Merged revisions 1675-1736 via svnmerge from

http://scons.tigris.org/svn/scons/branches/core ........ r1689 | stevenknight | 2006-11-06 20:56:29 -0600 (Mon, 06 Nov 2006) | 1 line 0.96.D483 - Merge changes for 0.96.93 packaging from the subsidiary branch. ........ r1690 | stevenknight | 2006-11-06 20:59:30 -0600 (Mon, 06 Nov 2006) | 1 line 0.96.D484 - Update HOWTO for releases. Fix name type in src/CHANGES.txt. ........ r1691 | stevenknight | 2006-11-08 13:55:36 -0600 (Wed, 08 Nov 2006) | 1 line 0.96.D485 - Fix MergeFlags() handling of None values. (John Pye) ........ r1692 | stevenknight | 2006-11-08 17:15:05 -0600 (Wed, 08 Nov 2006) | 1 line 0.96.D486 - Directly execute commands on Windows when possible. (Jay Kint) ........ r1693 | stevenknight | 2006-11-08 18:54:49 -0600 (Wed, 08 Nov 2006) | 1 line 0.96.D487 - Remove the semi-colon from the list of characters that determine when we use cmd ........ r1694 | stevenknight | 2006-11-09 01:34:06 -0600 (Thu, 09 Nov 2006) | 1 line 0.96.D488 - Pick up latex/bibtex 'Rerun to get citations correct' messages. (Dmitry Mikhin) ........ r1695 | stevenknight | 2006-11-11 08:36:33 -0600 (Sat, 11 Nov 2006) | 1 line 0.96.D489 - Back out the direct-execution-on-Windows change until we solve a corner case. ........ r1696 | stevenknight | 2006-11-15 10:33:10 -0600 (Wed, 15 Nov 2006) | 1 line 0.96.D490 - Fix the sconsign script when the .sconsign.dblite file is specified with its suf ........ r1697 | stevenknight | 2006-11-18 10:45:50 -0600 (Sat, 18 Nov 2006) | 4 lines Complete move of test/sconsign/script.py to underneath test/sconsign/script/. (This got left out of the previous checkin due to an error in the script that resubmits Aegis changes to Subversion.) ........ r1698 | stevenknight | 2006-11-18 11:05:26 -0600 (Sat, 18 Nov 2006) | 1 line 0.96.D491 - Allow an Options converter to take the construction environment as a parameter. ........ r1699 | stevenknight | 2006-11-30 15:34:37 -0600 (Thu, 30 Nov 2006) | 1 line 0.96.D492 - Reverse the order in which we try the arguments Options converters, first a sing ........ r1700 | stevenknight | 2006-11-30 16:03:09 -0600 (Thu, 30 Nov 2006) | 1 line 0.96.D493 - Speed up rel_path() by avoiding recomputation of intermediate directory relative ........ r1701 | stevenknight | 2006-11-30 16:14:16 -0600 (Thu, 30 Nov 2006) | 1 line 0.96.D494 - More efficient get_suffix(): compute it once when we set the name. ........ r1702 | stevenknight | 2006-11-30 16:22:55 -0600 (Thu, 30 Nov 2006) | 1 line 0.96.D495 - Fix missing XML end tags. ........ r1703 | stevenknight | 2006-11-30 17:15:25 -0600 (Thu, 30 Nov 2006) | 1 line 0.96.D496 - Turn Memoizer into a simple counter for --debug=memoizer, not something that doe ........ r1704 | stevenknight | 2006-11-30 20:30:50 -0600 (Thu, 30 Nov 2006) | 1 line 0.96.D497 - Add the scons-time script, with doc and tests. ........ r1705 | stevenknight | 2006-11-30 23:28:20 -0600 (Thu, 30 Nov 2006) | 1 line 0.96.D498 - Update the copyright years string. ........ r1706 | stevenknight | 2006-12-01 11:54:22 -0600 (Fri, 01 Dec 2006) | 1 line 0.96.D499 - Fix _do_Lookup => _doLookup value-caching misspellings. (Ben Leslie) ........ r1707 | stevenknight | 2006-12-01 12:03:46 -0600 (Fri, 01 Dec 2006) | 1 line 0.96.D500 - Fix copyright test against debian build. (Walter Franzini) ........ r1708 | stevenknight | 2006-12-01 14:23:29 -0600 (Fri, 01 Dec 2006) | 1 line 0.96.D501 - Add #include lines for test portability. (Gary Oberbrunner) ........ r1709 | stevenknight | 2006-12-01 14:51:12 -0600 (Fri, 01 Dec 2006) | 1 line 0.96.D502 - Fix tests under Python versions with no profiler (pstats module). ........ r1710 | stevenknight | 2006-12-01 20:04:49 -0600 (Fri, 01 Dec 2006) | 1 line 0.96.D503 - Remove unnecessary os.path.normpath() calls. (Gary Oberbrunner) ........ r1711 | stevenknight | 2006-12-01 20:34:31 -0600 (Fri, 01 Dec 2006) | 1 line 0.96.D504 - Accomodate arbitray white space after a SWIG %module keyword. (Anonymous) ........ r1712 | stevenknight | 2006-12-05 14:49:54 -0600 (Tue, 05 Dec 2006) | 1 line 0.96.D506 - Cache substitutions of of Builder source suffixes. Use a new PathList module, and a refactor Node.FS.Rfindalldirs() method, to cache calculations of values like CPPPATH. ........ r1713 | stevenknight | 2006-12-05 18:43:36 -0600 (Tue, 05 Dec 2006) | 1 line 0.96.D507 - Use cached stat() values in diskchecks. ........ r1714 | stevenknight | 2006-12-05 21:11:24 -0600 (Tue, 05 Dec 2006) | 1 line 0.96.D508 - Fix Memoizer hit counts for methods memoizing simple values. Clean up the code for memoizing return values in a dictionary. Fix comments. ........ r1715 | stevenknight | 2006-12-06 07:23:18 -0600 (Wed, 06 Dec 2006) | 1 line 0.96.D369 - More efficient Node.FS.Dir.current() check. Fix some Windows test portability issues. ........ r1716 | stevenknight | 2006-12-06 12:24:32 -0600 (Wed, 06 Dec 2006) | 2 lines Undo previous checkin (distributed incorrect Aegis change number). ........ r1717 | stevenknight | 2006-12-06 12:34:53 -0600 (Wed, 06 Dec 2006) | 1 line 0.96.D505 - Update ae-{cvs,svn}-ci for newer versions of aetar, and to not truncate descriptions. ........ r1718 | stevenknight | 2006-12-07 23:01:41 -0600 (Thu, 07 Dec 2006) | 1 line 0.96.D509 - Only look for mslink on Windows systems. (Sohail Somani) ........ r1719 | stevenknight | 2006-12-07 23:18:33 -0600 (Thu, 07 Dec 2006) | 1 line 0.96.D510 - Have the D compiler Tool use the same logic for shared libraries, too. (Paolo Invernizzi) ........ r1720 | stevenknight | 2006-12-07 23:29:47 -0600 (Thu, 07 Dec 2006) | 1 line 0.96.D511 - Generalize a JobTests.py test so it doesn't assume a specific order in which the operating system executes the threads. ........ r1721 | stevenknight | 2006-12-07 23:39:37 -0600 (Thu, 07 Dec 2006) | 1 line 0.96.D512 - Back out the Tool/dmd.py change; it breaks shared library linking for other lanuages beside D in the construction environment. ........ r1722 | stevenknight | 2006-12-07 23:47:11 -0600 (Thu, 07 Dec 2006) | 1 line 0.96.D513 - Test fixes: Windows portability, handle changes to Python 2.5 messages. ........ r1723 | stevenknight | 2006-12-08 00:00:13 -0600 (Fri, 08 Dec 2006) | 1 line 0.96.D514 - Change how the 'as' Tool is imported to accomodate the Python 2.6 'as' keyword. ........ r1724 | stevenknight | 2006-12-08 11:19:27 -0600 (Fri, 08 Dec 2006) | 1 line 0.96.D515 - Cache both Node.FS.find_file() and Node.FS.Dri.srcdir_find_file(). ........ r1725 | stevenknight | 2006-12-08 17:27:35 -0600 (Fri, 08 Dec 2006) | 1 line 0.96.D516 - Better error when we try to fetch contents from an Entry that doesn't exist. (Tom Parker) ........ r1726 | stevenknight | 2006-12-08 23:28:55 -0600 (Fri, 08 Dec 2006) | 1 line 0.96.D517 - Make sure we pick up the scons-local directory regardless of where we chdir internally. ........ r1727 | stevenknight | 2006-12-11 16:25:53 -0600 (Mon, 11 Dec 2006) | 1 line 0.96.D518 - Cache results of Executor.get_unignored_sources() and Executor.process_sources(). Eliminate some map() and disambiguate() calls when scanning for implicit dependencies. ........ r1728 | stevenknight | 2006-12-12 14:32:22 -0600 (Tue, 12 Dec 2006) | 1 line 0.96.D519 - Fix SideEffect() when -j is used. ........ r1729 | stevenknight | 2006-12-12 16:58:15 -0600 (Tue, 12 Dec 2006) | 1 line 0.96.D520 - Add a srcdir keyword to Builder calls. ........ r1730 | stevenknight | 2006-12-12 21:40:59 -0600 (Tue, 12 Dec 2006) | 1 line 0.96.D521 - TeX/LaTeX updates, including handling files in subdirectories. (Joel B. Mohler, Rob Managan, Dmitry Mikhin) ........ r1731 | stevenknight | 2006-12-14 15:01:02 -0600 (Thu, 14 Dec 2006) | 1 line 0.96.D522 - Propogate TypeErrors during variable substitution for display to the user. ........ r1732 | stevenknight | 2006-12-14 20:01:49 -0600 (Thu, 14 Dec 2006) | 1 line 0.96.D523 - Fix the os.path.join() calls in EnvironmentTests.py. ........ r1733 | stevenknight | 2006-12-15 07:48:22 -0600 (Fri, 15 Dec 2006) | 1 line 0.96.D524 - Fix source directories as dependencies of an Alias (0.96.93 problem found by LilyPond). ........ r1735 | stevenknight | 2006-12-15 12:43:45 -0600 (Fri, 15 Dec 2006) | 1 line 0.96.D525 - Allow printing Debug.caller() output (or other end-of-run debugging info) when using -h. ........ r1736 | stevenknight | 2006-12-15 16:30:08 -0600 (Fri, 15 Dec 2006) | 1 line 0.96.D526 - Add an option to debug IndexError and NameError exceptions during variable substitution. ........
author: Steven Knight <knight@baldmt.com> 2006-12-16 01:43:01 (GMT)
committer: Steven Knight <knight@baldmt.com> 2006-12-16 01:43:01 (GMT)
commit: c4d04b3b45e7b71a1b28053b90084bcf2fdf9c0e (patch)
tree: 8a0d07c078ac21bf1ab689eacf06577069bb9231 /src/engine/SCons
parent: b32cd624a5ad9526d28584b8e6c4a7958f436424 (diff)
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46 files changed, 1798 insertions, 1326 deletions
diff --git a/src/engine/SCons/Action.py b/src/engine/SCons/Action.py
index 4576164..503dc9f 100644
--- a/src/engine/SCons/Action.py
+++ b/src/engine/SCons/Action.py
@@ -233,9 +233,6 @@ class ActionBase:
     """Base class for all types of action objects that can be held by
     other objects (Builders, Executors, etc.)  This provides the
     common methods for manipulating and combining those actions."""
-    
-    if SCons.Memoize.use_memoizer:
-        __metaclass__ = SCons.Memoize.Memoized_Metaclass
 
     def __cmp__(self, other):
         return cmp(self.__dict__, other)
@@ -266,15 +263,6 @@ class ActionBase:
         return SCons.Executor.Executor(self, env, overrides,
                                        tlist, slist, executor_kw)
 
-if SCons.Memoize.use_old_memoization():
-    _Base = ActionBase
-    class ActionBase(SCons.Memoize.Memoizer, _Base):
-        "Cache-backed version of ActionBase"
-        def __init__(self, *args, **kw):
-            apply(_Base.__init__, (self,)+args, kw)
-            SCons.Memoize.Memoizer.__init__(self)
-
-
 class _ActionAction(ActionBase):
     """Base class for actions that create output objects."""
     def __init__(self, strfunction=_null, presub=_null, chdir=None, exitstatfunc=None, **kw):
@@ -563,9 +551,6 @@ class CommandGeneratorAction(ActionBase):
 
 class LazyAction(CommandGeneratorAction, CommandAction):
 
-    if SCons.Memoize.use_memoizer:
-        __metaclass__ = SCons.Memoize.Memoized_Metaclass
-
     def __init__(self, var, *args, **kw):
         if __debug__: logInstanceCreation(self, 'Action.LazyAction')
         apply(CommandAction.__init__, (self, '$'+var)+args, kw)
@@ -580,7 +565,6 @@ class LazyAction(CommandGeneratorAction, CommandAction):
         return CommandGeneratorAction
 
     def _generate_cache(self, env):
-        """__cacheable__"""
         c = env.get(self.var, '')
         gen_cmd = apply(Action, (c,)+self.gen_args, self.gen_kw)
         if not gen_cmd:
@@ -599,13 +583,6 @@ class LazyAction(CommandGeneratorAction, CommandAction):
         c = self.get_parent_class(env)
         return c.get_contents(self, target, source, env)
 
-if not SCons.Memoize.has_metaclass:
-    _Base = LazyAction
-    class LazyAction(SCons.Memoize.Memoizer, _Base):
-        def __init__(self, *args, **kw):
-            SCons.Memoize.Memoizer.__init__(self)
-            apply(_Base.__init__, (self,)+args, kw)
-
 
 
 class FunctionAction(_ActionAction):
diff --git a/src/engine/SCons/Builder.py b/src/engine/SCons/Builder.py
index 16f1191..d5f566a 100644
--- a/src/engine/SCons/Builder.py
+++ b/src/engine/SCons/Builder.py
@@ -126,6 +126,7 @@ import SCons.Action
 from SCons.Debug import logInstanceCreation
 from SCons.Errors import InternalError, UserError
 import SCons.Executor
+import SCons.Memoize
 import SCons.Node
 import SCons.Node.FS
 import SCons.Util
@@ -370,6 +371,8 @@ class BuilderBase:
     if SCons.Memoize.use_memoizer:
         __metaclass__ = SCons.Memoize.Memoized_Metaclass
 
+    memoizer_counters = []
+
     def __init__(self,  action = None,
                         prefix = '',
                         suffix = '',
@@ -387,6 +390,7 @@ class BuilderBase:
                         is_explicit = 1,
                         **overrides):
         if __debug__: logInstanceCreation(self, 'Builder.BuilderBase')
+        self._memo = {}
         self.action = action
         self.multi = multi
         if SCons.Util.is_Dict(prefix):
@@ -604,6 +608,16 @@ class BuilderBase:
             ekw = self.executor_kw.copy()
             ekw['chdir'] = chdir
         if kw:
+            if kw.has_key('srcdir'):
+                def prependDirIfRelative(f, srcdir=kw['srcdir']):
+                    import os.path
+                    if SCons.Util.is_String(f) and not os.path.isabs(f):
+                        f = os.path.join(srcdir, f)
+                    return f
+                if not SCons.Util.is_List(source):
+                    source = [source]
+                source = map(prependDirIfRelative, source)
+                del kw['srcdir']
             if self.overrides:
                 env_kw = self.overrides.copy()
                 env_kw.update(kw)
@@ -636,9 +650,34 @@ class BuilderBase:
             suffix = suffix(env, sources)
         return env.subst(suffix)
 
+    def _src_suffixes_key(self, env):
+        return id(env)
+
+    memoizer_counters.append(SCons.Memoize.CountDict('src_suffixes', _src_suffixes_key))
+
     def src_suffixes(self, env):
-        "__cacheable__"
-        return map(lambda x, s=self, e=env: e.subst(x), self.src_suffix)
+        """
+        Returns the list of source suffixes for this Builder.
+
+        The suffix list may contain construction variable expansions,
+        so we have to evaluate the individual strings.  To avoid doing
+        this over and over, we memoize the results for each construction
+        environment.
+        """
+        memo_key = id(env)
+        try:
+            memo_dict = self._memo['src_suffixes']
+        except KeyError:
+            memo_dict = {}
+            self._memo['src_suffixes'] = memo_dict
+        else:
+            try:
+                return memo_dict[memo_key]
+            except KeyError:
+                pass
+        result = map(lambda x, s=self, e=env: e.subst(x), self.src_suffix)
+        memo_dict[memo_key] = result
+        return result
 
     def set_src_suffix(self, src_suffix):
         if not src_suffix:
@@ -673,13 +712,7 @@ class BuilderBase:
         """
         self.emitter[suffix] = emitter
 
-if SCons.Memoize.use_old_memoization():
-    _Base = BuilderBase
-    class BuilderBase(SCons.Memoize.Memoizer, _Base):
-        "Cache-backed version of BuilderBase"
-        def __init__(self, *args, **kw):
-            apply(_Base.__init__, (self,)+args, kw)
-            SCons.Memoize.Memoizer.__init__(self)
+
 
 class ListBuilder(SCons.Util.Proxy):
     """A Proxy to support building an array of targets (for example,
@@ -718,6 +751,9 @@ class MultiStepBuilder(BuilderBase):
     builder is NOT invoked if the suffix of a source file matches
     src_suffix.
     """
+
+    memoizer_counters = []
+
     def __init__(self,  src_builder,
                         action = None,
                         prefix = '',
@@ -738,8 +774,32 @@ class MultiStepBuilder(BuilderBase):
             src_builder = [ src_builder ]
         self.src_builder = src_builder
 
+    def _get_sdict_key(self, env):
+        return id(env)
+
+    memoizer_counters.append(SCons.Memoize.CountDict('_get_sdict', _get_sdict_key))
+
     def _get_sdict(self, env):
-        "__cacheable__"
+        """
+        Returns a dictionary mapping all of the source suffixes of all
+        src_builders of this Builder to the underlying Builder that
+        should be called first.
+
+        This dictionary is used for each target specified, so we save a
+        lot of extra computation by memoizing it for each construction
+        environment.
+        """
+        memo_key = id(env)
+        try:
+            memo_dict = self._memo['_get_sdict']
+        except KeyError:
+            memo_dict = {}
+            self._memo['_get_sdict'] = memo_dict
+        else:
+            try:
+                return memo_dict[memo_key]
+            except KeyError:
+                pass
         sdict = {}
         for bld in self.src_builder:
             if SCons.Util.is_String(bld):
@@ -749,6 +809,7 @@ class MultiStepBuilder(BuilderBase):
                     continue
             for suf in bld.src_suffixes(env):
                 sdict[suf] = bld
+        memo_dict[memo_key] = sdict
         return sdict
         
     def _execute(self, env, target, source, overwarn={}, executor_kw={}):
@@ -810,14 +871,36 @@ class MultiStepBuilder(BuilderBase):
             ret.append(bld)
         return ret
 
+    def _src_suffixes_key(self, env):
+        return id(env)
+
+    memoizer_counters.append(SCons.Memoize.CountDict('src_suffixes', _src_suffixes_key))
+
     def src_suffixes(self, env):
-        """Return a list of the src_suffix attributes for all
-        src_builders of this Builder.
-        __cacheable__
         """
+        Returns the list of source suffixes for all src_builders of this
+        Builder.
+
+        The suffix list may contain construction variable expansions,
+        so we have to evaluate the individual strings.  To avoid doing
+        this over and over, we memoize the results for each construction
+        environment.
+        """
+        memo_key = id(env)
+        try:
+            memo_dict = self._memo['src_suffixes']
+        except KeyError:
+            memo_dict = {}
+            self._memo['src_suffixes'] = memo_dict
+        else:
+            try:
+                return memo_dict[memo_key]
+            except KeyError:
+                pass
         suffixes = BuilderBase.src_suffixes(self, env)
         for builder in self.get_src_builders(env):
             suffixes.extend(builder.src_suffixes(env))
+        memo_dict[memo_key] = suffixes
         return suffixes
 
 class CompositeBuilder(SCons.Util.Proxy):
diff --git a/src/engine/SCons/BuilderTests.py b/src/engine/SCons/BuilderTests.py
index c5b428c..4e196e2 100644
--- a/src/engine/SCons/BuilderTests.py
+++ b/src/engine/SCons/BuilderTests.py
@@ -339,6 +339,11 @@ class BuilderTestCase(unittest.TestCase):
         else:
             raise "Did not catch expected UserError."
 
