reverted distutils its 3.1 state. All new work is now happening in disutils2, and distutils is now feature-frozen.
diff --git a/Lib/distutils/extension.py b/Lib/distutils/extension.py
index ebe5437..5c07bda 100644
--- a/Lib/distutils/extension.py
+++ b/Lib/distutils/extension.py
@@ -6,6 +6,7 @@
 __revision__ = "$Id$"
 
 import os
+import sys
 import warnings
 
 # This class is really only used by the "build_ext" command, so it might
@@ -134,17 +135,14 @@
 
 def read_setup_file(filename):
     """Reads a Setup file and returns Extension instances."""
-    warnings.warn('distutils.extensions.read_setup_file is deprecated. '
-                  'It will be removed in the next Python release.')
-    _sysconfig = __import__('sysconfig')
-    from distutils.sysconfig import (expand_makefile_vars,
+    from distutils.sysconfig import (parse_makefile, expand_makefile_vars,
                                      _variable_rx)
 
     from distutils.text_file import TextFile
     from distutils.util import split_quoted
 
     # First pass over the file to gather "VAR = VALUE" assignments.
-    vars = _sysconfig._parse_makefile(filename)
+    vars = parse_makefile(filename)
 
     # Second pass to gobble up the real content: lines of the form
     #   <module> ... [<sourcefile> ...] [<cpparg> ...] [<library> ...]
@@ -164,10 +162,7 @@
             file.warn("'%s' lines not handled yet" % line)
             continue
 
-        with warnings.catch_warnings():
-            warnings.simplefilter("ignore")
-            line = expand_makefile_vars(line, vars)
-
+        line = expand_makefile_vars(line, vars)
         words = split_quoted(line)
 
         # NB. this parses a slightly different syntax than the old