[SYCL] Do not make auto& range parallel_for a future breaking change (#11897)

Author: jzc

sycl/include/sycl/handler.hpp

@@ -1261,9 +1261,10 @@ class __SYCL_EXPORT handler {
                   "first argument of sycl::item type, or of a type which is "
                   "implicitly convertible from sycl::item");
 
+    using RefLambdaArgType = std::add_lvalue_reference_t<LambdaArgType>;
     static_assert(
-        (std::is_invocable_v<KernelType, LambdaArgType> ||
-         std::is_invocable_v<KernelType, LambdaArgType, kernel_handler>),
+        (std::is_invocable_v<KernelType, RefLambdaArgType> ||
+         std::is_invocable_v<KernelType, RefLambdaArgType, kernel_handler>),
         "SYCL kernel lambda/functor has an unexpected signature, it should be "
         "invocable with sycl::item and optionally sycl::kernel_handler");
 #endif

sycl/test/basic_tests/handler/handler_generic_lambda_interface.cpp

@@ -53,10 +53,6 @@ int main() {
   test_parallel_for_work_group<class Group2Name, sycl::group<2>>(sycl::range<2>{1, 1});
   test_parallel_for_work_group<class Group3Name, sycl::group<3>>(sycl::range<3>{1, 1, 1});
 
-#ifndef PREVIEW_BREAKING_CHANGES
-  // For backwards compatibility, we still support some invalid variants of
-  // kernel lambdas. These test cases should be removed once we make conformant
-  // mode the default.
   sycl::queue q;
   q.submit([&](sycl::handler &cgh) {
     cgh.parallel_for(sycl::range{1}, [=](auto &) {});
@@ -67,7 +63,6 @@ int main() {
   q.submit([&](sycl::handler &cgh) {
     cgh.parallel_for(sycl::range{1, 1, 1}, [=](auto &) {});
   });
-#endif
 
   return 0;
 }

sycl/test/basic_tests/handler/parallel_for_arg_restrictions.cpp

@@ -71,18 +71,6 @@ int main() {
     CGH.parallel_for(sycl::nd_range{sycl::range{1, 1, 1}, sycl::range{1, 1, 1}},
                      [=](ConvertibleFromItem<3>) {});
   });
-  Q.submit([&](sycl::handler &CGH) {
-    // expected-error@sycl/handler.hpp:* {{SYCL kernel lambda/functor has an unexpected signature, it should be invocable with sycl::item and optionally sycl::kernel_handler}}
-    CGH.parallel_for(sycl::range{1}, [=](auto &) {});
-  });
-  Q.submit([&](sycl::handler &CGH) {
-    // expected-error@sycl/handler.hpp:* {{SYCL kernel lambda/functor has an unexpected signature, it should be invocable with sycl::item and optionally sycl::kernel_handler}}
-    CGH.parallel_for(sycl::range{1, 1}, [=](auto &) {});
-  });
-  Q.submit([&](sycl::handler &CGH) {
-    // expected-error@sycl/handler.hpp:* {{SYCL kernel lambda/functor has an unexpected signature, it should be invocable with sycl::item and optionally sycl::kernel_handler}}
-    CGH.parallel_for(sycl::range{1, 1, 1}, [=](auto &) {});
-  });
 
   Q.submit([&](sycl::handler &CGH) {
     // expected-error@sycl/handler.hpp:* {{sycl::parallel_for(sycl::range) kernel must have the first argument of sycl::item type, or of a type which is implicitly convertible from sycl::item}}