=== modified file 'Lib/distutils/command/build_ext.py'
--- Lib/distutils/command/build_ext.py	2010-01-29 11:46:31 +0000
+++ Lib/distutils/command/build_ext.py	2010-07-07 18:21:04 +0000
@@ -515,7 +515,7 @@
                   "a list of source filenames" % ext.name)
         sources = list(sources)
 
-        ext_path = self.get_ext_fullpath(ext.name)
+        ext_path = self.get_ext_fullpath(ext.name, ext)
         depends = sources + ext.depends
         if not (self.force or newer_group(depends, ext_path, 'newer')):
             log.debug("skipping '%s' extension (up-to-date)", ext.name)
@@ -669,7 +669,7 @@
 
     # -- Name generators -----------------------------------------------
     # (extension names, filenames, whatever)
-    def get_ext_fullpath(self, ext_name):
+    def get_ext_fullpath(self, ext_name, ext=None):
         """Returns the path of the filename for a given extension.
 
         The file is located in `build_lib` or directly in the package
@@ -677,7 +677,7 @@
         """
         fullname = self.get_ext_fullname(ext_name)
         modpath = fullname.split('.')
-        filename = self.get_ext_filename(modpath[-1])
+        filename = self.get_ext_filename(modpath[-1], ext)
 
         if not self.inplace:
             # no further work needed
@@ -705,7 +705,7 @@
         else:
             return self.package + '.' + ext_name
 
-    def get_ext_filename(self, ext_name):
+    def get_ext_filename(self, ext_name, ext=None):
         r"""Convert the name of an extension (eg. "foo.bar") into the name
         of the file from which it will be loaded (eg. "foo/bar.so", or
         "foo\bar.pyd").
@@ -717,6 +717,17 @@
             ext_path[len(ext_path) - 1] = ext_path[len(ext_path) - 1][:8]
         # extensions in debug_mode are named 'module_d.pyd' under windows
         so_ext = _sysconfig.get_config_var('SO')
+        if ext is not None and ext.so_abi_tag is not None:
+            tag, sep, file_ext = so_ext.rpartition('.')
+            # The ABI tag could be the empty string, in which case there is no
+            # tag, just the .so extension.  Otherwise, we can replace the
+            # ABI tag hard coded in the Makefile with the one requested in the
+            # Extension instance.
+            if ext.so_abi_tag == '':
+                so_ext = sep + file_ext
+            else:
+                so_ext = sep + so_abi_tag + sep + file_ext
+
         if os.name == 'nt' and self.debug:
             return os.path.join(*ext_path) + '_d' + so_ext
         return os.path.join(*ext_path) + so_ext

=== modified file 'Lib/distutils/extension.py'
--- Lib/distutils/extension.py	2010-01-29 11:41:03 +0000
+++ Lib/distutils/extension.py	2010-07-07 18:21:04 +0000
@@ -125,6 +125,9 @@
         self.language = language
         self.optional = optional
 
+        # Optional shared library ABI tag.
+        self.so_abi_tag = kw.pop('so_abi_tag', None)
+
         # If there are unknown keyword options, warn about them
         if len(kw) > 0:
             options = [repr(option) for option in kw]

=== modified file 'Lib/distutils/tests/test_build_ext.py'
--- Lib/distutils/tests/test_build_ext.py	2010-04-02 21:38:52 +0000
+++ Lib/distutils/tests/test_build_ext.py	2010-07-07 18:21:04 +0000
@@ -330,8 +330,8 @@
         finally:
             os.chdir(old_wd)
         self.assertTrue(os.path.exists(so_file))
-        self.assertEquals(os.path.splitext(so_file)[-1],
-                          sysconfig.get_config_var('SO'))
+        so_ext = sysconfig.get_config_var('SO')
+        self.assertTrue(so_file.endswith(so_ext))
         so_dir = os.path.dirname(so_file)
         self.assertEquals(so_dir, other_tmp_dir)
 
