dict(list(zip(old_bkids, old_bkidsigs)))
+        nsig = dict(list(zip(new_bkids, new_bkidsigs)))
+
+        # The sources and dependencies we'll want to report are all stored
+        # as relative paths to this target's directory, but we want to
+        # report them relative to the top-level SConstruct directory,
+        # so we only print them after running them through this lambda
+        # to turn them into the right relative Node and then return
+        # its string.
+        def stringify( s, E=self.dir.Entry ) :
+            if hasattr( s, 'dir' ) :
+                return str(E(s))
+            return str(s)
+
+        lines = []
+
+        removed = [x for x in old_bkids if not x in new_bkids]
+        if removed:
+            removed = list(map(stringify, removed))
+            fmt = "`%s' is no longer a dependency\n"
+            lines.extend([fmt % s for s in removed])
+
+        for k in new_bkids:
+            if not k in old_bkids:
+                lines.append("`%s' is a new dependency\n" % stringify(k))
+            elif _decider_map[k.changed_since_last_build](k, self, osig[k]):
+                lines.append("`%s' changed\n" % stringify(k))
+
+        if len(lines) == 0 and old_bkids != new_bkids:
+            lines.append("the dependency order changed:\n" +
+                         "%sold: %s\n" % (' '*15, list(map(stringify, old_bkids))) +
+                         "%snew: %s\n" % (' '*15, list(map(stringify, new_bkids))))
+
+        if len(lines) == 0:
+            def fmt_with_title(title, strlines):
+                lines = strlines.split('\n')
+                sep = '\n' + ' '*(15 + len(title))
+                return ' '*15 + title + sep.join(lines) + '\n'
+            if old.bactsig != new.bactsig:
+                if old.bact == new.bact:
+                    lines.append("the contents of the build action changed\n" +
+                                 fmt_with_title('action: ', new.bact))
+
+                    # lines.append("the contents of the build action changed [%s] [%s]\n"%(old.bactsig,new.bactsig) +
+                    #              fmt_with_title('action: ', new.bact))
+                else:
+                    lines.append("the build action changed:\n" +
+                                 fmt_with_title('old: ', old.bact) +
+                                 fmt_with_title('new: ', new.bact))
+
+        if len(lines) == 0:
+            return "rebuilding `%s' for unknown reasons\n" % self
+
+        preamble = "rebuilding `%s' because" % self
+        if len(lines) == 1:
+            return "%s %s"  % (preamble, lines[0])
+        else:
+            lines = ["%s:\n" % preamble] + lines
+            return ( ' '*11).join(lines)
+
+class NodeList(collections.UserList):
+    def __str__(self):
+        return str(list(map(str, self.data)))
+
+def get_children(node, parent): return node.children()
+def ignore_cycle(node, stack): pass
+def do_nothing(node, parent): pass
+
+class Walker(object):
+    """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 get_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 get_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 node in self.history:
+                    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
+        return None
+
+    def is_done(self):
+        return not self.stack
+
+
+arg2nodes_lookups = []
+
+# Local Variables:
+# tab-width:4
+# indent-tabs-mode:nil
+# End:
+# vim: set expandtab tabstop=4 shiftwidth=4: