Merge commit 'upstream/2.0.0'

8 files changed, 295 insertions, 410 deletions

diff --git a/src/engine/SCons/Node/Alias.py b/src/engine/SCons/Node/Alias.py
index ff4a47e..291ac4d 100644
--- a/src/engine/SCons/Node/Alias.py
+++ b/src/engine/SCons/Node/Alias.py
@@ -30,23 +30,22 @@ This creates a hash of global Aliases (dummy targets).
 # WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #
 
-__revision__ = "src/engine/SCons/Node/Alias.py 4720 2010/03/24 03:14:11 jars"
+__revision__ = "src/engine/SCons/Node/Alias.py 5023 2010/06/14 22:05:46 scons"
 
-import string
-import UserDict
+import collections
 
 import SCons.Errors
 import SCons.Node
 import SCons.Util
 
-class AliasNameSpace(UserDict.UserDict):
+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 = apply(SCons.Node.Alias.Alias, (name,), kw)
+            a = SCons.Node.Alias.Alias(name, **kw)
             self[name] = a
         return a
 
@@ -95,8 +94,8 @@ class Alias(SCons.Node.Node):
     def get_contents(self):
         """The contents of an alias is the concatenation
         of the content signatures of all its sources."""
-        childsigs = map(lambda n: n.get_csig(), self.children())
-        return string.join(childsigs, '')
+        childsigs = [n.get_csig() for n in self.children()]
+        return ''.join(childsigs)
 
     def sconsign(self):
         """An Alias is not recorded in .sconsign files"""
diff --git a/src/engine/SCons/Node/AliasTests.py b/src/engine/SCons/Node/AliasTests.py
index e7a16b3..56a5564 100644
--- a/src/engine/SCons/Node/AliasTests.py
+++ b/src/engine/SCons/Node/AliasTests.py
@@ -21,7 +21,7 @@
 # WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #
 
-__revision__ = "src/engine/SCons/Node/AliasTests.py 4720 2010/03/24 03:14:11 jars"
+__revision__ = "src/engine/SCons/Node/AliasTests.py 5023 2010/06/14 22:05:46 scons"
 
 import sys
 import unittest
@@ -51,7 +51,7 @@ class AliasTestCase(unittest.TestCase):
     def test_get_contents(self):
         """Test the get_contents() method
         """
-        class DummyNode:
+        class DummyNode(object):
             def __init__(self, contents):
                 self.contents = contents
             def get_csig(self):
@@ -119,7 +119,7 @@ if __name__ == "__main__":
     ]
     for tclass in tclasses:
         names = unittest.getTestCaseNames(tclass, 'test_')
-        suite.addTests(map(tclass, names))
+        suite.addTests(list(map(tclass, names)))
     if not unittest.TextTestRunner().run(suite).wasSuccessful():
         sys.exit(1)
 
diff --git a/src/engine/SCons/Node/FS.py b/src/engine/SCons/Node/FS.py
index 10641e9..9298d98 100644
--- a/src/engine/SCons/Node/FS.py
+++ b/src/engine/SCons/Node/FS.py
@@ -31,73 +31,17 @@ that can be used by scripts or modules looking for the canonical default.
 # 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__ = "src/engine/SCons/Node/FS.py 4720 2010/03/24 03:14:11 jars"
+__revision__ = "src/engine/SCons/Node/FS.py 5023 2010/06/14 22:05:46 scons"
 
-from itertools import izip
-import cStringIO
 import fnmatch
 import os
-import os.path
 import re
 import shutil
 import stat
-import string
 import sys
 import time
-
-try:
-    import codecs
-except ImportError:
-    pass
-else:
-    # TODO(2.2):  Remove when 2.3 becomes the minimal supported version.
-    try:
-        codecs.BOM_UTF8
-    except AttributeError:
-        codecs.BOM_UTF8 = '\xef\xbb\xbf'
-    try:
-        codecs.BOM_UTF16_LE
-        codecs.BOM_UTF16_BE
-    except AttributeError:
-        codecs.BOM_UTF16_LE = '\xff\xfe'
-        codecs.BOM_UTF16_BE = '\xfe\xff'
-
-    # Provide a wrapper function to handle decoding differences in
-    # different versions of Python.  Normally, we'd try to do this in the
-    # compat layer (and maybe it still makes sense to move there?) but
-    # that doesn't provide a way to supply the string class used in
-    # pre-2.3 Python versions with a .decode() method that all strings
-    # naturally have.  Plus, the 2.[01] encodings behave differently
-    # enough that we have to settle for a lowest-common-denominator
-    # wrapper approach.
-    #
-    # Note that the 2.[012] implementations below may be inefficient
-    # because they perform an explicit look up of the encoding for every
-    # decode, but they're old enough (and we want to stop supporting
-    # them soon enough) that it's not worth complicating the interface.
-    # Think of it as additional incentive for people to upgrade...
-    try:
-        ''.decode
-    except AttributeError:
-        # 2.0 through 2.2:  strings have no .decode() method
-        try:
-            codecs.lookup('ascii').decode
-        except AttributeError:
-            # 2.0 and 2.1:  encodings are a tuple of functions, and the
-            # decode() function returns a (result, length) tuple.
-            def my_decode(contents, encoding):
-                return codecs.lookup(encoding)[1](contents)[0]
-        else:
-            # 2.2:  encodings are an object with methods, and the
-            # .decode() method returns just the decoded bytes.
-            def my_decode(contents, encoding):
-                return codecs.lookup(encoding).decode(contents)
-    else:
-        # 2.3 or later:  use the .decode() string method
-        def my_decode(contents, encoding):
-            return contents.decode(encoding)
+import codecs
 
 import SCons.Action
 from SCons.Debug import logInstanceCreation
@@ -256,11 +200,11 @@ def set_duplicate(duplicate):
     }
 
     if not duplicate in Valid_Duplicates:
-        raise SCons.Errors.InternalError, ("The argument of set_duplicate "
+        raise SCons.Errors.InternalError("The argument of set_duplicate "
                                            "should be in Valid_Duplicates")
     global Link_Funcs
     Link_Funcs = []
-    for func in string.split(duplicate,'-'):
+    for func in duplicate.split('-'):
         if link_dict[func]:
             Link_Funcs.append(link_dict[func])
 
@@ -334,7 +278,7 @@ def get_MkdirBuilder():
                                              name = "MkdirBuilder")
     return MkdirBuilder
 
-class _Null:
+class _Null(object):
     pass
 
 _null = _Null()
@@ -373,25 +317,23 @@ if os.path.normcase("TeSt") == os.path.normpath("TeSt") and not _is_cygwin:
         return x
 else:
     def _my_normcase(x):
-        return string.upper(x)
+        return x.upper()
 
 
 
-class DiskChecker:
+class DiskChecker(object):
     def __init__(self, type, do, ignore):
         self.type = type
         self.do = do
         self.ignore = ignore
-        self.set_do()
-    def set_do(self):
-        self.__call__ = self.do
-    def set_ignore(self):
-        self.__call__ = self.ignore
+        self.func = do
+    def __call__(self, *args, **kw):
+        return self.func(*args, **kw)
     def set(self, list):
         if self.type in list:
-            self.set_do()
+            self.func = self.do
         else:
-            self.set_ignore()
+            self.func = self.ignore
 
 def do_diskcheck_match(node, predicate, errorfmt):
     result = predicate()
@@ -407,7 +349,7 @@ def do_diskcheck_match(node, predicate, errorfmt):
     except (AttributeError, KeyError):
         pass
     if result:
-        raise TypeError, errorfmt % node.abspath
+        raise TypeError(errorfmt % node.abspath)
 
 def ignore_diskcheck_match(node, predicate, errorfmt):
     pass
@@ -459,11 +401,14 @@ def set_diskcheck(list):
         dc.set(list)
 
 def diskcheck_types():
-    return map(lambda dc: dc.type, diskcheckers)
+    return [dc.type for dc in diskcheckers]
 
