Name

VK_EXT_debug_report - instance extension

VK_EXT_debug_report

Name String

VK_EXT_debug_report

Extension Type

Instance extension

Registered Extension Number

12

Revision

10

Ratification Status

Not ratified

Extension and Version Dependencies

None

API Interactions

• Interacts with VK_VERSION_1_1

Deprecation State

• Deprecated by VK_EXT_debug_utils extension

Special Use

• Debugging tools

Contact

• Courtney Goeltzenleuchter @courtney-g%0A*Here describe the issue or question you have about the VK_EXT_debug_report extension*

Other Extension Metadata

Last Modified Date

2020-12-14

IP Status

No known IP claims.

Contributors

• Courtney Goeltzenleuchter, LunarG
• Dan Ginsburg, Valve
• Jon Ashburn, LunarG
• Mark Lobodzinski, LunarG

Description

Due to the nature of the Vulkan interface, there is very little error information available to the developer and application. By enabling optional validation layers and using the VK_EXT_debug_report extension, developers can obtain much more detailed feedback on the application’s use of Vulkan. This extension defines a way for layers and the implementation to call back to the application for events of interest to the application.

New Object Types

• DebugReportCallbackEXT

New Commands

• createDebugReportCallbackEXT

• debugReportMessageEXT
• destroyDebugReportCallbackEXT

New Structures

• Extending InstanceCreateInfo:

  • DebugReportCallbackCreateInfoEXT

New Function Pointers

• PFN_vkDebugReportCallbackEXT

New Enums

• DebugReportFlagBitsEXT

• DebugReportObjectTypeEXT

New Bitmasks

• DebugReportFlagsEXT

New Enum Constants

• EXT_DEBUG_REPORT_EXTENSION_NAME

• EXT_DEBUG_REPORT_SPEC_VERSION

• Extending ObjectType:

  • OBJECT_TYPE_DEBUG_REPORT_CALLBACK_EXT

• Extending Result:

  • ERROR_VALIDATION_FAILED_EXT

• Extending StructureType:

  • STRUCTURE_TYPE_DEBUG_REPORT_CALLBACK_CREATE_INFO_EXT
  • STRUCTURE_TYPE_DEBUG_REPORT_CREATE_INFO_EXT

If Vulkan Version 1.1 is supported:

• Extending DebugReportObjectTypeEXT:

  • DEBUG_REPORT_OBJECT_TYPE_DESCRIPTOR_UPDATE_TEMPLATE_EXT
  • DEBUG_REPORT_OBJECT_TYPE_SAMPLER_YCBCR_CONVERSION_EXT

Examples

VK_EXT_debug_report allows an application to register multiple callbacks with the validation layers. Some callbacks may log the information to a file, others may cause a debug break point or other application-defined behavior. An application can register callbacks even when no validation layers are enabled, but they will only be called for loader and, if implemented, driver events.

To capture events that occur while creating or destroying an instance an application can link a DebugReportCallbackCreateInfoEXT structure to the pNext chain of the InstanceCreateInfo structure passed to createInstance.

Example uses: Create three callback objects. One will log errors and warnings to the debug console using Windows OutputDebugString. The second will cause the debugger to break at that callback when an error happens and the third will log warnings to stdout.

    VkResult res;
    VkDebugReportCallbackEXT cb1, cb2, cb3;

    VkDebugReportCallbackCreateInfoEXT callback1 = {
        .sType = VK_STRUCTURE_TYPE_DEBUG_REPORT_CALLBACK_CREATE_INFO_EXT,
        .pNext = NULL,
        .flags = VK_DEBUG_REPORT_ERROR_BIT_EXT |
                 VK_DEBUG_REPORT_WARNING_BIT_EXT,
        .pfnCallback = myOutputDebugString,
        .pUserData = NULL
    };
    res = vkCreateDebugReportCallbackEXT(instance, &callback1, &cb1);
    if (res != VK_SUCCESS)
       

    callback.flags = VK_DEBUG_REPORT_ERROR_BIT_EXT;
    callback.pfnCallback = myDebugBreak;
    callback.pUserData = NULL;
    res = vkCreateDebugReportCallbackEXT(instance, &callback, &cb2);
    if (res != VK_SUCCESS)
       

    VkDebugReportCallbackCreateInfoEXT callback3 = {
        .sType = VK_STRUCTURE_TYPE_DEBUG_REPORT_CALLBACK_CREATE_INFO_EXT,
        .pNext = NULL,
        .flags = VK_DEBUG_REPORT_WARNING_BIT_EXT,
        .pfnCallback = mystdOutLogger,
        .pUserData = NULL
    };
    res = vkCreateDebugReportCallbackEXT(instance, &callback3, &cb3);
    if (res != VK_SUCCESS)
       

    ...

    
    vkDestroyDebugReportCallbackEXT(instance, cb1);
    vkDestroyDebugReportCallbackEXT(instance, cb2);
    vkDestroyDebugReportCallbackEXT(instance, cb3);

In the initial release of the VK_EXT_debug_report extension, the token STRUCTURE_TYPE_DEBUG_REPORT_CREATE_INFO_EXT was used. Starting in version 2 of the extension branch, STRUCTURE_TYPE_DEBUG_REPORT_CALLBACK_CREATE_INFO_EXT is used instead for consistency with Vulkan naming rules. The older enum is still available for backwards compatibility.

