问c++。valgrind输出: Syscall param open(filename)指向无法寻址的字节

EN

//alot of includes and using namespace std.

Engine::Engine(char** args) {
    processConfFile(args[1]);
}

void Engine::processConfFile ( char* fileName) {
    string* fileContent = fileToString(fileName); //this line is specified at the stacktrace
    stringstream contentstream(*fileContent);
// parsing and stuff
    delete fileContent;
}

string* Engine::fileToString(const char* fileName) const{
    string* content = new string();
    ifstream ifs (fileName); // this line produces the error
    if (ifs) {
        content->assign((istreambuf_iterator<char>(ifs)), (istreambuf_iterator<char>()));
        ifs.close();
    }
    else {
        //TODO logger error.
    }
    return content;
}