Merge #6257

6257: Cmake Tests: Delete operator check for size_t arg r=hkaiser a=SAtacker

- Clang fails to recognize the global delete operator which has 2 arguments the second one being std::size_t
- Reference - https://godbolt.org/z/q1hMrfKjv
- Fixes #6246

Signed-off-by: Shreyas Atre <shreyasatre16@gmail.com>




Co-authored-by: Shreyas Atre <shreyasatre16@gmail.com>
Co-authored-by: Shreyas Atre <61797109+SAtacker@users.noreply.github.com>

cmake/HPX_AddConfigTest.cmake

@@ -350,6 +350,15 @@ function(hpx_check_for_cxx11_std_shared_ptr_lwg3018)
   )
 endfunction()
 
+# ##############################################################################
+function(hpx_check_for_cxx14_delete_operator_with_size)
+  add_hpx_config_test(
+    HPX_WITH_CXX14_DELETE_OPERATOR_WITH_SIZE
+    SOURCE cmake/tests/cxx_14_delete_operator_with_size.cpp
+    FILE ${ARGN}
+  )
+endfunction()
+
 # ##############################################################################
 function(hpx_check_for_c11_aligned_alloc)
   add_hpx_config_test(

cmake/HPX_PerformCxxFeatureTests.cmake

@@ -49,6 +49,10 @@ function(hpx_perform_cxx_feature_tests)
 
   hpx_check_for_c11_aligned_alloc(DEFINITIONS HPX_HAVE_C11_ALIGNED_ALLOC)
 
+  hpx_check_for_cxx14_delete_operator_with_size(
+    DEFINITIONS HPX_WITH_CXX14_DELETE_OPERATOR_WITH_SIZE
+  )
+
   hpx_check_for_cxx17_std_aligned_alloc(
     DEFINITIONS HPX_HAVE_CXX17_STD_ALIGNED_ALLOC
   )

cmake/tests/cxx_14_delete_operator_with_size.cpp

@@ -0,0 +1,19 @@
+//  Copyright (c) 2023 Shreyas Atre
+//
+//  SPDX-License-Identifier: BSL-1.0
+//  Distributed under the Boost Software License, Version 1.0. (See accompanying
+//  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#include <cstddef>
+#include <memory>
+
+/// clang fails to compile this with libstdc++ even though gcc does fine
+
+int main()
+{
+    using dealloc_fn = void (*)(void*, std::size_t);
+    dealloc_fn const dealloc = [](void* const p, std::size_t const s) {
+        ::operator delete[](p, s + sizeof(std::size_t) + sizeof(dealloc_fn));
+    };
+    (void) dealloc;
+}

libs/core/type_support/include/hpx/type_support/generator.hpp

@@ -322,11 +322,15 @@ namespace hpx {
                 void* const ptr = ::operator new[](
                     size + sizeof(std::size_t) + sizeof(dealloc_fn));
 
-                dealloc_fn const dealloc = [](void* const p,
-                                               std::size_t const s) {
-                    ::operator delete[](
-                        p, s + sizeof(std::size_t) + sizeof(dealloc_fn));
-                };
+                dealloc_fn const dealloc =
+                    [](void* const p, [[maybe_unused]] std::size_t const s) {
+#if defined(HPX_WITH_CXX14_DELETE_OPERATOR_WITH_SIZE)
+                        ::operator delete[](
+                            p, s + sizeof(std::size_t) + sizeof(dealloc_fn));
+#else
+                        ::operator delete[](p);
+#endif
+                    };
 
                 char* address = static_cast<char*>(ptr);
                 *reinterpret_cast<std::size_t*>(address) = size;