redef fun box_extern(value, mtype)
	do
		if mtype isa MClassType and mtype.mclass.kind == extern_kind and
		   mtype.mclass.name != "CString" then
			var valtype = compiler.mainmodule.pointer_type
			var res = self.new_var(mtype)
			compiler.undead_types.add(mtype)
			self.require_declaration("BOX_{valtype.c_name}")
			self.add("{res} = BOX_{valtype.c_name}({value}); /* boxing {value.mtype} */")
			self.require_declaration("type_{mtype.c_name}")
			self.add("{res}->type = &type_{mtype.c_name};")
			self.require_declaration("class_{mtype.c_name}")
			self.add("{res}->class = &class_{mtype.c_name};")
			return res
		else
			return value
		end
	end

	redef fun box_extern(value, mtype)
	do
		if not mtype isa MClassType or mtype.mclass.kind != extern_kind or
			mtype.mclass.name == "CString" then return value

		var valtype = value.mtype.as(MClassType)
		var res = self.new_var(mtype)
		if not compiler.runtime_type_analysis.live_types.has(value.mtype.as(MClassType)) then
			self.add("/*no boxing of {value.mtype}: {value.mtype} is not live! */")
			self.add("PRINT_ERROR(\"Dead code executed!\\n\"); fatal_exit(1);")
			return res
		end
		self.add("{res} = BOX_{valtype.c_name}({value}); /* boxing {value.mtype} */")
		return res
	end

	redef fun box_extern(value, mtype)
	do
		if mtype isa MClassType and mtype.mclass.kind == extern_kind and
		   mtype.mclass.name != "CString" then
			var valtype = compiler.mainmodule.pointer_type
			var res = self.new_var(mtype)
			if compiler.runtime_type_analysis != null and not compiler.runtime_type_analysis.live_types.has(value.mtype.as(MClassType)) then
				self.add("/*no boxing of {value.mtype}: {value.mtype} is not live! */")
				self.add("PRINT_ERROR(\"Dead code executed!\\n\"); fatal_exit(1);")
				return res
			end
			self.require_declaration("BOX_{valtype.c_name}")
			self.add("{res} = BOX_{valtype.c_name}({value}); /* boxing {value.mtype} */")
			self.require_declaration("class_{mtype.c_name}")
			self.add("{res}->class = &class_{mtype.c_name};")
			return res
		else
			return value
		end
	end