In the initial release of the VK_EXT_debug_report extension, the token DEBUG_REPORT_OBJECT_TYPE_DEBUG_REPORT_EXT was used. Starting in version 8 of the extension branch, DEBUG_REPORT_OBJECT_TYPE_DEBUG_REPORT_CALLBACK_EXT_EXT is used instead for consistency with Vulkan naming rules. The older enum is still available for backwards compatibility.

Issues

1) What is the hierarchy / seriousness of the message flags? E.g. ERROR > WARN > PERF_WARN …​

RESOLVED: There is no specific hierarchy. Each bit is independent and should be checked via bitwise AND. For example:

    if (localFlags & VK_DEBUG_REPORT_ERROR_BIT_EXT) {
        process error message
    }
    if (localFlags & VK_DEBUG_REPORT_DEBUG_BIT_EXT) {
        process debug message
    }

The validation layers do use them in a hierarchical way (ERROR > WARN > PERF, WARN > DEBUG > INFO) and they (at least at the time of this writing) only set one bit at a time. But it is not a requirement of this extension.

It is possible that a layer may intercept and change, or augment the flags with extension values the application’s debug report handler may not be familiar with, so it is important to treat each flag independently.

2) Should there be a VU requiring DebugReportCallbackCreateInfoEXT::flags to be non-zero?

RESOLVED: It may not be very useful, but we do not need VU statement requiring the DebugReportCallbackCreateInfoEXT::msgFlags at create-time to be non-zero. One can imagine that apps may prefer it as it allows them to set the mask as desired - including nothing - at runtime without having to check.

3) What is the difference between DEBUG_REPORT_DEBUG_BIT_EXT and DEBUG_REPORT_INFORMATION_BIT_EXT?

RESOLVED: DEBUG_REPORT_DEBUG_BIT_EXT specifies information that could be useful debugging the Vulkan implementation itself.

4) How do you compare handles returned by the debug_report callback to the application’s handles?

RESOLVED: Due to the different nature of dispatchable and nondispatchable handles there is no generic way (that we know of) that works for common C and C++ compilers in both 32-bit and 64-bit ABIs. We recommend applications use the same cast that the validation layers use:

+

reinterpret_cast<uint64_t &>(dispatchableHandle)
(uint64_t)(nondispatchableHandle)

+ This does require that the application treat dispatchable and nondispatchable handles differently.

Version History

• Revision 1, 2015-05-20 (Courtney Goetzenleuchter)

  • Initial draft, based on LunarG KHR spec, other KHR specs

• Revision 2, 2016-02-16 (Courtney Goetzenleuchter)

  • Update usage, documentation

• Revision 3, 2016-06-14 (Courtney Goetzenleuchter)

  • Update VK_EXT_DEBUG_REPORT_SPEC_VERSION to indicate added support for vkCreateInstance and vkDestroyInstance

• Revision 4, 2016-12-08 (Mark Lobodzinski)

  • Added Display_KHR, DisplayModeKHR extension objects
  • Added ObjectTable_NVX, IndirectCommandsLayout_NVX extension objects
  • Bumped spec revision
  • Retroactively added version history

• Revision 5, 2017-01-31 (Baldur Karlsson)

  • Moved definition of DebugReportObjectTypeEXT from debug marker chapter

• Revision 6, 2017-01-31 (Baldur Karlsson)

  • Added VK_DEBUG_REPORT_OBJECT_TYPE_DESCRIPTOR_UPDATE_TEMPLATE_KHR_EXT

• Revision 7, 2017-04-20 (Courtney Goeltzenleuchter)

  • Clarify wording and address questions from developers.

• Revision 8, 2017-04-21 (Courtney Goeltzenleuchter)

  • Remove unused enum VkDebugReportErrorEXT

• Revision 9, 2017-09-12 (Tobias Hector)

  • Added interactions with Vulkan 1.1

• Revision 10, 2020-12-14 (Courtney Goetzenleuchter)

  • Add issue 4 discussing matching handles returned by the extension, based on suggestion in public issue 368.

See Also

No cross-references are available

Document Notes

For more information, see the Vulkan Specification.

This page is a generated document. Fixes and changes should be made to the generator scripts, not directly.