 
 
 class EntryProxy(SCons.Util.Proxy):
+
+    __str__ = SCons.Util.Delegate('__str__')
+
     def __get_abspath(self):
         entry = self.get()
         return SCons.Subst.SpecialAttrWrapper(entry.get_abspath(),
@@ -497,7 +442,7 @@ class EntryProxy(SCons.Util.Proxy):
             return self
         else:
             entry = self.get()
-            r = string.replace(entry.get_path(), os.sep, '/')
+            r = entry.get_path().replace(os.sep, '/')
             return SCons.Subst.SpecialAttrWrapper(r, entry.name + "_posix")
 
     def __get_windows_path(self):
@@ -507,7 +452,7 @@ class EntryProxy(SCons.Util.Proxy):
             return self
         else:
             entry = self.get()
-            r = string.replace(entry.get_path(), os.sep, '\\')
+            r = entry.get_path().replace(os.sep, '\\')
             return SCons.Subst.SpecialAttrWrapper(r, entry.name + "_windows")
 
     def __get_srcnode(self):
@@ -620,8 +565,8 @@ class Base(SCons.Node.Node):
         """
         if isinstance(self, klass) or klass is Entry:
             return
-        raise TypeError, "Tried to lookup %s '%s' as a %s." %\
-              (self.__class__.__name__, self.path, klass.__name__)
+        raise TypeError("Tried to lookup %s '%s' as a %s." %\
+              (self.__class__.__name__, self.path, klass.__name__))
 
     def get_dir(self):
         return self.dir
@@ -647,7 +592,7 @@ class Base(SCons.Node.Node):
             return self._memo['_save_str']
         except KeyError:
             pass
-        result = intern(self._get_str())
+        result = sys.intern(self._get_str())
         self._memo['_save_str'] = result
         return result
 
@@ -753,8 +698,8 @@ class Base(SCons.Node.Node):
         try: i = path_elems.index(dir)
         except ValueError: pass
         else: path_elems = path_elems[i+1:]
-        path_elems = map(lambda n: n.name, path_elems)
-        return string.join(path_elems, os.sep)
+        path_elems = [n.name for n in path_elems]
+        return os.sep.join(path_elems)
 
     def set_src_builder(self, builder):
         """Set the source code builder for this node."""
@@ -911,7 +856,7 @@ class Entry(Base):
                 self._morph()
             elif must_exist:
                 msg = "No such file or directory: '%s'" % self.abspath
-                raise SCons.Errors.UserError, msg
+                raise SCons.Errors.UserError(msg)
             else:
                 self.__class__ = File
                 self._morph()
@@ -990,7 +935,7 @@ class Entry(Base):
     def rel_path(self, other):
         d = self.disambiguate()
         if d.__class__ is Entry:
-            raise "rel_path() could not disambiguate File/Dir"
+            raise Exception("rel_path() could not disambiguate File/Dir")
         return d.rel_path(other)
 
     def new_ninfo(self):
@@ -1010,7 +955,7 @@ class Entry(Base):
 _classEntry = Entry
 
 
-class LocalFS:
+class LocalFS(object):
 
     if SCons.Memoize.use_memoizer:
         __metaclass__ = SCons.Memoize.Memoized_Metaclass
@@ -1249,7 +1194,7 @@ class FS(LocalFS):
             root = directory.root
 
         if os.sep != '/':
-            p = string.replace(p, os.sep, '/')
+            p = p.replace(os.sep, '/')
         return root._lookup_abs(p, fsclass, create)
 
     def Entry(self, name, directory = None, create = 1):
@@ -1294,11 +1239,11 @@ class FS(LocalFS):
         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."
+            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)
+            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):
@@ -1327,12 +1272,12 @@ class FS(LocalFS):
                 if start_dir.is_under(bd):
                     # If already in the build-dir location, don't reflect
                     return [orig], fmt % str(orig)
-                p = apply(os.path.join, [bd.path] + tail)
+                p = os.path.join(bd.path, *tail)
                 targets.append(self.Entry(p))
             tail = [dir.name] + tail
             dir = dir.up()
         if targets:
-            message = fmt % string.join(map(str, targets))
+            message = fmt % ' '.join(map(str, targets))
         return targets, message
 
     def Glob(self, pathname, ondisk=True, source=True, strings=False, cwd=None):
@@ -1574,9 +1519,9 @@ class Dir(Base):
             i = self.path_elements.index(other) + 1
 
             path_elems = ['..'] * (len(self.path_elements) - i) \
-                         + map(lambda n: n.name, other.path_elements[i:])
+                         + [n.name for n in other.path_elements[i:]]
              
-            result = string.join(path_elems, os.sep)
+            result = os.sep.join(path_elems)
 
         memo_dict[other] = result
 
@@ -1622,7 +1567,7 @@ class Dir(Base):
         """A null "builder" for directories."""
         global MkdirBuilder
         if self.builder is not MkdirBuilder:
-            apply(SCons.Node.Node.build, [self,], kw)
+            SCons.Node.Node.build(self, **kw)
 
     #
     #
@@ -1641,7 +1586,7 @@ class Dir(Base):
             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
+                raise SCons.Errors.StopError(parent.path)
             parent = p
         listDirs.reverse()
         for dirnode in listDirs:
@@ -1682,12 +1627,9 @@ class Dir(Base):
         """Return content signatures and names of all our children
         separated by new-lines. Ensure that the nodes are sorted."""
         contents = []
-        name_cmp = lambda a, b: cmp(a.name, b.name)
-        sorted_children = self.children()[:]
-        sorted_children.sort(name_cmp)
-        for node in sorted_children:
+        for node in sorted(self.children(), key=lambda t: t.name):
             contents.append('%s %s\n' % (node.get_csig(), node.name))
-        return string.join(contents, '')
+        return ''.join(contents)
 
     def get_csig(self):
         """Compute the content signature for Directory nodes. In
@@ -1783,7 +1725,7 @@ class Dir(Base):
                 d[name] = result
             return result
         else:
-            return d.has_key(name)
+            return name in d
 
     memoizer_counters.append(SCons.Memoize.CountValue('srcdir_list'))
 
@@ -1911,12 +1853,11 @@ class Dir(Base):
         in any way (or ignored, passing None is common).
         """
         entries = self.entries
-        names = entries.keys()
+        names = list(entries.keys())
         names.remove('.')
         names.remove('..')
         func(arg, self, names)
-        select_dirs = lambda n, e=entries: isinstance(e[n], Dir)
-        for dirname in filter(select_dirs, 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):
@@ -1953,9 +1894,8 @@ class Dir(Base):
         """
         dirname, basename = os.path.split(pathname)
         if not dirname:
-            result = self._glob1(basename, ondisk, source, strings)
-            result.sort(lambda a, b: cmp(str(a), str(b)))
-            return result
+            return sorted(self._glob1(basename, ondisk, source, strings),
+                          key=lambda t: str(t))
         if has_glob_magic(dirname):
             list = self.glob(dirname, ondisk, source, strings=False)
         else:
@@ -1964,10 +1904,9 @@ class Dir(Base):
         for dir in list:
             r = dir._glob1(basename, ondisk, source, strings)
             if strings:
-                r = map(lambda x, d=str(dir): os.path.join(d, x), r)
+                r = [os.path.join(str(dir), x) for x in r]
             result.extend(r)
-        result.sort(lambda a, b: cmp(str(a), str(b)))
-        return result
+        return sorted(result, key=lambda a: str(a))
 
     def _glob1(self, pattern, ondisk=True, source=False, strings=False):
         """
@@ -1990,9 +1929,8 @@ class Dir(Base):
             # 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 ('.', '..') ]
-            entry_names = filter(lambda n: n not in ('.', '..'), dir.entries.keys())
-            node_names = map(lambda n, e=dir.entries: e[n].name, entry_names)
+            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
@@ -2015,7 +1953,7 @@ class Dir(Base):
                     # after we exit this loop.
                     if pattern[0] != '.':
                         #disk_names = [ d for d in disk_names if d[0] != '.' ]
-                        disk_names = filter(lambda x: x[0] != '.', disk_names)
+                        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:
@@ -2031,14 +1969,14 @@ class Dir(Base):
         names = set(names)
         if pattern[0] != '.':
             #names = [ n for n in names if n[0] != '.' ]
-            names = filter(lambda x: x[0] != '.', names)
+            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 ]
-        return map(lambda n, e=self.entries:  e[_my_normcase(n)], names)
+        return [self.entries[_my_normcase(n)] for n in names]
 
