vkCreateInstance 抛出分段错误

Question

我正在尝试学习一些 Vulkan，但我对 vkCreateInstance 有一个奇怪的问题。它似乎会引发分段错误，但仅在非常特定的情况下。为了更清楚，这里有一些代码：

int main() {
    // Load Vulkan Functions, extensions and stuff
    VkApplicationInfo applicationInfo;
    applicationInfo.sType = VK_STRUCTURE_TYPE_APPLICATION_INFO;
    applicationInfo.pNext = nullptr;
    applicationInfo.pApplicationName = "VulkanDoodles";
    applicationInfo.applicationVersion = VK_MAKE_VERSION(1,0,0);
    applicationInfo.pEngineName = "EngineNamePlaceholder";
    applicationInfo.engineVersion = VK_MAKE_VERSION(1,0,0);
    applicationInfo.apiVersion = VK_MAKE_VERSION(1,0,0);

    VkInstanceCreateInfo instanceCreateInfo;
    instanceCreateInfo.sType = VK_STRUCTURE_TYPE_INSTANCE_CREATE_INFO;
    instanceCreateInfo.pNext = nullptr;
    instanceCreateInfo.flags = 0;
    instanceCreateInfo.pApplicationInfo = &applicationInfo;
    instanceCreateInfo.ppEnabledLayerNames = nullptr;
    instanceCreateInfo.enabledExtensionCount = (uint32_t)desired_extensions.size();
    instanceCreateInfo.ppEnabledExtensionNames = &desired_extensions[0];

    VkInstance instance;
    if(vk::vkCreateInstance(&instanceCreateInfo, nullptr, &instance) != VK_SUCCESS){
        std::cout << "Could not create instance" << std::endl;
        return -1;
    }
    // rest of the code
    return 0;
}

它工作正常，创建了实例。所以我决定将代码放在一个函数中以提高可读性。但是像下面这样的代码不再起作用了：

VkInstance CreateInstance(const std::vector<const char*> extensions){
    VkApplicationInfo applicationInfo;
    applicationInfo.sType = VK_STRUCTURE_TYPE_APPLICATION_INFO;
    applicationInfo.pNext = nullptr;
    applicationInfo.pApplicationName = "VulkanDoodles";
    applicationInfo.applicationVersion = VK_MAKE_VERSION(1,0,0);
    applicationInfo.pEngineName = "EngineNamePlaceholder";
    applicationInfo.engineVersion = VK_MAKE_VERSION(1,0,0);
    applicationInfo.apiVersion = VK_MAKE_VERSION(1,0,0);

    VkInstanceCreateInfo instanceCreateInfo;
    instanceCreateInfo.sType = VK_STRUCTURE_TYPE_INSTANCE_CREATE_INFO;
    instanceCreateInfo.pNext = nullptr;
    instanceCreateInfo.flags = 0;
    instanceCreateInfo.pApplicationInfo = &applicationInfo;
    instanceCreateInfo.ppEnabledLayerNames = nullptr;
    instanceCreateInfo.enabledExtensionCount = (uint32_t)extensions.size();
    instanceCreateInfo.ppEnabledExtensionNames = &extensions[0];
    VkInstance instance;
    if(vk::vkCreateInstance(&instanceCreateInfo, nullptr, &instance) != VK_SUCCESS){
        std::cout << "Could not create instance" << std::endl;
    }
    return instance;
}

int main(){
    // Load Vulkan Functions, extensions and stuff
    VkInstance instance = CreateInstance(desired_extensions);
    // rest of the code
}

对vkCreateInstance 的调用会引发分段错误。考虑到下一个代码片段确实可以正常工作，扩展向量似乎不是问题：

VkInstanceCreateInfo CreateInstanceInfo(const std::vector<const char*>& extensions){
    VkApplicationInfo applicationInfo;
    applicationInfo.sType = VK_STRUCTURE_TYPE_APPLICATION_INFO;
    applicationInfo.pNext = nullptr;
    applicationInfo.pApplicationName = "VulkanDoodles";
    applicationInfo.applicationVersion = VK_MAKE_VERSION(1,0,0);
    applicationInfo.pEngineName = "EngineNamePlaceholder";
    applicationInfo.engineVersion = VK_MAKE_VERSION(1,0,0);
    applicationInfo.apiVersion = VK_MAKE_VERSION(1,0,0);

    VkInstanceCreateInfo instanceCreateInfo;
    instanceCreateInfo.sType = VK_STRUCTURE_TYPE_INSTANCE_CREATE_INFO;
    instanceCreateInfo.pNext = nullptr;
    instanceCreateInfo.flags = 0;
    instanceCreateInfo.pApplicationInfo = &applicationInfo;
    instanceCreateInfo.ppEnabledLayerNames = nullptr;
    instanceCreateInfo.enabledExtensionCount = (uint32_t)extensions.size();
    instanceCreateInfo.ppEnabledExtensionNames = &extensions[0];

    return instanceCreateInfo;
}

VkInstance CreateInstance(const VkInstanceCreateInfo& instanceCreateInfo){
    VkInstance instance;
    if(vk::vkCreateInstance(&instanceCreateInfo, nullptr, &instance) != VK_SUCCESS){
        std::cout << "Could not create instance" << std::endl;
    }
    return instance;
}

int main(){
    // Load Vulkan Functions, extensions and stuff
    VkInstanceCreateInfo instanceCreateInfo = CreateInstanceInfo(desired_extensions);
    VkInstance instance = CreateInstance(instanceCreateInfo);
    // rest of the code
}

如前所述，这可以正常工作，我猜VkInstanceCreateInfo 变量必须在main 函数内声明。

所以我的问题是：

为什么vkCreateInstance 会抛出段错误？为什么只是有时？是不是有什么奇怪的事情发生了？

任何见解都会非常有帮助。

另外，我正在使用 Linux Mint 和 CLion 以及 cmake 3.13 版（不确定这是否重要）

Answer 1

您的中间代码 sn-p 缺少 enabledLayerCount 初始化，因此您让驱动程序执行 OOBA。

您的最后一个 sn-p 返回instanceCreateInfo，其中pApplicationInfo 指向销毁的VkApplicationInfo，当它被vkCreateInstance 使用时。您使驱动程序取消引用指向已破坏内存的指针。