+        builder = SCons.Builder.Builder(action="foo")
+        target = builder(env, None, source='n22', srcdir='src_dir')[0]
+        p = target.sources[0].path
+        assert p == os.path.join('src_dir', 'n22'), p
+
     def test_mistaken_variables(self):
         """Test keyword arguments that are often mistakes
         """
@@ -1182,6 +1187,13 @@ class BuilderTestCase(unittest.TestCase):
                                        target_factory=MyNode,
                                        source_factory=MyNode)
 
+        builder2a=SCons.Builder.Builder(action='foo',
+                                        emitter="$FOO",
+                                        target_factory=MyNode,
+                                        source_factory=MyNode)
+
+        assert builder2 == builder2a, repr(builder2.__dict__) + "\n" + repr(builder2a.__dict__)
+
         tgt = builder2(env2, target='foo5', source='bar')[0]
         assert str(tgt) == 'foo5', str(tgt)
         assert str(tgt.sources[0]) == 'bar', str(tgt.sources[0])
@@ -1197,12 +1209,6 @@ class BuilderTestCase(unittest.TestCase):
         assert 'baz' in map(str, tgt.sources), map(str, tgt.sources)
         assert 'bar' in map(str, tgt.sources), map(str, tgt.sources)
 
-        builder2a=SCons.Builder.Builder(action='foo',
-                                        emitter="$FOO",
-                                        target_factory=MyNode,
-                                        source_factory=MyNode)
-        assert builder2 == builder2a, repr(builder2.__dict__) + "\n" + repr(builder2a.__dict__)
-
         # Test that, if an emitter sets a builder on the passed-in
         # targets and passes back new targets, the new builder doesn't
         # get overwritten.
@@ -1595,7 +1601,7 @@ class CompositeBuilderTestCase(unittest.TestCase):
 if __name__ == "__main__":
     suite = unittest.TestSuite()
     tclasses = [
-#        BuilderTestCase,
+        BuilderTestCase,
         CompositeBuilderTestCase
     ]
     for tclass in tclasses:
diff --git a/src/engine/SCons/Defaults.py b/src/engine/SCons/Defaults.py
index 7513c0d..96c3cf8 100644
--- a/src/engine/SCons/Defaults.py
+++ b/src/engine/SCons/Defaults.py
@@ -48,9 +48,10 @@ import sys
 import SCons.Action
 import SCons.Builder
 import SCons.Environment
-import SCons.Tool
+import SCons.PathList
 import SCons.Sig
 import SCons.Subst
+import SCons.Tool
 
 # A placeholder for a default Environment (for fetching source files
 # from source code management systems and the like).  This must be
@@ -214,7 +215,10 @@ def _concat(prefix, list, suffix, env, f=lambda x: x, target=None, source=None):
 
     if SCons.Util.is_List(list):
         list = SCons.Util.flatten(list)
-    list = f(env.subst_path(list, target=target, source=source))
+
+    l = f(SCons.PathList.PathList(list).subst_path(env, target, source))
+    if not l is None:
+        list = l
 
     result = []
 
diff --git a/src/engine/SCons/Environment.py b/src/engine/SCons/Environment.py
index a5bffc8..4761ea0 100644
--- a/src/engine/SCons/Environment.py
+++ b/src/engine/SCons/Environment.py
@@ -166,6 +166,10 @@ def _set_BUILDERS(env, key, value):
         env._dict[key] = BuilderDict(kwbd, env)
     env._dict[key].update(value)
 
+def _del_SCANNERS(env, key):
+    del env._dict[key]
+    env.scanner_map_delete()
+
 def _set_SCANNERS(env, key, value):
     env._dict[key] = value
     env.scanner_map_delete()
@@ -279,29 +283,35 @@ class SubstitutionEnvironment:
         self.lookup_list = SCons.Node.arg2nodes_lookups
         self._dict = kw.copy()
         self._init_special()
+        #self._memo = {}
 
     def _init_special(self):
-        """Initial the dispatch table for special handling of
+        """Initial the dispatch tables for special handling of
         special construction variables."""
-        self._special = {}
+        self._special_del = {}
+        self._special_del['SCANNERS'] = _del_SCANNERS
+
+        self._special_set = {}
         for key in reserved_construction_var_names:
-            self._special[key] = _set_reserved
-        self._special['BUILDERS'] = _set_BUILDERS
-        self._special['SCANNERS'] = _set_SCANNERS
+            self._special_set[key] = _set_reserved
+        self._special_set['BUILDERS'] = _set_BUILDERS
+        self._special_set['SCANNERS'] = _set_SCANNERS
 
     def __cmp__(self, other):
         return cmp(self._dict, other._dict)
 
     def __delitem__(self, key):
-        "__cache_reset__"
-        del self._dict[key]
+        special = self._special_del.get(key)
+        if special:
+            special(self, key)
+        else:
+            del self._dict[key]
 
     def __getitem__(self, key):
         return self._dict[key]
 
     def __setitem__(self, key, value):
-        "__cache_reset__"
-        special = self._special.get(key)
+        special = self._special_set.get(key)
         if special:
             special(self, key, value)
         else:
@@ -663,8 +673,10 @@ class SubstitutionEnvironment:
             except KeyError:
                 orig = value
             else:
-                if len(orig) == 0: orig = []
-                elif not SCons.Util.is_List(orig): orig = [orig]
+                if not orig:
+                    orig = []
+                elif not SCons.Util.is_List(orig): 
+                    orig = [orig]
                 orig = orig + value
             t = []
             if key[-4:] == 'PATH':
@@ -694,6 +706,8 @@ class Base(SubstitutionEnvironment):
     if SCons.Memoize.use_memoizer:
         __metaclass__ = SCons.Memoize.Memoized_Metaclass
 
+    memoizer_counters = []
+
     #######################################################################
     # This is THE class for interacting with the SCons build engine,
     # and it contains a lot of stuff, so we're going to try to keep this
@@ -725,6 +739,7 @@ class Base(SubstitutionEnvironment):
         with the much simpler base class initialization.
         """
         if __debug__: logInstanceCreation(self, 'Environment.Base')
+        self._memo = {}
         self.fs = SCons.Node.FS.default_fs or SCons.Node.FS.FS()
         self.ans = SCons.Node.Alias.default_ans
         self.lookup_list = SCons.Node.arg2nodes_lookups
@@ -786,7 +801,6 @@ class Base(SubstitutionEnvironment):
             return None
 
     def get_calculator(self):
-        "__cacheable__"
         try:
             module = self._calc_module
             c = apply(SCons.Sig.Calculator, (module,), CalculatorArgs)
@@ -800,7 +814,6 @@ class Base(SubstitutionEnvironment):
     def get_factory(self, factory, default='File'):
         """Return a factory function for creating Nodes for this
         construction environment.
-        __cacheable__
         """
         name = default
         try:
@@ -827,50 +840,54 @@ class Base(SubstitutionEnvironment):
             factory = getattr(self.fs, name)
         return factory
 
+    memoizer_counters.append(SCons.Memoize.CountValue('_gsm'))
+
     def _gsm(self):
-        "__cacheable__"
         try:
-            scanners = self._dict['SCANNERS']
+            return self._memo['_gsm']
         except KeyError:
-            return None
+            pass
 
-        sm = {}
-        # Reverse the scanner list so that, if multiple scanners
-        # claim they can scan the same suffix, earlier scanners
-        # in the list will overwrite later scanners, so that
-        # the result looks like a "first match" to the user.
-        if not SCons.Util.is_List(scanners):
-            scanners = [scanners]
+        result = {}
+
+        try:
+            scanners = self._dict['SCANNERS']
+        except KeyError:
+            pass
         else:
-            scanners = scanners[:] # copy so reverse() doesn't mod original
-        scanners.reverse()
-        for scanner in scanners:
-            for k in scanner.get_skeys(self):
-                sm[k] = scanner
-        return sm
+            # Reverse the scanner list so that, if multiple scanners
+            # claim they can scan the same suffix, earlier scanners
+            # in the list will overwrite later scanners, so that
+            # the result looks like a "first match" to the user.
+            if not SCons.Util.is_List(scanners):
+                scanners = [scanners]
+            else:
+                scanners = scanners[:] # copy so reverse() doesn't mod original
+            scanners.reverse()
+            for scanner in scanners:
+                for k in scanner.get_skeys(self):
+                    result[k] = scanner
+
+        self._memo['_gsm'] = result
+
+        return result
         
     def get_scanner(self, skey):
         """Find the appropriate scanner given a key (usually a file suffix).
         """
-        sm = self._gsm()
-        try: return sm[skey]
-        except (KeyError, TypeError): return None
+        return self._gsm().get(skey)
 
-    def _smd(self):
-        "__reset_cache__"
-        pass
-    
     def scanner_map_delete(self, kw=None):
         """Delete the cached scanner map (if we need to).
         """
-        if not kw is None and not kw.has_key('SCANNERS'):
-            return
-        self._smd()
+        try:
+            del self._memo['_gsm']
+        except KeyError:
+            pass
 
     def _update(self, dict):
         """Update an environment's values directly, bypassing the normal
         checks that occur when users try to set items.
-        __cache_reset__
         """
         self._dict.update(dict)
 
@@ -1014,7 +1031,9 @@ class Base(SubstitutionEnvironment):
             clone._dict['BUILDERS'] = BuilderDict(cbd, clone)
         except KeyError:
             pass
-        
+
+        clone._memo = {}
+
         apply_tools(clone, tools, toolpath)
 
         # Apply passed-in variables after the new tools.
@@ -1030,7 +1049,7 @@ class Base(SubstitutionEnvironment):
         return apply(self.Clone, args, kw)
 
     def Detect(self, progs):
-        """Return the first available program in progs.  __cacheable__
+        """Return the first available program in progs.
         """
         if not SCons.Util.is_List(progs):
             progs = [ progs ]
@@ -1306,7 +1325,7 @@ class Base(SubstitutionEnvironment):
         tool(self)
 
     def WhereIs(self, prog, path=None, pathext=None, reject=[]):
-        """Find prog in the path.  __cacheable__
+        """Find prog in the path.
         """
         if path is None:
             try:
@@ -1841,12 +1860,3 @@ def NoSubstitutionProxy(subject):
             self.raw_to_mode(nkw)
             return apply(SCons.Subst.scons_subst, nargs, nkw)
     return _NoSubstitutionProxy(subject)
-
-if SCons.Memoize.use_old_memoization():
-    _Base = Base
-    class Base(SCons.Memoize.Memoizer, _Base):
-        def __init__(self, *args, **kw):
-            SCons.Memoize.Memoizer.__init__(self)
-            apply(_Base.__init__, (self,)+args, kw)
-    Environment = Base
-
diff --git a/src/engine/SCons/EnvironmentTests.py b/src/engine/SCons/EnvironmentTests.py
index edf3740..f0f73da 100644
--- a/src/engine/SCons/EnvironmentTests.py
+++ b/src/engine/SCons/EnvironmentTests.py
@@ -728,6 +728,10 @@ sys.exit(1)
         env.MergeFlags('-X')
         assert env['CCFLAGS'] == ['-X'], env['CCFLAGS']
 
+        env = SubstitutionEnvironment(CCFLAGS=None)
+        env.MergeFlags('-Y')
+        assert env['CCFLAGS'] == ['-Y'], env['CCFLAGS']
+
         env = SubstitutionEnvironment()
         env.MergeFlags({'A':['aaa'], 'B':['bbb']})
         assert env['A'] == ['aaa'], env['A']
@@ -992,7 +996,7 @@ class BaseTestCase(unittest.TestCase,TestEnvironmentFixture):
                           LIBLINKSUFFIX = 'bar')
 
         def RDirs(pathlist, fs=env.fs):
-            return fs.Rfindalldirs(pathlist, fs.Dir('xx'))
+            return fs.Dir('xx').Rfindalldirs(pathlist)
 
         env['RDirs'] = RDirs
         flags = env.subst_list('$_LIBFLAGS', 1)[0]
@@ -2782,7 +2786,7 @@ def generate(env):
         tgt = env.Install('export', 'build')
         paths = map(str, tgt)
         paths.sort()
-        expect = ['export/build']
+        expect = [os.path.join('export', 'build')]
         assert paths == expect, paths
         for tnode in tgt:
             assert tnode.builder == InstallBuilder
@@ -2790,7 +2794,10 @@ def generate(env):
         tgt = env.Install('export', ['build', 'build/foo1'])
         paths = map(str, tgt)
         paths.sort()
-        expect = ['export/build', 'export/foo1']
+        expect = [
+            os.path.join('export', 'build'),
+            os.path.join('export', 'foo1'),
+        ]
         assert paths == expect, paths
         for tnode in tgt:
             assert tnode.builder == InstallBuilder
diff --git a/src/engine/SCons/Executor.py b/src/engine/SCons/Executor.py
index ffc1ba3..4b15010 100644
--- a/src/engine/SCons/Executor.py
+++ b/src/engine/SCons/Executor.py
@@ -47,6 +47,8 @@ class Executor:
     if SCons.Memoize.use_memoizer:
         __metaclass__ = SCons.Memoize.Memoized_Metaclass
 
+    memoizer_counters = []
+
     def __init__(self, action, env=None, overridelist=[{}],
                  targets=[], sources=[], builder_kw={}):
         if __debug__: logInstanceCreation(self, 'Executor.Executor')
@@ -58,6 +60,7 @@ class Executor:
         self.targets = targets
         self.sources = sources[:]
         self.builder_kw = builder_kw
+        self._memo = {}
 
     def set_action_list(self, action):
         if not SCons.Util.is_List(action):
@@ -72,7 +75,6 @@ class Executor:
     def get_build_env(self):
         """Fetch or create the appropriate build Environment
         for this Executor.
-        __cacheable__
         """
         # Create the build environment instance with appropriate
         # overrides.  These get evaluated against the current
@@ -125,8 +127,7 @@ class Executor:
         self.do_execute(target, exitstatfunc, kw)
 
     def cleanup(self):
-        "__reset_cache__"
-        pass
+        self._memo = {}
 
     def add_sources(self, sources):
         """Add source files to this Executor's list.  This is necessary
@@ -151,25 +152,30 @@ class Executor:
 
 
     def __str__(self):
-        "__cacheable__"
         return self.my_str()
 
     def nullify(self):
-        "__reset_cache__"
+        self.cleanup()
         self.do_execute = self.do_nothing
         self.my_str     = lambda S=self: ''
 
+    memoizer_counters.append(SCons.Memoize.CountValue('get_contents'))
+
     def get_contents(self):
-        """Fetch the signature contents.  This, along with
-        get_raw_contents(), is the real reason this class exists, so we
-        can compute this once and cache it regardless of how many target
-        or source Nodes there are.
-        __cacheable__
+        """Fetch the signature contents.  This is the main reason this
+        class exists, so we can compute this once and cache it regardless
+        of how many target or source Nodes there are.
         """
+        try:
+            return self._memo['get_contents']
+        except KeyError:
+            pass
         env = self.get_build_env()
         get = lambda action, t=self.targets, s=self.sources, e=env: \
                      action.get_contents(t, s, e)
-        return string.join(map(get, self.get_action_list()), "")
+        result = string.join(map(get, self.get_action_list()), "")
+        self._memo['get_contents'] = result
+        return result
 
     def get_timestamp(self):
         """Fetch a time stamp for this Executor.  We don't have one, of
@@ -219,20 +225,58 @@ class Executor:
 
     def get_missing_sources(self):
         """
-        __cacheable__
         """
         return filter(lambda s: s.missing(), self.sources)
 
-    def get_unignored_sources(self, ignore):
-        """__cacheable__"""
+    def _get_unignored_sources_key(self, ignore=()):
+        return tuple(ignore)
+
+    memoizer_counters.append(SCons.Memoize.CountDict('get_unignored_sources', _get_unignored_sources_key))
+
+    def get_unignored_sources(self, ignore=()):
+        ignore = tuple(ignore)
+        try:
+            memo_dict = self._memo['get_unignored_sources']
+        except KeyError:
+            memo_dict = {}
+            self._memo['get_unignored_sources'] = memo_dict
+        else:
+            try:
+                return memo_dict[ignore]
+            except KeyError:
+                pass
+
         sourcelist = self.sources
         if ignore:
             sourcelist = filter(lambda s, i=ignore: not s in i, sourcelist)
+
+        memo_dict[ignore] = sourcelist
+
         return sourcelist
 
-    def process_sources(self, func, ignore=[]):
-        """__cacheable__"""
-        return map(func, self.get_unignored_sources(ignore))
+    def _process_sources_key(self, func, ignore=()):
+        return (func, tuple(ignore))
+
+    memoizer_counters.append(SCons.Memoize.CountDict('process_sources', _process_sources_key))
+
+    def process_sources(self, func, ignore=()):
+        memo_key = (func, tuple(ignore))
+        try:
+            memo_dict = self._memo['process_sources']
+        except KeyError:
+            memo_dict = {}
+            self._memo['process_sources'] = memo_dict
+        else:
+            try:
+                return memo_dict[memo_key]
+            except KeyError:
+                pass
+
+        result = map(func, self.get_unignored_sources(ignore))
+
+        memo_dict[memo_key] = result
+
+        return result
 
 
 _Executor = Executor
@@ -258,13 +302,3 @@ class Null(_Executor):
         return None
     def cleanup(self):
         pass
-
-
-
-if SCons.Memoize.use_old_memoization():
-    _Base = Executor
-    class Executor(SCons.Memoize.Memoizer, _Base):
-        def __init__(self, *args, **kw):
-            SCons.Memoize.Memoizer.__init__(self)
-            apply(_Base.__init__, (self,)+args, kw)
-
diff --git a/src/engine/SCons/JobTests.py b/src/engine/SCons/JobTests.py
index d2c019f..e38e251 100644
--- a/src/engine/SCons/JobTests.py
+++ b/src/engine/SCons/JobTests.py
@@ -259,16 +259,14 @@ class ParallelTestCase(unittest.TestCase):
             jobs.run()
 
             # The key here is that we get(1) and get(2) from the
-            # resultsQueue before we put(3).
+            # resultsQueue before we put(3), but get(1) and get(2) can
+            # be in either order depending on how the first two parallel
+            # tasks get scheduled by the operating system.
             expect = [
-                'put(1)',
-                'put(2)',
-                'get(1)',
-                'get(2)',
-                'put(3)',
-                'get(3)',
+                ['put(1)', 'put(2)', 'get(1)', 'get(2)', 'put(3)', 'get(3)'],
+                ['put(1)', 'put(2)', 'get(2)', 'get(1)', 'put(3)', 'get(3)'],
             ]
-            assert ThreadPoolCallList == expect, ThreadPoolCallList
+            assert ThreadPoolCallList in expect, ThreadPoolCallList
 
         finally:
             SCons.Job.ThreadPool = SaveThreadPool
diff --git a/src/engine/SCons/Memoize.py b/src/engine/SCons/Memoize.py
index c2a3027..6a46350 100644
--- a/src/engine/SCons/Memoize.py
+++ b/src/engine/SCons/Memoize.py
@@ -1,66 +1,3 @@
-"""Memoizer
-
-Memoizer -- base class to provide automatic, optimized caching of
-method return values for subclassed objects.  Caching is activated by
-the presence of "__cacheable__" in the doc of a method (acts like a
-decorator).  The presence of "__cache_reset__" or "__reset_cache__"
-in the doc string instead indicates a method that should reset the
-cache, discarding any currently cached values.
-
-Note: current implementation is optimized for speed, not space.  The
-cache reset operation does not actually discard older results, and in
-fact, all cached results (and keys) are held indefinitely.
-
-Most of the work for this is done by copying and modifying the class
-definition itself, rather than the object instances.  This will
-therefore allow all instances of a class to get caching activated
-without requiring lengthy initialization or other management of the
-instance.
-
-[This could also be done using metaclassing (which would require
-Python 2.2) and decorators (which would require Python 2.4).  Current
-implementation is used due to Python 1.5.2 compatability requirement
-contraint.]
-
-A few notes:
-
-    * All local methods/attributes use a prefix of "_MeMoIZeR" to avoid
-      namespace collisions with the attributes of the objects
-      being cached.
-
-    * Based on performance evaluations of dictionaries, caching is
-      done by providing each object with a unique key attribute and
-      using the value of that attribute as an index for dictionary
-      lookup.  If an object doesn't have one of these attributes,
-      fallbacks are utilized (although they will be somewhat slower).
-
-      * To support this unique-value attribute correctly, it must be
-        removed whenever a __cmp__ operation is performed, and it must
-        be updated whenever a copy.copy or copy.deepcopy is performed,
-        so appropriate manipulation is provided by the Caching code
-        below.
-
-    * Cached values are stored in the class (indexed by the caching
-      key attribute, then by the name of the method called and the
-      constructed key of the arguments passed).  By storing them here
-      rather than on the instance, the instance can be compared,
-      copied, and pickled much easier.
-
-Some advantages:
-
-    * The method by which caching is implemented can be changed in a
-      single location and it will apply globally.
-
-    * Greatly simplified client code: remove lots of try...except or
-      similar handling of cached lookup.  Also usually more correct in
-      that it based caching on all input arguments whereas many
-      hand-implemented caching operations often miss arguments that
-      might affect results.
-
-    * Caching can be globally disabled very easily (for testing, etc.)
-
-"""
-
 #
 # __COPYRIGHT__
 #
@@ -86,752 +23,247 @@ Some advantages:
 
 __revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
 
-#TBD: for pickling, should probably revert object to unclassed state...
+__doc__ = """Memoizer
 
-import copy
-import os
-import string
-import sys
+A metaclass implementation to count hits and misses of the computed
+values that various methods cache in memory.
 
-# A flag controlling whether or not we actually use memoization.
-use_memoizer = 1
+Use of this modules assumes that wrapped methods be coded to cache their
+values in a consistent way.  Here is an example of wrapping a method
+that returns a computed value, with no input parameters:
 
-#
-# Generate a key for an object that is to be used as the caching key
-# for that object.
-#
-# Current implementation: singleton generating a monotonically
-# increasing integer
+    memoizer_counters = []                                      # Memoization
 
-class MemoizerKey:
-    def __init__(self):
-        self._next_keyval = 0
-    def __call__(self):
-        r = self._next_keyval
-        self._next_keyval = self._next_keyval + 1
-        return str(r)
-Next_Memoize_Key = MemoizerKey()
+    memoizer_counters.append(SCons.Memoize.CountValue('foo'))   # Memoization
 
+    def foo(self):
 
-#
-# Memoized Class management.
-#
-# Classes can be manipulated just like object instances; we are going
-# to do some of that here, without the benefit of metaclassing
-# introduced in Python 2.2 (it would be nice to use that, but this
-# attempts to maintain backward compatibility to Python 1.5.2).
-#
-# The basic implementation therefore is to update the class definition
-# for any objects that we want to enable caching for.  The updated
-# definition performs caching activities for those methods
-# appropriately marked in the original class.
-#
-# When an object is created, its class is switched to this updated,
-# cache-enabled class definition, thereby enabling caching operations.
-#
-# To get an instance to used the updated, caching class, the instance
-# must declare the Memoizer as a base class and make sure to call the
-# Memoizer's __init__ during the instance's __init__.  The Memoizer's
-# __init__ will perform the class updating.
-
-# For Python 2.2 and later, where metaclassing is supported, it is
-# sufficient to provide a "__metaclass__ = Memoized_Metaclass" as part
-# of the class definition; the metaclassing will automatically invoke
-# the code herein properly.
-
-##import cPickle
-##def ALT0_MeMoIZeR_gen_key(argtuple, kwdict):
-##    return cPickle.dumps( (argtuple,kwdict) )
-
-def ALT1_MeMoIZeR_gen_key(argtuple, kwdict):
-    return repr(argtuple) + '|' + repr(kwdict)
-
-def ALT2_MeMoIZeR_gen_key(argtuple, kwdict):
-    return string.join(map(lambda A:
-                           getattr(A, '_MeMoIZeR_Key', str(A)),
-                           argtuple) + \
-                       map(lambda D:
-                           str(D[0])+
-                           getattr(D[1], '_MeMoIZeR_Key', str(D[1])),
-                           kwdict.items()),
-                       '|')
-
-def ALT3_MeMoIZeR_gen_key(argtuple, kwdict):
-    ret = []
-    for A in argtuple:
-        X = getattr(A, '_MeMoIZeR_Key', None)
-        if X:
-            ret.append(X)
-        else:
-            ret.append(str(A))
-    for K,V in kwdict.items():
-        ret.append(str(K))
-        X = getattr(V, '_MeMoIZeR_Key', None)
-        if X:
-            ret.append(X)
-        else:
-            ret.append(str(V))
-    return string.join(ret, '|')
-
-def ALT4_MeMoIZeR_gen_key(argtuple, kwdict):
-    if kwdict:
-        return string.join(map(lambda A:
-                               getattr(A, '_MeMoIZeR_Key', None) or str(A),
-                               argtuple) + \
-                           map(lambda D:
-                               str(D[0])+
-                               (getattr(D[1], '_MeMoIZeR_Key', None) or str(D[1])),
-                               kwdict.items()),
-                           '|')
-    return string.join(map(lambda A:
-                        getattr(A, '_MeMoIZeR_Key', None) or str(A),
-                        argtuple),
-                       '!')
-
-def ALT5_MeMoIZeR_gen_key(argtuple, kwdict):
-    A = string.join(map(str, argtuple), '|')
-    K = ''
-    if kwdict:
-        I = map(lambda K,D=kwdict: str(K)+'='+str(D[K]), kwdict.keys())
-        K = string.join(I, '|')
-    return string.join([A,K], '!')
-
-def ALT6_MeMoIZeR_gen_key(argtuple, kwdict):
-    A = string.join(map(str, map(id, argtuple)), '|')
-    K = ''
-    if kwdict:
-        I = map(lambda K,D=kwdict: str(K)+'='+str(id(D[K])), kwdict.keys())
-        K = string.join(I, '|')
-    return string.join([A,K], '!')
-
-def ALT7_MeMoIZeR_gen_key(argtuple, kwdict):
-    A = string.join(map(repr, argtuple), '|')
-    K = ''
-    if kwdict:
-        I = map(lambda K,D=kwdict: repr(K)+'='+repr(D[K]), kwdict.keys())
-        K = string.join(I, '|')
-    return string.join([A,K], '!')
-
-def ALT8_MeMoIZeR_gen_key(argtuple, kwdict):
-    ret = []
-    for A in argtuple:
-        X = getattr(A, '_MeMoIZeR_Key', None)
-        if X:
-            ret.append(X)
-        else:
-            ret.append(repr(A))
-    for K,V in kwdict.items():
-        ret.append(str(K))
-        X = getattr(V, '_MeMoIZeR_Key', None)
-        if X:
-            ret.append(X)
-        else:
-            ret.append(repr(V))
-    return string.join(ret, '|')
+        try:                                                    # Memoization
+            return self._memo['foo']                            # Memoization
+        except KeyError:                                        # Memoization
+            pass                                                # Memoization
 
