MacOS X: Enable 4-way universal builds

This patch adds a new configure argument on OSX:
        --with-universal-archs=[32-bit|64-bit|all]

When used with the --enable-universalsdk option this controls which
CPU architectures are includes in the framework. The default is 32-bit,
meaning i386 and ppc. The most useful alternative is 'all', which includes
all 4 CPU architectures supported by MacOS X (i386, ppc, x86_64 and ppc64).

This includes limited support for the Carbon bindings in 64-bit mode as well,
limited because (a) I haven't done extensive testing and (b) a large portion
of the Carbon API's aren't available in 64-bit mode anyway.

I've also duplicated a feature of Apple's build of python: setting the
environment variable 'ARCHFLAGS' controls the '-arch' flags used for building
extensions using distutils.

setup.py

@@ -248,6 +248,19 @@ class PyBuildExt(build_ext):
                 'WARNING: skipping import check for Carbon-based "%s"' %
                 ext.name)
             return
+
+        if self.get_platform() == 'darwin' and (
+                sys.maxint > 2**32 and '-arch' in ext.extra_link_args):
+            # Don't bother doing an import check when an extension was
+            # build with an explicit '-arch' flag on OSX. That's currently
+            # only used to build 32-bit only extensions in a 4-way
+            # universal build and loading 32-bit code into a 64-bit
+            # process will fail.
+            self.announce(
+                'WARNING: skipping import check for "%s"' %
+                ext.name)
+            return
+
         # Workaround for Cygwin: Cygwin currently has fork issues when many
         # modules have been imported
         if self.get_platform() == 'cygwin':
@@ -541,10 +554,12 @@ class PyBuildExt(build_ext):
 
         # readline
         do_readline = self.compiler.find_library_file(lib_dirs, 'readline')
-        if platform == 'darwin':
+        if platform == 'darwin': # and os.uname()[2] < '9.':
             # MacOSX 10.4 has a broken readline. Don't try to build
             # the readline module unless the user has installed a fixed
             # readline package
+            # FIXME: The readline emulation on 10.5 is better, but the
+            # readline module doesn't compile out of the box.
             if find_file('readline/rlconf.h', inc_dirs, []) is None:
                 do_readline = False
         if do_readline:
@@ -1304,11 +1319,24 @@ class PyBuildExt(build_ext):
                            '_Dlg', '_Drag', '_Evt', '_File', '_Folder', '_Fm',
                            '_Help', '_Icn', '_IBCarbon', '_List',
                            '_Menu', '_Mlte', '_OSA', '_Res', '_Qd', '_Qdoffs',
-                           '_Scrap', '_Snd', '_TE', '_Win',
+                           '_Scrap', '_Snd', '_TE',
                           ]
             for name in CARBON_EXTS:
                 addMacExtension(name, carbon_kwds)
 
+            # Workaround for a bug in the version of gcc shipped with Xcode 3.
+            # The _Win extension should build just like the other Carbon extensions, but
+            # this actually results in a hard crash of the linker.
+            #
+            if '-arch ppc64' in cflags and '-arch ppc' in cflags:
+                win_kwds = {'extra_compile_args': carbon_extra_compile_args + ['-arch', 'i386', '-arch', 'ppc'],
+                               'extra_link_args': ['-framework', 'Carbon', '-arch', 'i386', '-arch', 'ppc'],
+                           }
+                addMacExtension('_Win', win_kwds)
+            else:
+                addMacExtension('_Win', carbon_kwds)
+
+
             # Application Services & QuickTime
             app_kwds = {'extra_compile_args': carbon_extra_compile_args,
                         'extra_link_args': ['-framework','ApplicationServices'],
@@ -1375,11 +1403,29 @@ class PyBuildExt(build_ext):
         include_dirs.append('/usr/X11R6/include')
         frameworks = ['-framework', 'Tcl', '-framework', 'Tk']
 
+        # All existing framework builds of Tcl/Tk don't support 64-bit
+        # architectures.
+        cflags = sysconfig.get_config_vars('CFLAGS')[0]
+        archs = re.findall('-arch\s+(\w+)', cflags)
+        if 'x86_64' in archs or 'ppc64' in archs:
+            try:
+                archs.remove('x86_64')
+            except ValueError:
+                pass
+            try:
+                archs.remove('ppc64')
+            except ValueError:
+                pass
+
+            for a in archs:
+                frameworks.append('-arch')
+                frameworks.append(a)
+
         ext = Extension('_tkinter', ['_tkinter.c', 'tkappinit.c'],
                         define_macros=[('WITH_APPINIT', 1)],
                         include_dirs = include_dirs,
                         libraries = [],
-                        extra_compile_args = frameworks,
+                        extra_compile_args = frameworks[2:],
                         extra_link_args = frameworks,
                         )
         self.extensions.append(ext)
@@ -1510,6 +1556,7 @@ class PyBuildExt(build_ext):
                                                   '_ctypes', 'libffi_osx'))
         sources = [os.path.join(ffi_srcdir, p)
                    for p in ['ffi.c',
+                             'x86/darwin64.S',
                              'x86/x86-darwin.S',
                              'x86/x86-ffi_darwin.c',
                              'x86/x86-ffi64.c',