bpo-26317: Support OBJC and OBJCXX configure command line variables (GH-20176)

Add support to the configure script for OBJC and OBJCXX command line options so that the macOS builds can use the clang compiler for the macOS-specific Objective C source files. This allows third-party compilers, like GNU gcc, to be used to build the rest of the project since some of the Objective C system header files are not compilable by GNU gcc.

Co-authored-by: Jeffrey Kintscher <websurfer@surf2c.net>
Co-authored-by: Terry Jan Reedy <tjreedy@udel.edu>

Doc/whatsnew/3.9.rst

@@ -892,6 +892,14 @@ Build Changes
   functions are now required to build Python.
   (Contributed by Victor Stinner in :issue:`39395`.)
 
+* The ``OBJC`` and ``OBJCXX`` standard command line options for the configure
+  script are now supported. This allows building fot macOS with a third-party
+  compiler, like GNU `gcc`, for everything except for the several
+  system-specific source files that need system headers that require the
+  Apple-supplied compile chain (e.g. the ``_scproxy`` helper module and
+  ``PythonLauncher.app``).
+  (Contributed by Jeffrey Kintscher in :issue:`26317`.)
+
 
 C API Changes
 =============

Mac/Makefile.in

@@ -21,6 +21,7 @@ PYTHONFRAMEWORK=@PYTHONFRAMEWORK@
 PYTHONFRAMEWORKIDENTIFIER=@PYTHONFRAMEWORKIDENTIFIER@
 LIPO_32BIT_FLAGS=@LIPO_32BIT_FLAGS@
 CC=@CC@
+OBJC=@OBJC@
 MACOSX_DEPLOYMENT_TARGET=@CONFIGURE_MACOSX_DEPLOYMENT_TARGET@
 export MACOSX_DEPLOYMENT_TARGET
 

Mac/PythonLauncher/Makefile.in

@@ -1,5 +1,7 @@
 CC=@CC@
 LD=@CC@
+OBJC=@OBJC@
+OBJCFLAFS=@OBJCFLAGS@
 BASECFLAGS=@BASECFLAGS@
 OPT=@OPT@
 CFLAGS=@CFLAGS@ $(BASECFLAGS) $(OPT)
@@ -52,25 +54,25 @@ Python\ Launcher.app:  Info.plist \
 	cp -R $(srcdir)/English.lproj "Python Launcher.app/Contents/Resources"
 
 FileSettings.o: $(srcdir)/FileSettings.m
-	$(CC) $(CFLAGS) -o $@ -c $(srcdir)/FileSettings.m
+	$(OBJC) $(CFLAGS) -o $@ -c $(srcdir)/FileSettings.m
 
 MyAppDelegate.o: $(srcdir)/MyAppDelegate.m
-	$(CC) $(CFLAGS) -o $@ -c $(srcdir)/MyAppDelegate.m
+	$(OBJC) $(CFLAGS) -o $@ -c $(srcdir)/MyAppDelegate.m
 
 MyDocument.o: $(srcdir)/MyDocument.m
-	$(CC) $(CFLAGS) -o $@ -c $(srcdir)/MyDocument.m
+	$(OBJC) $(CFLAGS) -o $@ -c $(srcdir)/MyDocument.m
 
 PreferencesWindowController.o: $(srcdir)/PreferencesWindowController.m
-	$(CC) $(CFLAGS) -o $@ -c $(srcdir)/PreferencesWindowController.m
+	$(OBJC) $(CFLAGS) -o $@ -c $(srcdir)/PreferencesWindowController.m
 
 doscript.o: $(srcdir)/doscript.m
-	$(CC) $(CFLAGS) -o $@ -c $(srcdir)/doscript.m
+	$(OBJC) $(CFLAGS) -o $@ -c $(srcdir)/doscript.m
 
 main.o: $(srcdir)/main.m
-	$(CC) $(CFLAGS) -o $@ -c $(srcdir)/main.m
+	$(OBJC) $(CFLAGS) -o $@ -c $(srcdir)/main.m
 
 Python\ Launcher: $(OBJECTS)
-	$(CC) $(LDFLAGS) -o "Python Launcher" $(OBJECTS) -framework AppKit -framework Carbon
+	$(OBJC) $(LDFLAGS) -o "Python Launcher" $(OBJECTS) -framework AppKit -framework Carbon
 