@@ -339,8 +339,7 @@
         cmd.run()
         so_file = cmd.get_outputs()[0]
         self.assertTrue(os.path.exists(so_file))
-        self.assertEquals(os.path.splitext(so_file)[-1],
-                          sysconfig.get_config_var('SO'))
+        self.assertTrue(so_file.endswith(so_ext))
         so_dir = os.path.dirname(so_file)
         self.assertEquals(so_dir, cmd.build_lib)
 

=== modified file 'Makefile.pre.in'
--- Makefile.pre.in	2010-06-27 19:40:18 +0000
+++ Makefile.pre.in	2010-07-07 18:21:04 +0000
@@ -35,6 +35,7 @@
 AR=		@AR@
 RANLIB=		@RANLIB@
 SVNVERSION=	@SVNVERSION@
+SOABI=          @SOABI@
 
 GNULD=          @GNULD@
 
@@ -554,6 +555,11 @@
 Modules/python.o: $(srcdir)/Modules/python.c
 	$(MAINCC) -c $(PY_CFLAGS) -o $@ $(srcdir)/Modules/python.c
 
+Python/dynload_shlib.o: $(srcdir)/Python/dynload_shlib.c Makefile
+	$(CC) -c $(PY_CFLAGS) \
+		$(SOABI) \
+		-o $@ $(srcdir)/Python/dynload_shlib.c
+
 $(IO_OBJS): $(IO_H)
 
 $(GRAMMAR_H) $(GRAMMAR_C): $(PGEN) $(GRAMMAR_INPUT)

=== modified file 'Python/dynload_shlib.c'
--- Python/dynload_shlib.c	2010-05-09 14:52:27 +0000
+++ Python/dynload_shlib.c	2010-07-07 18:21:04 +0000
@@ -30,6 +30,11 @@
 #define LEAD_UNDERSCORE ""
 #endif
 
+/* The .so extension module ABI tag, supplied by the Makefile via
+   Makefile.pre.in and configure.  This is used to discriminate between
+   incompatible .so files so that extensions for different Python builds can
+   live in the same directory.  E.g. foomodule.cpython-32.so
+*/
 
 const struct filedescr _PyImport_DynLoadFiletab[] = {
 #ifdef __CYGWIN__
@@ -48,9 +53,13 @@
 #else
     {".so", "rb", C_EXTENSION},
     {"module.so", "rb", C_EXTENSION},
-#endif
-#endif
-#endif
+#ifdef SOABI
+    {"." SOABI ".so", "rb", C_EXTENSION},
+    {"module." SOABI ".so", "rb", C_EXTENSION},
+#endif  /* SOABI */
+#endif  /* __VMS */
+#endif  /* defined(PYOS_OS2) && defined(PYCC_GCC) */
+#endif  /* __CYGWIN__ */
     {0, 0}
 };
 

=== modified file 'configure'
--- configure	2010-06-27 22:34:03 +0000
+++ configure	2010-07-07 18:21:04 +0000
@@ -1,5 +1,5 @@
 #! /bin/sh
-# From configure.in Revision: 82090 .
+# From configure.in Revision.
 # Guess values for system-dependent variables and create Makefiles.
 # Generated by GNU Autoconf 2.65 for python 3.2.
 #
@@ -679,6 +679,7 @@
 ARCH_RUN_32BIT
 UNIVERSALSDK
 CONFIG_ARGS
+SOABI
 SOVERSION
 VERSION
 target_alias
@@ -722,6 +723,7 @@
 ac_subst_files=''
 ac_user_opts='
 enable_option_checking
+with_so_abi_tag
 enable_universalsdk
 with_universal_archs
 with_framework_name
@@ -1386,6 +1388,8 @@
 Optional Packages:
   --with-PACKAGE[=ARG]    use PACKAGE [ARG=yes]
   --without-PACKAGE       do not use PACKAGE (same as --with-PACKAGE=no)
+  --with-so-abi-tag=TAG   specify a tag to uniquely identify .so file ABI
+                          compliance; e.g. foo.<TAG>.so
   --with-universal-archs=ARCH
                           select architectures for universal build ("32-bit",
                           "64-bit", "3-way", "intel" or "all")
@@ -1929,11 +1933,11 @@
        cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 $ac_includes_default
+	     enum { N = $2 / 2 - 1 };
 int
 main ()
 {
-static int test_array [1 - 2 * !(enum { N = $2 / 2 - 1 };
-	     0 < ($ac_type) ((((($ac_type) 1 << N) << N) - 1) * 2 + 1))];
+static int test_array [1 - 2 * !(0 < ($ac_type) ((((($ac_type) 1 << N) << N) - 1) * 2 + 1))];
 test_array [0] = 0
 
