Merged revisions 2647-2719 via svnmerge from

http://scons.tigris.org/svn/scons/branches/core

........
  r2649 | stevenknight | 2008-02-08 06:43:30 -0800 (Fri, 08 Feb 2008) | 3 lines

  Make the "bootstrap" copy directory relative to the script location
  regardless of where the user is when executing.
........
  r2650 | stevenknight | 2008-02-09 09:26:40 -0800 (Sat, 09 Feb 2008) | 3 lines

  Chdir back to the original directory before removing our temporary
  directory, to avoid "Permission denied" errors on Windows.
........
  r2651 | stevenknight | 2008-02-09 10:02:09 -0800 (Sat, 09 Feb 2008) | 3 lines

  Fix floating-point numbers confusing our notion of the .class
  files that will be generated in certain configurations.
........
  r2652 | stevenknight | 2008-02-09 10:26:48 -0800 (Sat, 09 Feb 2008) | 4 lines

  Issue 1868:  change the RootDir "lookup path" from '/' to '' so that
  looking up '/foo' returns the same node as looking up 'foo' when the
  current directory is the root.
........
  r2653 | stevenknight | 2008-02-09 11:16:17 -0800 (Sat, 09 Feb 2008) | 3 lines

  Issue 1902:  Document all the values that can now be fetched with GetOption.
  Additional formatting cleanups.
........
  r2654 | stevenknight | 2008-02-09 11:37:50 -0800 (Sat, 09 Feb 2008) | 3 lines

  Fix handling file names that contain substrings of multiple spaces
  when using ActionFactory instances like Copy() and Move().
........
  r2655 | stevenknight | 2008-02-09 13:36:14 -0800 (Sat, 09 Feb 2008) | 3 lines

  Issue 1898:  Fix use of a variable expansion in a source file name
  (like foo$OBJSUFFIX) when trying to match source builder suffixes.
........
  r2656 | stevenknight | 2008-02-09 20:58:32 -0800 (Sat, 09 Feb 2008) | 3 lines

  Issue 1903:  don't allow Java generics syntax to interfere with
  identifying an anonymous inner class.
........
  r2657 | stevenknight | 2008-02-09 21:02:37 -0800 (Sat, 09 Feb 2008) | 3 lines

  Left out the \w from the regular expression that matches generics,
  so we wouldn't match alphanumerics, only alphabetics.
........
  r2658 | stevenknight | 2008-02-09 23:33:03 -0800 (Sat, 09 Feb 2008) | 3 lines

  Issue 1899:  Enhance Chmod(), Delete(), Mkdir() and Touch() to take
  lists of Nodes or strings.
........
  r2659 | stevenknight | 2008-02-10 00:15:24 -0800 (Sun, 10 Feb 2008) | 4 lines

  Issue 1878:  Add comment lines to the generated config.h file describing
  the intent of the various #define/#undef lines.
  (David Cournapeau)
........
  r2660 | stevenknight | 2008-02-11 18:15:27 -0800 (Mon, 11 Feb 2008) | 3 lines

  Issue 1682:  Fix the ability to save and restore the ListOption value
  'all' in newer Python versions that have an all() built-in function.
........
  r2661 | stevenknight | 2008-02-27 07:25:18 -0800 (Wed, 27 Feb 2008) | 3 lines

  Issue 1919:  Optimize the SCons.Util.is_*() and SCons.Util.flatten()
  functions.  More efficient suffix selection in Selector.__call__() method.
........
  r2662 | stevenknight | 2008-02-28 06:43:29 -0800 (Thu, 28 Feb 2008) | 3 lines

  Fix SCons.Util.is_List() method to use the passed-in ListTypes variable.
  (Daniel Svensson)
........
  r2663 | stevenknight | 2008-02-28 06:57:44 -0800 (Thu, 28 Feb 2008) | 4 lines

  Issue 1884:  avoid an infinite loop when trying to use saved copies of
  the ToolInitializer objects that we use to initialize the env.Install()
  and env.InstallAs() methods.
........
  r2664 | garyo | 2008-02-28 07:25:25 -0800 (Thu, 28 Feb 2008) | 1 line

  Fix long-style command-line args in runtest.py (they were missing from getopt call).
........
  r2665 | garyo | 2008-02-28 09:31:42 -0800 (Thu, 28 Feb 2008) | 1 line

  runtest.py: Use qmtest instead of qmtest.py; newer QMTest releases may only have qmtest in /usr/bin.
........
  r2666 | stevenknight | 2008-02-28 12:10:02 -0800 (Thu, 28 Feb 2008) | 3 lines

  Remove dead code that was at one time apparently intended to grab the
  external environment's %INCLUDE% values.
........
  r2667 | stevenknight | 2008-02-28 12:16:40 -0800 (Thu, 28 Feb 2008) | 3 lines

  Move the regular expression and function that check for whether a
  construction variable name is legal from Util.py to Environment.py.
........
  r2668 | stevenknight | 2008-02-28 20:24:36 -0800 (Thu, 28 Feb 2008) | 2 lines

  Fix qmtest.py references (replace with qmtest) in tests and infrastructure.
........
  r2669 | stevenknight | 2008-02-28 20:27:05 -0800 (Thu, 28 Feb 2008) | 7 lines

