Add Visitor method to handle template parameter pack in kernel names

Author: srividya-sundaram

clang/lib/Sema/SemaSYCL.cpp

@@ -2838,6 +2838,11 @@ class SYCLKernelNameTypeVisitor
       ConstTemplateArgumentVisitor<SYCLKernelNameTypeVisitor>;
   bool IsInvalid = false;
 
+  void VisitTemplateArgs(ArrayRef<TemplateArgument> Args) {
+    for (size_t I = 0, E = Args.size(); I < E; ++I)
+      Visit(Args[I]);
+  }
+
 public:
   SYCLKernelNameTypeVisitor(Sema &S, SourceLocation KernelInvocationFuncLoc)
       : S(S), KernelInvocationFuncLoc(KernelInvocationFuncLoc) {}
@@ -2849,19 +2854,18 @@ class SYCLKernelNameTypeVisitor
       return;
     const CXXRecordDecl *RD = T->getAsCXXRecordDecl();
     if (!RD) {
-      if (T->isNullPtrType())
+      if (T->isNullPtrType()) {
         S.Diag(KernelInvocationFuncLoc, diag::err_sycl_kernel_incorrectly_named)
             << /* kernel name cannot be a type in the std namespace */ 3;
-      IsInvalid = true;
+        IsInvalid = true;
+      }
       return;
     }
     // If KernelNameType has template args visit each template arg via
     // ConstTemplateArgumentVisitor
     if (const auto *TSD = dyn_cast<ClassTemplateSpecializationDecl>(RD)) {
-      const TemplateArgumentList &Args = TSD->getTemplateArgs();
-      for (unsigned I = 0; I < Args.size(); I++) {
-        Visit(Args[I]);
-      }
+      ArrayRef<TemplateArgument> Args = TSD->getTemplateArgs().asArray();
+      VisitTemplateArgs(Args);
     } else {
       InnerTypeVisitor::Visit(T.getTypePtr());
     }
@@ -2949,6 +2953,10 @@ class SYCLKernelNameTypeVisitor
           VisitEnumType(ET);
     }
   }
+
+  void VisitPackTemplateArgument(const TemplateArgument &TA) {
+    VisitTemplateArgs(TA.getPackAsArray());
+  }
 };
 
 void Sema::CheckSYCLKernelCall(FunctionDecl *KernelFunc, SourceRange CallLoc,
@@ -3452,6 +3460,7 @@ void SYCLIntegrationHeader::emitForwardClassDecls(
   const CXXRecordDecl *RD = T->getAsCXXRecordDecl();
 
   if (!RD) {
+
     return;
   }
 

clang/test/CodeGenSYCL/stdtypes_kernel_type.cpp

@@ -13,12 +13,14 @@ class U;
 template <typename T>
 struct Templated_kernel_name;
 
+template <typename T, typename... Args> class TemplParamPack;
+
 using namespace cl::sycl;
 queue q;
 
 int main() {
 #ifdef CHECK_ERROR
-  // expected-error@Inputs/sycl.hpp:328 4 {{kernel name cannot be a type in the "std" namespace}}
+  // expected-error@Inputs/sycl.hpp:328 5 {{kernel name cannot be a type in the "std" namespace}}
   q.submit([&](handler &h) {
     // expected-note@+1{{in instantiation of function template specialization}}
     h.single_task<std::nullptr_t>([=] {});
@@ -35,7 +37,10 @@ int main() {
     // expected-note@+1{{in instantiation of function template specialization}}
     h.single_task<Templated_kernel_name<std::U>>([=] {});
   });
-
+  q.submit([&](handler &cgh) {
+    // expected-note@+1{{in instantiation of function template specialization}}
+    cgh.single_task<TemplParamPack<int, float, std::nullptr_t, double>>([]() {});
+  });
 #endif
 
   // Although in the std namespace, these resolve to builtins such as `int` that are allowed in kernel names

clang/test/CodeGenSYCL/template-template-parameter.cpp

@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 -fsycl -fsycl-is-device -fsycl-int-bb=%t.h -sycl-std=2020 %s
+// RUN: %clang_cc1 -fsycl -fsycl-is-device -fsycl-int-header=%t.h -sycl-std=2020 %s
 // RUN: FileCheck -input-file=%t.h %s
 
 #include "Inputs/sycl.hpp"