[SYCL] Kernel free function num args functionality (intel#19868)

This is a cherry-pick of intel#19517

This PR adds possibility to get kernel free function number of arguments
according to

[docs](https://github.com/intel/llvm/blob/sycl/sycl/doc/extensions/proposed/sycl_ext_oneapi_free_function_kernels.asciidoc#behavior-with-kernel-bundle-functions-in-the-core-sycl-specification)
Tests were added according to test plan.



Patch-by: dklochkov-intel <[email protected]>

Author: AlexeySachkov

clang/lib/Sema/SemaSYCL.cpp

@@ -6666,6 +6666,34 @@ class FreeFunctionPrinter {
           FD->getTemplateSpecializationArgs());
   }
 
+  /// Emits free function kernel info specialization for shimN.
+  /// \param ShimCounter The counter for the shim function.
+  /// \param KParamsSize The number of kernel free function arguments.
+  /// \param KName The name of the kernel free function.
+  void printFreeFunctionKernelInfo(const unsigned ShimCounter,
+                                   const size_t KParamsSize,
+                                   std::string_view KName) {
+    O << "\n";
+    O << "namespace sycl {\n";
+    O << "inline namespace _V1 {\n";
+    O << "namespace detail {\n";
+    O << "//Free Function Kernel info specialization for shim" << ShimCounter
+      << "\n";
+    O << "template <> struct FreeFunctionInfoData<__sycl_shim" << ShimCounter
+      << "()> {\n";
+    O << "  __SYCL_DLL_LOCAL\n";
+    O << "  static constexpr unsigned getNumParams() { return " << KParamsSize
+      << "; }\n";
+    O << "  __SYCL_DLL_LOCAL\n";
+    O << "  static constexpr const char *getFunctionName() { return ";
+    O << "\"" << KName << "\"; }\n";
+    O << "};\n";
+    O << "} // namespace detail\n"
+      << "} // namespace _V1\n"
+      << "} // namespace sycl\n";
+    O << "\n";
+  }
+
 private:
   /// Helper method to get string with template types
   /// \param TAL The template argument list.
@@ -6915,6 +6943,11 @@ void SYCLIntegrationHeader::emit(raw_ostream &O) {
   O << "  \"\",\n";
   O << "};\n\n";
 
+  O << "static constexpr unsigned kernel_args_sizes[] = {";
+  for (unsigned I = 0; I < KernelDescs.size(); I++) {
+    O << KernelDescs[I].Params.size() << ", ";
+  }
+  O << "};\n\n";
   O << "// array representing signatures of all kernels defined in the\n";
   O << "// corresponding source\n";
   O << "static constexpr\n";
@@ -7127,6 +7160,7 @@ void SYCLIntegrationHeader::emit(raw_ostream &O) {
     FFPrinter.printFreeFunctionShim(K.SyclKernel, ShimCounter, ParmList);
     O << ";\n";
     O << "}\n";
+    FFPrinter.printFreeFunctionKernelInfo(ShimCounter, K.Params.size(), K.Name);
     Policy.SuppressDefaultTemplateArgs = true;
     Policy.EnforceDefaultTemplateArgs = false;
 
@@ -7156,22 +7190,21 @@ void SYCLIntegrationHeader::emit(raw_ostream &O) {
 
   if (FreeFunctionCount > 0) {
     O << "\n#include <sycl/kernel_bundle.hpp>\n";
-  }
-  ShimCounter = 1;
-  for (const KernelDesc &K : KernelDescs) {
-    if (!S.isFreeFunction(K.SyclKernel))
-      continue;
-
-    O << "\n// Definition of kernel_id of " << K.Name << "\n";
+    O << "#include <sycl/detail/kernel_global_info.hpp>\n";
     O << "namespace sycl {\n";
-    O << "template <>\n";
-    O << "inline kernel_id ext::oneapi::experimental::get_kernel_id<__sycl_shim"
-      << ShimCounter << "()>() {\n";
-    O << "  return sycl::detail::get_kernel_id_impl(std::string_view{\""
-      << K.Name << "\"});\n";
-    O << "}\n";
-    O << "}\n";
-    ++ShimCounter;
+    O << "inline namespace _V1 {\n";
+    O << "namespace detail {\n";
+    O << "struct GlobalMapUpdater {\n";
+    O << "  GlobalMapUpdater() {\n";
+    O << "    sycl::detail::free_function_info_map::add("
+      << "sycl::detail::kernel_names, sycl::detail::kernel_args_sizes, "
+      << KernelDescs.size() << ");\n";
+    O << "  }\n";
+    O << "};\n";
+    O << "static GlobalMapUpdater updater;\n";
+    O << "} // namespace detail\n";
+    O << "} // namespace _V1\n";
+    O << "} // namespace sycl\n";
   }
 }