  Speed up the SubstitionEnvironment.__setitem__() method by: 1) avoiding
  checking for whether the variable name is legal if it already exists; 2)
  use the regular expression directly when checking the form for illegality;
  3) more efficient check for whether a variable name is special.  Add a
  timing script so we can document why we implemented it as we did and
  revisit it in the future if need be.
........
  r2670 | stevenknight | 2008-02-28 20:51:44 -0800 (Thu, 28 Feb 2008) | 2 lines

  Add a shell script that generates context-diff output for review.
........
  r2671 | GregNoel | 2008-03-01 00:40:16 -0800 (Sat, 01 Mar 2008) | 1 line

  add test to env.__setitem__ benchmark
........
  r2672 | GregNoel | 2008-03-01 02:00:12 -0800 (Sat, 01 Mar 2008) | 1 line

  compatibility changes for env.__setitem__ benchmark
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  r2673 | stevenknight | 2008-03-01 09:56:57 -0800 (Sat, 01 Mar 2008) | 3 lines

  Capture a vanilla copy of the Python 2.[45] timeit.py module, as a
  basis for being able to use this to time Python 2.2 (and earlier).
........
  r2674 | stevenknight | 2008-03-01 10:04:11 -0800 (Sat, 01 Mar 2008) | 3 lines

  Work around a race in the order in which we detect and report the build
  failures by letting the error messages show up in either order on stdout.
........
  r2675 | stevenknight | 2008-03-01 10:05:24 -0800 (Sat, 01 Mar 2008) | 3 lines

  Back-port the captured timeit.py module, and the env.__setitem__.py
  script itself, to Python versions before 2.3.
........
  r2676 | GregNoel | 2008-03-01 14:01:03 -0800 (Sat, 01 Mar 2008) | 1 line

  add banner information, remove inadvertent tabs
........
  r2677 | stevenknight | 2008-03-02 05:04:52 -0800 (Sun, 02 Mar 2008) | 3 lines

  Don't look for a Copyright string in the source-packaged bench/timeit.py
  module that we captured.
........
  r2678 | stevenknight | 2008-03-02 14:59:39 -0800 (Sun, 02 Mar 2008) | 6 lines

  Issue 1884:  Allow env.{Install,InstallAs}() to be replaced by user-
  supplied wrappers that call the underlying builder.

  Fix how environment cloning so it only clones dynamically-added method
  attributes that the user hasn't also overwritten explicity.
........
  r2679 | stevenknight | 2008-03-04 07:48:53 -0800 (Tue, 04 Mar 2008) | 3 lines

  Fix env.{Dir,Entry,File}() when the input is a list, broken last December
  when env.subst() was modified to return lists as-is.
........
  r2680 | stevenknight | 2008-03-04 08:24:06 -0800 (Tue, 04 Mar 2008) | 2 lines

  Fix printing Python Value Nodes in --debug=explain output.  (Jim Randall)
........
  r2681 | garyo | 2008-03-04 12:37:39 -0800 (Tue, 04 Mar 2008) | 1 line

  Make File(), Dir() and Entry() return lists when passed a sequence.
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  r2682 | garyo | 2008-03-05 15:24:00 -0800 (Wed, 05 Mar 2008) | 1 line

  InstallBuilderWrapper and InstallBuilderWrapper should accept keyword args and pass them to the base builder, like other builders.
........
  r2683 | stevenknight | 2008-03-06 06:32:13 -0800 (Thu, 06 Mar 2008) | 2 lines

  Python 1.5.2 compatibility:  use apply() instead of **kw.
........
  r2684 | garyo | 2008-03-14 13:07:09 -0700 (Fri, 14 Mar 2008) | 1 line

  Fix QMTest problem with $TERM variable in user's environment causing test failures.
........
  r2685 | bdbaddog | 2008-03-14 13:16:20 -0700 (Fri, 14 Mar 2008) | 13 lines

  * Added java_where_includes - gets path list for java JDK's include dirs
  * Added java_where_java_home - gets  JAVA_HOME  path
  * Added path's to find java for sun's JDK rpm install to java_where_jar
  * moved paths() to be outside of java_ENV() routine and available for other routines to use as well as tests
  * set TERM to be dumb to fix broken readline causing massive failures on FC8 (only updated Gary's comments to include note about broken FC8 readline, as Gary committed the TERM just prior to my checkin)
  * Modified the following tests to use the above changes:
     * test/SWIG/SWIGOUTDIR.py
     * test/Java/swig-dependencies.py
     * test/Java/multi-step.py
     * test/Repository/Java.py
     * test/runtest/fallback.py  [ This test also has been changed to remove more than one qmtest in your PATH, previously it would only remove one path which had qmtest, my system had a local and a system version ]
........
  r2686 | stevenknight | 2008-03-15 20:50:07 -0700 (Sat, 15 Mar 2008) | 4 lines

  Add a warning about deprecating support for Python versions 1.5, 2.0
  and 2.1.  Fix the ability to SetOption('warn') so people can disable
  the warning by adding something to a SConscript file.
........
  r2687 | stevenknight | 2008-03-15 21:48:26 -0700 (Sat, 15 Mar 2008) | 3 lines