 class RootDir(Dir):
     """A class for the root directory of a file system.
@@ -2111,7 +2049,7 @@ class RootDir(Dir):
         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
+                raise SCons.Errors.UserError(msg)
             # There is no Node for this path name, and we're allowed
             # to create it.
             dir_name, file_name = os.path.split(p)
@@ -2200,7 +2138,7 @@ class FileBuildInfo(SCons.Node.BuildInfoBase):
                 except AttributeError:
                     s = str(n)
                 else:
-                    s = string.replace(s, os.sep, '/')
+                    s = s.replace(os.sep, '/')
                 return s
         for attr in ['bsources', 'bdepends', 'bimplicit']:
             try:
@@ -2208,7 +2146,7 @@ class FileBuildInfo(SCons.Node.BuildInfoBase):
             except AttributeError:
                 pass
             else:
-                setattr(self, attr, map(node_to_str, val))
+                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
@@ -2238,7 +2176,7 @@ class FileBuildInfo(SCons.Node.BuildInfoBase):
             except AttributeError:
                 continue
             nodes = []
-            for s, ni in izip(strings, nodeinfos):
+            for s, ni in zip(strings, nodeinfos):
                 if not isinstance(s, SCons.Node.Node):
                     s = ni.str_to_node(s)
                 nodes.append(s)
@@ -2247,11 +2185,11 @@ class FileBuildInfo(SCons.Node.BuildInfoBase):
         result = []
         bkids = self.bsources + self.bdepends + self.bimplicit
         bkidsigs = self.bsourcesigs + self.bdependsigs + self.bimplicitsigs
-        for bkid, bkidsig in izip(bkids, bkidsigs):
+        for bkid, bkidsig in zip(bkids, bkidsigs):
             result.append(str(bkid) + ': ' +
-                          string.join(bkidsig.format(names=names), ' '))
+                          ' '.join(bkidsig.format(names=names)))
         result.append('%s [%s]' % (self.bactsig, self.bact))
-        return string.join(result, '\n')
+        return '\n'.join(result)
 
 class File(Base):
     """A class for files in a file system.
@@ -2286,9 +2224,7 @@ class File(Base):
     def Dirs(self, pathlist):
         """Create a list of directories relative to the SConscript
         directory of this file."""
-        # TODO(1.5)
-        # return [self.Dir(p) for p in pathlist]
-        return map(lambda p, s=self: s.Dir(p), pathlist)
+        return [self.Dir(p) for p in pathlist]
 
     def File(self, name):
         """Create a file node named 'name' relative to
@@ -2336,38 +2272,24 @@ class File(Base):
             raise
         return contents
 
-    try:
-        import codecs
-    except ImportError:
-        get_text_contents = get_contents
-    else:
-        # 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.
-        def get_text_contents(self):
-            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 side step all the complication by
-            # explicitly stripping the BOM before we decode().
-            if contents.startswith(codecs.BOM_UTF8):
-                contents = contents[len(codecs.BOM_UTF8):]
-                # TODO(2.2):  Remove when 2.3 becomes floor.
-                #contents = contents.decode('utf-8')
-                contents = my_decode(contents, 'utf-8')
-            elif contents.startswith(codecs.BOM_UTF16_LE):
-                contents = contents[len(codecs.BOM_UTF16_LE):]
-                # TODO(2.2):  Remove when 2.3 becomes floor.
-                #contents = contents.decode('utf-16-le')
-                contents = my_decode(contents, 'utf-16-le')
-            elif contents.startswith(codecs.BOM_UTF16_BE):
-                contents = contents[len(codecs.BOM_UTF16_BE):]
-                # TODO(2.2):  Remove when 2.3 becomes floor.
-                #contents = contents.decode('utf-16-be')
-                contents = my_decode(contents, 'utf-16-be')
-            return contents
+    # 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.
+    def get_text_contents(self):
+        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.startswith(codecs.BOM_UTF8):
+            return contents[len(codecs.BOM_UTF8):].decode('utf-8')
+        if contents.startswith(codecs.BOM_UTF16_LE):
+            return contents[len(codecs.BOM_UTF16_LE):].decode('utf-16-le')
+        if contents.startswith(codecs.BOM_UTF16_BE):
+            return contents[len(codecs.BOM_UTF16_BE):].decode('utf-16-be')
+        return contents
 
     def get_content_hash(self):
         """
@@ -2603,7 +2525,7 @@ class File(Base):
         if scanner:
             # result = [n.disambiguate() for n in scanner(self, env, path)]
             result = scanner(self, env, path)
-            result = map(lambda N: N.disambiguate(), result)
+            result = [N.disambiguate() for N in result]
         else:
             result = []
 
@@ -2741,7 +2663,7 @@ class File(Base):
                     self._createDir()
                 except SCons.Errors.StopError, drive:
                     desc = "No drive `%s' for target `%s'." % (drive, self)
-                    raise SCons.Errors.StopError, desc
+                    raise SCons.Errors.StopError(desc)
 
     #
     #
@@ -2760,7 +2682,7 @@ class File(Base):
         e = Link(self, src, None)
         if isinstance(e, SCons.Errors.BuildError):
             desc = "Cannot duplicate `%s' in `%s': %s." % (src.path, self.dir.path, e.errstr)
-            raise SCons.Errors.StopError, desc
+            raise SCons.Errors.StopError(desc)
         self.linked = 1
         # The Link() action may or may not have actually
         # created the file, depending on whether the -n
@@ -3019,7 +2941,7 @@ class File(Base):
         children = self.children()
         executor = self.get_executor()
         # sigs = [n.get_cachedir_csig() for n in children]
-        sigs = map(lambda n: n.get_cachedir_csig(), children)
+        sigs = [n.get_cachedir_csig() for n in children]
         sigs.append(SCons.Util.MD5signature(executor.get_contents()))
         sigs.append(self.path)
         result = self.cachesig = SCons.Util.MD5collect(sigs)
@@ -3034,7 +2956,7 @@ def get_default_fs():
         default_fs = FS()
     return default_fs
 
-class FileFinder:
+class FileFinder(object):
     """
     """
     if SCons.Memoize.use_memoizer:
@@ -3117,8 +3039,8 @@ class FileFinder:
         if verbose and not callable(verbose):
             if not SCons.Util.is_String(verbose):
                 verbose = "find_file"
-            verbose = '  %s: ' % verbose
-            verbose = lambda s, v=verbose: sys.stdout.write(v + s)
+            _verbose = u'  %s: ' % verbose
+            verbose = lambda s: sys.stdout.write(_verbose + s)
 
         filedir, filename = os.path.split(filename)
         if filedir:
@@ -3150,10 +3072,10 @@ class FileFinder:
             #    if isinstance(node, Dir) or isinstance(node, Entry):
             #        return node
             #    return None
-            #paths = filter(None, map(filedir_lookup, paths))
+            #paths = [_f for _f in map(filedir_lookup, paths) if _f]
 
             self.default_filedir = filedir
-            paths = filter(None, map(self.filedir_lookup, paths))
+            paths = [_f for _f in map(self.filedir_lookup, paths) if _f]
 
         result = None
         for dir in paths:
diff --git a/src/engine/SCons/Node/FSTests.py b/src/engine/SCons/Node/FSTests.py
index c059925..ee6a2f5 100644
--- a/src/engine/SCons/Node/FSTests.py
+++ b/src/engine/SCons/Node/FSTests.py
@@ -20,12 +20,14 @@
 # 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
 
-__revision__ = "src/engine/SCons/Node/FSTests.py 4720 2010/03/24 03:14:11 jars"
+__revision__ = "src/engine/SCons/Node/FSTests.py 5023 2010/06/14 22:05:46 scons"
+
+import SCons.compat
 
 import os
 import os.path
-import string
 import sys
 import time
 import unittest
@@ -40,16 +42,9 @@ import SCons.Warnings
 
 built_it = None
 
-# This will be built-in in 2.3.  For now fake it.
-try :
-    True , False
-except NameError :
-    True = 1 ; False = 0
-
-
 scanner_count = 0
 
