Added a test that the C++ runtime is really useable (i.e. exports the symbols that we need).

CMake/CMakeLists.txt

@@ -0,0 +1,7 @@
+cmake_minimum_required(VERSION 2.8)
+
+add_executable(test_cxx_runtime typeinfo_test.cc)
+set(CMAKE_CXX_IMPLICIT_LINK_LIBRARIES "")
+target_link_libraries(test_cxx_runtime ${CXX_RUNTIME})
+set_target_properties(test_cxx_runtime PROPERTIES
+	LINKER_LANGUAGE C)

CMake/typeinfo_test.cc

@@ -0,0 +1,61 @@
+#include <stdint.h>
+
+namespace __cxxabiv1
+{
+	struct __class_type_info;
+}
+
+using __cxxabiv1::__class_type_info;
+
+namespace std
+{
+	/**
+	 * std::type_info defined with the GCC ABI.  This may not be exposed in
+	 * public headers, but is required for correctly implementing the unified
+	 * exception model.
+	 */
+	class type_info
+	{
+				public:
+				virtual ~type_info();
+				bool operator==(const type_info &) const;
+				bool operator!=(const type_info &) const;
+				bool before(const type_info &) const;
+				type_info();
+				private:
+				type_info(const type_info& rhs);
+				type_info& operator= (const type_info& rhs);
+				const char *__type_name;
+				protected:
+				type_info(const char *name): __type_name(name) { }
+				public:
+				const char* name() const { return __type_name; }
+				virtual bool __is_pointer_p() const;
+				virtual bool __is_function_p() const;
+				virtual bool __do_catch(const type_info *thrown_type,
+				                        void **thrown_object,
+				                        unsigned outer) const;
+				virtual bool __do_upcast(
+				                const __class_type_info *target,
+				                void **thrown_object) const;
+	};
+}
+
+class type_info2 : public std::type_info
+{
+	public:
+	virtual bool __is_pointer_p() const; 
+	virtual bool __is_function_p() const { return true; }
+	virtual bool __do_catch(const type_info *thrown_type,
+	                        void **thrown_object,
+	                        unsigned outer) const { return true; }
+	virtual bool __do_upcast(
+	                const __class_type_info *target,
+	                void **thrown_object) const { return true; }
+};
+bool type_info2::__is_pointer_p() const { return true; }
+
+int main()
+{
+	return 0;
+}

CMakeLists.txt

@@ -193,7 +193,13 @@ if (ENABLE_OBJCXX)
 	# a separate libobjcxx.
 	if (CXX_RUNTIME)
 		message(STATUS "Using ${CXX_RUNTIME} as the C++ runtime library")
-		if (FORCE_LIBOBJCXX)
+		try_compile( USERUNTIME 
+			"${CMAKE_BINARY_DIR}/CMake"
+			"${CMAKE_SOURCE_DIR}/CMake"
+			test_cxx_runtime
+			CMAKE_FLAGS "-DCXX_RUNTIME=${CXX_RUNTIME}")
+		message(STATUS "Is runtime useable? ${USERUNTIME}")
+		if (${FORCE_LIBOBJCXX} OR NOT ${USERUNTIME})
 			message(STATUS "Forcing build of stand-alone libobjcxx")
 			add_library(objcxx SHARED ${libobjcxx_CXX_SRCS})
 			set_target_properties(objcxx PROPERTIES