  Issue 1942:  Document the Dir(), File() and Entry() methods of Dir
  and File Nodes.  (Greg Noel)
........
  r2688 | GregNoel | 2008-03-16 00:05:04 -0700 (Sun, 16 Mar 2008) | 1 line

  Add parse_flags keyword option
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  r2689 | stevenknight | 2008-03-16 00:32:33 -0700 (Sun, 16 Mar 2008) | 3 lines

  Print a message if we're skipping the build of a package because the
  necessary underlying tool doesn't exist.
........
  r2690 | stevenknight | 2008-03-16 00:40:28 -0700 (Sun, 16 Mar 2008) | 7 lines

  Add --warn=no-python-version to the $SCONSFLAGS variable when running
  tests under deprecated Python versions, so the warning doesn't interfere
  with running normal tests under those version.

  Have the test/python-version.py remove --warn=no-python-version from the
  $SCONSFLAGS variable, since it's explicitly testing that behavior.
........
  r2691 | stevenknight | 2008-03-16 08:20:54 -0700 (Sun, 16 Mar 2008) | 4 lines

  Handle ripple effects from setting $SCONSFLAGS to suppress the deprecation
  under older Python versions by commonizing and moving much of the logic
  in QMTest/TestSCons.py.
........
  r2692 | stevenknight | 2008-03-16 08:47:52 -0700 (Sun, 16 Mar 2008) | 5 lines

  Update the warning message for running under a deprecated Python
  version (text courtesy Greg Noel).  Make that warning a subclass of the
  DeprecatedWarning class, so the message can also be disabled by setting
  --warn=no-deprecated.
........
  r2693 | stevenknight | 2008-03-16 11:19:52 -0700 (Sun, 16 Mar 2008) | 4 lines

  Shorten the deprecated-python-version warning.
  Use sys.version_info to check, instead of hard-coded string comparisons.
  Edit the release note.
........
  r2694 | stevenknight | 2008-03-16 11:29:10 -0700 (Sun, 16 Mar 2008) | 3 lines

  Have the warning mention both that 2.2 is the base un-deprecated version
  and the version they're running without getting too wordy.
........
  r2695 | stevenknight | 2008-03-16 12:00:22 -0700 (Sun, 16 Mar 2008) | 2 lines

  Skip test/SWIG/SWIGOUTDIR.py if no installed jni.h files are found.
........
  r2696 | stevenknight | 2008-03-18 18:01:46 -0700 (Tue, 18 Mar 2008) | 2 lines

  Remove old, commented-out deprecation test code.
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  r2697 | stevenknight | 2008-03-19 17:54:55 -0700 (Wed, 19 Mar 2008) | 2 lines

  Deprecate env.Copy() with a suppressable message.
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  r2699 | stevenknight | 2008-03-20 08:20:22 -0700 (Thu, 20 Mar 2008) | 2 lines

  Move the debug-nomemoizer.py test to the test/Deprecated subdirectory.
........
  r2700 | stevenknight | 2008-03-20 08:37:51 -0700 (Thu, 20 Mar 2008) | 2 lines

  Issue 1954:  Adds deprecation warnings for --debug={dtree,stree,tree}.
........
  r2701 | stevenknight | 2008-03-23 00:33:25 -0700 (Sun, 23 Mar 2008) | 7 lines

  Add VariantDir() as a replacement for BuildDir().
  Change "build directory" references in text (comments and
  documentation) to "variant directory."
  Move and rename tests that named BuildDir in their path.
  Add a release note about the forthcoming deprecation of BuildDir().
  Add a test/Deprecated/BuildDir.py to track backwards compatibility.
........
  r2702 | stevenknight | 2008-03-24 11:23:39 -0700 (Mon, 24 Mar 2008) | 4 lines

  Change the VariantDir() and SConscrip "build_dir" keyword to "variant_dir."
  Still support "build_dir" for (you guessed it) backwards compatibility.
  Add documentation update and release note.
........
  r2703 | garyo | 2008-03-25 07:57:01 -0700 (Tue, 25 Mar 2008) | 1 line

  Improve Install error message when target and source list lengths don't match.
........
  r2704 | garyo | 2008-03-25 08:10:24 -0700 (Tue, 25 Mar 2008) | 1 line

  Allow executing main scons.py script without running scons, using standard if __name__==__main__ idiom.
........
  r2705 | stevenknight | 2008-03-26 08:51:58 -0700 (Wed, 26 Mar 2008) | 3 lines

  Update scripts that use {Source,Target}Signatures() to use Decider()
  or the default behavior.  Update test condition checks as necessary.
........
  r2706 | stevenknight | 2008-03-27 14:13:50 -0700 (Thu, 27 Mar 2008) | 2 lines

  Update some leftover uses of env.Copy() in some test scripts to env.Clone().
........
  r2707 | stevenknight | 2008-03-27 14:20:33 -0700 (Thu, 27 Mar 2008) | 6 lines

  Fix use of SetOption('warn') to disable warning messages.
  Refactor the Script.Main._setup_warn() function into
  Warnings.process_warn_strings().
  Split test/option--warn.py into separate test/option/warn-*.py scripts
  for the individual subtests it contained.
........
  r2708 | stevenknight | 2008-03-27 15:17:44 -0700 (Thu, 27 Mar 2008) | 5 lines

