[SYCL] Use host device explicitly and add default ctor tests (intel/llvm-test-suite#1169)

SYCL2020 changes the default constructor of both platform and device
from using host to using the objects associated with the default device
selector. This commit adjusts for this change in behaviour.
Additionally, this commit also adds tests for the default constructor
behaviour for both platform and device.

Signed-off-by: Larsen, Steffen <steffen.larsen@intel.com>

Author: steffenlarsen

SYCL/Basic/default_device.cpp

@@ -0,0 +1,21 @@
+//==--------- default_device.cpp - SYCL device default ctor 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
+//
+//===----------------------------------------------------------------------===//
+
+// RUN: %clangxx -fsycl -fsycl-targets=%sycl_triple %s -o %t.out
+// RUN: %HOST_RUN_PLACEHOLDER %t.out
+// RUN: %CPU_RUN_PLACEHOLDER %t.out
+// RUN: %GPU_RUN_PLACEHOLDER %t.out
+// RUN: %ACC_RUN_PLACEHOLDER %t.out
+
+#include <sycl/sycl.hpp>
+
+int main() {
+  sycl::device Dev;
+  assert(Dev == sycl::device{sycl::default_selector_v});
+  return 0;
+}

SYCL/Basic/default_platform.cpp

@@ -0,0 +1,21 @@
+//==------- default_platform.cpp - SYCL platform default ctor 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
+//
+//===----------------------------------------------------------------------===//
+
+// RUN: %clangxx -fsycl -fsycl-targets=%sycl_triple %s -o %t.out
+// RUN: %HOST_RUN_PLACEHOLDER %t.out
+// RUN: %CPU_RUN_PLACEHOLDER %t.out
+// RUN: %GPU_RUN_PLACEHOLDER %t.out
+// RUN: %ACC_RUN_PLACEHOLDER %t.out
+
+#include <sycl/sycl.hpp>
+
+int main() {
+  sycl::platform Plt;
+  assert(Plt == sycl::platform{sycl::default_selector_v});
+  return 0;
+}

SYCL/Basic/device_equality.cpp

@@ -37,8 +37,8 @@ int main() {
   assert((dev1 == dev2) && "Device 1 == Device 2");
   assert((plat1 == plat2) && "Platform 1 == Platform 2");
 
-  device h1;
-  device h2;
+  device h1{host_selector{}};
+  device h2{host_selector{}};
 
   assert(h1.is_host() && "Device h1 is host");
   assert(h2.is_host() && "Device h2 is host");

SYCL/FilterSelector/select.cpp

@@ -23,7 +23,6 @@ int main() {
   std::vector<device> GPUs;
   std::vector<device> Accels;
   std::vector<device> Devs;
-  device host;
 
   CPUs = device::get_devices(info::device_type::cpu);
   GPUs = device::get_devices(info::device_type::gpu);

SYCL/USM/pointer_query.cpp

@@ -29,7 +29,6 @@ int main() {
     return 0;
 
   usm::alloc Kind;
-  device D;
 
   // Test device allocs
   array = (int *)malloc_device(N * sizeof(int), q);
@@ -48,7 +47,7 @@ int main() {
       return 3;
     }
   }
-  D = get_pointer_device(array, ctxt);
+  device D = get_pointer_device(array, ctxt);
   if (D != dev) {
     return 4;
   }