 Info.plist: $(srcdir)/Info.plist.in
 	sed 's/%VERSION%/'"`$(RUNSHARED) $(BUILDPYTHON) -c 'import platform; print(platform.python_version())'`"'/g' < $(srcdir)/Info.plist.in > Info.plist

Makefile.pre.in

@@ -35,6 +35,7 @@ abs_builddir=	@abs_builddir@
 
 CC=		@CC@
 CXX=		@CXX@
+OBJC=		@OBJC@
 MAINCC=		@MAINCC@
 LINKCC=		@LINKCC@
 AR=		@AR@
@@ -613,12 +614,22 @@ $(srcdir)/Modules/_blake2/blake2s_impl.c: $(srcdir)/Modules/_blake2/blake2b_impl
 	$(PYTHON_FOR_REGEN) $(srcdir)/Modules/_blake2/blake2b2s.py
 	$(PYTHON_FOR_REGEN) $(srcdir)/Tools/clinic/clinic.py -f $@
 
+# _scproxy.o needs to be built outside of setup.py so that we can force
+# the use of the OBJC compiler when the CC compiler is different. For
+# example, it allows _scproxy.c to be compiled using the clang compiler
+# while the rest of the project uses the GNU C compiler.
+#
+# see issue #26317 for details
+@SCPROXY@Modules/_scproxy.o:	$(srcdir)/Modules/_scproxy.c $(srcdir)/Include/Python.h
+@SCPROXY@	$(OBJC) -c $(CCSHARED) $(PY_CORE_CFLAGS) -o $@ $<
+@NOSCPROXY@.PHONY:	Modules/_scproxy.o
+
 # Build the shared modules
 # Under GNU make, MAKEFLAGS are sorted and normalized; the 's' for
 # -s, --silent or --quiet is always the first char.
 # Under BSD make, MAKEFLAGS might be " -s -v x=y".
 # Ignore macros passed by GNU make, passed after --
-sharedmods: $(BUILDPYTHON) pybuilddir.txt Modules/_math.o
+sharedmods: $(BUILDPYTHON) pybuilddir.txt Modules/_math.o Modules/_scproxy.o
 	@case "`echo X $$MAKEFLAGS | sed 's/^X //;s/ -- .*//'`" in \
 	    *\ -s*|s*) quiet="-q";; \
 	    *) quiet="";; \

Misc/ACKS

@@ -882,6 +882,7 @@ Sam Kimbrel
 Tomohiko Kinebuchi
 James King
 W. Trevor King
+Jeffrey Kintscher
 Paul Kippes
 Steve Kirsch
 Sebastian Kirsche

Misc/NEWS.d/next/Build/2019-05-14-05-35-14.bpo-26317.no8mw-.rst

@@ -0,0 +1 @@
+The OBJC and OBJCXX standard command line options for the configure script are now supported. This allows building fot macOS with a third-party compiler, like GNU gcc, for everything except for the several system-specific source files that need system headers that require the Apple-supplied compile chain (e.g. the _scproxy helper module and PythonLauncher.app).  Patch by Jeffrey Kintscher.

aclocal.m4

@@ -55,7 +55,7 @@ dnl
 dnl See the "Since" comment for each macro you use to see what version
 dnl of the macros you require.
 m4_defun([PKG_PREREQ],
-[m4_define([PKG_MACROS_VERSION], [0.29.1])
+[m4_define([PKG_MACROS_VERSION], [0.29.2])
 m4_if(m4_version_compare(PKG_MACROS_VERSION, [$1]), -1,
     [m4_fatal([pkg.m4 version $1 or higher is required but ]PKG_MACROS_VERSION[ found])])
 ])dnl PKG_PREREQ
@@ -156,7 +156,7 @@ AC_ARG_VAR([$1][_CFLAGS], [C compiler flags for $1, overriding pkg-config])dnl
 AC_ARG_VAR([$1][_LIBS], [linker flags for $1, overriding pkg-config])dnl
 
 pkg_failed=no
-AC_MSG_CHECKING([for $1])
+AC_MSG_CHECKING([for $2])
 
 _PKG_CONFIG([$1][_CFLAGS], [cflags], [$2])
 _PKG_CONFIG([$1][_LIBS], [libs], [$2])
@@ -166,11 +166,11 @@ and $1[]_LIBS to avoid the need to call pkg-config.
 See the pkg-config man page for more details.])
 
