The shader compiler targets Vulkan 1.3 / SPIR-V 1.6, where glslang lowers a
fragment discard to OpDemoteToHelperInvocation; five committed modules
(sky, mesh_detail, mesh_atmospheric, both directional-shadow cutouts)
declare the capability, and vkCreateShaderModule reported
VUID-VkShaderModuleCreateInfo-pCode-08740 twice per launch under the
Khronos validation layer because the device never enabled the feature.
The feature is core 1.3 (the device gate already requires 1.3), so it is
read through the existing Vulkan13Features chain, enabled at device
creation next to dynamicRendering/synchronization2/maintenance4, and
gated as required in VulkanCapabilityRecord with its own failure text.
Found by the first validation-layer self-gate of Campaign OVERHAUL v2
(S3 chunk 4 round 2); no register row, no behavior change on a
conformant driver.
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
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