   ;
@@ -1944,11 +1948,11 @@
   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 $ac_includes_default
+	        enum { N = $2 / 2 - 1 };
 int
 main ()
 {
-static int test_array [1 - 2 * !(enum { N = $2 / 2 - 1 };
-		($ac_type) ((((($ac_type) 1 << N) << N) - 1) * 2 + 1)
+static int test_array [1 - 2 * !(($ac_type) ((((($ac_type) 1 << N) << N) - 1) * 2 + 1)
 		 < ($ac_type) ((((($ac_type) 1 << N) << N) - 1) * 2 + 2))];
 test_array [0] = 0
 
@@ -2696,9 +2700,29 @@
 
 VERSION=3.2
 
+# Version number or Python's own shared library file.
 
 SOVERSION=1.0
 
+# ABI version string for Python extension modules.  This appears between the
+# periods in shared library file names, e.g. foo.<SOABI>.so.  Use the empty
+# string to specify no value.
+
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for --with-so-abi-tag" >&5
+$as_echo_n "checking for --with-so-abi-tag... " >&6; }
+
+# Check whether --with-so-abi-tag was given.
+if test "${with_so_abi_tag+set}" = set; then :
+  withval=$with_so_abi_tag;
+    SOABI=$withval
+else
+
+    SOABI=
+fi
+
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $SOABI" >&5
+$as_echo "$SOABI" >&6; }
+
 # The later defininition of _XOPEN_SOURCE disables certain features
 # on Linux, so we need _GNU_SOURCE to re-enable them (makedev, tm_zone).
 
@@ -7425,6 +7449,16 @@
 		esac
 		;;
 	CYGWIN*)   SO=.dll;;
+        Linux*)
+                if test -z "$SOABI"
+                then
+                    SO=.so
+                    SOABI=-USOABI
+                else
+                    SO=.${SOABI}.so
+                    SOABI="-DSOABI=\\\"$SOABI\\\""
+                fi
+                ;;
 	*)	   SO=.so;;
 	esac
 else

=== modified file 'configure.in'
--- configure.in	2010-06-19 18:58:37 +0000
+++ configure.in	2010-07-07 18:21:04 +0000
@@ -52,9 +52,23 @@
 AC_SUBST(VERSION)
 VERSION=PYTHON_VERSION
 
+# Version number or Python's own shared library file.
 AC_SUBST(SOVERSION)
 SOVERSION=1.0
 
+# ABI version string for Python extension modules.  This appears between the
+# periods in shared library file names, e.g. foo.<SOABI>.so.  Use the empty
+# string to specify no value.
+AC_SUBST(SOABI)
+AC_MSG_CHECKING(for --with-so-abi-tag)
+AC_ARG_WITH(so-abi-tag,
+            AS_HELP_STRING([--with-so-abi-tag=TAG],
+                           [specify a tag to uniquely identify .so file ABI compliance; e.g. foo.<TAG>.so]),
+[
+    SOABI=$withval], [
+    SOABI= ])
+AC_MSG_RESULT($SOABI)
+
 # The later defininition of _XOPEN_SOURCE disables certain features
 # on Linux, so we need _GNU_SOURCE to re-enable them (makedev, tm_zone).
 AC_DEFINE(_GNU_SOURCE, 1, [Define on Linux to activate all library features])
@@ -1656,6 +1670,16 @@
 		esac
 		;;
 	CYGWIN*)   SO=.dll;;
+        Linux*)
+                if test -z "$SOABI"
+                then
+                    SO=.so
+                    SOABI=-USOABI
+                else
+                    SO=.${SOABI}.so
+                    SOABI="-DSOABI=\\\"$SOABI\\\""
+                fi
+                ;;
 	*)	   SO=.so;;
 	esac
 else