  Deprecate the {Target,Source}Signatures() functions and methods.
  Move the test scripts underneath the test/Deprecated directory.
  Update man page with the new --warn=* options (and some that
  were overlooked on previous checkins).  Add a release note.
........
  r2709 | stevenknight | 2008-03-27 23:22:38 -0700 (Thu, 27 Mar 2008) | 2 lines

  More conversion of env.Copy() calls to env.Clone().
........
  r2710 | stevenknight | 2008-03-28 00:09:40 -0700 (Fri, 28 Mar 2008) | 3 lines

  Test updates for old Python versions (1.5.2) now that we generate a
  warning message about the deprecation.
........
  r2711 | stevenknight | 2008-03-28 22:11:03 -0700 (Fri, 28 Mar 2008) | 3 lines

  Chmod the built packages in build/dist to 0644 so they're publicy readable
  when they're copied over to the snapshot system.
........
  r2712 | stevenknight | 2008-03-28 22:11:54 -0700 (Fri, 28 Mar 2008) | 3 lines

  Issue 1951:  have Copy() preserve file times and mode when copying
  over individual files.  (Leanid Nazdrynau)
........
  r2713 | stevenknight | 2008-03-29 06:49:27 -0700 (Sat, 29 Mar 2008) | 3 lines

  Don't bother checking for equivalent file access times.  Under system
  load it can vary because we do actually access the file.
........
  r2714 | GregNoel | 2008-03-29 17:24:25 -0700 (Sat, 29 Mar 2008) | 1 line

  Fix regression test using Python 1.5.2 on OS X
........
  r2715 | GregNoel | 2008-03-29 20:44:19 -0700 (Sat, 29 Mar 2008) | 1 line

  'Copy' conflicts with 'copy' on case-insensitive file systems
........
  r2716 | stevenknight | 2008-03-29 21:00:13 -0700 (Sat, 29 Mar 2008) | 3 lines

  Capture scripts for downloading and installing different versions of
  Python and SCons.
........
  r2717 | stevenknight | 2008-03-30 08:48:28 -0700 (Sun, 30 Mar 2008) | 3 lines

  Fix a regression in how subst_path() handles lists (like a ListOption)
  in expansions of things like $CPPDEFINES and $CPPPATH.
........
  r2718 | stevenknight | 2008-03-30 10:02:21 -0700 (Sun, 30 Mar 2008) | 6 lines

  User's Guide updates:
  --  Paragraph about deprecated BuildDir().
  --  Updated output using the jar -C option.
  --  Updated default environment Dump().
  --  Updated --debug=stacktrace output.
........
  r2719 | stevenknight | 2008-03-31 00:50:08 -0700 (Mon, 31 Mar 2008) | 2 lines

  Update the branch for 0.98.
........