-class Scanner:
+class Scanner(object):
     def __init__(self, node=None):
         global scanner_count
         scanner_count = scanner_count + 1
@@ -66,7 +61,7 @@ class Scanner:
     def recurse_nodes(self, nodes):
         return nodes
 
-class Environment:
+class Environment(object):
     def __init__(self):
         self.scanner = Scanner()
     def Dictionary(self, *args):
@@ -80,7 +75,7 @@ class Environment:
     def _update(self, dict):
         pass
 
-class Action:
+class Action(object):
     def __call__(self, targets, sources, env, **kw):
         global built_it
         if kw.get('execute', 1):
@@ -97,7 +92,7 @@ class Action:
     def get_implicit_deps(self, target, source, env):
         return []
 
-class Builder:
+class Builder(object):
     def __init__(self, factory, action=Action()):
         self.factory = factory
         self.env = Environment()
@@ -341,7 +336,7 @@ class VariantDirTestCase(unittest.TestCase):
 
         f11 = fs.File('src/file11')
         t, m = f11.alter_targets()
-        bdt = map(lambda n: n.path, t)
+        bdt = [n.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
@@ -349,11 +344,11 @@ class VariantDirTestCase(unittest.TestCase):
         f12 = fs.File('src/file12')
         f12.builder = 1
         bdt, m = f12.alter_targets()
-        assert bdt == [], map(lambda n: n.path, bdt)
+        assert bdt == [], [n.path for n in bdt]
 
         d13 = fs.Dir('src/new_dir')
         t, m = d13.alter_targets()
-        bdt = map(lambda n: n.path, t)
+        bdt = [n.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
@@ -364,7 +359,7 @@ class VariantDirTestCase(unittest.TestCase):
 
         save_Link = SCons.Node.FS.Link
         def Link_IOError(target, source, env):
-            raise IOError, (17, "Link_IOError")
+            raise IOError(17, "Link_IOError")
         SCons.Node.FS.Link = SCons.Action.Action(Link_IOError, None)
 
         test.write(['work', 'src', 'IOError'], "work/src/IOError\n")
@@ -434,7 +429,7 @@ class VariantDirTestCase(unittest.TestCase):
         assert r == d1, "%s != %s" % (r, d1)
 
         # verify the link creation attempts in file_link()
-        class LinkSimulator :
+        class LinkSimulator (object):
             """A class to intercept os.[sym]link() calls and track them."""
 
             def __init__( self, duplicate, link, symlink, copy ) :
@@ -445,7 +440,7 @@ class VariantDirTestCase(unittest.TestCase):
                 self.have['copy'] = copy
 
                 self.links_to_be_called = []
-                for link in string.split(self.duplicate, '-'):
+                for link in self.duplicate.split('-'):
                     if self.have[link]:
                         self.links_to_be_called.append(link)
 
@@ -817,7 +812,7 @@ class FileBuildInfoTestCase(_tempdirTestCase):
             'actionsig [action]',
         ]
 
-        expect = string.join(expect_lines, '\n')
+        expect = '\n'.join(expect_lines)
         format = bi1.format()
         assert format == expect, (repr(expect), repr(format))
 
@@ -898,7 +893,7 @@ class FSTestCase(_tempdirTestCase):
         except TypeError:
             pass
         else:
-            raise Exception, "did not catch expected TypeError"
+            raise Exception("did not catch expected TypeError")
 
         assert x1.Entry(x4) == x4
         try:
@@ -906,7 +901,7 @@ class FSTestCase(_tempdirTestCase):
         except TypeError:
             pass
         else:
-            raise Exception, "did not catch expected TypeError"
+            raise Exception("did not catch expected TypeError")
 
         x6 = x1.File(x6)
         assert isinstance(x6, SCons.Node.FS.File)
@@ -921,12 +916,12 @@ class FSTestCase(_tempdirTestCase):
         drive, path = os.path.splitdrive(os.getcwd())
 
         def _do_Dir_test(lpath, path_, abspath_, up_path_, sep, fileSys=fs, drive=drive):
-            dir = fileSys.Dir(string.replace(lpath, '/', sep))
+            dir = fileSys.Dir(lpath.replace('/', sep))
 
             if os.sep != '/':
-                path_ = string.replace(path_, '/', os.sep)
-                abspath_ = string.replace(abspath_, '/', os.sep)
-                up_path_ = string.replace(up_path_, '/', 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:
@@ -937,7 +932,7 @@ class FSTestCase(_tempdirTestCase):
             path = strip_slash(path_)
             abspath = strip_slash(abspath_)
             up_path = strip_slash(up_path_)
-            name = string.split(abspath, os.sep)[-1]
+            name = abspath.split(os.sep)[-1]
 
             assert dir.name == name, \
                    "dir.name %s != expected name %s" % \
@@ -978,7 +973,7 @@ class FSTestCase(_tempdirTestCase):
             Dir_test('#',           './',          sub_dir,           sub)
 
             try:
-                f2 = fs.File(string.join(['f1', 'f2'], sep), directory = d1)
+                f2 = fs.File(sep.join(['f1', 'f2']), directory = d1)
             except TypeError, x:
                 assert str(x) == ("Tried to lookup File '%s' as a Dir." %
                                   d1_f1), x
@@ -986,7 +981,7 @@ class FSTestCase(_tempdirTestCase):
                 raise
 
             try:
-                dir = fs.Dir(string.join(['d1', 'f1'], sep))
+                dir = fs.Dir(sep.join(['d1', 'f1']))
             except TypeError, x:
                 assert str(x) == ("Tried to lookup File '%s' as a Dir." %
                                   d1_f1), x
@@ -1051,7 +1046,7 @@ class FSTestCase(_tempdirTestCase):
         assert built_it
 
         def match(path, expect):
-            expect = string.replace(expect, '/', os.sep)
+            expect = expect.replace('/', os.sep)
             assert path == expect, "path %s != expected %s" % (path, expect)
 
         e1 = fs.Entry("d1")
@@ -1152,7 +1147,7 @@ class FSTestCase(_tempdirTestCase):
 
         # 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:
+        class DummyNode(object):
             pass
 
         deps = f12.get_found_includes(env, s, DummyNode())
@@ -1195,17 +1190,12 @@ class FSTestCase(_tempdirTestCase):
         f1 = fs.File(test.workpath("binary_file"))
         assert f1.get_contents() == "Foo\x1aBar", f1.get_contents()
 
-        try:
-            # TODO(1.5)
-            eval('test_string = u"Foo\x1aBar"')
-        except SyntaxError:
-            pass
-        else:
-            # This tests to make sure we can decode UTF-8 text files.
-            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()
+        # 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()
 
         def nonexistent(method, s):
             try:
@@ -1213,7 +1203,7 @@ class FSTestCase(_tempdirTestCase):
             except SCons.Errors.UserError:
                 pass
             else:
-                raise Exception, "did not catch expected UserError"
+                raise Exception("did not catch expected UserError")
 
         nonexistent(fs.Entry, 'nonexistent')
         nonexistent(fs.Entry, 'nonexistent/foo')
@@ -1318,7 +1308,7 @@ class FSTestCase(_tempdirTestCase):
             # 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
+            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()
@@ -1336,7 +1326,7 @@ class FSTestCase(_tempdirTestCase):
         f2 = test.workpath('tdir2', 'file2')
         test.write(f1, 'file1\n')
         test.write(f2, 'file2\n')
-        current_time = float(int(time.time() / 2) * 2)
+        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))
@@ -1434,7 +1424,7 @@ class FSTestCase(_tempdirTestCase):
         test.subdir('sub', ['sub', 'dir'])
 
         def drive_workpath(drive, dirs, test=test):
-            x = apply(test.workpath, dirs)
+            x = test.workpath(*dirs)
             drive, path = os.path.splitdrive(x)
             return 'X:' + path
 
