Add support for OS X/Darwin

Add AM_CONDITIONAL to fix error generated from kit/Makefile.am



git-svn-id: https://hamlib.svn.sourceforge.net/svnroot/hamlib/trunk@2768 7ae35d74-ebe9-4afe-98af-79ac388436b8

configure.ac.ltv1

@@ -199,6 +199,11 @@ darwin* | rhapsody*)
   # TODO: check the compiler actually does support these options
   CFLAGS="${CFLAGS} -no-cpp-precomp"
   CXXFLAGS="${CXXFLAGS} -no-cpp-precomp"
+  # Tell the OS X linker to allocate enough space inside the
+  # libhamlib.X.dylib shared object for install_name_tool(1) to
+  # work. This is useful when including hamlib in an app bundle.
+  OSXLDFLAGS="-Wl,-headerpad_max_install_names"
+  AC_SUBST([OSXLDFLAGS])
   ;;
 mingw* | pw32* | cygwin*)
   WINLDFLAGS="-Wl,--output-def,libhamlib.def -Wl,--add-stdcall-alias"
@@ -386,7 +391,7 @@ if test "${cf_with_cxx}" = "yes" ; then
 		[AC_DEFINE(HAVE_USRP,[1],[Define if usrp is available])])
   fi
 fi
-
+AM_CONDITIONAL(ENABLE_CXX, test x"${cf_with_cxx}" = "xyes")
 
 PKG_CHECK_MODULES(LIBUSB, libusb >= 0.1, , 
 		  [AC_MSG_WARN([libusb pkg-config not found, USB backends will be disabled])])