2 files changed, 659 insertions, 0 deletions

diff --git a/bench/env.__setitem__.py b/bench/env.__setitem__.py
new file mode 100644
index 00000000..3826176f
--- /dev/null
+++ b/bench/env.__setitem__.py
@@ -0,0 +1,362 @@
+# __COPYRIGHT__
+#
+# Benchmarks for testing various possible implementations of the
+# env.__setitem__() method(s) in the src/engine/SCons/Environment.py
+# module.
+
+import os.path
+import re
+import string
+import sys
+import timeit
+
+# Utility Timing class and function from:
+# ASPN: Python Cookbook : Timing various python statements
+# http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/544297
+#
+# These wrap the basic timeit function to make it a little more
+# convenient to do side-by-side tests of code.
+
+class Timing:
+    def __init__(self, name, num, init, statement):
+        self.__timer = timeit.Timer(statement, init)
+        self.__num   = num
+        self.name    = name
+        self.statement = statement
+        self.__result  = None
+        
+    def timeit(self):
+        self.__result = self.__timer.timeit(self.__num)
+        
+    def getResult(self):
+        return self.__result
+
+def times(num=1000000, init='', title='Results:', **statements):
+    # time each statement
+    timings = []
+    for n, s in statements.items():
+        t = Timing(n, num, init, s)
+        t.timeit()
+        timings.append(t)
+    
+    print
+    print title
+    l = []
+    for i in timings: l.append((i.getResult(),i.name))
+    l.sort()
+    for i in l: print "  %9.3f s   %s" % i
+
+# Import the necessary local SCons.* modules used by some of our
+# alternative implementations below, first manipulating sys.path so
+# we pull in the right local modules without forcing the user to set
+# PYTHONPATH.
+
+import __main__
+try:
+    filename = __main__.__file__
+except AttributeError:
+    filename = sys.argv[0]
+script_dir = os.path.split(filename)[0]
+if script_dir:
+    script_dir = script_dir + '/'
+sys.path = [os.path.abspath(script_dir + '../src/engine')] + sys.path
+
+import SCons.Errors
+import SCons.Environment
+
+is_valid_construction_var = SCons.Environment.is_valid_construction_var
+global_valid_var = re.compile(r'[_a-zA-Z]\w*$')
+
+# The classes with different __setitem__() implementations that we're
+# going to horse-race.
+#
+# The base class (Environment) should contain *all* class initialization
+# of anything that will be used by any of the competing sub-class
+# implementations.  Each timing run will create an instance of the class,
+# and all competing sub-classes should share the same initialization
+# overhead so our timing focuses on just the __setitem__() performance.
+#
+# All subclasses should be prefixed with env_, in which case they'll be
+# picked up automatically by the code below for testing.
+#
+# The env_Original subclass contains the original implementation (which
+# actually had the is_valid_construction_var() function in SCons.Util
+# originally).
+#
+# The other subclasses (except for env_Best) each contain *one*
+# significant change from the env_Original implementation.  The doc string
+# describes the change, and is what gets displayed in the final timing.
+# The doc strings of these other subclasses are "grouped" informally
+# by a prefix that kind of indicates what specific aspect of __setitem__()
+# is being varied and tested.
+#
+# The env_Best subclass contains the "best practices" from each of
+# the different "groups" of techniques tested in the other subclasses,
+# and is where to experiment with different combinations of techniques.
+# After we're done should be the one that shows up at the top of the
+# list as we run our timings.
+
+class Environment:
+    _special_set = {
+        'BUILDERS' : None,
+        'SCANNERS' : None,
+        'TARGET'   : None,
+        'TARGETS'  : None,
+        'SOURCE'   : None,
+        'SOURCES'  : None,
+    }
+    _special_set_keys = _special_set.keys()
+    _valid_var = re.compile(r'[_a-zA-Z]\w*$')
+    def __init__(self, **kw):
+        self._dict = kw
+
+class env_Original(Environment):
+    """Original __setitem__()"""
+    def __setitem__(self, key, value):
+        special = self._special_set.get(key)
+        if special:
+            special(self, key, value)
+        else:
+            if not SCons.Environment.is_valid_construction_var(key):
+                raise SCons.Errors.UserError, "Illegal construction variable `%s'" % key
+            self._dict[key] = value
+
+class env_Global_is_valid(Environment):
+    """is_valid_construction_var():  use a global function"""
+    def __setitem__(self, key, value):
+        special = self._special_set.get(key)
+        if special:
+            special(self, key, value)
+        else:
+            if not is_valid_construction_var(key):
+                raise SCons.Errors.UserError, "Illegal construction variable `%s'" % key
+            self._dict[key] = value
+
+class env_Method_is_valid(Environment):
+    """is_valid_construction_var():  use a method"""
+    def is_valid_construction_var(self, varstr):
+        """Return if the specified string is a legitimate construction
+        variable.
+        """
+        return self._valid_var.match(varstr)
+
+    def __setitem__(self, key, value):
+        special = self._special_set.get(key)
+        if special:
+            special(self, key, value)
+        else:
+            if not self.is_valid_construction_var(key):
+                raise SCons.Errors.UserError, "Illegal construction variable `%s'" % key
+            self._dict[key] = value
+
+class env_regex_attribute_is_valid(Environment):
+    """is_valid_construction_var():  use a regex attribute"""
+    def __setitem__(self, key, value):
+        special = self._special_set.get(key)
+        if special:
+            special(self, key, value)
+        else:
+            if not self._valid_var.match(key):
+                raise SCons.Errors.UserError, "Illegal construction variable `%s'" % key
+            self._dict[key] = value
+
+class env_global_regex_is_valid(Environment):
+    """is_valid_construction_var():  use a global regex"""
+    def __setitem__(self, key, value):
+        special = self._special_set.get(key)