@@ -1466,11 +1456,11 @@ class FSTestCase(_tempdirTestCase):
             seps = seps + ['/']
 
         def _do_Dir_test(lpath, path_, up_path_, sep, fileSys=fs):
-            dir = fileSys.Dir(string.replace(lpath, '/', sep))
+            dir = fileSys.Dir(lpath.replace('/', sep))
 
             if os.sep != '/':
-                path_ = string.replace(path_, '/', os.sep)
-                up_path_ = string.replace(up_path_, '/', 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:
@@ -1478,7 +1468,7 @@ class FSTestCase(_tempdirTestCase):
                 return p
             path = strip_slash(path_)
             up_path = strip_slash(up_path_)
-            name = string.split(path, os.sep)[-1]
+            name = path.split(os.sep)[-1]
 
             assert dir.name == name, \
                    "dir.name %s != expected name %s" % \
@@ -1577,8 +1567,8 @@ class FSTestCase(_tempdirTestCase):
 
         d1 = fs.Dir('d1')
         d2 = d1.Dir('d2')
-        dirs = string.split(os.path.normpath(d2.abspath), os.sep)
-        above_path = apply(os.path.join, ['..']*len(dirs) + ['above'])
+        dirs = os.path.normpath(d2.abspath).split(os.sep)
+        above_path = os.path.join(*['..']*len(dirs) + ['above'])
         above = d2.Dir(above_path)
 
     def test_rel_path(self):
@@ -1667,16 +1657,11 @@ class FSTestCase(_tempdirTestCase):
     def test_proxy(self):
         """Test a Node.FS object wrapped in a proxy instance"""
         f1 = self.fs.File('fff')
-        class Proxy:
-            # Simplest possibly Proxy class that works for our test,
-            # this is stripped down from SCons.Util.Proxy.
-            def __init__(self, subject):
-                self.__subject = subject
-            def __getattr__(self, name):
-                return getattr(self.__subject, name)
-        p = Proxy(f1)
+        class MyProxy(SCons.Util.Proxy):
+            __str__ = SCons.Util.Delegate('__str__')
+        p = MyProxy(f1)
         f2 = self.fs.Entry(p)
-        assert f1 is f2, (f1, f2)
+        assert f1 is f2, (f1, str(f1), f2, str(f2))
 
 
 
@@ -1730,8 +1715,7 @@ class DirTestCase(_tempdirTestCase):
         fs.Dir(os.path.join('ddd', 'd1', 'f4'))
         fs.Dir(os.path.join('ddd', 'd1', 'f5'))
         dir.scan()
-        kids = map(lambda x: x.path, dir.children(None))
-        kids.sort()
+        kids = sorted([x.path for x in dir.children(None)])
         assert kids == [os.path.join('ddd', 'd1'),
                         os.path.join('ddd', 'f1'),
                         os.path.join('ddd', 'f2'),
@@ -1756,8 +1740,7 @@ class DirTestCase(_tempdirTestCase):
         e = self.fs.Dir(os.path.join('d', 'empty'))
         s = self.fs.Dir(os.path.join('d', 'sub'))
 
-        #TODO(1.5) files = d.get_contents().split('\n')
-        files = string.split(d.get_contents(), '\n')
+        files = d.get_contents().split('\n')
 
         assert e.get_contents() == '', e.get_contents()
         assert e.get_text_contents() == '', e.get_text_contents()
@@ -1776,14 +1759,12 @@ class DirTestCase(_tempdirTestCase):
 
         fs.File(os.path.join('ddd', 'f1'))
         dir.scan()
-        kids = map(lambda x: x.path, dir.children())
-        kids.sort()
+        kids = sorted([x.path for x in dir.children()])
         assert kids == [os.path.join('ddd', 'f1')], kids
 
         fs.File(os.path.join('ddd', 'f2'))
         dir.scan()
-        kids = map(lambda x: x.path, dir.children())
-        kids.sort()
+        kids = sorted([x.path for x in dir.children()])
         assert kids == [os.path.join('ddd', 'f1'),
                         os.path.join('ddd', 'f2')], kids
 
@@ -1818,8 +1799,8 @@ class DirTestCase(_tempdirTestCase):
         self.fs.VariantDir(sub2, src, duplicate=0)
 
         def check(result, expect):
-            result = map(str, result)
-            expect = map(os.path.normpath, expect)
+            result = list(map(str, result))
+            expect = list(map(os.path.normpath, expect))
             assert result == expect, result
 
         s = src.srcdir_list()
@@ -1922,8 +1903,8 @@ class DirTestCase(_tempdirTestCase):
         exists_e.exists = return_true
 
         def check(result, expect):
-            result = map(str, result)
-            expect = map(os.path.normpath, expect)
+            result = list(map(str, result))
+            expect = list(map(os.path.normpath, expect))
             assert result == expect, result
 
         # First check from the source directory.
@@ -2095,14 +2076,17 @@ class EntryTestCase(_tempdirTestCase):
         assert e4n.__class__ is SCons.Node.FS.File, e4n.__class__
         assert not exists, "e4n exists?"
 
-        class MyCalc:
+        class MyCalc(object):
             def __init__(self, val):
                 self.max_drift = 0
-                class M:
+                class M(object):
                     def __init__(self, val):
                         self.val = val
                     def collect(self, args):
-                        return reduce(lambda x, y: x+y, args)
+                        result = 0
+                        for a in args:
+                            result += a
+                        return result
                     def signature(self, executor):
                         return self.val + 222
                 self.module = M(val)
@@ -2135,7 +2119,7 @@ class FileTestCase(_tempdirTestCase):
         d1 = self.fs.Dir('subdir/d1')
         d2 = self.fs.Dir('subdir/d2')
         dirs = fff.Dirs(['d1', 'd2'])
-        assert dirs == [d1, d2], map(str, dirs)
+        assert dirs == [d1, d2], list(map(str, dirs))
 
     def test_exists(self):
         """Test the File.exists() method"""
@@ -2248,8 +2232,7 @@ class GlobTestCase(_tempdirTestCase):
         strings_kwargs = copy.copy(kwargs)
         strings_kwargs['strings'] = True
         for input, string_expect, node_expect in cases:
-            r = apply(self.fs.Glob, (input,), strings_kwargs)
-            r.sort()
+            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
@@ -2259,26 +2242,25 @@ class GlobTestCase(_tempdirTestCase):
         # 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 = apply(self.fs.Glob, (input,), kwargs)
+            r = self.fs.Glob(input, **kwargs)
             if node_expect:
-                r.sort(lambda a,b: cmp(a.path, b.path))
+                r = sorted(r, key=lambda a: a.path)
                 result = []
                 for n in node_expect:
-                    if type(n) == type(''):
+                    if isinstance(n, str):
                         n = self.fs.Entry(n)
                     result.append(n)
                 fmt = lambda n: "%s %s" % (repr(n), repr(str(n)))
             else:
-                r = map(str, r)
-                r.sort()
+                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(map(fmt, result))
+                pprint.pprint(list(map(fmt, result)))
                 print "Glob(%s) got:" % repr(input)
-                pprint.pprint(map(fmt, r))
+                pprint.pprint(list(map(fmt, r)))
                 self.fail()
 
     def test_exact_match(self):
@@ -2538,7 +2520,7 @@ class RepositoryTestCase(_tempdirTestCase):
         ]
 
         rep = self.fs.Dir('#').getRepositories()
-        r = map(lambda x, np=os.path.normpath: np(str(x)), rep)
+        r = [os.path.normpath(str(x)) for x in rep]
         assert r == expect, r
 
     def test_get_all_rdirs(self):
@@ -2560,7 +2542,7 @@ class RepositoryTestCase(_tempdirTestCase):
         ]
 
         rep = self.fs.Dir('#').get_all_rdirs()
-        r = map(lambda x, np=os.path.normpath: np(str(x)), rep)
+        r = [os.path.normpath(str(x)) for x in rep]
         assert r == expect, r
 
     def test_rentry(self):
@@ -2742,25 +2724,25 @@ class RepositoryTestCase(_tempdirTestCase):
         rep3_sub_d1 = fs.Dir(test.workpath('rep3', 'sub', 'd1'))
 
         r = fs.Top.Rfindalldirs((d1,))
-        assert r == [d1], map(str, r)
+        assert r == [d1], list(map(str, r))
 
         r = fs.Top.Rfindalldirs((d1, d2))
-        assert r == [d1, d2], map(str, r)
+        assert r == [d1, d2], list(map(str, r))
 
         r = fs.Top.Rfindalldirs(('d1',))
-        assert r == [d1, rep1_d1, rep2_d1, rep3_d1], map(str, r)
+        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], map(str, r)
+        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], map(str, r)
+        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], map(str, r)
+        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], map(str, r)
+        assert r == [d1, rep1_d1, rep2_d1, rep3_d1, d2], list(map(str, r))
 
     def test_rexists(self):
         """Test the Entry.rexists() method"""
@@ -2800,7 +2782,7 @@ class RepositoryTestCase(_tempdirTestCase):
             # 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
+            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()
@@ -2831,8 +2813,8 @@ class RepositoryTestCase(_tempdirTestCase):
         try:
             eval('test_string = u"Con\x1aTents\n"')
         except SyntaxError:
-            import UserString
-            class FakeUnicodeString(UserString.UserString):
+            import collections
+            class FakeUnicodeString(collections.UserString):
                 def encode(self, encoding):
                     return str(self)
             test_string = FakeUnicodeString("Con\x1aTents\n")
@@ -2892,10 +2874,10 @@ class find_fileTestCase(unittest.TestCase):
         nodes.append(SCons.Node.FS.find_file('pseudo', paths))
         nodes.append(SCons.Node.FS.find_file('same', paths))
 
