[SYCL] Add support for has_extension free functions (#7059)

Implemented `has_extension` free functions defined in SYCL 2020
spec in `sycl::opencl` namespace:
https://registry.khronos.org/SYCL/specs/sycl-2020/html/sycl-2020.html#_extension_query

Author: Andrew Lamzed-Short

sycl/include/sycl/backend/opencl.hpp

@@ -11,6 +11,8 @@
 
 #include <sycl/backend.hpp>
 
+#include <string>
+
 namespace sycl {
 __SYCL_INLINE_VER_NAMESPACE(_V1) {
 namespace opencl {
@@ -25,6 +27,11 @@ __SYCL_EXPORT context make_context(pi_native_handle NativeHandle);
 __SYCL_EXPORT queue make_queue(const context &Context,
                                pi_native_handle InteropHandle);
 
+__SYCL_EXPORT bool has_extension(const sycl::platform &SyclPlatform,
+                                 const std::string &Extension);
+__SYCL_EXPORT bool has_extension(const sycl::device &SyclDevice,
+                                 const std::string &Extension);
+
 // Construction of SYCL platform.
 template <typename T, typename detail::enable_if_t<
                           std::is_same<T, platform>::value> * = nullptr>

sycl/source/backend/opencl.cpp

@@ -13,6 +13,9 @@
 #include <detail/queue_impl.hpp>
 #include <sycl/sycl.hpp>
 
+#include <memory>
+#include <string_view>
+
 namespace sycl {
 __SYCL_INLINE_VER_NAMESPACE(_V1) {
 namespace opencl {
@@ -44,6 +47,70 @@ __SYCL_EXPORT queue make_queue(const context &Context,
   return detail::make_queue(NativeHandle, Context, nullptr, false,
                             ContextImpl->get_async_handler(), backend::opencl);
 }
+
+//----------------------------------------------------------------------------
+// Free functions to query OpenCL backend extensions
+__SYCL_EXPORT bool has_extension(const sycl::platform &SyclPlatform,
+                                 const std::string &Extension) {
+  if (SyclPlatform.get_backend() != sycl::backend::opencl) {
+    throw sycl::exception(
+        errc::backend_mismatch,
+        "has_extension can only be used with an OpenCL backend");
+  }
+
+  std::shared_ptr<sycl::detail::platform_impl> PlatformImpl =
+      getSyclObjImpl(SyclPlatform);
+  detail::RT::PiPlatform PluginPlatform = PlatformImpl->getHandleRef();
+  const plugin &Plugin = PlatformImpl->getPlugin();
+
+  // Manual invocation of plugin API to avoid using deprecated
+  // info::platform::extensions call.
+  size_t ResultSize = 0;
+  Plugin.call<PiApiKind::piPlatformGetInfo>(
+      PluginPlatform, PI_PLATFORM_INFO_EXTENSIONS, /*param_value_size=*/0,
+      /*param_value_size=*/nullptr, &ResultSize);
+  if (ResultSize == 0)
+    return false;
+
+  std::unique_ptr<char[]> Result(new char[ResultSize]);
+  Plugin.call<PiApiKind::piPlatformGetInfo>(PluginPlatform,
+                                            PI_PLATFORM_INFO_EXTENSIONS,
+                                            ResultSize, Result.get(), nullptr);
+
+  std::string_view ExtensionsString(Result.get());
+  return ExtensionsString.find(Extension) != std::string::npos;
+}
+
+__SYCL_EXPORT bool has_extension(const sycl::device &SyclDevice,
+                                 const std::string &Extension) {
+  if (SyclDevice.get_backend() != sycl::backend::opencl) {
+    throw sycl::exception(
+        errc::backend_mismatch,
+        "has_extension can only be used with an OpenCL backend");
+  }
+
+  std::shared_ptr<sycl::detail::device_impl> DeviceImpl =
+      getSyclObjImpl(SyclDevice);
+  detail::RT::PiDevice PluginDevice = DeviceImpl->getHandleRef();
+  const plugin &Plugin = DeviceImpl->getPlugin();
+
+  // Manual invocation of plugin API to avoid using deprecated
+  // info::device::extensions call.
+  size_t ResultSize = 0;
+  Plugin.call<PiApiKind::piDeviceGetInfo>(
+      PluginDevice, PI_DEVICE_INFO_EXTENSIONS, /*param_value_size=*/0,
+      /*param_value_size=*/nullptr, &ResultSize);
+  if (ResultSize == 0)
+    return false;
+
+  std::unique_ptr<char[]> Result(new char[ResultSize]);
+  Plugin.call<PiApiKind::piDeviceGetInfo>(PluginDevice,
+                                          PI_DEVICE_INFO_EXTENSIONS, ResultSize,
+                                          Result.get(), nullptr);
+
+  std::string_view ExtensionsString(Result.get());
+  return ExtensionsString.find(Extension) != std::string::npos;
+}
 } // namespace opencl
 } // __SYCL_INLINE_VER_NAMESPACE(_V1)
 } // namespace sycl