+        if special:
+            special(self, key, value)
+        else:
+            if not global_valid_var.match(key):
+                raise SCons.Errors.UserError, "Illegal construction variable `%s'" % key
+            self._dict[key] = value
+
+class env_special_set_has_key(Environment):
+    """_special_set.get():  use _special_set.has_key() instead"""
+    def __setitem__(self, key, value):
+        if self._special_set.has_key(key):
+            self._special_set[key](self, key, value)
+        else:
+            if not SCons.Environment.is_valid_construction_var(key):
+                raise SCons.Errors.UserError, "Illegal construction variable `%s'" % key
+            self._dict[key] = value
+
+class env_key_in_tuple(Environment):
+    """_special_set.get():  use "key in tuple" instead"""
+    def __setitem__(self, key, value):
+        if key in ('BUILDERS', 'SCANNERS', 'TARGET', 'TARGETS', 'SOURCE', 'SOURCES'):
+            self._special_set[key](self, key, value)
+        else:
+            if not SCons.Environment.is_valid_construction_var(key):
+                raise SCons.Errors.UserError, "Illegal construction variable `%s'" % key
+            self._dict[key] = value
+
+class env_key_in_list(Environment):
+    """_special_set.get():  use "key in list" instead"""
+    def __setitem__(self, key, value):
+        if key in ['BUILDERS', 'SCANNERS', 'TARGET', 'TARGETS', 'SOURCE', 'SOURCES']:
+            self._special_set[key](self, key, value)
+        else:
+            if not SCons.Environment.is_valid_construction_var(key):
+                raise SCons.Errors.UserError, "Illegal construction variable `%s'" % key
+            self._dict[key] = value
+
+class env_key_in_attribute(Environment):
+    """_special_set.get():  use "key in attribute" instead"""
+    def __setitem__(self, key, value):
+        if key in self._special_set_keys:
+            self._special_set[key](self, key, value)
+        else:
+            if not SCons.Environment.is_valid_construction_var(key):
+                raise SCons.Errors.UserError, "Illegal construction variable `%s'" % key
+            self._dict[key] = value
+
+class env_try_except(Environment):
+    """avoid is_valid_construction_var():  use try:-except:"""
+    def __setitem__(self, key, value):
+        special = self._special_set.get(key)
+        if special:
+            special(self, key, value)
+        else:
+            try:
+                self._dict[key]
+            except KeyError:
+                if not SCons.Environment.is_valid_construction_var(key):
+                    raise SCons.Errors.UserError, "Illegal construction variable `%s'" % key
+            self._dict[key] = value
+
+class env_not_has_key(Environment):
+    """avoid is_valid_construction_var():  use not .has_key()"""
+    def __setitem__(self, key, value):
+        special = self._special_set.get(key)
+        if special:
+            special(self, key, value)
+        else:
+            if not self._dict.has_key(key) \
+                and not SCons.Environment.is_valid_construction_var(key):
+                    raise SCons.Errors.UserError, "Illegal construction variable `%s'" % key
+            self._dict[key] = value
+
+class env_Best_attribute(Environment):
+    """Best __setitem__(), with an attribute"""
+    def __setitem__(self, key, value):
+        if key in self._special_set_keys:
+            self._special_set[key](self, key, value)
+        else:
+            if not self._dict.has_key(key) \
+               and not global_valid_var.match(key):
+                    raise SCons.Errors.UserError, "Illegal construction variable `%s'" % key
+            self._dict[key] = value
+
+class env_Best_has_key(Environment):
+    """Best __setitem__(), with has_key"""
+    def __setitem__(self, key, value):
+        if self._special_set.has_key(key):
+            self._special_set[key](self, key, value)
+        else:
+            if not self._dict.has_key(key) \
+               and not global_valid_var.match(key):
+                    raise SCons.Errors.UserError, "Illegal construction variable `%s'" % key
+            self._dict[key] = value
+
+class env_Best_list(Environment):
+    """Best __setitem__(), with a list"""
+    def __setitem__(self, key, value):
+        if key in ['BUILDERS', 'SCANNERS', 'TARGET', 'TARGETS', 'SOURCE', 'SOURCES']:
+            self._special_set[key](self, key, value)
+        else:
+            if not self._dict.has_key(key) \
+               and not global_valid_var.match(key):
+                    raise SCons.Errors.UserError, "Illegal construction variable `%s'" % key
+            self._dict[key] = value
+
+try:
+    ''.isalnum
+except AttributeError:
+    pass
+else:
+    class env_isalnum(Environment):
+        """Greg's Folly: isalnum instead of probe"""
+        def __setitem__(self, key, value):
+            if self._special_set.has_key(key):
+                self._special_set[key](self, key, value)
+            else:
+                if not key.isalnum() and not global_valid_var.match(key):
+                    raise SCons.Errors.UserError, "Illegal construction variable `%s'" % key
+                self._dict[key] = value
+
+# We'll use the names of all the env_* classes we find later to build
+# the dictionary of statements to be timed, and the import statement
+# that the timer will use to get at these classes.
+
+class_names = []
+for n in locals().keys():
+    #if n.startswith('env_'):
+    if n[:4] == 'env_':
+        class_names.append(n)
+
+# This is *the* function that gets timed.  It will get called for the
+# specified number of iterations for the cross product of the number of
+# classes we're testing and the number of data sets (defined below).
+
+iterations = 10000
+
+def do_it(names, env_class):
+    e = env_class()
+    for key in names:
+        e[key] = 1
+
+# Build the list of "statements" that will be tested.  For each class
+# we're testing, the doc string describing the class is the key, and
+# the statement we test is a simple "doit(names, {class})" call.
+
+statements = {}
+
+for class_name in class_names:
+    ec = eval(class_name)
+    statements[ec.__doc__] = 'do_it(names, %s)' % class_name
