Partially revert a5e8209 [SYCL] Remove IsDeprecatedDeviceCopyable (#16615) (#16744)

Restore (logically) previous condition while keeping the rest of
cleanups in place. Deprecation warning never worked, so I'm not even
trying to implement that.

Author: aelovikov-intel

sycl/include/sycl/detail/is_device_copyable.hpp

@@ -93,20 +93,25 @@ namespace detail {
 template <typename T, typename> struct CheckFieldsAreDeviceCopyable;
 template <typename T, typename> struct CheckBasesAreDeviceCopyable;
 
+template <typename T>
+inline constexpr bool is_deprecated_device_copyable_v =
+    is_device_copyable_v<T> || (std::is_trivially_copy_constructible_v<T> &&
+                                std::is_trivially_destructible_v<T>);
+
 template <typename T, unsigned... FieldIds>
 struct CheckFieldsAreDeviceCopyable<T, std::index_sequence<FieldIds...>> {
-  static_assert(
-      ((is_device_copyable_v<decltype(__builtin_field_type(T, FieldIds))> &&
-        ...)),
-      "The specified type is not device copyable");
+  static_assert(((is_deprecated_device_copyable_v<
+                      decltype(__builtin_field_type(T, FieldIds))> &&
+                  ...)),
+                "The specified type is not device copyable");
 };
 
 template <typename T, unsigned... BaseIds>
 struct CheckBasesAreDeviceCopyable<T, std::index_sequence<BaseIds...>> {
-  static_assert(
-      ((is_device_copyable_v<decltype(__builtin_base_type(T, BaseIds))> &&
-        ...)),
-      "The specified type is not device copyable");
+  static_assert(((is_deprecated_device_copyable_v<
+                      decltype(__builtin_base_type(T, BaseIds))> &&
+                  ...)),
+                "The specified type is not device copyable");
 };
 
 // All the captures of a lambda or functor of type FuncT passed to a kernel

sycl/test/basic_tests/is_device_copyable.cpp

@@ -25,6 +25,14 @@ struct BCopyable {
   BCopyable(const BCopyable &x) : i(x.i) {}
 };
 
+// Not trivially copyable, but trivially copy constructible/destructible.
+// Such types are passed to kernels to stay compatible with deprecated
+// sycl 1.2.1 rules.
+struct C : A {
+  const A C2;
+  C() : A{0}, C2{2} {}
+};
+
 // Not copyable type, but it will be declared as device copyable.
 struct DCopyable {
   int i;
@@ -59,6 +67,7 @@ void test() {
   A IamGood;
   IamGood.i = 0;
   BCopyable IamBadButCopyable(1);
+  C IamAlsoGood;
   DCopyable IamAlsoBadButCopyable{0};
   marray<int, 5> MarrayForCopyableIsCopyable(0);
   range<2> Range{1,2};
@@ -69,6 +78,7 @@ void test() {
     int A = IamGood.i;
     int B = IamBadButCopyable.i;
     int C = IamAlsoBadButCopyable.i;
+    int D = IamAlsoGood.i;
     int E = MarrayForCopyableIsCopyable[0];
     int F = Range[1];
     int G = Id[2];

sycl/test/basic_tests/is_device_copyable_neg.cpp

@@ -56,18 +56,18 @@ void test() {
   B IamAlsoBad{0};
   marray<B, 2> MarrayForNotCopyable;
   queue Q;
-  // expected-error@*:* {{static assertion failed due to requirement 'is_device_copyable_v<A>': The specified type is not device copyable}}
+  // expected-error@*:* {{static assertion failed due to requirement 'is_deprecated_device_copyable_v<A>': The specified type is not device copyable}}
   Q.single_task<class TestA>([=] {
     int A = IamBad.i;
     int B = IamAlsoBad.i;
     int MB = MarrayForNotCopyable[0].i;
   });
 
   FunctorA FA;
-  // expected-error@*:* {{static assertion failed due to requirement 'is_device_copyable_v<C>': The specified type is not device copyable}}
+  // expected-error@*:* {{static assertion failed due to requirement 'is_deprecated_device_copyable_v<C>': The specified type is not device copyable}}
   Q.single_task<class TestB>(FA);
 
   FunctorB FB;
-  // expected-error@*:* {{static assertion failed due to requirement 'is_device_copyable_v<D>': The specified type is not device copyable}}
+  // expected-error@*:* {{static assertion failed due to requirement 'is_deprecated_device_copyable_v<D>': The specified type is not device copyable}}
   Q.single_task<class TestC>(FB);
 }