 if test $pkg_failed = yes; then
-   	AC_MSG_RESULT([no])
+        AC_MSG_RESULT([no])
         _PKG_SHORT_ERRORS_SUPPORTED
         if test $_pkg_short_errors_supported = yes; then
 	        $1[]_PKG_ERRORS=`$PKG_CONFIG --short-errors --print-errors --cflags --libs "$2" 2>&1`
-        else 
+        else
 	        $1[]_PKG_ERRORS=`$PKG_CONFIG --print-errors --cflags --libs "$2" 2>&1`
         fi
 	# Put the nasty error message in config.log where it belongs
@@ -187,7 +187,7 @@ installed software in a non-standard prefix.
 _PKG_TEXT])[]dnl
         ])
 elif test $pkg_failed = untried; then
-     	AC_MSG_RESULT([no])
+        AC_MSG_RESULT([no])
 	m4_default([$4], [AC_MSG_FAILURE(
 [The pkg-config script could not be found or is too old.  Make sure it
 is in your PATH or set the PKG_CONFIG environment variable to the full

configure

@@ -716,6 +716,14 @@ MULTIARCH_CPPFLAGS
 PLATFORM_TRIPLET
 MULTIARCH
 ac_ct_CXX
+NOSCPROXY
+SCPROXY
+ac_ct_OBJCXX
+OBJCXXFLAGS
+OBJCXX
+ac_ct_OBJC
+OBJCFLAGS
+OBJC
 MAINCC
 CXX
 SED
@@ -860,6 +868,10 @@ LDFLAGS
 LIBS
 CPPFLAGS
 CPP
+OBJC
+OBJCFLAGS
+OBJCXX
+OBJCXXFLAGS
 PROFILE_TASK
 PKG_CONFIG
 PKG_CONFIG_PATH
@@ -1599,6 +1611,10 @@ Some influential environment variables:
   CPPFLAGS    (Objective) C/C++ preprocessor flags, e.g. -I<include dir> if
               you have headers in a nonstandard directory <include dir>
   CPP         C preprocessor
+  OBJC        Objective C compiler command
+  OBJCFLAGS   Objective C compiler flags
+  OBJCXX      Objective C++ compiler command
+  OBJCXXFLAGS Objective C++ compiler flags
   PROFILE_TASK
               Python args for PGO generation task
   PKG_CONFIG  path to pkg-config utility
@@ -1762,6 +1778,82 @@ fi
 
 } # ac_fn_c_try_cpp
 
+# ac_fn_objc_try_compile LINENO
+# -----------------------------
+# Try to compile conftest.$ac_ext, and return whether this succeeded.
+ac_fn_objc_try_compile ()
+{
+  as_lineno=${as_lineno-"$1"} as_lineno_stack=as_lineno_stack=$as_lineno_stack
+  rm -f conftest.$ac_objext
+  if { { ac_try="$ac_compile"
+case "(($ac_try" in
+  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
+  *) ac_try_echo=$ac_try;;
+esac
+eval ac_try_echo="\"\$as_me:${as_lineno-$LINENO}: $ac_try_echo\""
+$as_echo "$ac_try_echo"; } >&5
+  (eval "$ac_compile") 2>conftest.err
+  ac_status=$?
+  if test -s conftest.err; then
+    grep -v '^ *+' conftest.err >conftest.er1
+    cat conftest.er1 >&5
+    mv -f conftest.er1 conftest.err
+  fi
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; } && {
+	 test -z "$ac_objc_werror_flag" ||
+	 test ! -s conftest.err
+       } && test -s conftest.$ac_objext; then :
+  ac_retval=0
+else
+  $as_echo "$as_me: failed program was:" >&5
+sed 's/^/| /' conftest.$ac_ext >&5
+
+	ac_retval=1
+fi
+  eval $as_lineno_stack; ${as_lineno_stack:+:} unset as_lineno
+  as_fn_set_status $ac_retval
+
+} # ac_fn_objc_try_compile
+
+# ac_fn_objcxx_try_compile LINENO
+# -------------------------------
+# Try to compile conftest.$ac_ext, and return whether this succeeded.
+ac_fn_objcxx_try_compile ()
+{
+  as_lineno=${as_lineno-"$1"} as_lineno_stack=as_lineno_stack=$as_lineno_stack
+  rm -f conftest.$ac_objext
+  if { { ac_try="$ac_compile"
+case "(($ac_try" in
+  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
+  *) ac_try_echo=$ac_try;;
+esac
+eval ac_try_echo="\"\$as_me:${as_lineno-$LINENO}: $ac_try_echo\""
+$as_echo "$ac_try_echo"; } >&5
+  (eval "$ac_compile") 2>conftest.err
+  ac_status=$?
+  if test -s conftest.err; then
+    grep -v '^ *+' conftest.err >conftest.er1
+    cat conftest.er1 >&5
+    mv -f conftest.er1 conftest.err
+  fi
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; } && {
+	 test -z "$ac_objcxx_werror_flag" ||
+	 test ! -s conftest.err
+       } && test -s conftest.$ac_objext; then :
+  ac_retval=0
+else
+  $as_echo "$as_me: failed program was:" >&5
+sed 's/^/| /' conftest.$ac_ext >&5
+
+	ac_retval=1
+fi
+  eval $as_lineno_stack; ${as_lineno_stack:+:} unset as_lineno
+  as_fn_set_status $ac_retval
+
+} # ac_fn_objcxx_try_compile
+
 # ac_fn_c_try_link LINENO
 # -----------------------
 # Try to link conftest.$ac_ext, and return whether this succeeded.
@@ -4641,6 +4733,525 @@ $as_echo "$ac_cv_path_SED" >&6; }
 