+
+# The common_imports string is used in the initialization of each
+# test run.  The timeit module insulates the test snippets from the
+# global namespace, so we have to import these explicitly from __main__.
+
+common_import_variables = ['do_it'] + class_names
+
+common_imports = """
+from __main__ import %s
+""" % string.join(common_import_variables, ', ')
+
+# The test data (lists of variable names) that we'll use for the runs.
+
+same_variable_names = ['XXX'] * 100
+uniq_variable_names = []
+for i in range(100): uniq_variable_names.append('X%05d' % i)
+mixed_variable_names = uniq_variable_names[:50] + same_variable_names[:50]
+
+# Lastly, put it all together...
+
+def run_it(title, init):
+      s = statements.copy()
+      s['num'] = iterations
+      s['title'] = title
+      s['init'] = init
+      apply(times,(),s)
+
+print 'Environment __setitem__ benchmark using',
+print 'Python', string.split(sys.version)[0],
+print 'on', sys.platform, os.name
+
+run_it('Results for re-adding an existing variable name 100 times:',
+      common_imports + """
+import __main__ ; names = __main__.same_variable_names
+""")
+
+run_it('Results for adding 100 variable names, 50 existing and 50 new:',
+      common_imports + """
+import __main__ ; names = __main__.mixed_variable_names
+""")
+
+run_it('Results for adding 100 new, unique variable names:',
+      common_imports + """
+import __main__ ; names = __main__.uniq_variable_names
+""")
diff --git a/bench/timeit.py b/bench/timeit.py
new file mode 100644
index 00000000..d5e33bb1
--- /dev/null
+++ b/bench/timeit.py
@@ -0,0 +1,297 @@
+#! /usr/bin/env python
+
+"""Tool for measuring execution time of small code snippets.
+
+This module avoids a number of common traps for measuring execution
+times.  See also Tim Peters' introduction to the Algorithms chapter in
+the Python Cookbook, published by O'Reilly.
+
+Library usage: see the Timer class.
+
+Command line usage:
+    python timeit.py [-n N] [-r N] [-s S] [-t] [-c] [-h] [statement]
+
+Options:
+  -n/--number N: how many times to execute 'statement' (default: see below)
+  -r/--repeat N: how many times to repeat the timer (default 3)
+  -s/--setup S: statement to be executed once initially (default 'pass')
+  -t/--time: use time.time() (default on Unix)
+  -c/--clock: use time.clock() (default on Windows)
+  -v/--verbose: print raw timing results; repeat for more digits precision
+  -h/--help: print this usage message and exit
+  statement: statement to be timed (default 'pass')
+
+A multi-line statement may be given by specifying each line as a
+separate argument; indented lines are possible by enclosing an
+argument in quotes and using leading spaces.  Multiple -s options are
+treated similarly.
+
+If -n is not given, a suitable number of loops is calculated by trying
+successive powers of 10 until the total time is at least 0.2 seconds.
+
+The difference in default timer function is because on Windows,
+clock() has microsecond granularity but time()'s granularity is 1/60th
+of a second; on Unix, clock() has 1/100th of a second granularity and
+time() is much more precise.  On either platform, the default timer
+functions measure wall clock time, not the CPU time.  This means that
+other processes running on the same computer may interfere with the
+timing.  The best thing to do when accurate timing is necessary is to
+repeat the timing a few times and use the best time.  The -r option is
+good for this; the default of 3 repetitions is probably enough in most
+cases.  On Unix, you can use clock() to measure CPU time.
+
+Note: there is a certain baseline overhead associated with executing a
+pass statement.  The code here doesn't try to hide it, but you should
+be aware of it.  The baseline overhead can be measured by invoking the
+program without arguments.
+
+The baseline overhead differs between Python versions!  Also, to
+fairly compare older Python versions to Python 2.3, you may want to
+use python -O for the older versions to avoid timing SET_LINENO
+instructions.
+"""
+
+try:
+    import gc
+except ImportError:
+    class _fake_gc:
+        def isenabled(self):
+            return None
+        def enable(self):
+            pass
+        def disable(self):
+            pass
+    gc = _fake_gc()
+import sys
+import time
+try:
+    import itertools
+except ImportError:
+    # Must be an older Python version (see timeit() below)
+    itertools = None
+
+import string
+
+__all__ = ["Timer"]
+
+dummy_src_name = "<timeit-src>"
+default_number = 1000000
+default_repeat = 3
+
+if sys.platform == "win32":
+    # On Windows, the best timer is time.clock()
+    default_timer = time.clock
+else:
+    # On most other platforms the best timer is time.time()
+    default_timer = time.time
+
+# Don't change the indentation of the template; the reindent() calls
+# in Timer.__init__() depend on setup being indented 4 spaces and stmt
+# being indented 8 spaces.
+template = """
+def inner(_it, _timer):
+    %(setup)s
+    _t0 = _timer()
+    for _i in _it:
+        %(stmt)s
+    _t1 = _timer()
+    return _t1 - _t0
+"""
+
+def reindent(src, indent):
+    """Helper to reindent a multi-line statement."""
+    return string.replace(src, "\n", "\n" + " "*indent)
+
+class Timer:
+    """Class for timing execution speed of small code snippets.
+
+    The constructor takes a statement to be timed, an additional
+    statement used for setup, and a timer function.  Both statements
+    default to 'pass'; the timer function is platform-dependent (see
+    module doc string).
+
+    To measure the execution time of the first statement, use the
+    timeit() method.  The repeat() method is a convenience to call
+    timeit() multiple times and return a list of results.
+
+    The statements may contain newlines, as long as they don't contain
+    multi-line string literals.
+    """
+
+    def __init__(self, stmt="pass", setup="pass", timer=default_timer):
+        """Constructor.  See class doc string."""
+        self.timer = timer
+        stmt = reindent(stmt, 8)
+        setup = reindent(setup, 4)
+        src = template % {'stmt': stmt, 'setup': setup}
+        self.src = src # Save for traceback display
