[SYCL] Add a diagnostic on attempt to pass a command group function object to q.single_task() (#5064)

Author: HabKaffee

sycl/include/CL/sycl/queue.hpp

@@ -688,8 +688,14 @@ class __SYCL_EXPORT queue {
   /// \param CodeLoc contains the code location of user code
   template <typename KernelName = detail::auto_name, typename KernelType>
   event single_task(_KERNELFUNCPARAM(KernelFunc) _CODELOCPARAM(&CodeLoc)) {
+    static_assert(
+        (detail::check_fn_signature<detail::remove_reference_t<KernelType>,
+                                    void()>::value ||
+         detail::check_fn_signature<detail::remove_reference_t<KernelType>,
+                                    void(kernel_handler)>::value),
+        "sycl::queue.single_task() requires a kernel instead of command group. "
+        "Use queue.submit() instead");
     _CODELOCARG(&CodeLoc);
-
     return submit(
         [&](handler &CGH) {
           CGH.template single_task<KernelName, KernelType>(KernelFunc);
@@ -705,6 +711,13 @@ class __SYCL_EXPORT queue {
   template <typename KernelName = detail::auto_name, typename KernelType>
   event single_task(event DepEvent,
                     _KERNELFUNCPARAM(KernelFunc) _CODELOCPARAM(&CodeLoc)) {
+    static_assert(
+        (detail::check_fn_signature<detail::remove_reference_t<KernelType>,
+                                    void()>::value ||
+         detail::check_fn_signature<detail::remove_reference_t<KernelType>,
+                                    void(kernel_handler)>::value),
+        "sycl::queue.single_task() requires a kernel instead of command group. "
+        "Use queue.submit() instead");
     _CODELOCARG(&CodeLoc);
     return submit(
         [&](handler &CGH) {
@@ -723,6 +736,13 @@ class __SYCL_EXPORT queue {
   template <typename KernelName = detail::auto_name, typename KernelType>
   event single_task(const std::vector<event> &DepEvents,
                     _KERNELFUNCPARAM(KernelFunc) _CODELOCPARAM(&CodeLoc)) {
+    static_assert(
+        (detail::check_fn_signature<detail::remove_reference_t<KernelType>,
+                                    void()>::value ||
+         detail::check_fn_signature<detail::remove_reference_t<KernelType>,
+                                    void(kernel_handler)>::value),
+        "sycl::queue.single_task() requires a kernel instead of command group. "
+        "Use queue.submit() instead");
     _CODELOCARG(&CodeLoc);
     return submit(
         [&](handler &CGH) {

sycl/test/basic_tests/single_task_error_message.cpp

@@ -0,0 +1,51 @@
+// RUN: %clangxx %fsycl-host-only -fsyntax-only -Xclang -verify -Xclang -verify-ignore-unexpected=note -o - %s
+#include <CL/sycl.hpp>
+#include <iostream>
+int main() {
+  {
+    int varA = 42;
+    int varB = 42;
+    int sum = 0;
+    sycl::queue myQueue{};
+    {
+      myQueue
+          .single_task([&](sycl::handler &cgh) {
+            // expected-error-re@CL/sycl/queue.hpp:691 {{static_assert failed due to requirement '{{.*}}' "sycl::queue.single_task() requires a kernel instead of command group.{{.*}} Use queue.submit() instead"}}
+            // expected-error-re@CL/sycl/detail/cg_types.hpp:191 {{no matching function for call to object of type '(lambda at {{.*}}single_task_error_message.cpp:{{.*}})'}}
+          })
+          .wait();
+    }
+  }
+  {
+    int varA = 42;
+    int varB = 42;
+    int sum = 0;
+    sycl::queue myQueue{};
+    {
+      sycl::event e{};
+      myQueue
+          .single_task(e,
+                       [&](sycl::handler &cgh) {
+                         // expected-error-re@CL/sycl/queue.hpp:714 {{static_assert failed due to requirement '{{.*}}' "sycl::queue.single_task() requires a kernel instead of command group.{{.*}} Use queue.submit() instead"}}
+                         // expected-error-re@CL/sycl/detail/cg_types.hpp:191 {{no matching function for call to object of type '(lambda at {{.*}}single_task_error_message.cpp:{{.*}})'}}
+                       })
+          .wait();
+    }
+  }
+  {
+    int varA = 42;
+    int varB = 42;
+    int sum = 0;
+    sycl::queue myQueue{};
+    {
+      std::vector<sycl::event> vector_event;
+      myQueue
+          .single_task(vector_event,
+                       [&](sycl::handler &cgh) {
+                         // expected-error-re@CL/sycl/queue.hpp:739 {{static_assert failed due to requirement '{{.*}}' "sycl::queue.single_task() requires a kernel instead of command group.{{.*}} Use queue.submit() instead"}}
+                         // expected-error-re@CL/sycl/detail/cg_types.hpp:191 {{no matching function for call to object of type '(lambda at {{.*}}single_task_error_message.cpp:{{.*}})'}}
+                       })
+          .wait();
+    }
+  }
+}