 
 
+
+if test "$ac_sys_system" = "Darwin"
+then
+	# MacOSX requires an Objective C compiler to
+	# build some Mac-specific code.
+	ac_ext=m
+ac_cpp='$OBJCPP $CPPFLAGS'
+ac_compile='$OBJC -c $OBJCFLAGS $CPPFLAGS conftest.$ac_ext >&5'
+ac_link='$OBJC -o conftest$ac_exeext $OBJCFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
+ac_compiler_gnu=$ac_cv_objc_compiler_gnu
+if test -n "$ac_tool_prefix"; then
+  for ac_prog in gcc objcc objc cc CC
+  do
+    # Extract the first word of "$ac_tool_prefix$ac_prog", so it can be a program name with args.
+set dummy $ac_tool_prefix$ac_prog; ac_word=$2
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
+$as_echo_n "checking for $ac_word... " >&6; }
+if ${ac_cv_prog_OBJC+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  if test -n "$OBJC"; then
+  ac_cv_prog_OBJC="$OBJC" # Let the user override the test.
+else
+as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
+for as_dir in $PATH
+do
+  IFS=$as_save_IFS
+  test -z "$as_dir" && as_dir=.
+    for ac_exec_ext in '' $ac_executable_extensions; do
+  if as_fn_executable_p "$as_dir/$ac_word$ac_exec_ext"; then
+    ac_cv_prog_OBJC="$ac_tool_prefix$ac_prog"
+    $as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
+    break 2
+  fi
+done
+  done
+IFS=$as_save_IFS
+
+fi
+fi
+OBJC=$ac_cv_prog_OBJC
+if test -n "$OBJC"; then
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $OBJC" >&5
+$as_echo "$OBJC" >&6; }
+else
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+fi
+
+
+    test -n "$OBJC" && break
+  done
+fi
+if test -z "$OBJC"; then
+  ac_ct_OBJC=$OBJC
+  for ac_prog in gcc objcc objc cc CC
+do
+  # Extract the first word of "$ac_prog", so it can be a program name with args.
+set dummy $ac_prog; ac_word=$2
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
+$as_echo_n "checking for $ac_word... " >&6; }
+if ${ac_cv_prog_ac_ct_OBJC+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  if test -n "$ac_ct_OBJC"; then
+  ac_cv_prog_ac_ct_OBJC="$ac_ct_OBJC" # Let the user override the test.
+else
+as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
+for as_dir in $PATH
+do
+  IFS=$as_save_IFS
+  test -z "$as_dir" && as_dir=.
+    for ac_exec_ext in '' $ac_executable_extensions; do
+  if as_fn_executable_p "$as_dir/$ac_word$ac_exec_ext"; then
+    ac_cv_prog_ac_ct_OBJC="$ac_prog"
+    $as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
+    break 2
+  fi
+done
+  done
+IFS=$as_save_IFS
+
+fi
+fi
+ac_ct_OBJC=$ac_cv_prog_ac_ct_OBJC
+if test -n "$ac_ct_OBJC"; then
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_ct_OBJC" >&5
+$as_echo "$ac_ct_OBJC" >&6; }
+else
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+fi
+
+
+  test -n "$ac_ct_OBJC" && break
+done
+
+  if test "x$ac_ct_OBJC" = x; then
+    OBJC="gcc"
+  else
+    case $cross_compiling:$ac_tool_warned in
+yes:)
+{ $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: using cross tools not prefixed with host triplet" >&5
+$as_echo "$as_me: WARNING: using cross tools not prefixed with host triplet" >&2;}
+ac_tool_warned=yes ;;
+esac
+    OBJC=$ac_ct_OBJC
+  fi
+fi
+
+# Provide some information about the compiler.
+$as_echo "$as_me:${as_lineno-$LINENO}: checking for Objective C compiler version" >&5
+set X $ac_compile
+ac_compiler=$2
+for ac_option in --version -v -V -qversion; do
+  { { ac_try="$ac_compiler $ac_option >&5"
+case "(($ac_try" in
+  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
+  *) ac_try_echo=$ac_try;;
+esac
+eval ac_try_echo="\"\$as_me:${as_lineno-$LINENO}: $ac_try_echo\""
+$as_echo "$ac_try_echo"; } >&5
+  (eval "$ac_compiler $ac_option >&5") 2>conftest.err
+  ac_status=$?
+  if test -s conftest.err; then
+    sed '10a\
+... rest of stderr output deleted ...
+         10q' conftest.err >conftest.er1
+    cat conftest.er1 >&5
+  fi
+  rm -f conftest.er1 conftest.err
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }
+done
+
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether we are using the GNU Objective C compiler" >&5
+$as_echo_n "checking whether we are using the GNU Objective C compiler... " >&6; }
+if ${ac_cv_objc_compiler_gnu+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main ()
+{
+#ifndef __GNUC__
+       choke me
