Wgpu: Validate Buffer and Texture Usages are Non-Empty

[kvark]

VALIDATION [VUID-VkBufferCreateInfo-usage-requiredbitmask (0)] : vkCreateBuffer: value of pCreateInfo->usage must not be 0. The Vulkan spec states: usage must not be 0 (https://www.khronos.org/registry/vulkan/specs/1.1-extensions/html/vkspec.html#VUID-VkBufferCreateInfo-usage-requiredbitmask)
object info: (type: UNKNOWN, hndl: 0)

If we see that a resource doesn't request any usage, we should artificially add one, e.g. TRANSFER_SRC.

[GabrielMajeri]

Are there any valid reasons to create resources with empty usage flags? Would it make more to disallow this and return an error?

[kvark]

I don't think there is any use of resources without usages, I'd say just not allow it.
Trying to recall/find what WebGPU upstream thinks about the issue. Do you recall @Kangz?

[Kangz]

I think we said that 0-sized buffers were ok, not sure about no usage though.

[GabrielMajeri]

Any update on this from the WebGPU side? Should we forbid empty usages or silently allow them?

[kvark]

Filed https://github.com/gpuweb/gpuweb/issues/1001

[cwfitzgerald]

The resolution from upstream is that empty buffer and texture usages should not be allowed. We need to add a bit of validation to make sure that's the case.