[SYCL] Avoid including std C++ headers into integration header file (#2662)

This is done to avoid compilation errors caused by usage TBB AND libstdc++ 10.X

libstdc++10 conditionally defines (i.e. if is not defined already) the macro _GLIBCXX_USE_TBB_PAR_BACKEND.
If the integration header file has includes of C++ headers, then that macro gets defined always. This does not let to define it properly in user's app (even if define is on the 1st line), which also causes different behavior for some C++ std files and compile error later.

Signed-off-by: Vyacheslav N Klochkov <[email protected]>

Author: v-klochkov

clang/lib/Sema/SemaSYCL.cpp

@@ -3657,7 +3657,7 @@ void SYCLIntegrationHeader::emit(raw_ostream &O) {
   O << "// This is auto-generated SYCL integration header.\n";
   O << "\n";
 
-  O << "#include <CL/sycl/detail/defines.hpp>\n";
+  O << "#include <CL/sycl/detail/defines_elementary.hpp>\n";
   O << "#include <CL/sycl/detail/kernel_desc.hpp>\n";
 
   O << "\n";

clang/test/CodeGenSYCL/stdtypes_kernel_type.cpp

@@ -2,7 +2,7 @@
 // RUN: %clang_cc1 -fsycl -fsycl-is-device -triple spir64-unknown-unknown-sycldevice -fsycl-int-header=%t.h %s
 // RUN: FileCheck -input-file=%t.h %s
 //
-// CHECK: #include <CL/sycl/detail/defines.hpp>
+// CHECK: #include <CL/sycl/detail/defines_elementary.hpp>
 // CHECK-NEXT: #include <CL/sycl/detail/kernel_desc.hpp>
 //
 // CHECK: static constexpr

sycl/include/CL/sycl/detail/defines.hpp

@@ -8,39 +8,9 @@
 
 #pragma once
 
-#include <climits>
-
-#ifndef __SYCL_DISABLE_NAMESPACE_INLINE__
-#define __SYCL_INLINE_NAMESPACE(X) inline namespace X
-#else
-#define __SYCL_INLINE_NAMESPACE(X) namespace X
-#endif // __SYCL_DISABLE_NAMESPACE_INLINE__
-
-#ifndef __has_attribute
-#define __has_attribute(x) 0
-#endif
-
-#ifndef __has_builtin
-#define __has_builtin(x) 0
-#endif
-
-#if __has_attribute(always_inline)
-#define ALWAYS_INLINE __attribute__((always_inline))
-#else
-#define ALWAYS_INLINE
-#endif
-
-#ifndef __has_builtin
-#define __has_builtin(x) 0
-#endif // __has_builtin
+#include <CL/sycl/detail/defines_elementary.hpp>
 
-#ifndef SYCL_EXTERNAL
-#define SYCL_EXTERNAL
-#endif
-
-#ifndef __SYCL_ID_QUERIES_FIT_IN_INT__
-#define __SYCL_ID_QUERIES_FIT_IN_INT__ 0
-#endif
+#include <climits>
 
 #if __SYCL_ID_QUERIES_FIT_IN_INT__ && __has_builtin(__builtin_assume)
 #define __SYCL_ASSUME_INT(x) __builtin_assume((x) <= INT_MAX)
@@ -50,16 +20,3 @@
 #warning "No assumptions will be emitted due to no __builtin_assume available"
 #endif
 #endif
-
-#ifdef _WIN32
-#define __SYCL_DEPRECATED(message) __declspec(deprecated(message))
-#else
-#define __SYCL_DEPRECATED(message) __attribute__((deprecated(message)))
-#endif
-
-// inline constexpr is a C++17 feature
-#if __cplusplus >= 201703L
-#define __SYCL_INLINE_CONSTEXPR inline constexpr
-#else
-#define __SYCL_INLINE_CONSTEXPR static constexpr
-#endif

sycl/include/CL/sycl/detail/defines_elementary.hpp

@@ -0,0 +1,50 @@
+//==--- defines_elementary.hpp ---- Preprocessor directives (simplified) ---==//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#pragma once
+
+#ifndef __SYCL_DISABLE_NAMESPACE_INLINE__
+#define __SYCL_INLINE_NAMESPACE(X) inline namespace X
+#else
+#define __SYCL_INLINE_NAMESPACE(X) namespace X
+#endif // __SYCL_DISABLE_NAMESPACE_INLINE__
+
+#ifndef __has_attribute
+#define __has_attribute(x) 0
+#endif
+
+#ifndef __has_builtin
+#define __has_builtin(x) 0
+#endif // __has_builtin
+
+#if __has_attribute(always_inline)
+#define ALWAYS_INLINE __attribute__((always_inline))
+#else
+#define ALWAYS_INLINE
+#endif
+
+#ifndef SYCL_EXTERNAL
+#define SYCL_EXTERNAL
+#endif
+
+#ifndef __SYCL_ID_QUERIES_FIT_IN_INT__
+#define __SYCL_ID_QUERIES_FIT_IN_INT__ 0
+#endif
+
+#ifdef _WIN32
+#define __SYCL_DEPRECATED(message) __declspec(deprecated(message))
+#else
+#define __SYCL_DEPRECATED(message) __attribute__((deprecated(message)))
+#endif
+
+// inline constexpr is a C++17 feature
+#if __cplusplus >= 201703L
+#define __SYCL_INLINE_CONSTEXPR inline constexpr
+#else
+#define __SYCL_INLINE_CONSTEXPR static constexpr
+#endif

sycl/include/CL/sycl/detail/kernel_desc.hpp

@@ -8,11 +8,10 @@
 
 #pragma once
 
-#include <CL/sycl/access/access.hpp>
-#include <CL/sycl/detail/defines.hpp>
-#include <CL/sycl/detail/export.hpp> // for DLL_LOCAL used in int. header
+// This header file must not include any standard C++ header files.
 
-#include <cstddef>
+#include <CL/sycl/detail/defines_elementary.hpp>
+#include <CL/sycl/detail/export.hpp>
 
 __SYCL_INLINE_NAMESPACE(cl) {
 namespace sycl {
@@ -71,14 +70,16 @@ template <char...> struct KernelInfoData {
 // C++14 like index_sequence and make_index_sequence
 // not needed C++14 members (value_type, size) not implemented
 template <class T, T...> struct integer_sequence {};
-template <size_t... I> using index_sequence = integer_sequence<size_t, I...>;
-template <size_t N>
-using make_index_sequence = __make_integer_seq<integer_sequence, size_t, N>;
+template <unsigned long long... I>
+using index_sequence = integer_sequence<unsigned long long, I...>;
+template <unsigned long long N>
+using make_index_sequence =
+    __make_integer_seq<integer_sequence, unsigned long long, N>;
 
 template <typename T> struct KernelInfoImpl {
 private:
   static constexpr auto n = __builtin_unique_stable_name(T);
-  template <size_t... I>
+  template <unsigned long long... I>
   static KernelInfoData<n[I]...> impl(index_sequence<I...>) {
     return {};
   }