+#endif
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_objc_try_compile "$LINENO"; then :
+  ac_compiler_gnu=yes
+else
+  ac_compiler_gnu=no
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+ac_cv_objc_compiler_gnu=$ac_compiler_gnu
+
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_objc_compiler_gnu" >&5
+$as_echo "$ac_cv_objc_compiler_gnu" >&6; }
+if test $ac_compiler_gnu = yes; then
+  GOBJC=yes
+else
+  GOBJC=
+fi
+ac_test_OBJCFLAGS=${OBJCFLAGS+set}
+ac_save_OBJCFLAGS=$OBJCFLAGS
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether $OBJC accepts -g" >&5
+$as_echo_n "checking whether $OBJC accepts -g... " >&6; }
+if ${ac_cv_prog_objc_g+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  ac_save_objc_werror_flag=$ac_objc_werror_flag
+   ac_objc_werror_flag=yes
+   ac_cv_prog_objc_g=no
+   OBJCFLAGS="-g"
+   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_objc_try_compile "$LINENO"; then :
+  ac_cv_prog_objc_g=yes
+else
+  OBJCFLAGS=""
+      cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_objc_try_compile "$LINENO"; then :
+
+else
+  ac_objc_werror_flag=$ac_save_objc_werror_flag
+	 OBJCFLAGS="-g"
+	 cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_objc_try_compile "$LINENO"; then :
+  ac_cv_prog_objc_g=yes
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+   ac_objc_werror_flag=$ac_save_objc_werror_flag
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_prog_objc_g" >&5
+$as_echo "$ac_cv_prog_objc_g" >&6; }
+if test "$ac_test_OBJCFLAGS" = set; then
+  OBJCFLAGS=$ac_save_OBJCFLAGS
+elif test $ac_cv_prog_objc_g = yes; then
+  if test "$GOBJC" = yes; then
+    OBJCFLAGS="-g -O2"
+  else
+    OBJCFLAGS="-g"
+  fi
+else
+  if test "$GOBJC" = yes; then
+    OBJCFLAGS="-O2"
+  else
+    OBJCFLAGS=
+  fi
+fi
+ac_ext=c
+ac_cpp='$CPP $CPPFLAGS'
+ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
+ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
+ac_compiler_gnu=$ac_cv_c_compiler_gnu
+
+	ac_ext=mm
+ac_cpp='$OBJCXXCPP $CPPFLAGS'
+ac_compile='$OBJCXX -c $OBJCXXFLAGS $CPPFLAGS conftest.$ac_ext >&5'
+ac_link='$OBJCXX -o conftest$ac_exeext $OBJCXXFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
+ac_compiler_gnu=$ac_cv_objcxx_compiler_gnu
+if test -n "$ac_tool_prefix"; then
+  for ac_prog in g++ objc++ objcxx c++ CXX
+  do
+    # Extract the first word of "$ac_tool_prefix$ac_prog", so it can be a program name with args.
+set dummy $ac_tool_prefix$ac_prog; ac_word=$2
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
+$as_echo_n "checking for $ac_word... " >&6; }
+if ${ac_cv_prog_OBJCXX+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  if test -n "$OBJCXX"; then
+  ac_cv_prog_OBJCXX="$OBJCXX" # Let the user override the test.
+else
+as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
+for as_dir in $PATH
+do
+  IFS=$as_save_IFS
+  test -z "$as_dir" && as_dir=.
+    for ac_exec_ext in '' $ac_executable_extensions; do
+  if as_fn_executable_p "$as_dir/$ac_word$ac_exec_ext"; then
+    ac_cv_prog_OBJCXX="$ac_tool_prefix$ac_prog"
+    $as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
+    break 2
+  fi
+done
+  done
+IFS=$as_save_IFS
+
+fi
+fi
+OBJCXX=$ac_cv_prog_OBJCXX
+if test -n "$OBJCXX"; then
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $OBJCXX" >&5
+$as_echo "$OBJCXX" >&6; }
+else
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+fi
+
+
+    test -n "$OBJCXX" && break
+  done
+fi
+if test -z "$OBJCXX"; then
+  ac_ct_OBJCXX=$OBJCXX
+  for ac_prog in g++ objc++ objcxx c++ CXX
+do
+  # Extract the first word of "$ac_prog", so it can be a program name with args.
+set dummy $ac_prog; ac_word=$2
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
+$as_echo_n "checking for $ac_word... " >&6; }
+if ${ac_cv_prog_ac_ct_OBJCXX+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  if test -n "$ac_ct_OBJCXX"; then
+  ac_cv_prog_ac_ct_OBJCXX="$ac_ct_OBJCXX" # Let the user override the test.
+else
+as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
+for as_dir in $PATH
+do
+  IFS=$as_save_IFS
+  test -z "$as_dir" && as_dir=.
+    for ac_exec_ext in '' $ac_executable_extensions; do
+  if as_fn_executable_p "$as_dir/$ac_word$ac_exec_ext"; then
+    ac_cv_prog_ac_ct_OBJCXX="$ac_prog"
