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>

2 files changed, 45 insertions, 0 deletions

diff --git a/tests/diagnostics/raypayload-missing-access-qualifiers.slang b/tests/diagnostics/raypayload-missing-access-qualifiers.slang
new file mode 100644
index 000000000..d22a6300b
--- /dev/null
+++ b/tests/diagnostics/raypayload-missing-access-qualifiers.slang
@@ -0,0 +1,37 @@
+// raypayload-missing-access-qualifiers.slang
+
+//DIAGNOSTIC_TEST:SIMPLE:
+
+// Test error for field in ray payload struct missing read/write access qualifiers
+
+struct [raypayload] RayPayload
+{
+    float4 color : read(caller, anyhit) : write(caller);
+    float4 colorMissingQualifiers; // Error expected here
+
+};
+
+uniform RWTexture2D<float4> resultTexture;
+uniform RaytracingAccelerationStructure sceneBVH;
+
+[shader("raygeneration")]
+void rayGenShaderA()
+{
+    int2 threadIdx = DispatchRaysIndex().xy;
+
+    float3 rayDir = float3(0, 0, 1);
+    float3 rayOrigin = 0;
+    rayOrigin.x = (threadIdx.x * 2) - 1;
+    rayOrigin.y = (threadIdx.y * 2) - 1;
+
+    // Trace the ray.
+    RayDesc ray;
+    ray.Origin = rayOrigin;
+    ray.Direction = rayDir;
+    ray.TMin = 0.001;
+    ray.TMax = 10000.0;
+    RayPayload payload = { float4(0, 0, 0, 0) , float4(0, 0, 0, 0)};
+    TraceRay(sceneBVH, RAY_FLAG_NONE, ~0, 0, 0, 0, ray, payload);
+
+    resultTexture[threadIdx.xy] = payload.color;
+}
diff --git a/tests/diagnostics/raypayload-missing-access-qualifiers.slang.expected b/tests/diagnostics/raypayload-missing-access-qualifiers.slang.expected
new file mode 100644
index 000000000..525e8529c
--- /dev/null
+++ b/tests/diagnostics/raypayload-missing-access-qualifiers.slang.expected
@@ -0,0 +1,8 @@
+result code = -1
+standard error = {
+tests/diagnostics/raypayload-missing-access-qualifiers.slang(10): error 40000: field 'colorMissingQualifiers' in ray payload struct must have either 'read' OR 'write' access qualifiers
+    float4 colorMissingQualifiers; // Error expected here
+           ^~~~~~~~~~~~~~~~~~~~~~
+}
+standard output = {
+}