Support for Payload Access Qualifiers (#3448) (#6595)

* Add support for Ray Payload Access Qualifiers (PAQs) (#3448)

- Added [raypayload] attribute for struct declarations
- Implemented field validation requiring read/write access qualifiers
- Added diagnostic error for missing qualifiers
- Enabled PAQs in DXC compiler and HLSL emission
- Added new test demonstrating PAQ syntax
- Implemented proper handling of ray payload attributes in IR generation

* format code

* Cleanup: Remove unused vars

* Add check to enablePAQ only for profile >= lib_6_7

* Review Fix - Add PAQ support for DX Raytracing

add enablePAQ flag to DownstreamCompileOpitons, improve PAQ handling
update raypayload-attribute-paq.slang to ensure hlsl and dxil is
validated

* Add diagnostic test for missing paq for lib_6_7

Compile using `-disable-payload-qualifiers` aka lib_6_6 profile
raypayload-attribute-no-struct.slang and
raypayload-attribute.slang

---------

Co-authored-by: slangbot <186143334+slangbot@users.noreply.github.com>
Co-authored-by: Ellie Hermaszewska <ellieh@nvidia.com>

1 files changed, 12 insertions, 2 deletions

diff --git a/source/slang/slang-emit-hlsl.cpp b/source/slang/slang-emit-hlsl.cpp
index 0f1ef3ee0..2d963866d 100644
--- a/source/slang/slang-emit-hlsl.cpp
+++ b/source/slang/slang-emit-hlsl.cpp
@@ -1667,8 +1667,18 @@ void HLSLSourceEmitter::emitPostKeywordTypeAttributesImpl(IRInst* inst)
     {
         m_writer->emit("[payload] ");
     }
-    // This can be re-enabled when we add PAQs: https://github.com/shader-slang/slang/issues/3448
-    const bool enablePAQs = false;
+
+    // Get the target profile to determine if PAQs are supported
+    bool enablePAQs = false;
+    auto profile = getTargetProgram()->getOptionSet().getProfile();
+    if (profile.getFamily() == ProfileFamily::DX)
+    {
+        // PAQs are default in Shader Model 6.7 and above when called with `--profile lib_6_7`
+
+        auto version = profile.getVersion();
+        enablePAQs = version >= ProfileVersion::DX_6_7;
+    }
+
     if (enablePAQs)
     {
         if (const auto payloadDecoration = inst->findDecoration<IRRayPayloadDecoration>())