+    $as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
+    break 2
+  fi
+done
+  done
+IFS=$as_save_IFS
+
+fi
+fi
+ac_ct_OBJCXX=$ac_cv_prog_ac_ct_OBJCXX
+if test -n "$ac_ct_OBJCXX"; then
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_ct_OBJCXX" >&5
+$as_echo "$ac_ct_OBJCXX" >&6; }
+else
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+fi
+
+
+  test -n "$ac_ct_OBJCXX" && break
+done
+
+  if test "x$ac_ct_OBJCXX" = x; then
+    OBJCXX="g++"
+  else
+    case $cross_compiling:$ac_tool_warned in
+yes:)
+{ $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: using cross tools not prefixed with host triplet" >&5
+$as_echo "$as_me: WARNING: using cross tools not prefixed with host triplet" >&2;}
+ac_tool_warned=yes ;;
+esac
+    OBJCXX=$ac_ct_OBJCXX
+  fi
+fi
+
+# Provide some information about the compiler.
+$as_echo "$as_me:${as_lineno-$LINENO}: checking for Objective C++ compiler version" >&5
+set X $ac_compile
+ac_compiler=$2
+for ac_option in --version -v -V -qversion; do
+  { { ac_try="$ac_compiler $ac_option >&5"
+case "(($ac_try" in
+  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
+  *) ac_try_echo=$ac_try;;
+esac
+eval ac_try_echo="\"\$as_me:${as_lineno-$LINENO}: $ac_try_echo\""
+$as_echo "$ac_try_echo"; } >&5
+  (eval "$ac_compiler $ac_option >&5") 2>conftest.err
+  ac_status=$?
+  if test -s conftest.err; then
+    sed '10a\
+... rest of stderr output deleted ...
+         10q' conftest.err >conftest.er1
+    cat conftest.er1 >&5
+  fi
+  rm -f conftest.er1 conftest.err
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }
+done
+
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether we are using the GNU Objective C++ compiler" >&5
+$as_echo_n "checking whether we are using the GNU Objective C++ compiler... " >&6; }
+if ${ac_cv_objcxx_compiler_gnu+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main ()
+{
+#ifndef __GNUC__
+       choke me
+#endif
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_objcxx_try_compile "$LINENO"; then :
+  ac_compiler_gnu=yes
+else
+  ac_compiler_gnu=no
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+ac_cv_objcxx_compiler_gnu=$ac_compiler_gnu
+
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_objcxx_compiler_gnu" >&5
+$as_echo "$ac_cv_objcxx_compiler_gnu" >&6; }
+if test $ac_compiler_gnu = yes; then
+  GOBJCXX=yes
+else
+  GOBJCXX=
+fi
+ac_test_OBJCXXFLAGS=${OBJCXXFLAGS+set}
+ac_save_OBJCXXFLAGS=$OBJCXXFLAGS
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether $OBJCXX accepts -g" >&5
+$as_echo_n "checking whether $OBJCXX accepts -g... " >&6; }
+if ${ac_cv_prog_objcxx_g+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  ac_save_objcxx_werror_flag=$ac_objcxx_werror_flag
+   ac_objcxx_werror_flag=yes
+   ac_cv_prog_objcxx_g=no
+   OBJCXXFLAGS="-g"
+   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_objcxx_try_compile "$LINENO"; then :
+  ac_cv_prog_objcxx_g=yes
+else
+  OBJCXXFLAGS=""
+      cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_objcxx_try_compile "$LINENO"; then :
+
+else
+  ac_objcxx_werror_flag=$ac_save_objcxx_werror_flag
+	 OBJCXXFLAGS="-g"
+	 cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_objcxx_try_compile "$LINENO"; then :
+  ac_cv_prog_objcxx_g=yes
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+   ac_objcxx_werror_flag=$ac_save_objcx_werror_flag
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_prog_objcxx_g" >&5
+$as_echo "$ac_cv_prog_objcxx_g" >&6; }
+if test "$ac_test_OBJCXXFLAGS" = set; then
+  OBJCXXFLAGS=$ac_save_OBJCXXFLAGS
+elif test $ac_cv_prog_objcxx_g = yes; then
+  if test "$GOBJCXX" = yes; then
+    OBJCXXFLAGS="-g -O2"
+  else
+    OBJCXXFLAGS="-g"
+  fi
+else
+  if test "$GOBJCXX" = yes; then
+    OBJCXXFLAGS="-O2"
+  else
+    OBJCXXFLAGS=
+  fi
+fi
+ac_ext=c
+ac_cpp='$CPP $CPPFLAGS'
+ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
+ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
+ac_compiler_gnu=$ac_cv_c_compiler_gnu
+
+
+
+	SCPROXY=
+	NOSCPROXY=#
+else
+	SCPROXY=#
+	NOSCPROXY=
+fi
+
+
+
+
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking for --with-cxx-main=<compiler>" >&5
 $as_echo_n "checking for --with-cxx-main=<compiler>... " >&6; }
 