-def ALT9_MeMoIZeR_gen_key(argtuple, kwdict):
-    ret = []
-    for A in argtuple:
-        try:
-            X = A.__dict__.get('_MeMoIZeR_Key', None) or repr(A)
-        except (AttributeError, KeyError):
-            X = repr(A)
-        ret.append(X)
-    for K,V in kwdict.items():
-        ret.append(str(K))
-        ret.append('=')
-        try:
-            X = V.__dict__.get('_MeMoIZeR_Key', None) or repr(V)
-        except (AttributeError, KeyError):
-            X = repr(V)
-        ret.append(X)
-    return string.join(ret, '|')
-
-#_MeMoIZeR_gen_key = ALT9_MeMoIZeR_gen_key    # 8.8, 0.20
-_MeMoIZeR_gen_key = ALT8_MeMoIZeR_gen_key    # 8.5, 0.18
-#_MeMoIZeR_gen_key = ALT7_MeMoIZeR_gen_key    # 8.7, 0.17
-#_MeMoIZeR_gen_key = ALT6_MeMoIZeR_gen_key    #
-#_MeMoIZeR_gen_key = ALT5_MeMoIZeR_gen_key    # 9.7, 0.20
-#_MeMoIZeR_gen_key = ALT4_MeMoIZeR_gen_key    # 8.6, 0.19
-#_MeMoIZeR_gen_key = ALT3_MeMoIZeR_gen_key    # 8.5, 0.20
-#_MeMoIZeR_gen_key = ALT2_MeMoIZeR_gen_key    # 10.1, 0.22
-#_MeMoIZeR_gen_key = ALT1_MeMoIZeR_gen_key    # 8.6 0.18
-
-
-
-## This is really the core worker of the Memoize module.  Any
-## __cacheable__ method ends up calling this function which tries to
-## return a previously cached value if it exists, and which calls the
-## actual function and caches the return value if it doesn't already
-## exist.
-##
-## This function should be VERY efficient: it will get called a lot
-## and its job is to be faster than what would be called.
-
-def Memoizer_cache_get(func, cdict, args, kw):
-    """Called instead of name to see if this method call's return
-    value has been cached.  If it has, just return the cached
-    value; if not, call the actual method and cache the return."""
-
-    obj = args[0]
-
-    ckey = obj._MeMoIZeR_Key + ':' + _MeMoIZeR_gen_key(args, kw)
-
-##    try:
-##        rval = cdict[ckey]
-##    except KeyError:
-##        rval = cdict[ckey] = apply(func, args, kw)
-
-    rval = cdict.get(ckey, "_MeMoIZeR")
-    if rval is "_MeMoIZeR":
-        rval = cdict[ckey] = apply(func, args, kw)
-
-##    rval = cdict.setdefault(ckey, apply(func, args, kw))
-
-##    if cdict.has_key(ckey):
-##        rval = cdict[ckey]
-##    else:
-##        rval = cdict[ckey] = apply(func, args, kw)
-
-    return rval
-
-def Memoizer_cache_get_self(func, cdict, self):
-    """Called instead of func(self) to see if this method call's
-    return value has been cached.  If it has, just return the cached
-    value; if not, call the actual method and cache the return.
-    Optimized version of Memoizer_cache_get for methods that take the
-    object instance as the only argument."""
-
-    ckey = self._MeMoIZeR_Key
-
-##    try:
-##        rval = cdict[ckey]
-##    except KeyError:
-##        rval = cdict[ckey] = func(self)
-
-    rval = cdict.get(ckey, "_MeMoIZeR")
-    if rval is "_MeMoIZeR":
-        rval = cdict[ckey] = func(self)
-
-##    rval = cdict.setdefault(ckey, func(self)))
-
-##    if cdict.has_key(ckey):
-##        rval = cdict[ckey]
-##    else:
-##        rval = cdict[ckey] = func(self)
-
-    return rval
-
-def Memoizer_cache_get_one(func, cdict, self, arg):
-    """Called instead of func(self, arg) to see if this method call's
-    return value has been cached.  If it has, just return the cached
-    value; if not, call the actual method and cache the return.
-    Optimized version of Memoizer_cache_get for methods that take the
-    object instance and one other argument only."""
-
-##    X = getattr(arg, "_MeMoIZeR_Key", None)
-##    if X:
-##        ckey = self._MeMoIZeR_Key +':'+ X
-##    else:
-##        ckey = self._MeMoIZeR_Key +':'+ str(arg)
-    ckey = self._MeMoIZeR_Key + ':' + \
-           (getattr(arg, "_MeMoIZeR_Key", None) or repr(arg))
-
-##    try:
-##        rval = cdict[ckey]
-##    except KeyError:
-##        rval = cdict[ckey] = func(self, arg)
-
-    rval = cdict.get(ckey, "_MeMoIZeR")
-    if rval is "_MeMoIZeR":
-        rval = cdict[ckey] = func(self, arg)
+        result = self.compute_foo_value()
 
-##    rval = cdict.setdefault(ckey, func(self, arg)))
-
-##    if cdict.has_key(ckey):
-##        rval = cdict[ckey]
-##    else:
-##        rval = cdict[ckey] = func(self, arg)
+        self._memo['foo'] = result                              # Memoization
 
-    return rval
+        return result
 
-#
-# Caching stuff is tricky, because the tradeoffs involved are often so
-# non-obvious, so we're going to support an alternate set of functions
-# that also count the hits and misses, to try to get a concrete idea of
-# which Memoizations seem to pay off.
-#
-# Because different configurations can have such radically different
-# performance tradeoffs, interpreting the hit/miss results will likely be
-# more of an art than a science.  In other words, don't assume that just
-# because you see no hits in one configuration that it's not worthwhile
-# Memoizing that method.
-#
-# Note that these are essentially cut-and-paste copies of the above
-# Memozer_cache_get*() implementations, with the addition of the
-# counting logic.  If the above implementations change, the
-# corresponding change should probably be made down below as well,
-# just to try to keep things in sync.
-#
+Here is an example of wrapping a method that will return different values
+based on one or more input arguments:
 
-class CounterEntry:
-    def __init__(self):
-        self.hit = 0
-        self.miss = 0
+    def _bar_key(self, argument):                               # Memoization
+        return argument                                         # Memoization
 
-import UserDict
-class Counter(UserDict.UserDict):
-    def __call__(self, obj, methname):
-        k = obj.__class__.__name__ + '.' + methname
-        try:
-            return self[k]
-        except KeyError:
-            c = self[k] = CounterEntry()
-            return c
-
-CacheCount = Counter()
-CacheCountSelf = Counter()
-CacheCountOne = Counter()
-
-def Dump():
-    items = CacheCount.items() + CacheCountSelf.items() + CacheCountOne.items()
-    items.sort()
-    for k, v in items:
-        print "    %7d hits %7d misses   %s()" % (v.hit, v.miss, k)
-
-def Count_cache_get(name, func, cdict, args, kw):
-    """Called instead of name to see if this method call's return
-    value has been cached.  If it has, just return the cached
-    value; if not, call the actual method and cache the return."""
-
-    obj = args[0]
-
-    ckey = obj._MeMoIZeR_Key + ':' + _MeMoIZeR_gen_key(args, kw)
-
-    c = CacheCount(obj, name)
-    rval = cdict.get(ckey, "_MeMoIZeR")
-    if rval is "_MeMoIZeR":
-        rval = cdict[ckey] = apply(func, args, kw)
-        c.miss = c.miss + 1
-    else:
-        c.hit = c.hit + 1
-
-    return rval
-
-def Count_cache_get_self(name, func, cdict, self):
-    """Called instead of func(self) to see if this method call's
-    return value has been cached.  If it has, just return the cached
-    value; if not, call the actual method and cache the return.
-    Optimized version of Memoizer_cache_get for methods that take the
-    object instance as the only argument."""
-
-    ckey = self._MeMoIZeR_Key
-
-    c = CacheCountSelf(self, name)
-    rval = cdict.get(ckey, "_MeMoIZeR")
-    if rval is "_MeMoIZeR":
-        rval = cdict[ckey] = func(self)
-        c.miss = c.miss + 1
-    else:
-        c.hit = c.hit + 1
-
-    return rval
-
-def Count_cache_get_one(name, func, cdict, self, arg):
-    """Called instead of func(self, arg) to see if this method call's
-    return value has been cached.  If it has, just return the cached
-    value; if not, call the actual method and cache the return.
-    Optimized version of Memoizer_cache_get for methods that take the
-    object instance and one other argument only."""
-
-    ckey = self._MeMoIZeR_Key + ':' + \
-           (getattr(arg, "_MeMoIZeR_Key", None) or repr(arg))
-
-    c = CacheCountOne(self, name)
-    rval = cdict.get(ckey, "_MeMoIZeR")
-    if rval is "_MeMoIZeR":
-        rval = cdict[ckey] = func(self, arg)
-        c.miss = c.miss + 1
-    else:
-        c.hit = c.hit + 1
-
-    return rval
-
-MCG_dict = {
-    'MCG'  : Memoizer_cache_get,
-    'MCGS' : Memoizer_cache_get_self,
-    'MCGO' : Memoizer_cache_get_one,
-}
-
-MCG_lambda = "lambda *args, **kw: MCG(methcode, methcached, args, kw)"
-MCGS_lambda = "lambda self: MCGS(methcode, methcached, self)"
-MCGO_lambda = "lambda self, arg: MCGO(methcode, methcached, self, arg)"
-
-def EnableCounting():
-    """Enable counting of Memoizer hits and misses by overriding the
-    globals that hold the non-counting versions of the functions and
-    lambdas we call with the counting versions.
-    """
-    global MCG_dict
-    global MCG_lambda
-    global MCGS_lambda
-    global MCGO_lambda
+    memoizer_counters.append(SCons.Memoize.CountDict('bar', _bar_key)) # Memoization
 
-    MCG_dict = {
-        'MCG'  : Count_cache_get,
-        'MCGS' : Count_cache_get_self,
-        'MCGO' : Count_cache_get_one,
-    }
+    def bar(self, argument):
 
-    MCG_lambda = "lambda *args, **kw: MCG(methname, methcode, methcached, args, kw)"
-    MCGS_lambda = "lambda self: MCGS(methname, methcode, methcached, self)"
-    MCGO_lambda = "lambda self, arg: MCGO(methname, methcode, methcached, self, arg)"
+        memo_key = argument                                     # Memoization
+        try:                                                    # Memoization
+            memo_dict = self._memo['bar']                       # Memoization
+        except KeyError:                                        # Memoization
+            memo_dict = {}                                      # Memoization
+            self._memo['dict'] = memo_dict                      # Memoization
+        else:                                                   # Memoization
+            try:                                                # Memoization
+                return memo_dict[memo_key]                      # Memoization
+            except KeyError:                                    # Memoization
+                pass                                            # Memoization
 
+        result = self.compute_bar_value(argument)
 
+        memo_dict[memo_key] = result                            # Memoization
 
-class _Memoizer_Simple:
+        return result
 
-    def __setstate__(self, state):
-        self.__dict__.update(state)
-        self.__dict__['_MeMoIZeR_Key'] = Next_Memoize_Key()
-        #kwq: need to call original's setstate if it had one...
+At one point we avoided replicating this sort of logic in all the methods
+by putting it right into this module, but we've moved away from that at
+present (see the "Historical Note," below.).
 
-    def _MeMoIZeR_reset(self):
-        self.__dict__['_MeMoIZeR_Key'] = Next_Memoize_Key()
-        return 1
+Deciding what to cache is tricky, because different configurations
+can have radically different performance tradeoffs, and because the
+tradeoffs involved are often so non-obvious.  Consequently, deciding
+whether or not to cache a given method will likely be more of an art than
+a science, but should still be based on available data from this module.
+Here are some VERY GENERAL guidelines about deciding whether or not to
+cache return values from a method that's being called a lot:
 
+    --  The first question to ask is, "Can we change the calling code
+        so this method isn't called so often?"  Sometimes this can be
+        done by changing the algorithm.  Sometimes the *caller* should
+        be memoized, not the method you're looking at.
 
-class _Memoizer_Comparable:
+    --  The memoized function should be timed with multiple configurations
+        to make sure it doesn't inadvertently slow down some other
+        configuration.
 
-    def __setstate__(self, state):
-        self.__dict__.update(state)
-        self.__dict__['_MeMoIZeR_Key'] = Next_Memoize_Key()
-        #kwq: need to call original's setstate if it had one...
+    --  When memoizing values based on a dictionary key composed of
+        input arguments, you don't need to use all of the arguments
+        if some of them don't affect the return values.
 
-    def _MeMoIZeR_reset(self):
-        self.__dict__['_MeMoIZeR_Key'] = Next_Memoize_Key()
-        return 1
+Historical Note:  The initial Memoizer implementation actually handled
+the caching of values for the wrapped methods, based on a set of generic
+algorithms for computing hashable values based on the method's arguments.
+This collected caching logic nicely, but had two drawbacks:
 
-    def __cmp__(self, other):
-        """A comparison might use the object dictionaries to
-        compare, so the dictionaries should contain caching
-        entries.  Make new dictionaries without those entries
-        to use with the underlying comparison."""
+    Running arguments through a generic key-conversion mechanism is slower
+    (and less flexible) than just coding these things directly.  Since the
+    methods that need memoized values are generally performance-critical,
+    slowing them down in order to collect the logic isn't the right
+    tradeoff.
 
-        if self is other:
-            return 0
+    Use of the memoizer really obscured what was being called, because
+    all the memoized methods were wrapped with re-used generic methods.
+    This made it more difficult, for example, to use the Python profiler
+    to figure out how to optimize the underlying methods.
+"""
 
-        # We are here as a cached object, but cmp will flip its
-        # arguments back and forth and recurse attempting to get base
-        # arguments for the comparison, so we might have already been
-        # stripped.
+import new
 
-        try:
-            saved_d1 = self.__dict__
-            d1 = copy.copy(saved_d1)
-            del d1['_MeMoIZeR_Key']
-        except KeyError:
-            return self._MeMoIZeR_cmp(other)
-        self.__dict__ = d1
+# A flag controlling whether or not we actually use memoization.
+use_memoizer = None
 
-        # Same thing for the other, but we should try to convert it
-        # here in case the _MeMoIZeR_cmp compares __dict__ objects
-        # directly.
+CounterList = []
 
-        saved_other = None
-        try:
-            if other.__dict__.has_key('_MeMoIZeR_Key'):
-                saved_other = other.__dict__
-                d2 = copy.copy(saved_other)
-                del d2['_MeMoIZeR_Key']
-                other.__dict__ = d2
-        except (AttributeError, KeyError):
-            pass
-
-        # Both self and other have been prepared: perform the test,
-        # then restore the original dictionaries and exit
-
-        rval = self._MeMoIZeR_cmp(other)
-
-        self.__dict__ = saved_d1
-        if saved_other:
-            other.__dict__ = saved_other
-
-        return rval
-
-
-def Analyze_Class(klass):
-    if klass.__dict__.has_key('_MeMoIZeR_converted'): return klass
-
-    original_name = str(klass)
-
-    D,R,C = _analyze_classmethods(klass.__dict__, klass.__bases__)
-
-    if C:
-        modelklass = _Memoizer_Comparable
-        lcldict = {'_MeMoIZeR_cmp':C}
-    else:
-        modelklass = _Memoizer_Simple
-        lcldict = {}
-
-    klass.__dict__.update(memoize_classdict(klass, modelklass, lcldict, D, R))
-
-    return klass
-
-
-# Note that each eval("lambda...") has a few \n's prepended to the
-# lambda, and furthermore that each of these evals has a different
-# number of \n's prepended.  This is to provide a little bit of info
-# for traceback or profile output, which generate things like 'File
-# "<string>", line X'.  X will be the number of \n's plus 1.
-
-# Also use the following routine to specify the "filename" portion so
-# that it provides useful information.  In addition, make sure it
-# contains 'os.sep + "SCons" + os.sep' for the
-# SCons.Script.find_deepest_user_frame operation.
-
-def whoami(memoizer_funcname, real_funcname):
-    return '...'+os.sep+'SCons'+os.sep+'Memoizer-'+ \
-           memoizer_funcname+'-lambda<'+real_funcname+'>'
-
-def memoize_classdict(klass, modelklass, new_klassdict, cacheable, resetting):
-    new_klassdict.update(modelklass.__dict__)
-    new_klassdict['_MeMoIZeR_converted'] = 1
-
-    for name,code in cacheable.items():
-        eval_dict = {
-            'methname' : name,
-            'methcode' : code,
-            'methcached' : {},
-        }
-        eval_dict.update(MCG_dict)
-        fc = code.func_code
-        if fc.co_argcount == 1 and not fc.co_flags & 0xC:
-            compiled = compile("\n"*1 + MCGS_lambda,
-                               whoami('cache_get_self', name),
-                               "eval")
-        elif fc.co_argcount == 2 and not fc.co_flags & 0xC:
-            compiled = compile("\n"*2 + MCGO_lambda,
-                               whoami('cache_get_one', name),
-                               "eval")
+class Counter:
+    """
+    Base class for counting memoization hits and misses.
+
+    We expect that the metaclass initialization will have filled in
+    the .name attribute that represents the name of the function
+    being counted.
+    """
+    def __init__(self, method_name):
+        """
+        """
+        self.method_name = method_name
+        self.hit = 0
+        self.miss = 0
+        CounterList.append(self)
+    def display(self):
+        fmt = "    %7d hits %7d misses    %s()"
+        print fmt % (self.hit, self.miss, self.name)
+    def __cmp__(self, other):
+        return cmp(self.name, other.name)
+
+class CountValue(Counter):
+    """
+    A counter class for simple, atomic memoized values.
+
+    A CountValue object should be instantiated in a class for each of
+    the class's methods that memoizes its return value by simply storing
+    the return value in its _memo dictionary.
+
+    We expect that the metaclass initialization will fill in the
+    .underlying_method attribute with the method that we're wrapping.
+    We then call the underlying_method method after counting whether
+    its memoized value has already been set (a hit) or not (a miss).
+    """
+    def __call__(self, *args, **kw):
+        obj = args[0]
+        if obj._memo.has_key(self.method_name):
+            self.hit = self.hit + 1
         else:
-            compiled = compile("\n"*3 + MCG_lambda,
-                               whoami('cache_get', name),
-                               "eval")
-        newmethod = eval(compiled, eval_dict, {})
-        new_klassdict[name] = newmethod
-
-    for name,code in resetting.items():
-        newmethod = eval(
-            compile(
-            "lambda obj_self, *args, **kw: (obj_self._MeMoIZeR_reset(), apply(rmethcode, (obj_self,)+args, kw))[1]",
-            whoami('cache_reset', name),
-            'eval'),
-            {'rmethcode':code}, {})
-        new_klassdict[name] = newmethod
-
-    return new_klassdict
-
-def _analyze_classmethods(klassdict, klassbases):
-    """Given a class, performs a scan of methods for that class and
-    all its base classes (recursively). Returns aggregated results of
-    _scan_classdict calls where subclass methods are superimposed over
-    base class methods of the same name (emulating instance->class
-    method lookup)."""
-
-    D = {}
-    R = {}
-    C = None
-
-    # Get cache/reset/cmp methods from subclasses
-
-    for K in klassbases:
-        if K.__dict__.has_key('_MeMoIZeR_converted'): continue
-        d,r,c = _analyze_classmethods(K.__dict__, K.__bases__)
-        D.update(d)
-        R.update(r)
-        C = c or C
-
-    # Delete base method info if current class has an override
-
-    for M in D.keys():
-        if M == '__cmp__': continue
-        if klassdict.has_key(M):
-            del D[M]
-    for M in R.keys():
-        if M == '__cmp__': continue
-        if klassdict.has_key(M):
-            del R[M]
-
-    # Get cache/reset/cmp from current class
-
-    d,r,c = _scan_classdict(klassdict)
-
-    # Update accumulated cache/reset/cmp methods
-
-    D.update(d)
-    R.update(r)
-    C = c or C
-
-    return D,R,C
-
-
-def _scan_classdict(klassdict):
-    """Scans the method dictionary of a class to find all methods
-    interesting to caching operations.  Returns a tuple of these
-    interesting methods:
-
-      ( dict-of-cachable-methods,
-        dict-of-cache-resetting-methods,
-        cmp_method_val or None)
-
-    Each dict has the name of the method as a key and the corresponding
-    value is the method body."""
-
-    cache_setters = {}
-    cache_resetters = {}
-    cmp_if_exists = None
-    already_cache_modified = 0
-
-    for attr,val in klassdict.items():
-        if not callable(val): continue
-        if attr == '__cmp__':
-            cmp_if_exists = val
-            continue  # cmp can't be cached and can't reset cache
-        if attr == '_MeMoIZeR_cmp':
-            already_cache_modified = 1
-            continue
-        if not val.__doc__: continue
-        if string.find(val.__doc__, '__cache_reset__') > -1:
-            cache_resetters[attr] = val
-            continue
-        if string.find(val.__doc__, '__reset_cache__') > -1:
-            cache_resetters[attr] = val
-            continue
-        if string.find(val.__doc__, '__cacheable__') > -1:
-            cache_setters[attr] = val
-            continue
-    if already_cache_modified: cmp_if_exists = 'already_cache_modified'
-    return cache_setters, cache_resetters, cmp_if_exists
+            self.miss = self.miss + 1
+        return apply(self.underlying_method, args, kw)
 
-#
-# Primary Memoizer class.  This should be a base-class for any class
-# that wants method call results to be cached.  The sub-class should
-# call this parent class's __init__ method, but no other requirements
-# are made on the subclass (other than appropriate decoration).
+class CountDict(Counter):
+    """
+    A counter class for memoized values stored in a dictionary, with
+    keys based on the method's input arguments.
+
+    A CountDict object is instantiated in a class for each of the
+    class's methods that memoizes its return value in a dictionary,
+    indexed by some key that can be computed from one or more of
+    its input arguments.
+
+    We expect that the metaclass initialization will fill in the
+    .underlying_method attribute with the method that we're wrapping.
+    We then call the underlying_method method after counting whether the
+    computed key value is already present in the memoization dictionary
+    (a hit) or not (a miss).
+    """
+    def __init__(self, method_name, keymaker):
+        """
+        """
+        Counter.__init__(self, method_name)
+        self.keymaker = keymaker
+    def __call__(self, *args, **kw):
+        obj = args[0]
+        try:
+            memo_dict = obj._memo[self.method_name]
+        except KeyError:
+            self.miss = self.miss + 1
+        else:
+            key = apply(self.keymaker, args, kw)
+            if memo_dict.has_key(key):
+                self.hit = self.hit + 1
+            else:
+                self.miss = self.miss + 1
+        return apply(self.underlying_method, args, kw)
 
 class Memoizer:
     """Object which performs caching of method calls for its 'primary'
     instance."""
 
     def __init__(self):
-        self.__class__ = Analyze_Class(self.__class__)
-        self._MeMoIZeR_Key =  Next_Memoize_Key()
+        pass
+
+# Find out if we support metaclasses (Python 2.2 and later).
 