-        file_names = map(str, nodes)
-        file_names = map(os.path.normpath, file_names)
+        file_names = list(map(str, nodes))
+        file_names = list(map(os.path.normpath, file_names))
         expect = ['./foo', './bar/baz', './pseudo', './bar/same']
-        expect = map(os.path.normpath, expect)
+        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
@@ -2904,11 +2886,11 @@ class find_fileTestCase(unittest.TestCase):
         # 'bar/baz' as a Dir.
         SCons.Node.FS.find_file('baz/no_file_here', paths)
 
-        import StringIO
+        import io
         save_sys_stdout = sys.stdout
 
         try:
-            sio = StringIO.StringIO()
+            sio = io.StringIO()
             sys.stdout = sio
             SCons.Node.FS.find_file('foo2', paths, verbose="xyz")
             expect = "  xyz: looking for 'foo2' in '.' ...\n" + \
@@ -2916,7 +2898,7 @@ class find_fileTestCase(unittest.TestCase):
             c = sio.getvalue()
             assert c == expect, c
 
-            sio = StringIO.StringIO()
+            sio = io.StringIO()
             sys.stdout = sio
             SCons.Node.FS.find_file('baz2', paths, verbose=1)
             expect = "  find_file: looking for 'baz2' in '.' ...\n" + \
@@ -2925,7 +2907,7 @@ class find_fileTestCase(unittest.TestCase):
             c = sio.getvalue()
             assert c == expect, c
 
-            sio = StringIO.StringIO()
+            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" + \
@@ -2965,8 +2947,8 @@ class stored_infoTestCase(unittest.TestCase):
         bi = f.get_stored_info()
         assert hasattr(bi, 'ninfo')
 
-        class MySConsign:
-            class Null:
+        class MySConsign(object):
+            class Null(object):
                 def __init__(self):
                     self.xyzzy = 7
             def get_entry(self, name):
@@ -3433,14 +3415,14 @@ class SaveStringsTestCase(unittest.TestCase):
         fs1.VariantDir('d0', 'src', duplicate=0)
         fs1.VariantDir('d1', 'src', duplicate=1)
 
-        s = map(str, nodes)
-        expect = map(os.path.normpath, ['src/f', 'd1/f', 'd0/b', 'd1/b'])
+        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 = map(str, nodes)
-        expect = map(os.path.normpath, ['src/f', 'src/f', 'd0/b', 'd1/b'])
+        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)
@@ -3449,14 +3431,14 @@ class SaveStringsTestCase(unittest.TestCase):
         fs2.VariantDir('d0', 'src', duplicate=0)
         fs2.VariantDir('d1', 'src', duplicate=1)
 
-        s = map(str, nodes)
-        expect = map(os.path.normpath, ['src/f', 'd1/f', 'd0/b', 'd1/b'])
+        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 = map(str, nodes)
-        expect = map(os.path.normpath, ['src/f', 'd1/f', 'd0/b', 'd1/b'])
+        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
 
 
@@ -3509,7 +3491,7 @@ if __name__ == "__main__":
     ]
     for tclass in tclasses:
         names = unittest.getTestCaseNames(tclass, 'test_')
-        suite.addTests(map(tclass, names))
+        suite.addTests(list(map(tclass, names)))
     if not unittest.TextTestRunner().run(suite).wasSuccessful():
         sys.exit(1)
 
diff --git a/src/engine/SCons/Node/NodeTests.py b/src/engine/SCons/Node/NodeTests.py
index c8e5d96..2a09187 100644
--- a/src/engine/SCons/Node/NodeTests.py
+++ b/src/engine/SCons/Node/NodeTests.py
@@ -19,17 +19,16 @@
 # 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__ = "src/engine/SCons/Node/NodeTests.py 4720 2010/03/24 03:14:11 jars"
+__revision__ = "src/engine/SCons/Node/NodeTests.py 5023 2010/06/14 22:05:46 scons"
+
+import SCons.compat
 
+import collections
 import os
 import re
-import string
 import sys
-import types
 import unittest
-import UserList
 
 import SCons.Errors
 import SCons.Node
@@ -50,13 +49,13 @@ def _actionAppend(a1, a2):
             all.append(curr_a)
         elif isinstance(curr_a, MyListAction):
             all.extend(curr_a.list)
-        elif type(curr_a) == type([1,2]):
+        elif isinstance(curr_a, list):
             all.extend(curr_a)
         else:
-            raise 'Cannot Combine Actions'
+            raise Exception('Cannot Combine Actions')
     return MyListAction(all)
 
-class MyActionBase:
+class MyActionBase(object):
     def __add__(self, other):
         return _actionAppend(self, other)
 
@@ -83,7 +82,7 @@ class MyAction(MyActionBase):
     def get_implicit_deps(self, target, source, env):
         return []
 
-class MyExecutor:
+class MyExecutor(object):
     def __init__(self, env=None, targets=[], sources=[]):
         self.env = env
         self.targets = targets
@@ -114,7 +113,7 @@ class MyListAction(MyActionBase):
         for A in self.list:
             A(target, source, env)
 
-class Environment:
+class Environment(object):
     def __init__(self, **kw):
         self._dict = {}
         self._dict.update(kw)
@@ -125,7 +124,7 @@ class Environment:
     def Override(self, overrides):
         d = self._dict.copy()
         d.update(overrides)
-        return apply(Environment, (), d)
+        return Environment(**d)
     def _update(self, dict):
         self._dict.update(dict)
     def get_factory(self, factory):
@@ -133,7 +132,7 @@ class Environment:
     def get_scanner(self, scanner_key):
         return self._dict['SCANNERS'][0]
 
-class Builder:
+class Builder(object):
     def __init__(self, env=None, is_explicit=1):
         if env is None: env = Environment()
         self.env = env
@@ -167,19 +166,19 @@ class ListBuilder(Builder):
         target = self.nodes[0]
         self.status = Builder.execute(self, target, source, env)
 
-class FailBuilder:
+class FailBuilder(object):
     def execute(self, target, source, env):
         return 1
 
-class ExceptBuilder:
+class ExceptBuilder(object):
     def execute(self, target, source, env):
         raise SCons.Errors.BuildError
 
-class ExceptBuilder2:
+class ExceptBuilder2(object):
     def execute(self, target, source, env):
-        raise "foo"
+        raise Exception("foo")
 
-class Scanner:
+class Scanner(object):
     called = None
     def __call__(self, node):
         self.called = 1
@@ -205,16 +204,19 @@ class MyNode(SCons.Node.Node):
     def get_found_includes(self, env, scanner, target):
         return scanner(self)
 
-class Calculator:
+class Calculator(object):
     def __init__(self, val):
         self.max_drift = 0
-        class M:
+        class M(object):
             def __init__(self, val):
                 self.val = val
             def signature(self, args):
                 return self.val
             def collect(self, args):
-                return reduce(lambda x, y: x+y, args, self.val)
+                result = self.val
+                for a in args:
+                    result += a
+                return result
         self.module = M(val)
 
