microsoft / microsoft/DirectXShaderCompiler

Empty Payload struct not recognized in DXIL

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bug
Dominant language
C++
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Description

When compiling an RT shader to Spir-v , the empty Payload struct is recognized - and the shader compiles just fine, however with DXIL the same shader fails to compile.

http://shader-playground.timjones.io/2ea9b49aff52b7bd018503d4a4df4bf5

struct Payload {}; [shader("miss")] void main(inout Payload payload) {}

I've tried disabling optimizations, however this did not have any effect.

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Research direction

Start by reproducing the failure from the linked Shader Playground case using the empty Payload struct and miss shader shown in the issue, comparing SPIR-V and DXIL compilation. Trace the DXIL handling of empty payload structures and define done as compiling this shader successfully for DXIL without breaking the existing SPIR-V behavior.

Written by the indexing model from the issue text.

Assessment

Tech stack
cpp
Domain
compilers
Issue type
Bug
Difficulty
4/5
Estimated time
3-5 days
Activity status
Stale
Clarity
Needs clarification
Newbie friendliness
35/100

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