-# Find out if we are pre-2.2
+class M:
+    def __init__(cls, name, bases, cls_dict):
+        cls.has_metaclass = 1
+
+class A:
+    __metaclass__ = M
 
 try:
-    vinfo = sys.version_info
+    has_metaclass = A.has_metaclass
 except AttributeError:
-    """Split an old-style version string into major and minor parts.  This
-    is complicated by the fact that a version string can be something
-    like 3.2b1."""
-    import re
-    version = string.split(string.split(sys.version, ' ')[0], '.')
-    vinfo = (int(version[0]), int(re.match('\d+', version[1]).group()))
-    del re
-
-need_version = (2, 2) # actual
-#need_version = (33, 0)  # always
-#need_version = (0, 0)  # never
-
-has_metaclass =  (vinfo[0] > need_version[0] or \
-                  (vinfo[0] == need_version[0] and
-                   vinfo[1] >= need_version[1]))
+    has_metaclass = None
+
+del M
+del A
 
 if not has_metaclass:
 
+    def Dump(title):
+        pass
+
     class Memoized_Metaclass:
         # Just a place-holder so pre-metaclass Python versions don't
         # have to have special code for the Memoized classes.
         pass
 
+    def EnableMemoization():
+        import SCons.Warnings
+        msg = 'memoization is not supported in this version of Python (no metaclasses)'
+        raise SCons.Warnings.NoMetaclassSupportWarning, msg
+
 else:
 
-    # Initialization is a wee bit of a hassle.  We want to do some of
-    # our own work for initialization, then pass on to the actual
-    # initialization function.  However, we have to be careful we
-    # don't interfere with (a) the super()'s initialization call of
-    # it's superclass's __init__, and (b) classes we are Memoizing
-    # that don't have their own __init__ but which have a super that
-    # has an __init__.  To do (a), we eval a lambda below where the
-    # actual init code is locally bound and the __init__ entry in the
-    # class's dictionary is replaced with the _MeMoIZeR_init call.  To
-    # do (b), we use _MeMoIZeR_superinit as a fallback if the class
-    # doesn't have it's own __init__.  Note that we don't use getattr
-    # to obtain the __init__ because we don't want to re-instrument
-    # parent-class __init__ operations (and we want to avoid the
-    # Object object's slot init if the class has no __init__).
-
-    def _MeMoIZeR_init(actual_init, self, args, kw):
-        self.__dict__['_MeMoIZeR_Key'] =  Next_Memoize_Key()
-        apply(actual_init, (self,)+args, kw)
-
-    def _MeMoIZeR_superinit(self, cls, args, kw):
-        apply(super(cls, self).__init__, args, kw)
+    def Dump(title=None):
+        if title:
+            print title
+        CounterList.sort()
+        for counter in CounterList:
+            counter.display()
 
     class Memoized_Metaclass(type):
         def __init__(cls, name, bases, cls_dict):
-            # Note that cls_dict apparently contains a *copy* of the
-            # attribute dictionary of the class; modifying cls_dict
-            # has no effect on the actual class itself.
-            D,R,C = _analyze_classmethods(cls_dict, bases)
-            if C:
-                modelklass = _Memoizer_Comparable
-                cls_dict['_MeMoIZeR_cmp'] = C
-            else:
-                modelklass = _Memoizer_Simple
-            klassdict = memoize_classdict(cls, modelklass, cls_dict, D, R)
-
-            init = klassdict.get('__init__', None)
-            if not init:
-                # Make sure filename has os.sep+'SCons'+os.sep so that
-                # SCons.Script.find_deepest_user_frame doesn't stop here
-                import inspect # It's OK, can't get here for Python < 2.1
-                filename = inspect.getsourcefile(_MeMoIZeR_superinit)
-                if not filename:
-                    # This file was compiled at a path name different from
-                    # how it's invoked now, so just make up something.
-                    filename = whoami('superinit', '???')
-                superinitcode = compile(
-                    "lambda self, *args, **kw: MPI(self, cls, args, kw)",
-                    filename,
-                    "eval")
-                superinit = eval(superinitcode,
-                                 {'cls':cls,
-                                  'MPI':_MeMoIZeR_superinit})
-                init = superinit
-
-            newinitcode = compile(
-                "\n"*(init.func_code.co_firstlineno-1) +
-                "lambda self, args, kw: _MeMoIZeR_init(real_init, self, args, kw)",
-                whoami('init', init.func_code.co_filename),
-                'eval')
-            newinit = eval(newinitcode,
-                           {'real_init':init,
-                            '_MeMoIZeR_init':_MeMoIZeR_init},
-                           {})
-            klassdict['__init__'] = lambda self, *args, **kw: newinit(self, args, kw)
-
-            super(Memoized_Metaclass, cls).__init__(name, bases, klassdict)
-            # Now, since klassdict doesn't seem to have affected the class
-            # definition itself, apply klassdict.
-            for attr in klassdict.keys():
-                setattr(cls, attr, klassdict[attr])
-
-def DisableMemoization():
-    global use_memoizer
-    use_memoizer = None
-
-def use_old_memoization():
-    return use_memoizer and not has_metaclass
+            super(Memoized_Metaclass, cls).__init__(name, bases, cls_dict)
+
+            for counter in cls_dict.get('memoizer_counters', []):
+                method_name = counter.method_name
+
+                counter.name = cls.__name__ + '.' + method_name
+                counter.underlying_method = cls_dict[method_name]
+
+                replacement_method = new.instancemethod(counter, None, cls)
+                setattr(cls, method_name, replacement_method)
+
+    def EnableMemoization():
+        global use_memoizer
+        use_memoizer = 1
diff --git a/src/engine/SCons/MemoizeTests.py b/src/engine/SCons/MemoizeTests.py
new file mode 100644
index 0000000..7102f30
--- /dev/null
+++ b/src/engine/SCons/MemoizeTests.py
@@ -0,0 +1,192 @@
+#
+# __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 SCons.Memoize
+
+
+
+class FakeObject:
+
+    __metaclass__ = SCons.Memoize.Memoized_Metaclass
+
+    memoizer_counters = []
+
+    def __init__(self):
+        self._memo = {}
+
+    def _dict_key(self, argument):
+        return argument
+
+    memoizer_counters.append(SCons.Memoize.CountDict('dict', _dict_key))
+
+    def dict(self, argument):
+
+        memo_key = argument
+        try:
+            memo_dict = self._memo['dict']
+        except KeyError:
+            memo_dict = {}
+            self._memo['dict'] = memo_dict
+        else:
+            try:
+                return memo_dict[memo_key]
+            except KeyError:
+                pass
+
+        result = self.compute_dict(argument)
+
+        memo_dict[memo_key] = result
+
+        return result
+
+    memoizer_counters.append(SCons.Memoize.CountValue('value'))
+
+    def value(self):
+
+        try:
+            return self._memo['value']
+        except KeyError:
+            pass
+
+        result = self.compute_value()
+
+        self._memo['value'] = result
+
+        return result
+
+    def get_memoizer_counter(self, name):
+        for mc in self.memoizer_counters:
+            if mc.method_name == name:
+                return mc
+        return  None
+
+class Returner:
+    def __init__(self, result):
+        self.result = result
+        self.calls = 0
+    def __call__(self, *args, **kw):
+        self.calls = self.calls + 1
+        return self.result
+
+
+class CountDictTestCase(unittest.TestCase):
+
+    def test___call__(self):
+        """Calling a Memoized dict method
+        """
+        obj = FakeObject()
+
+        called = []
+
+        fd1 = Returner(1)
+        fd2 = Returner(2)
+
+        obj.compute_dict = fd1
+
+        r = obj.dict(11)
+        assert r == 1, r
+
+        obj.compute_dict = fd2
+
+        r = obj.dict(12)
+        assert r == 2, r
+
+        r = obj.dict(11)
+        assert r == 1, r
+
+        obj.compute_dict = fd1
+
+        r = obj.dict(11)
+        assert r == 1, r
+
+        r = obj.dict(12)
+        assert r == 2, r
+
+        assert fd1.calls == 1, fd1.calls
+        assert fd2.calls == 1, fd2.calls
+
+        c = obj.get_memoizer_counter('dict')
+
+        if SCons.Memoize.has_metaclass:
+            assert c.hit == 3, c.hit
+            assert c.miss == 2, c.miss
+        else:
+            assert c.hit == 0, c.hit
+            assert c.miss == 0, c.miss
+
+
+class CountValueTestCase(unittest.TestCase):
+
+    def test___call__(self):
+        """Calling a Memoized value method
+        """
+        obj = FakeObject()
+
+        called = []
+
+        fv1 = Returner(1)
+        fv2 = Returner(2)
+
+        obj.compute_value = fv1
+
+        r = obj.value()
+        assert r == 1, r
+        r = obj.value()
+        assert r == 1, r
+
+        obj.compute_value = fv2
+
+        r = obj.value()
+        assert r == 1, r
+        r = obj.value()
+        assert r == 1, r
+
+        assert fv1.calls == 1, fv1.calls
+        assert fv2.calls == 0, fv2.calls
+
+        c = obj.get_memoizer_counter('value')
+
+        if SCons.Memoize.has_metaclass:
+            assert c.hit == 3, c.hit
+            assert c.miss == 1, c.miss
+        else:
+            assert c.hit == 0, c.hit
+            assert c.miss == 0, c.miss
+
+
+if __name__ == "__main__":
+    suite = unittest.TestSuite()
+    tclasses = [
+        CountDictTestCase,
+        CountValueTestCase,
+    ]
+    for tclass in tclasses:
+        names = unittest.getTestCaseNames(tclass, 'test_')
+        suite.addTests(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 382bca3..08b8d7d 100644
--- a/src/engine/SCons/Node/FS.py
+++ b/src/engine/SCons/Node/FS.py
@@ -346,9 +346,20 @@ class DiskChecker:
             self.set_ignore()
 
 def do_diskcheck_match(node, predicate, errorfmt):
-    path = node.abspath
-    if predicate(path):
-        raise TypeError, errorfmt % path
+    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.abspath
 
 def ignore_diskcheck_match(node, predicate, errorfmt):
     pass
@@ -520,6 +531,8 @@ class Base(SCons.Node.Node):
     object identity comparisons.
     """
 
+    memoizer_counters = []
+
     def __init__(self, name, directory, fs):
         """Initialize a generic Node.FS.Base object.
         
@@ -531,6 +544,7 @@ class Base(SCons.Node.Node):
         SCons.Node.Node.__init__(self)
 
         self.name = name
+        self.suffix = SCons.Util.splitext(name)[1]
         self.fs = fs
 
         assert directory, "A directory must be provided"
@@ -550,20 +564,11 @@ class Base(SCons.Node.Node):
         self.cwd = None # will hold the SConscript directory for target nodes
         self.duplicate = directory.duplicate
 
-    def clear(self):
-        """Completely clear a Node.FS.Base object of all its cached
-        state (so that it can be re-evaluated by interfaces that do
-        continuous integration builds).
-        __cache_reset__
-        """
-        SCons.Node.Node.clear(self)
-
     def get_dir(self):
         return self.dir
 
     def get_suffix(self):
-        "__cacheable__"
-        return SCons.Util.splitext(self.name)[1]
+        return self.suffix
 
     def rfile(self):
         return self
@@ -576,9 +581,16 @@ class Base(SCons.Node.Node):
             return self._save_str()
         return self._get_str()
 
+    memoizer_counters.append(SCons.Memoize.CountValue('_save_str'))
+
     def _save_str(self):
-        "__cacheable__"
-        return self._get_str()
+        try:
+            return self._memo['_save_str']
+        except KeyError:
+            pass
+        result = self._get_str()
+        self._memo['_save_str'] = result
+        return result
 
     def _get_str(self):
         if self.duplicate or self.is_derived():
@@ -587,17 +599,20 @@ class Base(SCons.Node.Node):
 
     rstr = __str__
 
+    memoizer_counters.append(SCons.Memoize.CountValue('stat'))
+
     def stat(self):
-        "__cacheable__"
-        try: return self.fs.stat(self.abspath)
-        except os.error: return None
+        try: return self._memo['stat']
+        except KeyError: pass
+        try: result = self.fs.stat(self.abspath)
+        except os.error: result = None
+        self._memo['stat'] = result
+        return result
 
     def exists(self):
-        "__cacheable__"
         return not self.stat() is None
 
     def rexists(self):
-        "__cacheable__"
         return self.rfile().exists()
 
     def getmtime(self):
@@ -640,7 +655,7 @@ class Base(SCons.Node.Node):
         """If this node is in a build path, return the node
         corresponding to its source file.  Otherwise, return
         ourself.
-        __cacheable__"""
+        """
         dir=self.dir
         name=self.name
         while dir:
@@ -707,9 +722,48 @@ class Base(SCons.Node.Node):
     def target_from_source(self, prefix, suffix, splitext=SCons.Util.splitext):
         return self.dir.Entry(prefix + splitext(self.name)[0] + suffix)
 
+    def _Rfindalldirs_key(self, pathlist):
+        return pathlist
+
+    memoizer_counters.append(SCons.Memoize.CountDict('Rfindalldirs', _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."""
-        return self.fs.Rfindalldirs(pathlist, self.cwd)
+        cwd = self.cwd or self.fs._cwd
+        return cwd.Rfindalldirs(pathlist)
 
 class Entry(Base):
     """This is the class for generic Node.FS entries--that is, things
@@ -723,13 +777,35 @@ class Entry(Base):
         pass
 
     def disambiguate(self):
-        if self.isdir() or self.srcnode().isdir():
+        """
+        """
+        if self.isdir():
             self.__class__ = Dir
             self._morph()
-        else:
+        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()
+            else:
+                self.__class__ = File
+                self._morph()
+                self.clear()
         return self
 
     def rfile(self):
@@ -759,7 +835,8 @@ class Entry(Base):
             return self.get_contents()
         if self.islink():
             return ''             # avoid errors for dangling symlinks
-        raise AttributeError
+        msg = "No such file or directory: '%s'" % self.abspath
+        raise SCons.Errors.UserError, msg
 
     def must_be_a_Dir(self):
         """Called to make sure a Node is a Dir.  Since we're an
@@ -867,14 +944,6 @@ class LocalFS:
             return ''
 
 
-if SCons.Memoize.use_old_memoization():
-    _FSBase = LocalFS
-    class LocalFS(SCons.Memoize.Memoizer, _FSBase):
-        def __init__(self, *args, **kw):
-            apply(_FSBase.__init__, (self,)+args, kw)
-            SCons.Memoize.Memoizer.__init__(self)
-
-
 #class RemoteFS:
 #    # Skeleton for the obvious methods we might need from the
 #    # abstraction layer for a remote filesystem.
@@ -886,6 +955,8 @@ if SCons.Memoize.use_old_memoization():
 
 class FS(LocalFS):
 
+    memoizer_counters = []
+
     def __init__(self, path = None):
         """Initialize the Node.FS subsystem.
 
@@ -897,6 +968,8 @@ class FS(LocalFS):
         """
         if __debug__: logInstanceCreation(self, 'Node.FS')
 
+        self._memo = {}
+
         self.Root = {}
         self.SConstruct_dir = None
         self.CachePath = None
@@ -915,10 +988,6 @@ class FS(LocalFS):
         self.Top.path = '.'
         self.Top.tpath = '.'
         self._cwd = self.Top
-
-    def clear_cache(self):
-        "__cache_reset__"
-        pass
     
     def set_SConstruct_dir(self, dir):
         self.SConstruct_dir = dir
@@ -942,6 +1011,11 @@ class FS(LocalFS):
         raise TypeError, "Tried to lookup %s '%s' as a %s." % \
               (node.__class__.__name__, node.path, klass.__name__)
         
+    def _doLookup_key(self, fsclass, name, directory = None, create = 1):
+        return (fsclass, name, directory)
+
+    memoizer_counters.append(SCons.Memoize.CountDict('_doLookup', _doLookup_key))
+
     def _doLookup(self, fsclass, name, directory = None, create = 1):
         """This method differs from the File and Dir factory methods in
         one important way: the meaning of the directory parameter.
@@ -949,7 +1023,18 @@ class FS(LocalFS):
         name is expected to be an absolute path.  If you try to look up a
         relative path with directory=None, then an AssertionError will be
         raised.
-        __cacheable__"""
+        """
+        memo_key = (fsclass, name, directory)
+        try:
+            memo_dict = self._memo['_doLookup']
+        except KeyError:
+            memo_dict = {}
+            self._memo['_doLookup'] = memo_dict
+        else:
+            try:
+                return memo_dict[memo_key]
+            except KeyError:
+                pass
 
         if not name:
             # This is a stupid hack to compensate for the fact that the
@@ -990,6 +1075,7 @@ class FS(LocalFS):
                     self.Root[''] = directory
 
         if not path_orig:
+            memo_dict[memo_key] = directory
             return directory
 
         last_orig = path_orig.pop()     # strip last element
@@ -1040,6 +1126,9 @@ class FS(LocalFS):
             directory.add_wkid(result)
         else:
             result = self.__checkClass(e, fsclass)
+
+        memo_dict[memo_key] = result
+
         return result 
 
     def _transformPath(self, name, directory):
@@ -1067,7 +1156,8 @@ class FS(LocalFS):
                 # Correct such that '#/foo' is equivalent
                 # to '#foo'.
                 name = name[1:]
-            name = os.path.join('.', os.path.normpath(name))
+            name = os.path.normpath(os.path.join('.', name))
+            return (name, directory)
         elif not directory:
             directory = self._cwd
         return (os.path.normpath(name), directory)
@@ -1116,7 +1206,6 @@ class FS(LocalFS):
         This method will raise TypeError if a directory is found at the
         specified path.
         """
-
         return self.Entry(name, directory, create, File)
     
     def Dir(self, name, directory = None, create = 1):
@@ -1129,7 +1218,6 @@ class FS(LocalFS):
         This method will raise TypeError if a normal file is found at the
         specified path.
         """
-
         return self.Entry(name, directory, create, Dir)
     
     def BuildDir(self, build_dir, src_dir, duplicate=1):
@@ -1155,22 +1243,6 @@ class FS(LocalFS):
                 d = self.Dir(d)
             self.Top.addRepository(d)
 
-    def Rfindalldirs(self, pathlist, cwd):
-        """__cacheable__"""
-        if SCons.Util.is_String(pathlist):
-            pathlist = string.split(pathlist, os.pathsep)
-        if not SCons.Util.is_List(pathlist):
-            pathlist = [pathlist]
-        result = []
-        for path in filter(None, pathlist):
-            if isinstance(path, SCons.Node.Node):
-                result.append(path)
-                continue
-            path, dir = self._transformPath(path, cwd)
-            dir = dir.Dir(path)
-            result.extend(dir.get_all_rdirs())
-        return result
-
     def CacheDebugWrite(self, fmt, target, cachefile):
         self.CacheDebugFP.write(fmt % (target, os.path.split(cachefile)[1]))
 
@@ -1194,7 +1266,10 @@ class FS(LocalFS):
 
         Climb the directory tree, and look up path names
         relative to any linked build directories we find.
-        __cacheable__
+
+        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
@@ -1223,6 +1298,8 @@ class Dir(Base):
     """A class for directories in a file system.
     """
 
+    memoizer_counters = []
+
     NodeInfo = DirNodeInfo
     BuildInfo = DirBuildInfo
 
@@ -1238,7 +1315,7 @@ class Dir(Base):
         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.
-        __cache_reset__"""
+        """
 
         self.repositories = []
         self.srcdir = None
@@ -1258,8 +1335,8 @@ class Dir(Base):
         self.get_executor().set_action_list(self.builder.action)
 
     def diskcheck_match(self):
-        diskcheck_match(self, self.fs.isfile,
-                           "File %s found where directory expected.")
+        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.
@@ -1305,13 +1382,19 @@ class Dir(Base):
 
     def getRepositories(self):
         """Returns a list of repositories for this directory.
-        __cacheable__"""
+        """
         if self.srcdir and not self.duplicate:
             return self.srcdir.get_all_rdirs() + self.repositories
         return self.repositories
 
+    memoizer_counters.append(SCons.Memoize.CountValue('get_all_rdirs'))
+
     def get_all_rdirs(self):
-        """__cacheable__"""
+        try:
+            return self._memo['get_all_rdirs']
+        except KeyError:
+            pass
+
         result = [self]
         fname = '.'
         dir = self
@@ -1320,6 +1403,9 @@ class Dir(Base):
                 result.append(rep.Dir(fname))
             fname = dir.name + os.sep + fname
             dir = dir.up()
+
+        self._memo['get_all_rdirs'] = result
+
         return result
 
     def addRepository(self, dir):
@@ -1331,29 +1417,54 @@ class Dir(Base):
     def up(self):
         return self.entries['..']
 
