[SYCL] Switch build of SYCL runtime to C++17 (#3447)

* switch build of SYCL RT and SYCL unit tests to use C++17 standard;
* fix build issues exposed by build with VS 2017 compiler;
* workaround problem in googletest (google/googletest#1616);
* update documentation accordingly.

Author: vladimirlaz

sycl/CMakeLists.txt

@@ -2,7 +2,7 @@ cmake_minimum_required(VERSION 3.14)
 
 project(sycl-solution)
 # Requirements
-set(CMAKE_CXX_STANDARD 14)
+set(CMAKE_CXX_STANDARD 17)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
 set(CMAKE_CXX_EXTENSIONS OFF)
 option(SYCL_ENABLE_WERROR "Treat all warnings as errors in SYCL project" OFF)

sycl/cmake/modules/AddSYCLUnitTest.cmake

@@ -45,13 +45,6 @@ macro(add_sycl_unittest test_dirname link_variant)
         -Wno-inconsistent-missing-override
     )
   endif()
-  # LLVM gtest uses LLVM utilities that require C++-14
-  # CXX_STANDARD_REQUIRED makes CXX_STANDARD a hard requirement.
-  set_target_properties(${test_dirname}
-    PROPERTIES
-      CXX_STANDARD 14
-      CXX_STANDARD_REQUIRED ON
-    )
 endmacro()
 
 macro(add_sycl_unittest_with_device test_dirname link_variant)

sycl/doc/GetStartedGuide.md

@@ -639,7 +639,7 @@ which contains all the symbols required.
 
 ## C++ standard
 
-* DPC++ runtime and headers require C++14 at least.
+* DPC++ runtime and headers require C++17 at least.
 * DPC++ compiler builds apps as C++17 apps by default. Higher versions of
   standard are supported as well.
 

sycl/include/CL/sycl/ONEAPI/accessor_property_list.hpp

@@ -193,17 +193,18 @@ class accessor_property_list : protected sycl::detail::PropertyListBase {
 
 #if __cplusplus >= 201703L
   template <typename T>
-  static constexpr
-      typename detail::enable_if_t<is_compile_time_property<T>::value, bool>
-      has_property() {
+  constexpr std::enable_if_t<is_compile_time_property<T>::value, bool>
+  has_property() const {
     return ContainsPropertyInstance<PropertyContainer<PropsT...>,
                                     T::template instance>::value;
   }
 
   template <typename T,
-            typename = typename detail::enable_if_t<
-                is_compile_time_property<T>::value && has_property<T>()>>
-  static constexpr auto get_property() {
+            typename = std::enable_if_t<
+                is_compile_time_property<T>::value &&
+                ContainsPropertyInstance<PropertyContainer<PropsT...>,
+                                         T::template instance>::value>>
+  constexpr auto get_property() const {
     return typename GetCompileTimePropertyHelper<PropertyContainer<PropsT...>,
                                                  T::template instance>::type{};
   }

sycl/include/CL/sycl/properties/accessor_properties.hpp

@@ -52,7 +52,7 @@ struct buffer_location {
 } // namespace property
 #if __cplusplus > 201402L
 template <int A>
-inline constexpr property::buffer_location::instance<A> buffer_location;
+inline constexpr property::buffer_location::instance<A> buffer_location{};
 #endif
 } // namespace INTEL
 namespace ONEAPI {

sycl/unittests/scheduler/NoHostUnifiedMemory.cpp

@@ -170,7 +170,7 @@ TEST_F(SchedulerTest, NoHostUnifiedMemory) {
     // Memory movement operations should be omitted for discard access modes.
     detail::Command *MemoryMove =
         MS.insertMemoryMove(Record, &DiscardReq, DefaultHostQueue);
-    EXPECT_EQ(MemoryMove, nullptr);
+    EXPECT_TRUE(MemoryMove == nullptr);
     // The current context for the record should still be modified.
     EXPECT_EQ(Record->MCurContext, DefaultHostQueue->getContextImplPtr());
   }

sycl/unittests/scheduler/WaitAfterCleanup.cpp

@@ -14,14 +14,14 @@ using namespace cl::sycl;
 TEST_F(SchedulerTest, WaitAfterCleanup) {
   auto Cmd = new MockCommand(detail::getSyclObjImpl(MQueue));
   auto Event = Cmd->getEvent();
-  ASSERT_NE(Event, nullptr) << "Command must have an event\n";
+  ASSERT_FALSE(Event == nullptr) << "Command must have an event\n";
 
   detail::Scheduler::getInstance().waitForEvent(Event);
   ASSERT_EQ(Event->getCommand(), Cmd)
       << "Command should not have been cleaned up yet\n";
 
   detail::Scheduler::getInstance().cleanupFinishedCommands(Event);
-  ASSERT_EQ(Event->getCommand(), nullptr)
+  ASSERT_TRUE(Event->getCommand() == nullptr)
       << "Command should have been cleaned up\n";
 
   detail::Scheduler::getInstance().waitForEvent(Event);