 
@@ -382,7 +384,7 @@ class NodeTestCase(unittest.TestCase):
         else:
             self.fail("did not catch expected AttributeError")
 
-        class Builder:
+        class Builder(object):
             action = 'act'
             env = 'env1'
             overrides = {}
@@ -616,7 +618,7 @@ class NodeTestCase(unittest.TestCase):
 
         class testNode2(SCons.Node.Node):
             def __str__(self): return 'null_binfo'
-        class FS:
+        class FS(object):
             pass
         node = testNode2()
         node.fs = FS()
@@ -625,8 +627,8 @@ class NodeTestCase(unittest.TestCase):
         assert result is None, result
 
         def get_null_info():
-            class Null_SConsignEntry:
-                class Null_BuildInfo:
+            class Null_SConsignEntry(object):
+                class Null_BuildInfo(object):
                     def prepare_dependencies(self):
                         pass
                 binfo = Null_BuildInfo()
@@ -786,7 +788,7 @@ class NodeTestCase(unittest.TestCase):
         except:
             pass
         else:
-            raise "did not catch expected exception"
+            raise Exception("did not catch expected exception")
         assert node.depends == [zero, one, two, three, four]
 
 
@@ -818,7 +820,7 @@ class NodeTestCase(unittest.TestCase):
         except:
             pass
         else:
-            raise "did not catch expected exception"
+            raise Exception("did not catch expected exception")
         assert node.sources == [zero, one, two, three, four], node.sources
 
     def test_add_ignore(self):
@@ -849,7 +851,7 @@ class NodeTestCase(unittest.TestCase):
         except:
             pass
         else:
-            raise "did not catch expected exception"
+            raise Exception("did not catch expected exception")
         assert node.ignore == [zero, one, two, three, four]
 
     def test_get_found_includes(self):
@@ -889,24 +891,24 @@ class NodeTestCase(unittest.TestCase):
         d2.found_includes = [e, f]
         f.found_includes = [g]
         deps = node.get_implicit_deps(env, s, target)
-        assert deps == [d1, d2, e, f, g], map(str, deps)
+        assert deps == [d1, d2, e, f, g], list(map(str, deps))
 
         # Recursive scanning eliminates duplicates
         e.found_includes = [f]
         deps = node.get_implicit_deps(env, s, target)
-        assert deps == [d1, d2, e, f, g], map(str, deps)
+        assert deps == [d1, d2, e, f, g], list(map(str, deps))
 
         # Scanner method can select specific nodes to recurse
         def no_fff(nodes):
-            return filter(lambda n: str(n)[0] != 'f', nodes)
+            return [n for n in nodes if str(n)[0] != 'f']
         s.recurse_nodes = no_fff
         deps = node.get_implicit_deps(env, s, target)
-        assert deps == [d1, d2, e, f], map(str, deps)
+        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, target)
-        assert deps == [d1, d2], map(str, deps)
+        assert deps == [d1, d2], list(map(str, deps))
 
     def test_get_env_scanner(self):
         """Test fetching the environment scanner for a Node
@@ -1102,22 +1104,22 @@ class NodeTestCase(unittest.TestCase):
 
         nw = SCons.Node.Walker(n1)
         assert not nw.is_done()
-        assert nw.next().name ==  "n1"
+        assert nw.get_next().name ==  "n1"
         assert nw.is_done()
-        assert nw.next() is None
+        assert nw.get_next() is None
 
         n2 = MyNode("n2")
         n3 = MyNode("n3")
         n1.add_source([n2, n3])
 
         nw = SCons.Node.Walker(n1)
-        n = nw.next()
+        n = nw.get_next()
         assert n.name ==  "n2", n.name
-        n = nw.next()
+        n = nw.get_next()
         assert n.name ==  "n3", n.name
-        n = nw.next()
+        n = nw.get_next()
         assert n.name ==  "n1", n.name
-        n = nw.next()
+        n = nw.get_next()
         assert n is None, n
 
         n4 = MyNode("n4")
@@ -1128,17 +1130,17 @@ class NodeTestCase(unittest.TestCase):
         n3.add_dependency([n6, n7])
 
         nw = SCons.Node.Walker(n1)
-        assert nw.next().name ==  "n4"
-        assert nw.next().name ==  "n5"
-        assert nw.history.has_key(n2)
-        assert nw.next().name ==  "n2"
-        assert nw.next().name ==  "n6"
-        assert nw.next().name ==  "n7"
-        assert nw.history.has_key(n3)
-        assert nw.next().name ==  "n3"
-        assert nw.history.has_key(n1)
-        assert nw.next().name ==  "n1"
-        assert nw.next() is None
+        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])
@@ -1151,16 +1153,16 @@ class NodeTestCase(unittest.TestCase):
         global cycle_detected
 
         nw = SCons.Node.Walker(n3, cycle_func = cycle)
-        n = nw.next()
+        n = nw.get_next()
         assert n.name == "n6", n.name
-        n = nw.next()
+        n = nw.get_next()
         assert n.name == "n8", n.name
         assert cycle_detected
         cycle_detected = None
-        n = nw.next()
+        n = nw.get_next()
         assert n.name == "n7", n.name
-        n = nw.next()
-        assert nw.next() is None
+        n = nw.get_next()
+        assert nw.get_next() is None
 
     def test_abspath(self):
         """Test the get_abspath() method."""
@@ -1275,16 +1277,9 @@ class NodeListTestCase(unittest.TestCase):
         nl = SCons.Node.NodeList([n3, n2, n1])
 
         l = [1]
-        ul = UserList.UserList([2])
-        try:
-            l.extend(ul)
-        except TypeError:
-            # An older version of Python (*cough* 1.5.2 *cough*)
-            # that doesn't allow UserList objects to extend lists.
-            pass
-        else:
-            s = str(nl)
-            assert s == "['n3', 'n2', 'n1']", s
+        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)
@@ -1293,7 +1288,7 @@ class NodeListTestCase(unittest.TestCase):
         # New-style classes report as "object"; classic classes report
         # as "instance"...
         r = re.sub("object", "instance", r)
-        l = string.join(["<MyNode instance at 0x>"]*3, ", ")
+        l = ", ".join(["<MyNode instance at 0x>"]*3)
         assert r == '[%s]' % l, r
 
 
@@ -1306,7 +1301,7 @@ if __name__ == "__main__":
                  NodeListTestCase ]
     for tclass in tclasses:
         names = unittest.getTestCaseNames(tclass, 'test_')
-        suite.addTests(map(tclass, names))
+        suite.addTests(list(map(tclass, names)))
     if not unittest.TextTestRunner().run(suite).wasSuccessful():
         sys.exit(1)
 
diff --git a/src/engine/SCons/Node/Python.py b/src/engine/SCons/Node/Python.py
index 53c2c80..be99d28 100644
--- a/src/engine/SCons/Node/Python.py
+++ b/src/engine/SCons/Node/Python.py
@@ -27,7 +27,7 @@ Python nodes.
 # WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #
 
-__revision__ = "src/engine/SCons/Node/Python.py 4720 2010/03/24 03:14:11 jars"
+__revision__ = "src/engine/SCons/Node/Python.py 5023 2010/06/14 22:05:46 scons"
 
 import SCons.Node
 
@@ -67,7 +67,7 @@ class Value(SCons.Node.Node):
 
     def build(self, **kw):
         if not hasattr(self, 'built_value'):
-            apply (SCons.Node.Node.build, (self,), kw)
+            SCons.Node.Node.build(self, **kw)
 
     is_up_to_date = SCons.Node.Node.children_are_up_to_date
 
diff --git a/src/engine/SCons/Node/PythonTests.py b/src/engine/SCons/Node/PythonTests.py
index dcf39ec..314b940 100644
--- a/src/engine/SCons/Node/PythonTests.py
+++ b/src/engine/SCons/Node/PythonTests.py
@@ -21,7 +21,7 @@
 # WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #
 
