Introduced EXTRA_CFLAGS as an environment variable used by the Makefile. Meant

to be used for flags that change binary compatibility.

Distutils was tweaked to also use the variable if used during compilation of
the interpreter.

Lib/distutils/sysconfig.py

@@ -146,8 +146,9 @@ def customize_compiler(compiler):
     varies across Unices and is stored in Python's Makefile.
     """
     if compiler.compiler_type == "unix":
-        (cc, cxx, opt, basecflags, ccshared, ldshared, so_ext) = \
-            get_config_vars('CC', 'CXX', 'OPT', 'BASECFLAGS', 'CCSHARED', 'LDSHARED', 'SO')
+        (cc, cxx, opt, extra_cflags, basecflags, ccshared, ldshared, so_ext) = \
+            get_config_vars('CC', 'CXX', 'OPT', 'EXTRA_CFLAGS', 'BASECFLAGS',
+                            'CCSHARED', 'LDSHARED', 'SO')
 
         if os.environ.has_key('CC'):
             cc = os.environ['CC']
@@ -171,7 +172,7 @@ def customize_compiler(compiler):
             opt = opt + ' ' + os.environ['CPPFLAGS']
             ldshared = ldshared + ' ' + os.environ['CPPFLAGS']
 
-        cc_cmd = cc + ' ' + opt
+        cc_cmd = ' '.join(str(x) for x in (cc, opt, extra_cflags) if x)
         compiler.set_executables(
             preprocessor=cpp,
             compiler=cc_cmd,

Makefile.pre.in

@@ -55,7 +55,7 @@ MAKESETUP=      $(srcdir)/Modules/makesetup
 # Compiler options
 OPT=		@OPT@
 BASECFLAGS=	@BASECFLAGS@
-CFLAGS=		$(BASECFLAGS) $(OPT)
+CFLAGS=		$(BASECFLAGS) $(OPT) $(EXTRA_CFLAGS)
 # Both CPPFLAGS and LDFLAGS need to contain the shell's value for setup.py to
 # be able to build extension modules using the directories specified in the
 # environment variables

Misc/NEWS

@@ -276,6 +276,11 @@ Library
 Build
 -----
 
+- EXTRA_CFLAGS has been introduced as an environment variable to hold compiler
+  flags that change binary compatibility.  Changes were also made to
+  distutils.sysconfig to also use the environment variable when used during
+  compilation of the interpreter.
+
 - SF patch 1171735: Darwin 8's headers are anal about POSIX compliance,
   and linking has changed (prebinding is now deprecated, and libcc_dynamic
   no longer exists). This configure patch makes things right.

Misc/SpecialBuilds.txt

 This file describes some special Python build types enabled via
 compile-time preprocessor defines.
 
-It is best to define these options in the OPT environment variable;
-``OPT="-DPy_REF_DEBUG" ./configure``.  If you want the default values of
-OPT to also be included you will need to add them in yourself manually.
+It is best to define these options in the EXTRA_FLAGS environment variable;
+``EXTRA_CFLAGS="-DPy_REF_DEBUG" ./configure``.
 
 ---------------------------------------------------------------------------
 Py_REF_DEBUG                                              introduced in 1.4

README

@@ -827,6 +827,9 @@ the -Wall and -Wstrict-prototypes options.
 Additional debugging code to help debug memory management problems can
 be enabled by using the --with-pydebug option to the configure script.
 
+For flags that change binary compatibility, use the EXTRA_CFLAGS
+variable.
+
 
 Profiling
 ---------