+    def _rel_path_key(self, other):
+        return str(other)
+
+    memoizer_counters.append(SCons.Memoize.CountDict('rel_path', _rel_path_key))
+
     def rel_path(self, other):
         """Return a path to "other" relative to this directory.
-        __cacheable__"""
-        if isinstance(other, Dir):
-            name = []
+        """
+        try:
+            memo_dict = self._memo['rel_path']
+        except KeyError:
+            memo_dict = {}
+            self._memo['rel_path'] = memo_dict
         else:
             try:
-                name = [other.name]
-                other = other.dir
-            except AttributeError:
-                return str(other)
+                return memo_dict[other]
+            except KeyError:
+                pass
+
         if self is other:
-            return name and name[0] or '.'
-        i = 0
-        for x, y in map(None, self.path_elements, other.path_elements):
-            if not x is y:
-                break
-            i = i + 1
-        path_elems = ['..']*(len(self.path_elements)-i) \
-                   + map(lambda n: n.name, other.path_elements[i:]) \
-                   + name
+
+            result = '.'
+
+        elif not other in self.path_elements:
+
+            try:
+                other_dir = other.dir
+            except AttributeError:
+                result = str(other)
+            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) \
+                         + map(lambda n: n.name, other.path_elements[i:])
              
-        return string.join(path_elems, os.sep)
+            result = string.join(path_elems, os.sep)
+
+        memo_dict[other] = result
+
+        return result
 
     def get_env_scanner(self, env, kw={}):
         return SCons.Defaults.DirEntryScanner
@@ -1362,10 +1473,13 @@ class Dir(Base):
         return SCons.Defaults.DirEntryScanner
 
     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.
-        __cacheable__"""
+        """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
@@ -1451,7 +1565,6 @@ class Dir(Base):
         return 1
 
     def rdir(self):
-        "__cacheable__"
         if not self.exists():
             norm_name = _my_normcase(self.name)
             for dir in self.dir.get_all_rdirs():
@@ -1500,7 +1613,6 @@ class Dir(Base):
         return self
 
     def entry_exists_on_disk(self, name):
-        """__cacheable__"""
         try:
             d = self.on_disk_entries
         except AttributeError:
@@ -1515,8 +1627,14 @@ class Dir(Base):
             self.on_disk_entries = d
         return d.has_key(_my_normcase(name))
 
+    memoizer_counters.append(SCons.Memoize.CountValue('srcdir_list'))
+
     def srcdir_list(self):
-        """__cacheable__"""
+        try:
+            return self._memo['srcdir_list']
+        except KeyError:
+            pass
+
         result = []
 
         dirname = '.'
@@ -1533,6 +1651,8 @@ class Dir(Base):
             dirname = dir.name + os.sep + dirname
             dir = dir.up()
 
+        self._memo['srcdir_list'] = result
+
         return result
 
     def srcdir_duplicate(self, name):
@@ -1547,8 +1667,23 @@ class Dir(Base):
                     return srcnode
         return None
 
+    def _srcdir_find_file_key(self, filename):
+        return filename
+
+    memoizer_counters.append(SCons.Memoize.CountDict('srcdir_find_file', _srcdir_find_file_key))
+
     def srcdir_find_file(self, filename):
-        """__cacheable__"""
+        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.is_pseudo_derived() or node.exists()):
@@ -1562,7 +1697,9 @@ class Dir(Base):
             except KeyError: node = rdir.file_on_disk(filename)
             else: node = func(node)
             if node:
-                return node, self
+                result = (node, self)
+                memo_dict[filename] = result
+                return result
 
         for srcdir in self.srcdir_list():
             for rdir in srcdir.get_all_rdirs():
@@ -1570,9 +1707,13 @@ class Dir(Base):
                 except KeyError: node = rdir.file_on_disk(filename)
                 else: node = func(node)
                 if node:
-                    return File(filename, self, self.fs), srcdir
+                    result = (File(filename, self, self.fs), srcdir)
+                    memo_dict[filename] = result
+                    return result
 
-        return None, None
+        result = (None, None)
+        memo_dict[filename] = result
+        return result
 
     def dir_on_disk(self, name):
         if self.entry_exists_on_disk(name):
@@ -1720,12 +1861,14 @@ class File(Base):
     """A class for files in a file system.
     """
 
+    memoizer_counters = []
+
     NodeInfo = FileNodeInfo
     BuildInfo = FileBuildInfo
 
     def diskcheck_match(self):
-        diskcheck_match(self, self.fs.isdir,
-                           "Directory %s found where file expected.")
+        diskcheck_match(self, self.isdir,
+                        "Directory %s found where file expected.")
 
     def __init__(self, name, directory, fs):
         if __debug__: logInstanceCreation(self, 'Node.FS.File')
@@ -1760,7 +1903,7 @@ class File(Base):
     #            'RDirs' : self.RDirs}
 
     def _morph(self):
-        """Turn a file system node into a File object.  __cache_reset__"""
+        """Turn a file system node into a File object."""
         self.scanner_paths = {}
         if not hasattr(self, '_local'):
             self._local = 0
@@ -1789,7 +1932,6 @@ class File(Base):
         self.dir.sconsign().set_entry(self.name, entry)
 
     def get_stored_info(self):
-        "__cacheable__"
         try:
             stored = self.dir.sconsign().get_entry(self.name)
         except (KeyError, OSError):
@@ -1816,14 +1958,37 @@ class File(Base):
     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)
+
+    memoizer_counters.append(SCons.Memoize.CountDict('get_found_includes', _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.
-        __cacheable__"""
-        if not scanner:
-            return []
-        return scanner(self, env, path)
+        """
+        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 = scanner(self, env, path)
+            result = map(lambda N: N.disambiguate(), result)
+        else:
+            result = []
+
+        memo_dict[memo_key] = result
+
+        return result
 
     def _createDir(self):
         # ensure that the directories for this node are
@@ -1875,13 +2040,17 @@ class File(Base):
 
     def built(self):
         """Called just after this node is successfully built.
-        __cache_reset__"""
+        """
         # Push this file out to cache before the superclass Node.built()
         # method has a chance to clear the build signature, which it
         # will do if this file has a source scanner.
+        #
+        # We have to clear the memoized values *before* we push it to
+        # cache so that the memoization of the self.exists() return
+        # value doesn't interfere.
+        self.clear_memoized_values()
         if self.fs.CachePath and self.exists():
             CachePush(self, [], None)
-        self.fs.clear_cache()
         SCons.Node.Node.built(self)
 
     def visited(self):
@@ -1926,11 +2095,10 @@ class File(Base):
         return self.fs.build_dir_target_climb(self, self.dir, [self.name])
 
     def is_pseudo_derived(self):
-        "__cacheable__"
         return self.has_src_builder()
 
     def _rmv_existing(self):
-        '__cache_reset__'
+        self.clear_memoized_values()
         Unlink(self, [], None)
         
     def prepare(self):
@@ -1973,29 +2141,36 @@ class File(Base):
         # _rexists attributes so they can be reevaluated.
         self.clear()
 
+    memoizer_counters.append(SCons.Memoize.CountValue('exists'))
+
     def exists(self):
-        "__cacheable__"
+        try:
+            return self._memo['exists']
+        except KeyError:
+            pass
         # Duplicate from source path if we are set up to do this.
         if self.duplicate and not self.is_derived() and not self.linked:
             src = self.srcnode()
-            if src is self:
-                return Base.exists(self)
-            # At this point, src is meant to be copied in a build directory.
-            src = src.rfile()
-            if src.abspath != self.abspath:
-                if src.exists():
-                    self.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 build directory.
-                    if Base.exists(self) or self.islink():
-                        self.fs.unlink(self.path)
-                    # Return None explicitly because the Base.exists() call
-                    # above will have cached its value if the file existed.
-                    return None
-        return Base.exists(self)
+            if not src is self:
+                # At this point, src is meant to be copied in a build directory.
+                src = src.rfile()
+                if src.abspath != self.abspath:
+                    if src.exists():
+                        self.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 build directory.
+                        if Base.exists(self) or self.islink():
+                            self.fs.unlink(self.path)
+                        # Return None explicitly because the Base.exists() call
+                        # above will have cached its value if the file existed.
+                        self._memo['exists'] = None
+                        return None
+        result = Base.exists(self)
+        self._memo['exists'] = result
+        return result
 
     #
     # SIGNATURE SUBSYSTEM
@@ -2063,7 +2238,6 @@ class File(Base):
         self.binfo = self.gen_binfo(calc)
         return self._cur2()
     def _cur2(self):
-        "__cacheable__"
         if self.always_build:
             return None
         if not self.exists():
@@ -2082,8 +2256,14 @@ class File(Base):
         else:
             return self.is_up_to_date()
 
+    memoizer_counters.append(SCons.Memoize.CountValue('rfile'))
+
     def rfile(self):
-        "__cacheable__"
+        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():
@@ -2092,8 +2272,10 @@ class File(Base):
                 if node and node.exists() and \
                    (isinstance(node, File) or isinstance(node, Entry) \
                     or not node.is_derived()):
-                        return node
-        return self
+                        result = node
+                        break
+        self._memo['rfile'] = result
+        return result
 
     def rstr(self):
         return str(self.rfile())
@@ -2121,72 +2303,82 @@ class File(Base):
 
 default_fs = None
 
-def find_file(filename, paths, verbose=None):
+class FileFinder:
+    """
     """
-    find_file(str, [Dir()]) -> [nodes]
+    if SCons.Memoize.use_memoizer:
+        __metaclass__ = SCons.Memoize.Memoized_Metaclass
 
-    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.
+    memoizer_counters = []
 
-    returns - the node created from the found file.
+    def __init__(self):
+        self._memo = {}
 
-    Find a node corresponding to either a derived file or a file
-    that exists already.
+    def _find_file_key(self, filename, paths, verbose=None):
+        return (filename, paths)
+        
+    memoizer_counters.append(SCons.Memoize.CountDict('find_file', _find_file_key))
 
-    Only the first file found is returned, and none is returned
-    if no file is found.
-    __cacheable__
-    """
-    if verbose:
-        if not SCons.Util.is_String(verbose):
-            verbose = "find_file"
-        if not callable(verbose):
-            verbose = '  %s: ' % verbose
-            verbose = lambda s, v=verbose: sys.stdout.write(v + s)
-    else:
-        verbose = lambda x: x
+    def find_file(self, filename, paths, verbose=None):
+        """
+        find_file(str, [Dir()]) -> [nodes]
+
+        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.
 
-    if callable(paths):
-        paths = paths()
+        returns - the node created from the found file.
 
-    # Give Entries a chance to morph into Dirs.
-    paths = map(lambda p: p.must_be_a_Dir(), paths)
+        Find a node corresponding to either a derived file or a file
+        that exists already.
 
-    filedir, filename = os.path.split(filename)
-    if filedir:
-        def filedir_lookup(p, fd=filedir):
+        Only the first file found is returned, and none is returned
+        if no file is found.
+        """
+        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 p.Dir(fd)
-            except TypeError:
-                # We tried to look up a Dir, but it seems there's already
-                # a File (or something else) there.  No big.
-                return None
-        paths = filter(None, map(filedir_lookup, paths))
-
-    for dir in paths:
-        verbose("looking for '%s' in '%s' ...\n" % (filename, dir))
-        node, d = dir.srcdir_find_file(filename)
-        if node:
-            verbose("... FOUND '%s' in '%s'\n" % (filename, d))
-            return node
-    return None
+                return memo_dict[memo_key]
+            except KeyError:
+                pass
 
-def find_files(filenames, paths):
-    """
-    find_files([str], [Dir()]) -> [nodes]
+        if verbose:
+            if not SCons.Util.is_String(verbose):
+                verbose = "find_file"
+            if not callable(verbose):
+                verbose = '  %s: ' % verbose
+                verbose = lambda s, v=verbose: sys.stdout.write(v + s)
+        else:
+            verbose = lambda x: x
 
-    filenames - a list of filenames to find
-    paths - a list of directory path *nodes* to search in
+        filedir, filename = os.path.split(filename)
+        if filedir:
+            def filedir_lookup(p, fd=filedir):
+                try:
+                    return p.Dir(fd)
+                except TypeError:
+                    # We tried to look up a Dir, but it seems there's
+                    # already a File (or something else) there.  No big.
+                    return None
+            paths = filter(None, map(filedir_lookup, paths))
 
-    returns - the nodes created from the found files.
+        result = None
+        for dir in paths:
+            verbose("looking for '%s' in '%s' ...\n" % (filename, dir))
+            node, d = dir.srcdir_find_file(filename)
+            if node:
+                verbose("... FOUND '%s' in '%s'\n" % (filename, d))
+                result = node
+                break
 
-    Finds nodes corresponding to either derived files or files
-    that exist already.
+        memo_dict[memo_key] = result
 
-    Only the first file found is returned for each filename,
-    and any files that aren't found are ignored.
-    """
-    nodes = map(lambda x, paths=paths: find_file(x, paths), filenames)
-    return filter(None, nodes)
+        return result
+
+find_file = FileFinder().find_file
diff --git a/src/engine/SCons/Node/FSTests.py b/src/engine/SCons/Node/FSTests.py
index 1b38ffe..434709c 100644
--- a/src/engine/SCons/Node/FSTests.py
+++ b/src/engine/SCons/Node/FSTests.py
@@ -740,14 +740,22 @@ class FileNodeInfoTestCase(_tempdirTestCase):
 
         test.write('fff', "fff\n")
 
-        assert ni.timestamp != os.path.getmtime('fff'), ni.timestamp
-        assert ni.size != os.path.getsize('fff'), ni.size
+        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)
 
         fff.clear()
         ni.update(fff)
 
-        assert ni.timestamp == os.path.getmtime('fff'), ni.timestamp
-        assert ni.size == os.path.getsize('fff'), ni.size
+        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):
@@ -1219,9 +1227,9 @@ class FSTestCase(_tempdirTestCase):
         exc_caught = 0
         try:
             e.get_contents()
-        except AttributeError:
+        except SCons.Errors.UserError:
             exc_caught = 1
-        assert exc_caught, "Should have caught an AttributError"
+        assert exc_caught, "Should have caught an IOError"
 
         test.write("file", "file\n")
         try:
@@ -1266,18 +1274,18 @@ class FSTestCase(_tempdirTestCase):
         assert t == 0, "expected 0, got %s" % str(t)
 
         test.subdir('tdir2')
-        d = fs.Dir('tdir2')
         f1 = test.workpath('tdir2', 'file1')
         f2 = test.workpath('tdir2', 'file2')
         test.write(f1, 'file1\n')
         test.write(f2, 'file2\n')
-        fs.File(f1)
-        fs.File(f2)
         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)
 
@@ -1861,9 +1869,9 @@ class EntryTestCase(_tempdirTestCase):
         exc_caught = None
         try:
             e3n.get_contents()
-        except AttributeError:
+        except SCons.Errors.UserError:
             exc_caught = 1
-        assert exc_caught, "did not catch expected AttributeError"
+        assert exc_caught, "did not catch expected SCons.Errors.UserError"
 
         test.subdir('e4d')
         test.write('e4f', "e4f\n")
@@ -2133,25 +2141,25 @@ class RepositoryTestCase(_tempdirTestCase):
         rep2_sub_d1 = fs.Dir(test.workpath('rep2', 'sub', 'd1'))
         rep3_sub_d1 = fs.Dir(test.workpath('rep3', 'sub', 'd1'))
 
-        r = fs.Rfindalldirs(d1, fs.Top)
+        r = fs.Top.Rfindalldirs((d1,))
         assert r == [d1], map(str, r)
 
-        r = fs.Rfindalldirs([d1, d2], fs.Top)
+        r = fs.Top.Rfindalldirs((d1, d2))
         assert r == [d1, d2], map(str, r)
 
-        r = fs.Rfindalldirs('d1', fs.Top)
+        r = fs.Top.Rfindalldirs(('d1',))
         assert r == [d1, rep1_d1, rep2_d1, rep3_d1], map(str, r)
 
-        r = fs.Rfindalldirs('#d1', fs.Top)
+        r = fs.Top.Rfindalldirs(('#d1',))
         assert r == [d1, rep1_d1, rep2_d1, rep3_d1], map(str, r)
 
-        r = fs.Rfindalldirs('d1', sub)
+        r = sub.Rfindalldirs(('d1',))
         assert r == [sub_d1, rep1_sub_d1, rep2_sub_d1, rep3_sub_d1], map(str, r)
 
-        r = fs.Rfindalldirs('#d1', sub)
+        r = sub.Rfindalldirs(('#d1',))
         assert r == [d1, rep1_d1, rep2_d1, rep3_d1], map(str, r)
 
-        r = fs.Rfindalldirs(['d1', d2], fs.Top)
+        r = fs.Top.Rfindalldirs(('d1', d2))
         assert r == [d1, rep1_d1, rep2_d1, rep3_d1, d2], map(str, r)
 
     def test_rexists(self):
@@ -2223,6 +2231,7 @@ class find_fileTestCase(unittest.TestCase):
         """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')
@@ -2237,7 +2246,7 @@ class find_fileTestCase(unittest.TestCase):
         node_pseudo = fs.File(test.workpath('pseudo'))
         node_pseudo.set_src_builder(1) # Any non-zero value.
 
-        paths = map(fs.Dir, ['.', 'same', './bar'])
+        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))
@@ -2261,19 +2270,18 @@ class find_fileTestCase(unittest.TestCase):
         try:
             sio = StringIO.StringIO()
             sys.stdout = sio
-            SCons.Node.FS.find_file('foo', paths, verbose="xyz")
-            expect = "  xyz: looking for 'foo' in '.' ...\n" + \
-                     "  xyz: ... FOUND 'foo' in '.'\n"
+            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 = StringIO.StringIO()
             sys.stdout = sio
-            SCons.Node.FS.find_file('baz', paths, verbose=1)
-            expect = "  find_file: looking for 'baz' in '.' ...\n" + \
-                     "  find_file: looking for 'baz' in 'same' ...\n" + \
-                     "  find_file: looking for 'baz' in 'bar' ...\n" + \
-                     "  find_file: ... FOUND 'baz' in 'bar'\n"
+            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
 
@@ -2717,12 +2725,29 @@ class disambiguateTestCase(unittest.TestCase):
         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.BuildDir(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__
@@ -2731,6 +2756,10 @@ class disambiguateTestCase(unittest.TestCase):
         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."""
diff --git a/src/engine/SCons/Node/__init__.py b/src/engine/SCons/Node/__init__.py
index 42be5b1..e5d064e 100644
--- a/src/engine/SCons/Node/__init__.py
+++ b/src/engine/SCons/Node/__init__.py
@@ -166,6 +166,8 @@ class Node:
     if SCons.Memoize.use_memoizer:
         __metaclass__ = SCons.Memoize.Memoized_Metaclass
 
+    memoizer_counters = []
+
     class Attrs:
         pass
 
@@ -210,6 +212,8 @@ class Node:
         self.post_actions = []
         self.linked = 0 # is this node linked to the build directory?
 
+        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).
@@ -223,7 +227,7 @@ class Node:
 
     def get_build_env(self):
         """Fetch the appropriate Environment to build this node.
-        __cacheable__"""
+        """
         return self.get_executor().get_build_env()
 
     def get_build_scanner_path(self, scanner):
@@ -349,8 +353,8 @@ class Node:
         """Completely clear a Node of all its cached state (so that it
         can be re-evaluated by interfaces that do continuous integration
         builds).
-        __reset_cache__
         """
+        self.clear_memoized_values()
         self.executor_cleanup()
         self.del_binfo()
         try:
@@ -361,13 +365,15 @@ class Node:
         self.found_includes = {}
         self.implicit = None
 
+    def clear_memoized_values(self):
+        self._memo = {}
+
     def visited(self):
         """Called just after this node has been visited
         without requiring a build.."""
         pass
 
     def builder_set(self, builder):
-        "__cache_reset__"
         self.builder = builder
 
     def has_builder(self):
@@ -424,7 +430,6 @@ class Node:
         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.
-        __cacheable__
         """
         return self.has_builder() or self.side_effect
 
@@ -474,7 +479,6 @@ class Node:
             d = filter(lambda x, seen=seen: not seen.has_key(x),
                        n.get_found_includes(env, scanner, path))
             if d:
-                d = map(lambda N: N.disambiguate(), d)
                 deps.extend(d)
                 for n in d:
                     seen[n] = 1
@@ -609,24 +613,34 @@ class Node:
         env = self.env or SCons.Defaults.DefaultEnvironment()
         return env.get_calculator()
 
+    memoizer_counters.append(SCons.Memoize.CountValue('calc_signature'))
+
     def calc_signature(self, calc=None):
         """
         Select and calculate the appropriate build signature for a node.
-        __cacheable__
 
         self - the node
         calc - the signature calculation module
         returns - the signature
         """
+        try:
+            return self._memo['calc_signature']
+        except KeyError:
+            pass
         if self.is_derived():
             import SCons.Defaults
 
             env = self.env or SCons.Defaults.DefaultEnvironment()
             if env.use_build_signature():
-                return self.get_bsig(calc)
+                result = self.get_bsig(calc)
+            else:
+                result = self.get_csig(calc)
         elif not self.rexists():
-            return None
-        return self.get_csig(calc)
+            result = None
+        else:
+            result = self.get_csig(calc)
+        self._memo['calc_signature'] = result
+        return result
 
     def new_ninfo(self):
         return self.NodeInfo(self)
@@ -661,7 +675,6 @@ class Node:
         node's children's signatures.  We expect that they're
         already built and updated by someone else, if that's
         what's wanted.
-        __cacheable__
         """
 
         if calc is None:
@@ -676,7 +689,7 @@ class Node:
         def calc_signature(node, calc=calc):
             return node.calc_signature(calc)
 
-        sources = executor.process_sources(None, self.ignore)
+        sources = executor.get_unignored_sources(self.ignore)
         sourcesigs = executor.process_sources(calc_signature, self.ignore)
 
         depends = self.depends
@@ -767,7 +780,6 @@ class Node:
         return self.exists()
 
     def missing(self):
-        """__cacheable__"""
         return not self.is_derived() and \
                not self.is_pseudo_derived() and \
                not self.linked and \
@@ -850,7 +862,7 @@ class Node:
             self.wkids.append(wkid)
 
     def _children_reset(self):
-        "__cache_reset__"
+        self.clear_memoized_values()
         # We need to let the Executor clear out any calculated
         # bsig info that it's cached so we can re-calculate it.
         self.executor_cleanup()
@@ -881,11 +893,17 @@ class Node:
         else:
             return self.sources + self.depends + self.implicit
 
