[SYCL] Fix getting host objects for impl objects (#967)

Impl fields in context_impl and program_impl are initialized with
nullptr for host opbjects. That caused segfault on accessing them.
Create host objects on access time.

Signed-off-by: Vladimir Lazarev <[email protected]>

Author: vladimirlaz

sycl/include/CL/sycl/detail/program_impl.hpp

@@ -324,6 +324,8 @@ class program_impl {
   }
 
   context get_context() const {
+    if (is_host())
+      return context();
     return createSyclObjFromImpl<context>(Context);
   }
 

sycl/source/detail/context_impl.cpp

@@ -101,6 +101,8 @@ cl_uint context_impl::get_info<info::context::reference_count>() const {
       this->getHandleRef());
 }
 template <> platform context_impl::get_info<info::context::platform>() const {
+  if (is_host())
+    return platform();
   return createSyclObjFromImpl<platform>(MPlatform);
 }
 template <>

sycl/test/basic_tests/info.cpp

@@ -310,7 +310,7 @@ int main() {
       dev, "Preferred interop user sync");
   // TODO test once subdevice creation is enabled
   // print_info<info::device::parent_device, device>(dev, "Parent device");
-  if(!dev.is_host()){
+  if (!dev.is_host()) {
     try {
       print_info<info::device::parent_device, device>(dev, "Parent device");
     } catch (invalid_object_error e) {
@@ -343,4 +343,21 @@ int main() {
   print_info<info::platform::vendor, string_class>(plt, "Vendor");
   print_info<info::platform::extensions, vector_class<string_class>>(
       plt, "Extensions");
+
+  std::cout << separator << "Queue information\n" << separator;
+  queue q(selector);
+  auto qdev = q.get_info<cl::sycl::info::queue::device>();
+  std::cout << "Device from queue information\n";
+  print_info<info::device::name, string_class>(qdev, "Name");
+  auto ctx = q.get_info<cl::sycl::info::queue::context>();
+
+  std::cout << separator << "Context information\n" << separator;
+  std::cout << "Devices from context information\n";
+  auto cdevs = ctx.get_info<cl::sycl::info::context::devices>();
+  for (auto cdev : cdevs) {
+    print_info<info::device::name, string_class>(cdev, "Name");
+  }
+  std::cout << separator << "Platform from context information\n" << separator;
+  auto cplt = ctx.get_info<cl::sycl::info::context::platform>();
+  print_info<info::platform::name, string_class>(cplt, "Name");
 }