Add precise check for allowing use of gl_InstanceID for specific vulkan raytracing stages . (#2096)

* Checks that gl_InstanceID is only used in specific execution models

source/val/validate_builtins.cpp

@@ -207,6 +207,11 @@ class BuiltInsValidator {
       const Instruction& referenced_inst,
       const Instruction& referenced_from_inst);
 
+  spv_result_t ValidateInstanceIdAtReference(
+      const Decoration& decoration, const Instruction& built_in_inst,
+      const Instruction& referenced_inst,
+      const Instruction& referenced_from_inst);
+
   spv_result_t ValidateInstanceIndexAtReference(
       const Decoration& decoration, const Instruction& built_in_inst,
       const Instruction& referenced_inst,
@@ -2098,6 +2103,43 @@ spv_result_t BuiltInsValidator::ValidateVertexIdOrInstanceIdAtDefinition(
               "to be used.";
   }
 
+  if (label == SpvBuiltInInstanceId) {
+    return ValidateInstanceIdAtReference(decoration, inst, inst, inst);
+  }
+  return SPV_SUCCESS;
+}
+
+spv_result_t BuiltInsValidator::ValidateInstanceIdAtReference(
+    const Decoration& decoration, const Instruction& built_in_inst,
+    const Instruction& referenced_inst,
+    const Instruction& referenced_from_inst) {
+  if (spvIsVulkanEnv(_.context()->target_env)) {
+    for (const SpvExecutionModel execution_model : execution_models_) {
+      switch (execution_model) {
+        case SpvExecutionModelIntersectionNV:
+        case SpvExecutionModelClosestHitNV:
+        case SpvExecutionModelAnyHitNV:
+          // Do nothing, valid stages
+          break;
+        default:
+          return _.diag(SPV_ERROR_INVALID_DATA, &referenced_from_inst)
+                 << "Vulkan spec allows BuiltIn InstanceId to be used "
+                    "only with IntersectionNV, ClosestHitNV and AnyHitNV "
+                    "execution models. "
+                 << GetReferenceDesc(decoration, built_in_inst, referenced_inst,
+                                     referenced_from_inst);
+          break;
+      }
+    }
+  }
+
+  if (function_id_ == 0) {
+    // Propagate this rule to all dependant ids in the global scope.
+    id_to_at_reference_checks_[referenced_from_inst.id()].push_back(std::bind(
+        &BuiltInsValidator::ValidateInstanceIdAtReference, this, decoration,
+        built_in_inst, referenced_from_inst, std::placeholders::_1));
+  }
+
   return SPV_SUCCESS;
 }
 

test/val/val_builtins_test.cpp

@@ -2209,6 +2209,44 @@ OpFunctionEnd
   EXPECT_THAT(SPV_SUCCESS, ValidateInstructions(SPV_ENV_VULKAN_1_0));
 }
 
+TEST_F(ValidateBuiltIns, DisallowInstanceIdWithRayGenShader) {
+  CodeGenerator generator = GetDefaultShaderCodeGenerator();
+  generator.capabilities_ += R"(
+OpCapability RayTracingNV
+)";
+
+  generator.extensions_ = R"(
+OpExtension "SPV_NV_ray_tracing"
+)";
+
+  generator.before_types_ = R"(
+OpMemberDecorate %input_type 0 BuiltIn InstanceId
+)";
+
+  generator.after_types_ = R"(
+%input_type = OpTypeStruct %u32
+%input_ptr = OpTypePointer Input %input_type
+%input_ptr_u32 = OpTypePointer Input %u32
+%input = OpVariable %input_ptr Input
+)";
+
+  EntryPoint entry_point;
+  entry_point.name = "main_d_r";
+  entry_point.execution_model = "RayGenerationNV";
+  entry_point.interfaces = "%input";
+  entry_point.body = R"(
+%input_member = OpAccessChain %input_ptr_u32 %input %u32_0
+)";
+  generator.entry_points_.push_back(std::move(entry_point));
+
+  CompileSuccessfully(generator.Build(), SPV_ENV_VULKAN_1_0);
+  ASSERT_EQ(SPV_ERROR_INVALID_DATA, ValidateInstructions(SPV_ENV_VULKAN_1_0));
+  EXPECT_THAT(getDiagnosticString(),
+              HasSubstr("Vulkan spec allows BuiltIn InstanceId to be used "
+                        "only with IntersectionNV, ClosestHitNV and "
+                        "AnyHitNV execution models"));
+}
+
 }  // namespace
 }  // namespace val
 }  // namespace spvtools