+    memoizer_counters.append(SCons.Memoize.CountValue('_children_get'))
+
     def _children_get(self):
-        "__cacheable__"
+        try:
+            return self._memo['children_get']
+        except KeyError:
+            pass
         children = self._all_children_get()
         if self.ignore:
             children = filter(self.do_not_ignore, children)
+        self._memo['children_get'] = children
         return children
 
     def all_children(self, scan=1):
@@ -1101,14 +1119,6 @@ else:
 del l
 del ul
 
-if SCons.Memoize.use_old_memoization():
-    _Base = Node
-    class Node(SCons.Memoize.Memoizer, _Base):
-        def __init__(self, *args, **kw):
-            apply(_Base.__init__, (self,)+args, kw)
-            SCons.Memoize.Memoizer.__init__(self)
-
-
 def get_children(node, parent): return node.children()
 def ignore_cycle(node, stack): pass
 def do_nothing(node, parent): pass
diff --git a/src/engine/SCons/Options/__init__.py b/src/engine/SCons/Options/__init__.py
index 83798b3..5c30be6 100644
--- a/src/engine/SCons/Options/__init__.py
+++ b/src/engine/SCons/Options/__init__.py
@@ -163,7 +163,10 @@ class Options:
             if option.converter and values.has_key(option.key):
                 value = env.subst('${%s}'%option.key)
                 try:
-                    env[option.key] = option.converter(value)
+                    try:
+                        env[option.key] = option.converter(value)
+                    except TypeError:
+                        env[option.key] = option.converter(value, env)
                 except ValueError, x:
                     raise SCons.Errors.UserError, 'Error converting option: %s\n%s'%(option.key, x)
 
diff --git a/src/engine/SCons/PathList.py b/src/engine/SCons/PathList.py
new file mode 100644
index 0000000..b757bd3
--- /dev/null
+++ b/src/engine/SCons/PathList.py
@@ -0,0 +1,217 @@
+#
+# __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__"
+
+__doc__ = """SCons.PathList
+
+A module for handling lists of directory paths (the sort of things
+that get set as CPPPATH, LIBPATH, etc.) with as much caching of data and
+efficiency as we can while still keeping the evaluation delayed so that we
+Do the Right Thing (almost) regardless of how the variable is specified.
+
+"""
+
+import os
+import string
+
+import SCons.Util
+
+#
+# Variables to specify the different types of entries in a PathList object:
+#
+
+TYPE_STRING_NO_SUBST = 0        # string with no '$'
+TYPE_STRING_SUBST = 1           # string containing '$'
+TYPE_OBJECT = 2                 # other object
+
+def node_conv(obj):
+    """
+    This is the "string conversion" routine that we have our substitutions
+    use to return Nodes, not strings.  This relies on the fact that an
+    EntryProxy object has a get() method that returns the underlying
+    Node that it wraps, which is a bit of architectural dependence
+    that we might need to break or modify in the future in response to
+    additional requirements.
+    """
+    try:
+        get = obj.get
+    except AttributeError:
+        pass
+    else:
+        obj = get()
+    return obj
+
+class _PathList:
+    """
+    An actual PathList object.
+    """
+    def __init__(self, pathlist):
+        """
+        Initializes a PathList object, canonicalizing the input and
+        pre-processing it for quicker substitution later.
+
+        The stored representation of the PathList is a list of tuples
+        containing (type, value), where the "type" is one of the TYPE_*
+        variables defined above.  We distinguish between:
+
+            strings that contain no '$' and therefore need no
+            delayed-evaluation string substitution (we expect that there
+            will be many of these and that we therefore get a pretty
+            big win from avoiding string substitution)
+
+            strings that contain '$' and therefore need substitution
+            (the hard case is things like '${TARGET.dir}/include',
+            which require re-evaluation for every target + source)
+
+            other objects (which may be something like an EntryProxy
+            that needs a method called to return a Node)
+
+        Pre-identifying the type of each element in the PathList up-front
+        and storing the type in the list of tuples is intended to reduce
+        the amount of calculation when we actually do the substitution
+        over and over for each target.
+        """
+        if SCons.Util.is_String(pathlist):
+            pathlist = string.split(pathlist, os.pathsep)
+        elif SCons.Util.is_List(pathlist) or SCons.Util.is_Tuple(pathlist):
+            pathlist = SCons.Util.flatten(pathlist)
+        else:
+            pathlist = [pathlist]
+
+        pl = []
+        for p in pathlist:
+            try:
+                index = string.find(p, '$')
+            except (AttributeError, TypeError):
+                type = TYPE_OBJECT
+            else:
+                if index == -1:
+                    type = TYPE_STRING_NO_SUBST
+                else:
+                    type = TYPE_STRING_SUBST
+            pl.append((type, p))
+
+        self.pathlist = tuple(pl)
+
+    def __len__(self): return len(self.pathlist)
+
+    def __getitem__(self, i): return self.pathlist[i]
+
+    def subst_path(self, env, target, source):
+        """
+        Performs construction variable substitution on a pre-digested
+        PathList for a specific target and source.
+        """
+        result = []
+        for type, value in self.pathlist:
+            if type == TYPE_STRING_SUBST:
+                value = env.subst(value, target=target, source=source,
+                                  conv=node_conv)
+            elif type == TYPE_OBJECT:
+                value = node_conv(value)
+            result.append(value)
+        return tuple(result)
+
+
+class PathListCache:
+    """
+    A class to handle caching of PathList lookups.
+
+    This class gets instantiated once and then deleted from the namespace,
+    so it's used as a Singleton (although we don't enforce that in the
+    usual Pythonic ways).  We could have just made the cache a dictionary
+    in the module namespace, but putting it in this class allows us to
+    use the same Memoizer pattern that we use elsewhere to count cache
+    hits and misses, which is very valuable.
+
+    Lookup keys in the cache are computed by the _PathList_key() method.
+    Cache lookup should be quick, so we don't spend cycles canonicalizing
+    all forms of the same lookup key.  For example, 'x:y' and ['x',
+    'y'] logically represent the same list, but we don't bother to
+    split string representations and treat those two equivalently.
+    (Note, however, that we do, treat lists and tuples the same.)
+
+    The main type of duplication we're trying to catch will come from
+    looking up the same path list from two different clones of the
+    same construction environment.  That is, given
+    
+        env2 = env1.Clone()
+
+    both env1 and env2 will have the same CPPPATH value, and we can
+    cheaply avoid re-parsing both values of CPPPATH by using the
+    common value from this cache.
+    """
+    if SCons.Memoize.use_memoizer:
+        __metaclass__ = SCons.Memoize.Memoized_Metaclass
+
+    memoizer_counters = []
+
+    def __init__(self):
+        self._memo = {}
+
+    def _PathList_key(self, pathlist):
+        """
+        Returns the key for memoization of PathLists.
+
+        Note that we want this to be quick, so we don't canonicalize
+        all forms of the same list.  For example, 'x:y' and ['x', 'y']
+        logically represent the same list, but we're not going to bother
+        massaging strings into canonical lists here.
+
+        The reason
+
+        """
+        if SCons.Util.is_List(pathlist):
+            pathlist = tuple(pathlist)
+        return pathlist
+        
+    memoizer_counters.append(SCons.Memoize.CountDict('PathList', _PathList_key))
+
+    def PathList(self, pathlist):
+        """
+        Returns the cached _PathList object for the specified pathlist,
+        creating and caching a new object as necessary.
+        """
+        pathlist = self._PathList_key(pathlist)
+        try:
+            memo_dict = self._memo['PathList']
+        except KeyError:
+            memo_dict = {}
+            self._memo['PathList'] = memo_dict
+        else:
+            try:
+                return memo_dict[pathlist]
+            except KeyError:
+                pass
+
+        result = _PathList(pathlist)
+
+        memo_dict[pathlist] = result
+
+        return result
+
+PathList = PathListCache().PathList
+
+
+del PathListCache
diff --git a/src/engine/SCons/PathListTests.py b/src/engine/SCons/PathListTests.py
new file mode 100644
index 0000000..d6fae0e
--- /dev/null
+++ b/src/engine/SCons/PathListTests.py
@@ -0,0 +1,145 @@
+#
+# __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 unittest
+
+import SCons.PathList
+
+
+class subst_pathTestCase(unittest.TestCase):
+
+    def setUp(self):
+
+        class FakeEnvironment:
+            def __init__(self, **kw):
+                self.kw = kw
+            def subst(self, s, target=None, source=None, conv=lambda x: x):
+                if s[0] == '$':
+                    s = s[1:]
+                    if s == 'target':
+                        s = target
+                    elif s == 'source':
+                        s = source
+                    else:
+                        s = self.kw[s]
+                return s
+
+        self.env = FakeEnvironment(AAA = 'aaa')
+
+    def test_object(self):
+        """Test the subst_path() method on an object
+        """
+
+        class A:
+            pass
+
+        a = A()
+
+        pl = SCons.PathList.PathList((a,))
+
+        result = pl.subst_path(self.env, 'y', 'z')
+
+        assert result == (a,), result
+
+    def test_object_get(self):
+        """Test the subst_path() method on an object with a get() method
+        """
+
+        class B:
+            def get(self):
+                return 'b'
+
+        b = B()
+
+        pl = SCons.PathList.PathList((b,))
+
+        result = pl.subst_path(self.env, 'y', 'z')
+
+        assert result == ('b',), result
+
+    def test_string(self):
+        """Test the subst_path() method on a non-substitution string
+        """
+
+        self.env.subst = lambda s, target, source, conv: 'NOT THIS STRING'
+
+        pl = SCons.PathList.PathList(('x'))
+
+        result = pl.subst_path(self.env, 'y', 'z')
+
+        assert result == ('x',), result
+
+    def test_subst(self):
+        """Test the subst_path() method on a substitution string
+        """
+
+        pl = SCons.PathList.PathList(('$AAA',))
+
+        result = pl.subst_path(self.env, 'y', 'z')
+
+        assert result == ('aaa',), result
+
+
+class PathListCacheTestCase(unittest.TestCase):
+
+    def test_no_PathListCache(self):
+        """Make sure the PathListCache class is not visible
+        """
+        try:
+            SCons.PathList.PathListCache
+        except AttributeError:
+            pass
+        else:
+            self.fail("Found PathListCache unexpectedly\n")
+
+
+class PathListTestCase(unittest.TestCase):
+
+    def test_PathList(self):
+        """Test the PathList() entry point
+        """
+
+        x1 = SCons.PathList.PathList(('x',))
+        x2 = SCons.PathList.PathList(['x',])
+
+        assert x1 is x2, (x1, x2)
+
+        x3 = SCons.PathList.PathList('x')
+
+        assert not x1 is x3, (x1, x3)
+
+
+if __name__ == "__main__":
+    suite = unittest.TestSuite()
+    tclasses = [
+        subst_pathTestCase,
+        PathListCacheTestCase,
+        PathListTestCase,
+    ]
+    for tclass in tclasses:
+        names = unittest.getTestCaseNames(tclass, 'test_')
+        suite.addTests(map(tclass, names))
+    if not unittest.TextTestRunner().run(suite).wasSuccessful():
+        sys.exit(1)
diff --git a/src/engine/SCons/Scanner/CTests.py b/src/engine/SCons/Scanner/CTests.py
index 2ca522b..5d6765d 100644
--- a/src/engine/SCons/Scanner/CTests.py
+++ b/src/engine/SCons/Scanner/CTests.py
@@ -179,17 +179,17 @@ class DummyEnvironment(UserDict.UserDict):
     def Dictionary(self, *args):
         return self.data
 
-    def subst(self, strSubst):
+    def subst(self, strSubst, target=None, source=None, conv=None):
         if strSubst[0] == '$':
             return self.data[strSubst[1:]]
         return strSubst
 
-    def subst_list(self, strSubst):
+    def subst_list(self, strSubst, target=None, source=None, conv=None):
         if strSubst[0] == '$':
             return [self.data[strSubst[1:]]]
         return [[strSubst]]
 
-    def subst_path(self, path, target=None, source=None):
+    def subst_path(self, path, target=None, source=None, conv=None):
         if type(path) != type([]):
             path = [path]
         return map(self.subst, path)
@@ -401,9 +401,12 @@ class CScannerTestCase13(unittest.TestCase):
     def runTest(self):
         """Find files in directories named in a substituted environment variable"""
         class SubstEnvironment(DummyEnvironment):
-            def subst(self, arg, test=test):
-                return test.workpath("d1")
-        env = SubstEnvironment(CPPPATH=["blah"])
+            def subst(self, arg, target=None, source=None, conv=None, test=test):
+                if arg == "$blah":
+                    return test.workpath("d1")
+                else:
+                    return arg
+        env = SubstEnvironment(CPPPATH=["$blah"])
         s = SCons.Scanner.C.CScanner()
         path = s.path(env)
         deps = s(env.File('f1.cpp'), env, path)
diff --git a/src/engine/SCons/Scanner/D.py b/src/engine/SCons/Scanner/D.py
index 2ea2614..5a0b383 100644
--- a/src/engine/SCons/Scanner/D.py
+++ b/src/engine/SCons/Scanner/D.py
@@ -46,7 +46,6 @@ def DScanner():
 
 class D(SCons.Scanner.Classic):
     def find_include(self, include, source_dir, path):
-        if callable(path): path=path()
         # translate dots (package separators) to slashes
         inc = string.replace(include, '.', '/')
 
diff --git a/src/engine/SCons/Scanner/Fortran.py b/src/engine/SCons/Scanner/Fortran.py
index 8f7a6ce..31a1e16 100644
--- a/src/engine/SCons/Scanner/Fortran.py
+++ b/src/engine/SCons/Scanner/Fortran.py
@@ -78,7 +78,6 @@ class F90Scanner(SCons.Scanner.Classic):
         apply(SCons.Scanner.Current.__init__, (self,) + args, kw)
 
     def scan(self, node, env, path=()):
-        "__cacheable__"
 
         # cache the includes list in node so we only scan it once:
         if node.includes != None:
@@ -112,6 +111,8 @@ class F90Scanner(SCons.Scanner.Classic):
         # is actually found in a Repository or locally.
         nodes = []
         source_dir = node.get_dir()
+        if callable(path):
+            path = path()
         for dep in mods_and_includes:
             n, i = self.find_include(dep, source_dir, path)
 
diff --git a/src/engine/SCons/Scanner/FortranTests.py b/src/engine/SCons/Scanner/FortranTests.py
index da4a023..82db694 100644
--- a/src/engine/SCons/Scanner/FortranTests.py
+++ b/src/engine/SCons/Scanner/FortranTests.py
@@ -232,12 +232,12 @@ class DummyEnvironment:
     def __delitem__(self,key):
         del self.Dictionary()[key]
 
-    def subst(self, arg):
+    def subst(self, arg, target=None, source=None, conv=None):
         if arg[0] == '$':
             return self[arg[1:]]
         return arg
 
-    def subst_path(self, path, target=None, source=None):
+    def subst_path(self, path, target=None, source=None, conv=None):
         if type(path) != type([]):
             path = [path]
         return map(self.subst, path)
@@ -461,10 +461,13 @@ class FortranScannerTestCase14(unittest.TestCase):
 class FortranScannerTestCase15(unittest.TestCase):
     def runTest(self):
         class SubstEnvironment(DummyEnvironment):
-            def subst(self, arg, test=test):
-                return test.workpath("d1")
+            def subst(self, arg, target=None, source=None, conv=None, test=test):
+                if arg == "$junk":
+                    return test.workpath("d1")
+                else:
+                    return arg
         test.write(['d1', 'f2.f'], "      INCLUDE 'fi.f'\n")
-        env = SubstEnvironment(["junk"])
+        env = SubstEnvironment(["$junk"])
         s = SCons.Scanner.Fortran.FortranScan()
         path = s.path(env)
         deps = s(env.File('fff1.f'), env, path)
diff --git a/src/engine/SCons/Scanner/IDLTests.py b/src/engine/SCons/Scanner/IDLTests.py
index 153951d..2332a57 100644
--- a/src/engine/SCons/Scanner/IDLTests.py
+++ b/src/engine/SCons/Scanner/IDLTests.py
@@ -199,10 +199,10 @@ class DummyEnvironment:
         else:
             raise KeyError, "Dummy environment only has CPPPATH attribute."
 
-    def subst(self, arg):
+    def subst(self, arg, target=None, source=None, conv=None):
         return arg
 
-    def subst_path(self, path, target=None, source=None):
+    def subst_path(self, path, target=None, source=None, conv=None):
         if type(path) != type([]):
             path = [path]
         return map(self.subst, path)
@@ -411,9 +411,12 @@ class IDLScannerTestCase11(unittest.TestCase):
 class IDLScannerTestCase12(unittest.TestCase):
     def runTest(self):
         class SubstEnvironment(DummyEnvironment):
-            def subst(self, arg, test=test):
-                return test.workpath("d1")
-        env = SubstEnvironment(["blah"])
+            def subst(self, arg, target=None, source=None, conv=None, test=test):
+                if arg == "$blah":
+                    return test.workpath("d1")
+                else:
+                    return arg
+        env = SubstEnvironment(["$blah"])
         s = SCons.Scanner.IDL.IDLScan()
         path = s.path(env)
         deps = s(env.File('t1.idl'), env, path)
diff --git a/src/engine/SCons/Scanner/LaTeX.py b/src/engine/SCons/Scanner/LaTeX.py
index 6451a58..d875e6e 100644
--- a/src/engine/SCons/Scanner/LaTeX.py
+++ b/src/engine/SCons/Scanner/LaTeX.py
@@ -31,13 +31,15 @@ __revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
 
 
 import SCons.Scanner
+import string
+import os.path
 
 def LaTeXScanner(fs = SCons.Node.FS.default_fs):
     """Return a prototype Scanner instance for scanning LaTeX source files"""
     ds = LaTeX(name = "LaTeXScanner",
                suffixes =  '$LATEXSUFFIXES',
                path_variable = 'TEXINPUTS',
-               regex = '\\\\(include|includegraphics(?:\[[^\]]+\])?|input){([^}]*)}',
+               regex = '\\\\(include|includegraphics(?:\[[^\]]+\])?|input|bibliography){([^}]*)}',
                recursive = 0)
     return ds
 
@@ -46,21 +48,75 @@ class LaTeX(SCons.Scanner.Classic):
 
     Unlike most scanners, which use regular expressions that just
     return the included file name, this returns a tuple consisting
-    of the keyword for the inclusion ("include", "includegraphics" or
-    "input"), and then the file name itself.  Base on a quick look at
-    LaTeX documentation, it seems that we need a should append .tex
-    suffix for "include" and "input" keywords, but leave the file name
-    untouched for "includegraphics."
+    of the keyword for the inclusion ("include", "includegraphics",
+    "input", or "bibliography"), and then the file name itself.  
+    Based on a quick look at LaTeX documentation, it seems that we 
+    need a should append .tex suffix for the "include" keywords, 
+    append .tex if there is no extension for the "input" keyword, 
+    but leave the file name untouched for "includegraphics." For
+    the "bibliography" keyword we need to add .bib if there is
+    no extension. (This need to be revisited since if there
+    is no extension for an :includegraphics" keyword latex will 
+    append .ps or .eps to find the file; while pdftex will use 
+    other extensions.)
     """
     def latex_name(self, include):
         filename = include[1]
-        if include[0][:15] != 'includegraphics':
+        if include[0] == 'input':
+            base, ext = os.path.splitext( filename )
+            if ext == "":
+                filename = filename + '.tex'
+        if (include[0] == 'include'):
             filename = filename + '.tex'
+        if include[0] == 'bibliography':
+            base, ext = os.path.splitext( filename )
+            if ext == "":
+                filename = filename + '.bib'
         return filename
     def sort_key(self, include):
         return SCons.Node.FS._my_normcase(self.latex_name(include))
     def find_include(self, include, source_dir, path):
-        if callable(path): path=path()
         i = SCons.Node.FS.find_file(self.latex_name(include),
                                     (source_dir,) + path)
         return i, include
+
+    def scan(self, node, path=()):
+        #
+        # Modify the default scan function to allow for the regular
+        # expression to return a comma separated list of file names
+        # as can be the case with the bibliography keyword.
+        #
+        # cache the includes list in node so we only scan it once:
+        if node.includes != None:
+            includes = node.includes
+        else:
+            includes = self.cre.findall(node.get_contents())
+            node.includes = includes
+
+        # This is a hand-coded DSU (decorate-sort-undecorate, or
+        # Schwartzian transform) pattern.  The sort key is the raw name
+        # of the file as specifed on the #include line (including the
+        # " or <, since that may affect what file is found), which lets
+        # us keep the sort order constant regardless of whether the file
+        # is actually found in a Repository or locally.
+        nodes = []
+        source_dir = node.get_dir()
+        for include in includes:
+            #
+            # Handle multiple filenames in include[1]
+            #
+            inc_list = string.split(include[1],',')
+            for j in range(len(inc_list)):
+                include_local = [include[0],inc_list[j]]
+                n, i = self.find_include(include_local, source_dir, path)
+
+            if n is None:
+                SCons.Warnings.warn(SCons.Warnings.DependencyWarning,
+                                    "No dependency generated for file: %s (included from: %s) -- file not found" % (i, node))
+            else:
+                sortkey = self.sort_key(include)
+                nodes.append((sortkey, n))
+
+        nodes.sort()
+        nodes = map(lambda pair: pair[1], nodes)
+        return nodes
diff --git a/src/engine/SCons/Scanner/LaTeXTests.py b/src/engine/SCons/Scanner/LaTeXTests.py
index 45a387a..9cfe3ca 100644
--- a/src/engine/SCons/Scanner/LaTeXTests.py
+++ b/src/engine/SCons/Scanner/LaTeXTests.py
@@ -70,17 +70,17 @@ class DummyEnvironment(UserDict.UserDict):
     def Dictionary(self, *args):
         return self.data
 
-    def subst(self, strSubst):
+    def subst(self, strSubst, target=None, source=None, conv=None):
         if strSubst[0] == '$':
             return self.data[strSubst[1:]]
         return strSubst
 
-    def subst_list(self, strSubst):
+    def subst_list(self, strSubst, target=None, source=None, conv=None):
         if strSubst[0] == '$':
             return [self.data[strSubst[1:]]]
         return [[strSubst]]
 
-    def subst_path(self, path, target=None, source=None):
+    def subst_path(self, path, target=None, source=None, conv=None):
         if type(path) != type([]):
             path = [path]
         return map(self.subst, path)
diff --git a/src/engine/SCons/Scanner/Prog.py b/src/engine/SCons/Scanner/Prog.py
index 54db9a8..e8d1669 100644
--- a/src/engine/SCons/Scanner/Prog.py
+++ b/src/engine/SCons/Scanner/Prog.py
@@ -80,8 +80,9 @@ def scan(node, env, libpath = ()):
 
     result = []
 
-    if callable(libpath): libpath = libpath()
-    
+    if callable(libpath):
+        libpath = libpath()
+
     find_file = SCons.Node.FS.find_file
     adjustixes = SCons.Util.adjustixes
     for lib in libs:
diff --git a/src/engine/SCons/Scanner/ProgTests.py b/src/engine/SCons/Scanner/ProgTests.py
index bac10b7..47d4afd 100644
--- a/src/engine/SCons/Scanner/ProgTests.py
+++ b/src/engine/SCons/Scanner/ProgTests.py
@@ -71,7 +71,7 @@ class DummyEnvironment:
     def __delitem__(self,key):
         del self.Dictionary()[key]
 