configure.ac

@@ -663,6 +663,25 @@ AC_PROG_SED
 
 AC_SUBST(CXX)
 AC_SUBST(MAINCC)
+
+if test "$ac_sys_system" = "Darwin"
+then
+	# MacOSX requires an Objective C compiler to
+	# build some Mac-specific code.
+	AC_PROG_OBJC
+	AC_PROG_OBJCXX
+	AC_SUBST(OBJC)
+	AC_SUBST(OBJCXX)
+	SCPROXY=
+	NOSCPROXY=#
+else
+	SCPROXY=#
+	NOSCPROXY=
+fi
+
+AC_SUBST(SCPROXY)
+AC_SUBST(NOSCPROXY)
+
 AC_MSG_CHECKING(for --with-cxx-main=<compiler>)
 AC_ARG_WITH(cxx_main,
             AS_HELP_STRING([--with-cxx-main@<:@=COMPILER@:>@],

setup.py

@@ -1583,10 +1583,11 @@ class PyBuildExt(build_ext):
             self.missing.append('ossaudiodev')
 
         if MACOS:
-            self.add(Extension('_scproxy', ['_scproxy.c'],
+            self.add(Extension('_scproxy', [],
                                extra_link_args=[
                                    '-framework', 'SystemConfiguration',
-                                   '-framework', 'CoreFoundation']))
+                                   '-framework', 'CoreFoundation'],
+                               extra_objects=['Modules/_scproxy.o']))
 
     def detect_compress_exts(self):
         # Andrew Kuchling's zlib module.  Note that some versions of zlib