/* Return: file_name:line_num */ std::string errorSource( v8::Isolate *isolate, const v8::Local<v8::Message> &message) { v8::String::Utf8Value origin_str( message->GetScriptResourceName()); int line_num_default = 0; int line_num = message->GetLineNumber( isolate->GetCurrentContext()).FromMaybe(line_num_default); return v8cffi_utils::toCString(origin_str) + ":" + std::to_string(line_num); }