-    def subst(self, s):
+    def subst(self, s, target=None, source=None, conv=None):
         try:
             if s[0] == '$':
                 return self._dict[s[1:]]
@@ -79,7 +79,7 @@ class DummyEnvironment:
             return ''
         return s
 
-    def subst_path(self, path, target=None, source=None):
+    def subst_path(self, path, target=None, source=None, conv=None):
         if type(path) != type([]):
             path = [path]
         return map(self.subst, path)
@@ -165,12 +165,12 @@ class ProgramScannerTestCase3(unittest.TestCase):
 class ProgramScannerTestCase5(unittest.TestCase):
     def runTest(self):
         class SubstEnvironment(DummyEnvironment):
-            def subst(self, arg, path=test.workpath("d1")):
-                if arg == "blah":
+            def subst(self, arg, target=None, source=None, conv=None, path=test.workpath("d1")):
+                if arg == "$blah":
                     return test.workpath("d1")
                 else:
                     return arg
-        env = SubstEnvironment(LIBPATH=[ "blah" ],
+        env = SubstEnvironment(LIBPATH=[ "$blah" ],
                                LIBS=string.split('l2 l3'))
         s = SCons.Scanner.Prog.ProgramScanner()
         path = s.path(env)
diff --git a/src/engine/SCons/Scanner/ScannerTests.py b/src/engine/SCons/Scanner/ScannerTests.py
index 29ca063..bd8546f 100644
--- a/src/engine/SCons/Scanner/ScannerTests.py
+++ b/src/engine/SCons/Scanner/ScannerTests.py
@@ -31,27 +31,23 @@ import SCons.Sig
 import SCons.Scanner
 
 class DummyFS:
-    def __init__(self, search_result=[]):
-        self.search_result = search_result
     def File(self, name):
         return DummyNode(name)
-    def Rfindalldirs(self, pathlist, cwd):
-        return self.search_result + pathlist
 
 class DummyEnvironment(UserDict.UserDict):
     def __init__(self, dict=None, **kw):
         UserDict.UserDict.__init__(self, dict)
         self.data.update(kw)
         self.fs = DummyFS()
-    def subst(self, strSubst):
+    def subst(self, strSubst, target=None, source=None, conv=None):
         if strSubst[0] == '$':
             return self.data[strSubst[1:]]
         return strSubst
-    def subst_list(self, strSubst):
+    def subst_list(self, strSubst, target=None, source=None, conv=None):
         if strSubst[0] == '$':
             return [self.data[strSubst[1:]]]
         return [[strSubst]]
-    def subst_path(self, path, target=None, source=None):
+    def subst_path(self, path, target=None, source=None, conv=None):
         if type(path) != type([]):
             path = [path]
         return map(self.subst, path)
@@ -61,20 +57,24 @@ class DummyEnvironment(UserDict.UserDict):
         return factory or self.fs.File
 
 class DummyNode:
-    def __init__(self, name):
+    def __init__(self, name, search_result=()):
         self.name = name
+        self.search_result = tuple(search_result)
     def rexists(self):
         return 1
     def __str__(self):
         return self.name
+    def Rfindalldirs(self, pathlist):
+        return self.search_result + pathlist
 
 class FindPathDirsTestCase(unittest.TestCase):
     def test_FindPathDirs(self):
         """Test the FindPathDirs callable class"""
 
         env = DummyEnvironment(LIBPATH = [ 'foo' ])
-        env.fs = DummyFS(['xxx'])
+        env.fs = DummyFS()
 
+        dir = DummyNode('dir', ['xxx'])
         fpd = SCons.Scanner.FindPathDirs('LIBPATH')
         result = fpd(env, dir)
         assert str(result) == "('xxx', 'foo')", result
@@ -473,10 +473,11 @@ class ClassicTestCase(unittest.TestCase):
         ret = s.function(n, env, ('foo3',))
         assert ret == ['def'], ret
 
-        # Verify that overall scan results are cached even if individual
-        # results are de-cached
-        ret = s.function(n, env, ('foo2',))
-        assert ret == ['abc'], 'caching inactive; got: %s'%ret
+        # We no longer cache overall scan results, which would be returned
+        # if individual results are de-cached.  If we ever restore that
+        # functionality, this test goes back here.
+        #ret = s.function(n, env, ('foo2',))
+        #assert ret == ['abc'], 'caching inactive; got: %s'%ret
 
         # Verify that it sorts what it finds.
         n.includes = ['xyz', 'uvw']
@@ -501,8 +502,6 @@ class ClassicCPPTestCase(unittest.TestCase):
         s = SCons.Scanner.ClassicCPP("Test", [], None, "")
 
         def _find_file(filename, paths):
-            if callable(paths):
-                paths = paths()
             return paths[0]+'/'+filename
 
         save = SCons.Node.FS.find_file
diff --git a/src/engine/SCons/Scanner/__init__.py b/src/engine/SCons/Scanner/__init__.py
index 1fd77e5..679efca 100644
--- a/src/engine/SCons/Scanner/__init__.py
+++ b/src/engine/SCons/Scanner/__init__.py
@@ -54,25 +54,6 @@ def Scanner(function, *args, **kw):
         return apply(Base, (function,) + args, kw)
 
 
-class _Binder:
-    def __init__(self, bindval):
-        self._val = bindval
-    def __call__(self):
-        return self._val
-    def __str__(self):
-        return str(self._val)
-        #debug: return 'B<%s>'%str(self._val)
-
-BinderDict = {}
-
-def Binder(path):
-    try:
-        return BinderDict[path]
-    except KeyError:
-        b = _Binder(path)
-        BinderDict[path] = b
-        return b
-
 
 class FindPathDirs:
     """A class to bind a specific *PATH variable name to a function that
@@ -80,16 +61,17 @@ class FindPathDirs:
     def __init__(self, variable):
         self.variable = variable
     def __call__(self, env, dir, target=None, source=None, argument=None):
-        # The goal is that we've made caching this unnecessary
-        # because the caching takes place at higher layers.
+        import SCons.PathList
         try:
             path = env[self.variable]
         except KeyError:
             return ()
 
-        path = env.subst_path(path, target=target, source=source)
-        path_tuple = tuple(env.fs.Rfindalldirs(path, dir))
-        return Binder(path_tuple)
+        dir = dir or env.fs._cwd
+        path = SCons.PathList.PathList(path).subst_path(env, target, source)
+        return tuple(dir.Rfindalldirs(path))
+
+
 
 class Base:
     """
@@ -97,9 +79,6 @@ class Base:
     straightforward, single-pass scanning of a single file.
     """
 
-    if SCons.Memoize.use_memoizer:
-        __metaclass__ = SCons.Memoize.Memoized_Metaclass
-
     def __init__(self,
                  function,
                  name = "NONE",
@@ -257,14 +236,6 @@ class Base:
 
     recurse_nodes = _recurse_no_nodes
 
-if SCons.Memoize.use_old_memoization():
-    _Base = Base
-    class Base(SCons.Memoize.Memoizer, _Base):
-        "Cache-backed version of Scanner Base"
-        def __init__(self, *args, **kw):
-            apply(_Base.__init__, (self,)+args, kw)
-            SCons.Memoize.Memoizer.__init__(self)
-
 
 class Selector(Base):
     """
@@ -333,8 +304,6 @@ class Classic(Current):
         apply(Current.__init__, (self,) + args, kw)
 
     def find_include(self, include, source_dir, path):
-        "__cacheable__"
-        if callable(path): path = path()
         n = SCons.Node.FS.find_file(include, (source_dir,) + tuple(path))
         return n, include
 
@@ -342,7 +311,6 @@ class Classic(Current):
         return SCons.Node.FS._my_normcase(include)
 
     def scan(self, node, path=()):
-        "__cacheable__"
 
         # cache the includes list in node so we only scan it once:
         if node.includes != None:
@@ -359,6 +327,8 @@ class Classic(Current):
         # is actually found in a Repository or locally.
         nodes = []
         source_dir = node.get_dir()
+        if callable(path):
+            path = path()
         for include in includes:
             n, i = self.find_include(include, source_dir, path)
 
@@ -384,14 +354,10 @@ class ClassicCPP(Classic):
     the contained filename in group 1.
     """
     def find_include(self, include, source_dir, path):
-        "__cacheable__"
-        if callable(path):
-            path = path()   #kwq: extend callable to find_file...
-
         if include[0] == '"':
-            paths = Binder( (source_dir,) + tuple(path) )
+            paths = (source_dir,) + tuple(path)
         else:
-            paths = Binder( tuple(path) + (source_dir,) )
+            paths = tuple(path) + (source_dir,)
 
         n = SCons.Node.FS.find_file(include[1], paths)
 
diff --git a/src/engine/SCons/Script/Main.py b/src/engine/SCons/Script/Main.py
index 2c18112..6eedbab 100644
--- a/src/engine/SCons/Script/Main.py
+++ b/src/engine/SCons/Script/Main.py
@@ -309,6 +309,7 @@ command_time = 0
 exit_status = 0 # exit status, assume success by default
 repositories = []
 num_jobs = 1 # this is modifed by SConscript.SetJobs()
+delayed_warnings = []
 
 diskcheck_all = SCons.Node.FS.diskcheck_types()
 diskcheck_option_set = None
@@ -671,12 +672,13 @@ class OptParser(OptionParser):
                              "build all Default() targets.")
 
         debug_options = ["count", "dtree", "explain", "findlibs",
-                         "includes", "memoizer", "memory",
-                         "nomemoizer", "objects",
+                         "includes", "memoizer", "memory", "objects",
                          "pdb", "presub", "stacktrace", "stree",
                          "time", "tree"]
 
-        def opt_debug(option, opt, value, parser, debug_options=debug_options):
+        deprecated_debug_options = [ "nomemoizer", ]
+
+        def opt_debug(option, opt, value, parser, debug_options=debug_options, deprecated_debug_options=deprecated_debug_options):
             if value in debug_options:
                 try:
                     if parser.values.debug is None:
@@ -684,6 +686,9 @@ class OptParser(OptionParser):
                 except AttributeError:
                     parser.values.debug = []
                 parser.values.debug.append(value)
+            elif value in deprecated_debug_options:
+                w = "The --debug=%s option is deprecated and has no effect." % value
+                delayed_warnings.append((SCons.Warnings.DeprecatedWarning, w))
             else:
                 raise OptionValueError("Warning:  %s is not a valid debug type" % value)
         self.add_option('--debug', action="callback", type="string",
@@ -945,6 +950,8 @@ class SConscriptSettableOptions:
     
 
 def _main(args, parser):
+    global exit_status
+
     # Here's where everything really happens.
 
     # First order of business:  set up default warnings and and then
@@ -954,6 +961,7 @@ def _main(args, parser):
                          SCons.Warnings.DeprecatedWarning,
                          SCons.Warnings.DuplicateEnvironmentWarning,
                          SCons.Warnings.MissingSConscriptWarning,
+                         SCons.Warnings.NoMetaclassSupportWarning,
                          SCons.Warnings.NoParallelSupportWarning,
                          SCons.Warnings.MisleadingKeywordsWarning, ]
     for warning in default_warnings:
@@ -962,6 +970,9 @@ def _main(args, parser):
     if options.warn:
         _setup_warn(options.warn)
 
+    for warning_type, message in delayed_warnings:
+        SCons.Warnings.warn(warning_type, message)
+
     # Next, we want to create the FS object that represents the outside
     # world's file system, as that's central to a lot of initialization.
     # To do this, however, we need to be in the directory from which we
@@ -1019,7 +1030,8 @@ def _main(args, parser):
             # Give them the options usage now, before we fail
             # trying to read a non-existent SConstruct file.
             parser.print_help()
-            sys.exit(0)
+            exit_status = 0
+            return
         raise SCons.Errors.UserError, "No SConstruct file found."
 
     if scripts[0] == "-":
@@ -1105,7 +1117,6 @@ def _main(args, parser):
         # reading SConscript files and haven't started building
         # things yet, stop regardless of whether they used -i or -k
         # or anything else.
-        global exit_status
         sys.stderr.write("scons: *** %s  Stop.\n" % e)
         exit_status = 2
         sys.exit(exit_status)
@@ -1134,7 +1145,8 @@ def _main(args, parser):
         else:
             print help_text
             print "Use scons -H for help about command-line options."
-        sys.exit(0)
+        exit_status = 0
+        return
 
     # Now that we've read the SConscripts we can set the options
     # that are SConscript settable:
@@ -1285,12 +1297,9 @@ def _main(args, parser):
     count_stats.append(('post-', 'build'))
 
 def _exec_main():
-    all_args = sys.argv[1:]
-    try:
-        all_args = string.split(os.environ['SCONSFLAGS']) + all_args
-    except KeyError:
-            # it's OK if there's no SCONSFLAGS
-            pass
+    sconsflags = os.environ.get('SCONSFLAGS', '')
+    all_args = string.split(sconsflags) + sys.argv[1:]
+
     parser = OptParser()
     global options
     options, args = parser.parse_args(all_args)
@@ -1353,8 +1362,7 @@ def main():
         #SCons.Debug.dumpLoggedInstances('*')
 
     if print_memoizer:
-        print "Memoizer (memory cache) hits and misses:"
-        SCons.Memoize.Dump()
+        SCons.Memoize.Dump("Memoizer (memory cache) hits and misses:")
 
     # Dump any development debug info that may have been enabled.
     # These are purely for internal debugging during development, so
diff --git a/src/engine/SCons/Script/SConscript.py b/src/engine/SCons/Script/SConscript.py
index dc896a0..749be6d 100644
--- a/src/engine/SCons/Script/SConscript.py
+++ b/src/engine/SCons/Script/SConscript.py
@@ -183,6 +183,7 @@ def _SConscript(fs, *files, **kw):
                     # the builder so that it doesn't get built *again*
                     # during the actual build phase.
                     f.build()
+                    f.built()
                     f.builder_set(None)
                     if f.exists():
                         _file_ = open(f.get_abspath(), "r")
@@ -286,9 +287,12 @@ def SConscript_exception(file=sys.stderr):
         # in SCons itself.  Show the whole stack.
         tb = exc_tb
     stack = traceback.extract_tb(tb)
-    type = str(exc_type)
-    if type[:11] == "exceptions.":
-        type = type[11:]
+    try:
+        type = exc_type.__name__
+    except AttributeError:
+        type = str(exc_type)
+        if type[:11] == "exceptions.":
+            type = type[11:]
     file.write('%s: %s:\n' % (type, exc_value))
     for fname, line, func, text in stack:
         file.write('  File "%s", line %d:\n' % (fname, line))
diff --git a/src/engine/SCons/Script/__init__.py b/src/engine/SCons/Script/__init__.py
index ce96867..55797df 100644
--- a/src/engine/SCons/Script/__init__.py
+++ b/src/engine/SCons/Script/__init__.py
@@ -44,29 +44,33 @@ import string
 import sys
 import UserList
 
-# Special chicken-and-egg handling of the "--debug=memoizer"
-# and "--debug=nomemoizer" flags:
+# Special chicken-and-egg handling of the "--debug=memoizer" flag:
 #
 # SCons.Memoize contains a metaclass implementation that affects how
-# the other classes are instantiated.  The Memoizer handles optional
-# counting of the hits and misses by using a different, parallel set of
-# functions, so we don't slow down normal operation any more than we
-# have to.  We can also tell it disable memoization completely.
+# the other classes are instantiated.  The Memoizer may add shim methods
+# to classes that have methods that cache computed values in order to
+# count and report the hits and misses.
 #
-# If we wait to enable the counting or disable memoization completely
-# until we've parsed the command line options normally, it will be too
-# late, because the Memoizer will have already analyzed the classes
-# that it's Memoizing and bound the (non-counting) versions of the
-# functions.  So we have to use a special-case, up-front check for
-# the "--debug=memoizer" and "--debug=nomemoizer" flags and do what's
-# appropriate before we import any of the other modules that use it.
+# If we wait to enable the Memoization until after we've parsed the
+# command line options normally, it will be too late, because the Memoizer
+# will have already analyzed the classes that it's Memoizing and decided
+# to not add the shims.  So we use a special-case, up-front check for
+# the "--debug=memoizer" flag and enable Memoizer before we import any
+# of the other modules that use it.
+
 _args = sys.argv + string.split(os.environ.get('SCONSFLAGS', ''))
 if "--debug=memoizer" in _args:
     import SCons.Memoize
-    SCons.Memoize.EnableCounting()
-if "--debug=nomemoizer" in _args:
-    import SCons.Memoize
-    SCons.Memoize.DisableMemoization()
+    import SCons.Warnings
+    try:
+        SCons.Memoize.EnableMemoization()
+    except SCons.Warnings.Warning:
+        # Some warning was thrown (inability to --debug=memoizer on
+        # Python 1.5.2 because it doesn't have metaclasses).  Arrange
+        # for it to be displayed or not after warnings are configured.
+        import Main
+        exc_type, exc_value, tb = sys.exc_info()
+        Main.delayed_warnings.append(exc_type, exc_value)
 del _args
 
 import SCons.Action
@@ -77,6 +81,7 @@ import SCons.Options
 import SCons.Platform
 import SCons.Scanner
 import SCons.SConf
+import SCons.Subst
 import SCons.Tool
 import SCons.Util
 import SCons.Defaults
@@ -127,6 +132,7 @@ call_stack              = _SConscript.call_stack
 
 #
 Action                  = SCons.Action.Action
+AllowSubstExceptions    = SCons.Subst.SetAllowableExceptions
 BoolOption              = SCons.Options.BoolOption
 Builder                 = SCons.Builder.Builder
 Configure               = _SConscript.Configure
diff --git a/src/engine/SCons/Subst.py b/src/engine/SCons/Subst.py
index b100473..115f7db 100644
--- a/src/engine/SCons/Subst.py
+++ b/src/engine/SCons/Subst.py
@@ -44,6 +44,24 @@ _strconv = [SCons.Util.to_String,
             SCons.Util.to_String,
             SCons.Util.to_String_for_signature]
 
+
+
+AllowableExceptions = (IndexError, NameError)
+
+def SetAllowableExceptions(*excepts):
+    global AllowableExceptions
+    AllowableExceptions = filter(None, excepts)
+
+def raise_exception(exception, target, s):
+    name = exception.__class__.__name__
+    msg = "%s `%s' trying to evaluate `%s'" % (name, exception, s)
+    if target:
+        raise SCons.Errors.BuildError, (target[0], msg)
+    else:
+        raise SCons.Errors.UserError, msg
+
+
+
 class Literal:
     """A wrapper for a string.  If you use this object wrapped
     around a string, then it will be interpreted as literal.
@@ -377,21 +395,19 @@ def scons_subst(strSubst, env, mode=SUBST_RAW, target=None, source=None, gvars={
                             key = key[1:-1]
                         try:
                             s = eval(key, self.gvars, lvars)
-                        except AttributeError, e:
-                            raise SCons.Errors.UserError, \
-                                  "Error trying to evaluate `%s': %s" % (s, e)
-                        except (IndexError, NameError, TypeError):
-                            return ''
-                        except SyntaxError,e:
-                            if self.target:
-                                raise SCons.Errors.BuildError, (self.target[0], "Syntax error `%s' trying to evaluate `%s'" % (e,s))
-                            else:
-                                raise SCons.Errors.UserError, "Syntax error `%s' trying to evaluate `%s'" % (e,s)
+                        except KeyboardInterrupt:
+                            raise
+                        except Exception, e:
+                            if e.__class__ in AllowableExceptions:
+                                return ''
+                            raise_exception(e, self.target, s)
                     else:
                         if lvars.has_key(key):
                             s = lvars[key]
                         elif self.gvars.has_key(key):
                             s = self.gvars[key]
+                        elif not NameError in AllowableExceptions:
+                            raise_exception(NameError(key), self.target, s)
                         else:
                             return ''
     
@@ -590,21 +606,19 @@ def scons_subst_list(strSubst, env, mode=SUBST_RAW, target=None, source=None, gv
                             key = key[1:-1]
                         try:
                             s = eval(key, self.gvars, lvars)
-                        except AttributeError, e:
-                            raise SCons.Errors.UserError, \
-                                  "Error trying to evaluate `%s': %s" % (s, e)
-                        except (IndexError, NameError, TypeError):
-                            return
-                        except SyntaxError,e:
-                            if self.target:
-                                raise SCons.Errors.BuildError, (self.target[0], "Syntax error `%s' trying to evaluate `%s'" % (e,s))
-                            else:
-                                raise SCons.Errors.UserError, "Syntax error `%s' trying to evaluate `%s'" % (e,s)
+                        except KeyboardInterrupt:
+                            raise
+                        except Exception, e:
+                            if e.__class__ in AllowableExceptions:
+                                return
+                            raise_exception(e, self.target, s)
                     else:
                         if lvars.has_key(key):
                             s = lvars[key]
                         elif self.gvars.has_key(key):
                             s = self.gvars[key]
+                        elif not NameError in AllowableExceptions:
+                            raise_exception(NameError(), self.target, s)
                         else:
                             return
 
diff --git a/src/engine/SCons/SubstTests.py b/src/engine/SCons/SubstTests.py
index 4de3348..e8419f1 100644
--- a/src/engine/SCons/SubstTests.py
+++ b/src/engine/SCons/SubstTests.py
@@ -290,7 +290,6 @@ class SubstTestCase(unittest.TestCase):
             "${FFF[0]}",            "G",
             "${FFF[7]}",            "",
             "${NOTHING[1]}",        "",
-            "${NONE[2]}",           "",
 