sycl/test/abi/sycl_symbols_linux.dump

@@ -3897,6 +3897,8 @@ _ZN4sycl3_V16mallocEmRKNS0_6deviceERKNS0_7contextENS0_3usm5allocERKNS0_6detail13
 _ZN4sycl3_V16opencl10make_queueERKNS0_7contextEm
 _ZN4sycl3_V16opencl11make_deviceEm
 _ZN4sycl3_V16opencl12make_contextEm
+_ZN4sycl3_V16opencl13has_extensionERKNS0_6deviceERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE
+_ZN4sycl3_V16opencl13has_extensionERKNS0_8platformERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE
 _ZN4sycl3_V16opencl13make_platformEm
 _ZN4sycl3_V16streamC1EmmRNS0_7handlerE
 _ZN4sycl3_V16streamC1EmmRNS0_7handlerERKNS0_13property_listE

sycl/test/abi/sycl_symbols_windows.dump

@@ -914,6 +914,8 @@
 ?hasUserDataPtr@SYCLMemObjT@detail@_V1@sycl@@QEBA_NXZ
 ?has_context@exception@_V1@sycl@@QEBA_NXZ
 ?has_extension@device@_V1@sycl@@QEBA_NAEBV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@@Z
+?has_extension@opencl@_V1@sycl@@YA_NAEBVdevice@23@AEBV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@@Z
+?has_extension@opencl@_V1@sycl@@YA_NAEBVplatform@23@AEBV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@@Z
 ?has_extension@platform@_V1@sycl@@QEBA_NAEBV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@@Z
 ?has_kernel@device_image_plain@detail@_V1@sycl@@QEBA_NAEBVkernel_id@34@@Z
 ?has_kernel@device_image_plain@detail@_V1@sycl@@QEBA_NAEBVkernel_id@34@AEBVdevice@34@@Z

sycl/unittests/SYCL2020/CMakeLists.txt

@@ -5,5 +5,6 @@ add_sycl_unittest(SYCL2020Tests OBJECT
   SpecializationConstant.cpp
   KernelBundle.cpp
   KernelID.cpp
+  HasExtension.cpp
 )
 

sycl/unittests/SYCL2020/HasExtension.cpp

@@ -0,0 +1,37 @@
+//==---- HasExtension.cpp --- Spec constants default values unit test ------==//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#include <sycl/backend/opencl.hpp>
+#include <sycl/sycl.hpp>
+
+#include <helpers/PiMock.hpp>
+
+#include <gtest/gtest.h>
+
+using namespace sycl;
+
+TEST(HasExtensionID, HasExtensionCallsCorrectPluginMethods) {
+  sycl::unittest::PiMock Mock;
+
+  sycl::platform Plt = Mock.getPlatform();
+  sycl::device Dev = Plt.get_devices()[0];
+
+  bool PlatformHasSubgroups = opencl::has_extension(Plt, "cl_khr_subgroups");
+  EXPECT_TRUE(PlatformHasSubgroups);
+
+  bool DeviceHasFP64 = opencl::has_extension(Dev, "cl_khr_fp64");
+  EXPECT_TRUE(DeviceHasFP64);
+
+  bool PlatformNotHasErroneousExtension =
+      opencl::has_extension(Plt, "test_for_unknown_platform_extension");
+  EXPECT_FALSE(PlatformNotHasErroneousExtension);
+
+  bool DeviceNotHasErroneousExtension =
+      opencl::has_extension(Dev, "test_for_unknown_device_extension");
+  EXPECT_FALSE(DeviceNotHasErroneousExtension);
+}