Address review comments

Author: srividya-sundaram

clang/lib/Sema/SemaSYCL.cpp

@@ -2994,8 +2994,8 @@ class SYCLKernelNameTypeVisitor
 
   void DiagnoseKernelNameType(const NamedDecl *DeclNamed) {
     /*
-    This is a helper function which throws an error if the given declaration
-    is:
+    This is a helper function which throws an error if the kernel name
+    declaration is:
       * declared within namespace 'std' (at any level)
         e.g., namespace std { namespace literals { class Whatever; } }
         h.single_task<std::literals::Whatever>([]() {});
@@ -3023,7 +3023,7 @@ class SYCLKernelNameTypeVisitor
     const DeclContext *DeclCtx = DeclNamed->getDeclContext();
     if (DeclCtx && !UnnamedLambdaEnabled) {
 
-      // Check if the declaration is declared within namespace
+      // Check if the kernel name declaration is declared within namespace
       // "std" or "anonymous" namespace (at any level).
       while (!DeclCtx->isTranslationUnit() && isa<NamespaceDecl>(DeclCtx)) {
         const auto *NSDecl = cast<NamespaceDecl>(DeclCtx);
@@ -3044,6 +3044,9 @@ class SYCLKernelNameTypeVisitor
         DeclCtx = DeclCtx->getParent();
       }
 
+      // Check if the kernel name is a Tag declaration
+      // local to a non-namespace scope (i.e. Inside a function or within
+      // another Tag etc).
       if (!DeclCtx->isTranslationUnit() && !isa<NamespaceDecl>(DeclCtx)) {
         if (const auto *Tag = dyn_cast<TagDecl>(DeclNamed)) {
           bool UnnamedTypeUsed = Tag->getIdentifier() == nullptr;

clang/test/SemaSYCL/stdtypes_kernel_type.cpp

@@ -1,5 +1,8 @@
 // RUN: %clang_cc1 -fsycl-is-device -sycl-std=2020 -DCHECK_ERROR -verify %s
 
+// This test verifies that an error is thrown if the kernel name declaration
+// is declared within 'std' namespace.
+
 #include "Inputs/sycl.hpp"
 
 namespace std {

clang/test/SemaSYCL/unnamed-kernel.cpp

@@ -1,6 +1,9 @@
 // RUN: %clang_cc1 -fsycl-is-device -internal-isystem %S/Inputs -fsyntax-only -sycl-std=2020 -verify %s
 // RUN: %clang_cc1 -fsycl-is-device -internal-isystem %S/Inputs -fsycl-unnamed-lambda -fsyntax-only -sycl-std=2020 -verify %s
 
+// This test verifies that an error is thrown when kernel names are declared within function/class scope
+// and if kernel names are empty.
+
 #include "sycl.hpp"
 
 #ifdef __SYCL_UNNAMED_LAMBDA__

sycl/test/functor/kernel_functor.cpp

@@ -2,7 +2,8 @@
 // RUN: cd %T
 // RUN: %RUN_ON_HOST %t.out
 
-//==--- kernel_functor.cpp - Functors as SYCL kernel test ------------------==//
+//==--- kernel_functor.cpp -
+// This test illustrates defining kernels as named function objects (functors)
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.