-__revision__ = "src/engine/SCons/Node/PythonTests.py 4720 2010/03/24 03:14:11 jars"
+__revision__ = "src/engine/SCons/Node/PythonTests.py 5023 2010/06/14 22:05:46 scons"
 
 import sys
 import unittest
@@ -51,7 +51,7 @@ class ValueTestCase(unittest.TestCase):
     def test_build(self):
         """Test "building" a Value Node
         """
-        class fake_executor:
+        class fake_executor(object):
             def __call__(self, node):
                 node.write('faked')
 
@@ -119,7 +119,7 @@ if __name__ == "__main__":
     ]
     for tclass in tclasses:
         names = unittest.getTestCaseNames(tclass, 'test_')
-        suite.addTests(map(tclass, names))
+        suite.addTests(list(map(tclass, names)))
     if not unittest.TextTestRunner().run(suite).wasSuccessful():
         sys.exit(1)
 
diff --git a/src/engine/SCons/Node/__init__.py b/src/engine/SCons/Node/__init__.py
index b0570b0..8d15b58 100644
--- a/src/engine/SCons/Node/__init__.py
+++ b/src/engine/SCons/Node/__init__.py
@@ -40,14 +40,12 @@ be able to depend on any other type of "thing."
 # 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__ = "src/engine/SCons/Node/__init__.py 4720 2010/03/24 03:14:11 jars"
+__revision__ = "src/engine/SCons/Node/__init__.py 5023 2010/06/14 22:05:46 scons"
 
+import collections
 import copy
-from itertools import chain, izip
-import string
-import UserList
+from itertools import chain
 
 from SCons.Debug import logInstanceCreation
 import SCons.Executor
@@ -57,7 +55,7 @@ import SCons.Util
 from SCons.Debug import Trace
 
 def classname(obj):
-    return string.split(str(obj.__class__), '.')[-1]
+    return str(obj.__class__).split('.')[-1]
 
 # Node states
 #
@@ -99,7 +97,7 @@ Annotate = do_nothing
 
 # Classes for signature info for Nodes.
 
-class NodeInfoBase:
+class NodeInfoBase(object):
     """
     The generic base class for signature information for a Node.
 
@@ -107,7 +105,7 @@ class NodeInfoBase:
     logic for dealing with their own Node-specific signature information.
     """
     current_version_id = 1
-    def __init__(self, node):
+    def __init__(self, node=None):
         # Create an object attribute from the class attribute so it ends up
         # in the pickled data in the .sconsign file.
         self._version_id = self.current_version_id
@@ -136,8 +134,7 @@ class NodeInfoBase:
             try:
                 field_list = self.field_list
             except AttributeError:
-                field_list = self.__dict__.keys()
-                field_list.sort()
+                field_list = sorted(self.__dict__.keys())
         fields = []
         for field in field_list:
             try:
@@ -150,7 +147,7 @@ class NodeInfoBase:
             fields.append(f)
         return fields
 
-class BuildInfoBase:
+class BuildInfoBase(object):
     """
     The generic base class for build information for a Node.
 
@@ -161,7 +158,7 @@ class BuildInfoBase:
     implicit dependencies, and action information.
     """
     current_version_id = 1
-    def __init__(self, node):
+    def __init__(self, node=None):
         # Create an object attribute from the class attribute so it ends up
         # in the pickled data in the .sconsign file.
         self._version_id = self.current_version_id
@@ -172,7 +169,7 @@ class BuildInfoBase:
     def merge(self, other):
         self.__dict__.update(other.__dict__)
 
-class Node:
+class Node(object):
     """The base Node class, for entities that we know how to
     build, or use to build other Nodes.
     """
@@ -182,7 +179,7 @@ class Node:
 
     memoizer_counters = []
 
-    class Attrs:
+    class Attrs(object):
         pass
 
     def __init__(self):
@@ -351,12 +348,12 @@ class Node:
         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)
+                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)
+                    raise SCons.Errors.StopError(msg % (i, self))
         self.binfo = self.get_binfo()
 
     def build(self, **kw):
@@ -372,7 +369,7 @@ class Node:
 
         """
         try:
-            apply(self.get_executor(), (self,), kw)
+            self.get_executor()(self, **kw)
         except SCons.Errors.BuildError, e:
             e.node = self
             raise
@@ -548,8 +545,7 @@ class Node:
         deps = []
         while nodes:
             n = nodes.pop(0)
-            d = filter(lambda x, seen=seen: not seen.has_key(x),
-                       n.get_found_includes(env, scanner, path))
+            d = [x for x in n.get_found_includes(env, scanner, path) if x not in seen]
             if d:
                 deps.extend(d)
                 for n in d:
@@ -832,7 +828,7 @@ class Node:
         except TypeError, e:
             e = e.args[0]
             if SCons.Util.is_List(e):
-                s = map(str, 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)))
@@ -849,7 +845,7 @@ class Node:
         except TypeError, e:
             e = e.args[0]
             if SCons.Util.is_List(e):
-                s = map(str, 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)))
@@ -863,7 +859,7 @@ class Node:
         except TypeError, e:
             e = e.args[0]
             if SCons.Util.is_List(e):
-                s = map(str, 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)))
@@ -1053,7 +1049,7 @@ class Node:
             if t: Trace(': old %s new %s' % (len(then), len(children)))
             result = True
 
-        for child, prev_ni in izip(children, then):
+        for child, prev_ni in zip(children, then):
             if child.changed_since_last_build(self, prev_ni):
                 if t: Trace(': %s changed' % child)
                 result = True
@@ -1199,8 +1195,8 @@ class Node:
         new_bkids    = new.bsources    + new.bdepends    + new.bimplicit
         new_bkidsigs = new.bsourcesigs + new.bdependsigs + new.bimplicitsigs
 
-        osig = dict(izip(old_bkids, old_bkidsigs))
-        nsig = dict(izip(new_bkids, new_bkidsigs))
+        osig = dict(zip(old_bkids, old_bkidsigs))
+        nsig = dict(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
@@ -1215,11 +1211,11 @@ class Node:
 
         lines = []
 
-        removed = filter(lambda x, nk=new_bkids: not x in nk, old_bkids)
+        removed = [x for x in old_bkids if not x in new_bkids]
         if removed:
-            removed = map(stringify, removed)
+            removed = list(map(stringify, removed))
             fmt = "`%s' is no longer a dependency\n"
-            lines.extend(map(lambda s, fmt=fmt: fmt % s, removed))
+            lines.extend([fmt % s for s in removed])
 
         for k in new_bkids:
             if not k in old_bkids:
@@ -1229,14 +1225,14 @@ class Node:
 
         if len(lines) == 0 and old_bkids != new_bkids:
             lines.append("the dependency order changed:\n" +
-                         "%sold: %s\n" % (' '*15, map(stringify, old_bkids)) +
-                         "%snew: %s\n" % (' '*15, map(stringify, new_bkids)))
+                         "%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 = string.split(strlines, '\n')
+                lines = strlines.split('\n')
                 sep = '\n' + ' '*(15 + len(title))
-                return ' '*15 + title + string.join(lines, sep) + '\n'
+                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" +
@@ -1254,31 +1250,22 @@ class Node:
             return "%s %s"  % (preamble, lines[0])
         else:
             lines = ["%s:\n" % preamble] + lines
-            return string.join(lines, ' '*11)
-
-try:
-    [].extend(UserList.UserList([]))
-except TypeError:
-    # Python 1.5.2 doesn't allow a list to be extended by list-like
-    # objects (such as UserList instances), so just punt and use
-    # real lists.
-    def NodeList(l):
-        return l
-else:
-    class NodeList(UserList.UserList):
-        def __str__(self):
-            return str(map(str, self.data))
+            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:
+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 next() call.
+    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
@@ -1298,7 +1285,7 @@ class Walker:
         self.history = {} # used to efficiently detect and avoid cycles
         self.history[node] = None
 
-    def next(self):
+    def get_next(self):
         """Return the next node for this walk of the tree.
 
         This function is intentionally iterative, not recursive,
@@ -1310,7 +1297,7 @@ class Walker:
                 node = self.stack[-1].wkids.pop(0)
                 if not self.stack[-1].wkids:
                     self.stack[-1].wkids = None
-                if self.history.has_key(node):
+                if node in self.history:
                     self.cycle_func(node, self.stack)
                 else:
                     node.wkids = copy.copy(self.kids_func(node, self.stack[-1]))