             # Test various combinations of strings and lists.
             #None,                   '',
@@ -336,7 +335,11 @@ class SubstTestCase(unittest.TestCase):
         while cases:
             input, expect = cases[:2]
             expect = cvt(expect)
-            result = apply(scons_subst, (input, env), kwargs)
+            try:
+                result = apply(scons_subst, (input, env), kwargs)
+            except Exception, e:
+                print "    input %s generated %s %s" % (repr(input), e.__class__.__name__, str(e))
+                failed = failed + 1
             if result != expect:
                 if failed == 0: print
                 print "    input %s => %s did not match %s" % (repr(input), repr(result), repr(expect))
@@ -459,8 +462,8 @@ class SubstTestCase(unittest.TestCase):
             scons_subst('${foo.bar}', env, gvars={'foo':Foo()})
         except SCons.Errors.UserError, e:
             expect = [
-                "Error trying to evaluate `${foo.bar}': bar",
-                "Error trying to evaluate `${foo.bar}': Foo instance has no attribute 'bar'",
+                "AttributeError `bar' trying to evaluate `${foo.bar}'",
+                "AttributeError `Foo instance has no attribute 'bar'' trying to evaluate `${foo.bar}'",
             ]
             assert str(e) in expect, e
         else:
@@ -470,9 +473,44 @@ class SubstTestCase(unittest.TestCase):
         try:
             scons_subst('$foo.bar.3.0', env)
         except SCons.Errors.UserError, e:
-            expect1 = "Syntax error `invalid syntax' trying to evaluate `$foo.bar.3.0'"
-            expect2 = "Syntax error `invalid syntax (line 1)' trying to evaluate `$foo.bar.3.0'"
-            assert str(e) in [expect1, expect2], e
+            expect = [
+                # Python 1.5
+                "SyntaxError `invalid syntax' trying to evaluate `$foo.bar.3.0'",
+                # Python 2.2, 2.3, 2.4
+                "SyntaxError `invalid syntax (line 1)' trying to evaluate `$foo.bar.3.0'",
+                # Python 2.5
+                "SyntaxError `invalid syntax (<string>, line 1)' trying to evaluate `$foo.bar.3.0'",
+            ]
+            assert str(e) in expect, e
+        else:
+            raise AssertionError, "did not catch expected UserError"
+
+        # Test that we handle type errors 
+        try:
+            scons_subst("${NONE[2]}", env, gvars={'NONE':None})
+        except SCons.Errors.UserError, e:
+            expect = [
+                # Python 1.5, 2.2, 2.3, 2.4
+                "TypeError `unsubscriptable object' trying to evaluate `${NONE[2]}'",
+                # Python 2.5 and later
+                "TypeError `'NoneType' object is unsubscriptable' trying to evaluate `${NONE[2]}'",
+            ]
+            assert str(e) in expect, e
+        else:
+            raise AssertionError, "did not catch expected UserError"
+
+        try:
+            def func(a, b, c):
+                pass
+            scons_subst("${func(1)}", env, gvars={'func':func})
+        except SCons.Errors.UserError, e:
+            expect = [
+                # Python 1.5
+                "TypeError `not enough arguments; expected 3, got 1' trying to evaluate `${func(1)}'",
+                # Python 2.2, 2.3, 2.4, 2.5
+                "TypeError `func() takes exactly 3 arguments (1 given)' trying to evaluate `${func(1)}'"
+            ]
+            assert str(e) in expect, repr(str(e))
         else:
             raise AssertionError, "did not catch expected UserError"
 
@@ -933,8 +971,8 @@ class SubstTestCase(unittest.TestCase):
             scons_subst_list('${foo.bar}', env, gvars={'foo':Foo()})
         except SCons.Errors.UserError, e:
             expect = [
-                "Error trying to evaluate `${foo.bar}': bar",
-                "Error trying to evaluate `${foo.bar}': Foo instance has no attribute 'bar'",
+                "AttributeError `bar' trying to evaluate `${foo.bar}'",
+                "AttributeError `Foo instance has no attribute 'bar'' trying to evaluate `${foo.bar}'",
             ]
             assert str(e) in expect, e
         else:
@@ -944,9 +982,12 @@ class SubstTestCase(unittest.TestCase):
         try:
             scons_subst_list('$foo.bar.3.0', env)
         except SCons.Errors.UserError, e:
-            expect1 = "Syntax error `invalid syntax' trying to evaluate `$foo.bar.3.0'"
-            expect2 = "Syntax error `invalid syntax (line 1)' trying to evaluate `$foo.bar.3.0'"
-            assert str(e) in [expect1, expect2], e
+            expect = [
+                "SyntaxError `invalid syntax' trying to evaluate `$foo.bar.3.0'",
+                "SyntaxError `invalid syntax (line 1)' trying to evaluate `$foo.bar.3.0'",
+                "SyntaxError `invalid syntax (<string>, line 1)' trying to evaluate `$foo.bar.3.0'",
+            ]
+            assert str(e) in expect, e
         else:
             raise AssertionError, "did not catch expected SyntaxError"
 
diff --git a/src/engine/SCons/Taskmaster.py b/src/engine/SCons/Taskmaster.py
index 7cdecf3..2ea3f0d 100644
--- a/src/engine/SCons/Taskmaster.py
+++ b/src/engine/SCons/Taskmaster.py
@@ -240,7 +240,7 @@ class Task:
         for t in self.targets:
             t.disambiguate().set_state(SCons.Node.executing)
             for s in t.side_effects:
-                s.set_state(SCons.Node.pending)
+                s.set_state(SCons.Node.executing)
 
     def make_ready_current(self):
         """Mark all targets in a task ready for execution if any target
@@ -256,7 +256,7 @@ class Task:
                 self.out_of_date.append(t)
                 t.set_state(SCons.Node.executing)
                 for s in t.side_effects:
-                    s.set_state(SCons.Node.pending)
+                    s.set_state(SCons.Node.executing)
 
     make_ready = make_ready_current
 
@@ -268,7 +268,7 @@ class Task:
                 parents[p] = parents.get(p, 0) + 1
         for t in self.targets:
             for s in t.side_effects:
-                if s.get_state() == SCons.Node.pending:
+                if s.get_state() == SCons.Node.executing:
                     s.set_state(SCons.Node.no_state)
                     for p in s.waiting_parents.keys():
                         if not parents.has_key(p):
@@ -515,12 +515,11 @@ class Taskmaster:
                     T.write(' waiting on unfinished children:\n    %s\n' % c)
                 continue
 
-            # Skip this node if it has side-effects that are
-            # currently being built:
-            side_effects = reduce(lambda E,N:
-                                  E or N.get_state() == SCons.Node.executing,
-                                  node.side_effects,
-                                  0)
+            # Skip this node if it has side-effects that are currently being
+            # built  themselves or waiting for something else being built.
+            side_effects = filter(lambda N:
+                                  N.get_state() == SCons.Node.executing,
+                                  node.side_effects)
             if side_effects:
                 map(lambda n, P=node: n.add_to_waiting_s_e(P), side_effects)
                 if S: S.side_effects = S.side_effects + 1
diff --git a/src/engine/SCons/TaskmasterTests.py b/src/engine/SCons/TaskmasterTests.py
index 8d71d71..4fefb9d 100644
--- a/src/engine/SCons/TaskmasterTests.py
+++ b/src/engine/SCons/TaskmasterTests.py
@@ -374,7 +374,7 @@ class TaskmasterTestCase(unittest.TestCase):
         tm = SCons.Taskmaster.Taskmaster([n1,n2,n3,n4,n5])
         t = tm.next_task()
         assert t.get_target() == n1
-        assert n4.state == SCons.Node.pending, n4.state
+        assert n4.state == SCons.Node.executing, n4.state
         t.executed()
         t.postprocess()
         t = tm.next_task()
diff --git a/src/engine/SCons/Tool/386asm.py b/src/engine/SCons/Tool/386asm.py
index f2a221b..1a59525 100644
--- a/src/engine/SCons/Tool/386asm.py
+++ b/src/engine/SCons/Tool/386asm.py
@@ -37,11 +37,11 @@ __revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
 from SCons.Tool.PharLapCommon import addPharLapPaths
 import SCons.Util
 
-import as
+as_module = __import__('as', globals(), locals(), [])
 
 def generate(env):
     """Add Builders and construction variables for ar to an Environment."""
-    as.generate(env)
+    as_module.generate(env)
 
     env['AS']        = '386asm'
     env['ASFLAGS']   = SCons.Util.CLVar('')
diff --git a/src/engine/SCons/Tool/dvipdf.py b/src/engine/SCons/Tool/dvipdf.py
index 51dfae1..179159e 100644
--- a/src/engine/SCons/Tool/dvipdf.py
+++ b/src/engine/SCons/Tool/dvipdf.py
@@ -66,7 +66,7 @@ def generate(env):
 
     env['DVIPDF']      = 'dvipdf'
     env['DVIPDFFLAGS'] = SCons.Util.CLVar('')
-    env['DVIPDFCOM']   = '$DVIPDF $DVIPDFFLAGS $SOURCE $TARGET'
+    env['DVIPDFCOM']   = 'cd ${TARGET.dir} && $DVIPDF $DVIPDFFLAGS ${SOURCE.file} ${TARGET.file}'
 
     # Deprecated synonym.
     env['PDFCOM']      = ['$DVIPDFCOM']
diff --git a/src/engine/SCons/Tool/dvips.py b/src/engine/SCons/Tool/dvips.py
index b987ea1..9996fc2 100644
--- a/src/engine/SCons/Tool/dvips.py
+++ b/src/engine/SCons/Tool/dvips.py
@@ -58,7 +58,9 @@ def generate(env):
     
     env['DVIPS']      = 'dvips'
     env['DVIPSFLAGS'] = SCons.Util.CLVar('')
-    env['PSCOM']      = '$DVIPS $DVIPSFLAGS -o $TARGET $SOURCE'
+    # I'm not quite sure I got the directories and filenames right for build_dir
+    # We need to be in the correct directory for the sake of latex \includegraphics eps included files.
+    env['PSCOM']      = 'cd ${TARGET.dir} && $DVIPS $DVIPSFLAGS -o ${TARGET.file} ${SOURCE.file}'
     env['PSPREFIX'] = ''
     env['PSSUFFIX'] = '.ps'
 
diff --git a/src/engine/SCons/Tool/gas.py b/src/engine/SCons/Tool/gas.py
index 3b35424..e44a28d 100644
--- a/src/engine/SCons/Tool/gas.py
+++ b/src/engine/SCons/Tool/gas.py
@@ -33,13 +33,13 @@ selection method.
 
 __revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
 
-import as
+as_module = __import__('as', globals(), locals(), [])
 
 assemblers = ['as', 'gas']
 
 def generate(env):
     """Add Builders and construction variables for as to an Environment."""
-    as.generate(env)
+    as_module.generate(env)
 
     env['AS']        = env.Detect(assemblers) or 'as'
 
diff --git a/src/engine/SCons/Tool/latex.py b/src/engine/SCons/Tool/latex.py
index 72371b3..c4934c3 100644
--- a/src/engine/SCons/Tool/latex.py
+++ b/src/engine/SCons/Tool/latex.py
@@ -64,7 +64,7 @@ def generate(env):
 
     env['LATEX']        = 'latex'
     env['LATEXFLAGS']   = SCons.Util.CLVar('')
-    env['LATEXCOM']     = '$LATEX $LATEXFLAGS $SOURCE'
+    env['LATEXCOM']     = 'cd ${TARGET.dir} && $LATEX $LATEXFLAGS ${SOURCE.file}'
     env['LATEXRETRIES'] = 3
 
 def exists(env):
diff --git a/src/engine/SCons/Tool/mslink.py b/src/engine/SCons/Tool/mslink.py
index 4458183..4b90e3d 100644
--- a/src/engine/SCons/Tool/mslink.py
+++ b/src/engine/SCons/Tool/mslink.py
@@ -222,8 +222,14 @@ def generate(env):
     env['LDMODULECOM'] = compositeLinkAction
 
 def exists(env):
+    platform = env.get('PLATFORM', '')
     if SCons.Tool.msvs.is_msvs_installed():
         # there's at least one version of MSVS installed.
         return 1
-    else:
+    elif platform in ('win32', 'cygwin'):
+        # Only explicitly search for a 'link' executable on Windows
+        # systems.  Some other systems (e.g. Ubuntu Linux) have an
+        # executable named 'link' and we don't want that to make SCons
+        # think Visual Studio is installed.
         return env.Detect('link')
+    return None
diff --git a/src/engine/SCons/Tool/msvc.xml b/src/engine/SCons/Tool/msvc.xml
index 1c0f3fa..be155bd 100644
--- a/src/engine/SCons/Tool/msvc.xml
+++ b/src/engine/SCons/Tool/msvc.xml
@@ -55,6 +55,7 @@ The default value expands expands to the appropriate
 Microsoft Visual C++ command-line options
 when the &cv-PCH; construction variable is set.
 </summary>
+</cvar>
 
 <cvar name="CCPDBFLAGS">
 <summary>
@@ -93,6 +94,7 @@ the &cv-CCPDBFLAGS; variable as follows:
 env['CCPDBFLAGS'] = '/Zi /Fd${TARGET}.pdb'
 </example>
 </summary>
+</cvar>
 
 <cvar name="PCH">
 <summary>
diff --git a/src/engine/SCons/Tool/pdflatex.py b/src/engine/SCons/Tool/pdflatex.py
index acf67b2..97420a8 100644
--- a/src/engine/SCons/Tool/pdflatex.py
+++ b/src/engine/SCons/Tool/pdflatex.py
@@ -67,7 +67,7 @@ def generate(env):
 
     env['PDFLATEX']      = 'pdflatex'
     env['PDFLATEXFLAGS'] = SCons.Util.CLVar('')
-    env['PDFLATEXCOM']   = '$PDFLATEX $PDFLATEXFLAGS $SOURCE'
+    env['PDFLATEXCOM']   = 'cd ${TARGET.dir} && $PDFLATEX $PDFLATEXFLAGS ${SOURCE.file}'
     env['LATEXRETRIES']  = 3
 
 def exists(env):
diff --git a/src/engine/SCons/Tool/pdftex.py b/src/engine/SCons/Tool/pdftex.py
index ddf5a23..e740fac 100644
--- a/src/engine/SCons/Tool/pdftex.py
+++ b/src/engine/SCons/Tool/pdftex.py
@@ -82,17 +82,13 @@ def generate(env):
 
     env['PDFTEX']      = 'pdftex'
     env['PDFTEXFLAGS'] = SCons.Util.CLVar('')
-    env['PDFTEXCOM']   = '$PDFTEX $PDFTEXFLAGS $SOURCE'
+    env['PDFTEXCOM']   = 'cd ${TARGET.dir} && $PDFTEX $PDFTEXFLAGS ${SOURCE.file}'
 
     # Duplicate from latex.py.  If latex.py goes away, then this is still OK.
     env['PDFLATEX']      = 'pdflatex'
     env['PDFLATEXFLAGS'] = SCons.Util.CLVar('')
-    env['PDFLATEXCOM']   = '$PDFLATEX $PDFLATEXFLAGS $SOURCE'
+    env['PDFLATEXCOM']   = 'cd ${TARGET.dir} && $PDFLATEX $PDFLATEXFLAGS ${SOURCE.file}'
     env['LATEXRETRIES']  = 3
 
-    env['BIBTEX']      = 'bibtex'
-    env['BIBTEXFLAGS'] = SCons.Util.CLVar('')
-    env['BIBTEXCOM']   = '$BIBTEX $BIBTEXFLAGS ${SOURCE.base}'
-
 def exists(env):
     return env.Detect('pdftex')
diff --git a/src/engine/SCons/Tool/swig.py b/src/engine/SCons/Tool/swig.py
index ed066a7..a8e12a2 100644
--- a/src/engine/SCons/Tool/swig.py
+++ b/src/engine/SCons/Tool/swig.py
@@ -49,19 +49,20 @@ def swigSuffixEmitter(env, source):
     else:
         return '$SWIGCFILESUFFIX'
 
-_reSwig = re.compile(r"%include\s+(\S+)")
+_reInclude = re.compile(r'%include\s+(\S+)')
+_reModule = re.compile(r'%module\s+(.+)')
 
 def recurse(path, searchPath):
-    global _reSwig
+    global _reInclude
     f = open(path)
     try: contents = f.read()
     finally: f.close()
 
     found = []
     # Better code for when we drop Python 1.5.2.
-    #for m in _reSwig.finditer(contents):
+    #for m in _reInclude.finditer(contents):
     #    fname = m.group(1)
-    for fname in _reSwig.findall(contents):
+    for fname in _reInclude.findall(contents):
         for dpath in searchPath:
             absPath = os.path.join(dpath, fname)
             if os.path.isfile(absPath):
@@ -88,7 +89,7 @@ def _swigEmitter(target, source, env):
             f = open(src)
             try:
                 for l in f.readlines():
-                    m = re.match("%module (.+)", l)
+                    m = _reModule.match(l)
                     if m:
                         mname = m.group(1)
             finally:
diff --git a/src/engine/SCons/Tool/tex.py b/src/engine/SCons/Tool/tex.py
index d613958..0329667 100644
--- a/src/engine/SCons/Tool/tex.py
+++ b/src/engine/SCons/Tool/tex.py
@@ -43,7 +43,13 @@ import SCons.Node.FS
 import SCons.Util
 
 warning_rerun_re = re.compile("^LaTeX Warning:.*Rerun", re.MULTILINE)
-undefined_references_re = re.compile("^LaTeX Warning:.*undefined references", re.MULTILINE)
+
+rerun_citations_str = "^LaTeX Warning:.*\n.*Rerun to get citations correct"
+rerun_citations_re = re.compile(rerun_citations_str, re.MULTILINE)
+
+undefined_references_str = '(^LaTeX Warning:.*undefined references)|(^Package \w+ Warning:.*undefined citations)'
+undefined_references_re = re.compile(undefined_references_str, re.MULTILINE)
+
 openout_aux_re = re.compile(r"\\openout.*`(.*\.aux)'")
 
 # An Action sufficient to build any generic tex file.
@@ -63,7 +69,8 @@ def InternalLaTeXAuxAction(XXXLaTeXAction, target = None, source= None, env=None
     """A builder for LaTeX files that checks the output in the aux file
     and decides how many times to use LaTeXAction, and BibTeXAction."""
 
-    basename, ext = SCons.Util.splitext(str(target[0]))
+    basename = SCons.Util.splitext(str(source[0]))[0]
+    basedir = os.path.split(str(source[0]))[0]
 
     # Run LaTeX once to generate a new aux file.
     XXXLaTeXAction(target, source, env)
@@ -82,11 +89,11 @@ def InternalLaTeXAuxAction(XXXLaTeXAction, target = None, source= None, env=None
 
     # Now decide if bibtex will need to be run.
     for auxfilename in auxfiles:
-        if os.path.exists(auxfilename):
-            content = open(auxfilename, "rb").read()
+        if os.path.exists(os.path.join(basedir, auxfilename)):
+            content = open(os.path.join(basedir, auxfilename), "rb").read()
             if string.find(content, "bibdata") != -1:
                 bibfile = env.fs.File(basename)
-                BibTeXAction(None, bibfile, env)
+                BibTeXAction(bibfile, bibfile, env)
                 break
 
     # Now decide if makeindex will need to be run.
@@ -94,7 +101,13 @@ def InternalLaTeXAuxAction(XXXLaTeXAction, target = None, source= None, env=None
     if os.path.exists(idxfilename):
         idxfile = env.fs.File(basename)
         # TODO: if ( idxfile has changed) ...
-        MakeIndexAction(None, idxfile, env)
+        MakeIndexAction(idxfile, idxfile, env)
+        XXXLaTeXAction(target, source, env)
+
+    # Now decide if latex will need to be run again due to table of contents.
+    tocfilename = basename + '.toc'
+    if os.path.exists(tocfilename):
+        # TODO: if ( tocfilename has changed) ...
         XXXLaTeXAction(target, source, env)
 
     # Now decide if latex needs to be run yet again.
@@ -104,6 +117,7 @@ def InternalLaTeXAuxAction(XXXLaTeXAction, target = None, source= None, env=None
             break
         content = open(logfilename, "rb").read()
         if not warning_rerun_re.search(content) and \
+           not rerun_citations_re.search(content) and \
            not undefined_references_re.search(content):
             break
         XXXLaTeXAction(target, source, env)
@@ -135,9 +149,12 @@ def TeXLaTeXFunction(target = None, source= None, env=None):
 def tex_emitter(target, source, env):
     base = SCons.Util.splitext(str(source[0]))[0]
     target.append(base + '.aux')
+    env.Precious(base + '.aux')
     target.append(base + '.log')
     for f in source:
         content = f.get_contents()
+        if string.find(content, r'\tableofcontents') != -1:
+            target.append(base + '.toc')
         if string.find(content, r'\makeindex') != -1:
             target.append(base + '.ilg')
             target.append(base + '.ind')
@@ -151,7 +168,10 @@ def tex_emitter(target, source, env):
     if os.path.exists(logfilename):
         content = open(logfilename, "rb").read()
         aux_files = openout_aux_re.findall(content)
-        target.extend(filter(lambda f, b=base+'.aux': f != b, aux_files))
+        aux_files = filter(lambda f, b=base+'.aux': f != b, aux_files)
+        dir = os.path.split(base)[0]
+        aux_files = map(lambda f, d=dir: d+os.sep+f, aux_files)
+        target.extend(aux_files)
 
     return (target, source)
 
@@ -194,21 +214,21 @@ def generate(env):
 
     env['TEX']      = 'tex'
     env['TEXFLAGS'] = SCons.Util.CLVar('')
-    env['TEXCOM']   = '$TEX $TEXFLAGS $SOURCE'
+    env['TEXCOM']   = 'cd ${TARGET.dir} && $TEX $TEXFLAGS ${SOURCE.file}'
 
     # Duplicate from latex.py.  If latex.py goes away, then this is still OK.
     env['LATEX']        = 'latex'
     env['LATEXFLAGS']   = SCons.Util.CLVar('')
-    env['LATEXCOM']     = '$LATEX $LATEXFLAGS $SOURCE'
+    env['LATEXCOM']     = 'cd ${TARGET.dir} && $LATEX $LATEXFLAGS ${SOURCE.file}'
     env['LATEXRETRIES'] = 3
 
     env['BIBTEX']      = 'bibtex'
     env['BIBTEXFLAGS'] = SCons.Util.CLVar('')
-    env['BIBTEXCOM']   = '$BIBTEX $BIBTEXFLAGS ${SOURCE.base}'
+    env['BIBTEXCOM']   = 'cd ${TARGET.dir} && $BIBTEX $BIBTEXFLAGS ${SOURCE.filebase}'
 
     env['MAKEINDEX']      = 'makeindex'
     env['MAKEINDEXFLAGS'] = SCons.Util.CLVar('')
-    env['MAKEINDEXCOM']   = '$MAKEINDEX $MAKEINDEXFLAGS $SOURCES'
+    env['MAKEINDEXCOM']   = 'cd ${TARGET.dir} && $MAKEINDEX $MAKEINDEXFLAGS ${SOURCE.file}'
 
 def exists(env):
     return env.Detect('tex')
diff --git a/src/engine/SCons/Warnings.py b/src/engine/SCons/Warnings.py
index 123f36b..27614bf 100644
--- a/src/engine/SCons/Warnings.py
+++ b/src/engine/SCons/Warnings.py
@@ -54,6 +54,9 @@ class DuplicateEnvironmentWarning(Warning):
 class MissingSConscriptWarning(Warning):
     pass
 
+class NoMetaclassSupportWarning(Warning):
+    pass
+
 class NoParallelSupportWarning(Warning):
     pass
author	Steven Knight <knight@baldmt.com>	2006-12-16 01:43:01 (GMT)
committer	Steven Knight <knight@baldmt.com>	2006-12-16 01:43:01 (GMT)
commit	c4d04b3b45e7b71a1b28053b90084bcf2fdf9c0e (patch)
tree	8a0d07c078ac21bf1ab689eacf06577069bb9231 /src/engine/SCons
parent	b32cd624a5ad9526d28584b8e6c4a7958f436424 (diff)
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