+        code = compile(src, dummy_src_name, "exec")
+        ns = {}
+        exec code in globals(), ns
+        self.inner = ns["inner"]
+
+    def print_exc(self, file=None):
+        """Helper to print a traceback from the timed code.
+
+        Typical use:
+
+            t = Timer(...)       # outside the try/except
+            try:
+                t.timeit(...)    # or t.repeat(...)
+            except:
+                t.print_exc()
+
+        The advantage over the standard traceback is that source lines
+        in the compiled template will be displayed.
+
+        The optional file argument directs where the traceback is
+        sent; it defaults to sys.stderr.
+        """
+        import linecache, traceback
+        linecache.cache[dummy_src_name] = (len(self.src),
+                                           None,
+                                           self.src.split("\n"),
+                                           dummy_src_name)
+        traceback.print_exc(file=file)
+
+    def timeit(self, number=default_number):
+        """Time 'number' executions of the main statement.
+
+        To be precise, this executes the setup statement once, and
+        then returns the time it takes to execute the main statement
+        a number of times, as a float measured in seconds.  The
+        argument is the number of times through the loop, defaulting
+        to one million.  The main statement, the setup statement and
+        the timer function to be used are passed to the constructor.
+        """
+        if itertools:
+            it = itertools.repeat(None, number)
+        else:
+            it = [None] * number
+        gcold = gc.isenabled()
+        gc.disable()
+        timing = self.inner(it, self.timer)
+        if gcold:
+            gc.enable()
+        return timing
+
+    def repeat(self, repeat=default_repeat, number=default_number):
+        """Call timeit() a few times.
+
+        This is a convenience function that calls the timeit()
+        repeatedly, returning a list of results.  The first argument
+        specifies how many times to call timeit(), defaulting to 3;
+        the second argument specifies the timer argument, defaulting
+        to one million.
+
+        Note: it's tempting to calculate mean and standard deviation
+        from the result vector and report these.  However, this is not
+        very useful.  In a typical case, the lowest value gives a
+        lower bound for how fast your machine can run the given code
+        snippet; higher values in the result vector are typically not
+        caused by variability in Python's speed, but by other
+        processes interfering with your timing accuracy.  So the min()
+        of the result is probably the only number you should be
+        interested in.  After that, you should look at the entire
+        vector and apply common sense rather than statistics.
+        """
+        r = []
+        for i in range(repeat):
+            t = self.timeit(number)
+            r.append(t)
+        return r
+
+def main(args=None):
+    """Main program, used when run as a script.
+
+    The optional argument specifies the command line to be parsed,
+    defaulting to sys.argv[1:].
+
+    The return value is an exit code to be passed to sys.exit(); it
+    may be None to indicate success.
+
+    When an exception happens during timing, a traceback is printed to
+    stderr and the return value is 1.  Exceptions at other times
+    (including the template compilation) are not caught.
+    """
+    if args is None:
+        args = sys.argv[1:]
+    import getopt
+    try:
+        opts, args = getopt.getopt(args, "n:s:r:tcvh",
+                                   ["number=", "setup=", "repeat=",
+                                    "time", "clock", "verbose", "help"])
+    except getopt.error, err:
+        print err
+        print "use -h/--help for command line help"
+        return 2
+    timer = default_timer
+    stmt = string.join(args, "\n") or "pass"
+    number = 0 # auto-determine
+    setup = []
+    repeat = default_repeat
+    verbose = 0
+    precision = 3
+    for o, a in opts:
+        if o in ("-n", "--number"):
+            number = int(a)
+        if o in ("-s", "--setup"):
+            setup.append(a)
+        if o in ("-r", "--repeat"):
+            repeat = int(a)
+            if repeat <= 0:
+                repeat = 1
+        if o in ("-t", "--time"):
+            timer = time.time
+        if o in ("-c", "--clock"):
+            timer = time.clock
+        if o in ("-v", "--verbose"):
+            if verbose:
+                precision = precision + 1
+            verbose = precision + 1
+        if o in ("-h", "--help"):
+            print __doc__,
+            return 0
+    setup = string.join(setup, "\n") or "pass"
+    # Include the current directory, so that local imports work (sys.path
+    # contains the directory of this script, rather than the current
+    # directory)
+    import os
+    sys.path.insert(0, os.curdir)
+    t = Timer(stmt, setup, timer)
+    if number == 0:
+        # determine number so that 0.2 <= total time < 2.0
+        for i in range(1, 10):
+            number = 10**i
+            try:
+                x = t.timeit(number)
+            except:
+                t.print_exc()
+                return 1
+            if verbose:
+                print "%d loops -> %.*g secs" % (number, precision, x)
+            if x >= 0.2:
+                break
+    try:
+        r = t.repeat(repeat, number)
+    except:
+        t.print_exc()
+        return 1
+    best = min(r)
+    if verbose:
+        print "raw times:", string.join(map(lambda x, p=precision: "%.*g" % (p, x), r))
+    print "%d loops," % number,
+    usec = best * 1e6 / number
+    if usec < 1000:
+        print "best of %d: %.*g usec per loop" % (repeat, precision, usec)
+    else:
+        msec = usec / 1000
+        if msec < 1000:
+            print "best of %d: %.*g msec per loop" % (repeat, precision, msec)
+        else:
+            sec = msec / 1000
+            print "best of %d: %.*g sec per loop" % (repeat, precision, sec)
+    return None
+
+if __name__ == "__main__":
+    sys.exit(main())