c++ - 使用 JSonCpp 调用纯虚函数

Question

当我关闭我的应用程序时，我一直收到这个消息。我知道它与 JsonCpp 有关，因为它仅在我使用 Json 值时发生。

我认为这与我如何创建 json 值有关，但由于没有任何教程，我不知道我应该怎么做

我的代码目前是:

static Json::Value root;   // will contains the root value after parsing.

unsigned int WindowSettings::WindowWidth = 800;
unsigned int WindowSettings::WindowHeight = 600;
bool WindowSettings::FullScreen = false;
unsigned short WindowSettings::AntiAliasing = 16;
bool WindowSettings::VSync = false;
short WindowSettings::FrameRateLimit = 60;
AspectRatios WindowSettings::AspectRatio = ar4p3;
Resolutions WindowSettings::Resolution = r800x600;
Json::Value WindowSettings::root = Json::Value();

void WindowSettings::remakeDefault()
{
    root["WindowWidth"] = WindowWidth;
    root["WindowHeight"] = WindowHeight;
    root["FullScreen"] = FullScreen;
    root["AntiAliasing"] = AntiAliasing;
    root["VSync"] = VSync;
    root["FrameRateLimit"] = FrameRateLimit;
    root["AspectRatio"] = AspectRatio;
    root["Resolution"] = Resolution;
    saveToFile("conf.json");
}

bool WindowSettings::saveToFile(const std::string &fileName)
{
    Json::FastWriter writer;
    // Make a new JSON document for the configuration. Preserve original comments.
    std::string outputConfig = writer.write( root );

    std::ofstream myfile;
    myfile.open (fileName.c_str(), std::ios::out | std::ios::trunc | std::ios::binary );
    if (myfile.is_open())
    {
        myfile << outputConfig.c_str();
        myfile.close();
    }
    return true;
}

我应该补充一点，当我不这样做时不会发生这种情况: root["blah"] = foo;

Answer 1

编辑

发现这是一个已知问题(例如 here)

Turns out this is due to some sort of bug in jsoncpp which makes it not work as global variables. Which I guess the old notion that global variables are bad news is hard to get away from. S*o I wrapped up all my json away from being globals and it works fine now. Less globals is certainly a good move*, whatever the case.

错误报告在这里 (zeromus):http://sourceforge.net/tracker/index.php?func=detail&aid=2934500&group_id=144446&atid=758826

状态是固定的:

I have fixed it by representing the fact that a Value has an implicit dependency on a given instance of ValueAllocator by giving it a ValueAllocatorHandle which is just reference counted and takes care of deleting a heap allocated allocator when the last Value goes out of scope.

---

一般来说，我怀疑构造函数/析构函数访问虚拟成员导致 UB(并且可能根本缺少虚拟析构函数)。

由于您提到应用程序关闭，static Json::Value root 是一个可疑对象。如果这是在 linux 上，我会在 valgrind 下运行它

sudo -E valgrind --db--attach=yes ./yourprogram

这可以确保您拥有必要的权限。当然，使用调试信息进行编译有很大帮助。