[libc++] Simplify when the sized global deallocations overloads are available

Author: philnik777

libcxx/include/new

@@ -104,18 +104,6 @@ void  operator delete[](void* ptr, void*) noexcept;
 #endif
 
 #if defined(__cpp_sized_deallocation) && __cpp_sized_deallocation >= 201309L
-#  define _LIBCPP_HAS_LANGUAGE_SIZED_DEALLOCATION 1
-#else
-#  define _LIBCPP_HAS_LANGUAGE_SIZED_DEALLOCATION 0
-#endif
-
-#if _LIBCPP_STD_VER >= 14 || _LIBCPP_HAS_LANGUAGE_SIZED_DEALLOCATION
-#  define _LIBCPP_HAS_LIBRARY_SIZED_DEALLOCATION 1
-#else
-#  define _LIBCPP_HAS_LIBRARY_SIZED_DEALLOCATION 0
-#endif
-
-#if _LIBCPP_HAS_LIBRARY_SIZED_DEALLOCATION && _LIBCPP_HAS_LANGUAGE_SIZED_DEALLOCATION
 #  define _LIBCPP_HAS_SIZED_DEALLOCATION 1
 #else
 #  define _LIBCPP_HAS_SIZED_DEALLOCATION 0
@@ -214,7 +202,7 @@ inline constexpr destroying_delete_t destroying_delete{};
     _LIBCPP_NOALIAS;
 _LIBCPP_OVERRIDABLE_FUNC_VIS void operator delete(void* __p) _NOEXCEPT;
 _LIBCPP_OVERRIDABLE_FUNC_VIS void operator delete(void* __p, const std::nothrow_t&) _NOEXCEPT;
-#  if _LIBCPP_HAS_LIBRARY_SIZED_DEALLOCATION
+#  if _LIBCPP_HAS_SIZED_DEALLOCATION
 _LIBCPP_OVERRIDABLE_FUNC_VIS void operator delete(void* __p, std::size_t __sz) _NOEXCEPT;
 #  endif
 
@@ -223,7 +211,7 @@ _LIBCPP_OVERRIDABLE_FUNC_VIS void operator delete(void* __p, std::size_t __sz) _
     _LIBCPP_NOALIAS;
 _LIBCPP_OVERRIDABLE_FUNC_VIS void operator delete[](void* __p) _NOEXCEPT;
 _LIBCPP_OVERRIDABLE_FUNC_VIS void operator delete[](void* __p, const std::nothrow_t&) _NOEXCEPT;
-#  if _LIBCPP_HAS_LIBRARY_SIZED_DEALLOCATION
+#  if _LIBCPP_HAS_SIZED_DEALLOCATION
 _LIBCPP_OVERRIDABLE_FUNC_VIS void operator delete[](void* __p, std::size_t __sz) _NOEXCEPT;
 #  endif
 
@@ -233,7 +221,7 @@ _LIBCPP_OVERRIDABLE_FUNC_VIS void operator delete[](void* __p, std::size_t __sz)
 operator new(std::size_t __sz, std::align_val_t, const std::nothrow_t&) _NOEXCEPT _LIBCPP_NOALIAS;
 _LIBCPP_OVERRIDABLE_FUNC_VIS void operator delete(void* __p, std::align_val_t) _NOEXCEPT;
 _LIBCPP_OVERRIDABLE_FUNC_VIS void operator delete(void* __p, std::align_val_t, const std::nothrow_t&) _NOEXCEPT;
-#    if _LIBCPP_HAS_LIBRARY_SIZED_DEALLOCATION
+#    if _LIBCPP_HAS_SIZED_DEALLOCATION
 _LIBCPP_OVERRIDABLE_FUNC_VIS void operator delete(void* __p, std::size_t __sz, std::align_val_t) _NOEXCEPT;
 #    endif
 
@@ -243,7 +231,7 @@ operator new[](std::size_t __sz, std::align_val_t) _THROW_BAD_ALLOC;
 operator new[](std::size_t __sz, std::align_val_t, const std::nothrow_t&) _NOEXCEPT _LIBCPP_NOALIAS;
 _LIBCPP_OVERRIDABLE_FUNC_VIS void operator delete[](void* __p, std::align_val_t) _NOEXCEPT;
 _LIBCPP_OVERRIDABLE_FUNC_VIS void operator delete[](void* __p, std::align_val_t, const std::nothrow_t&) _NOEXCEPT;
-#    if _LIBCPP_HAS_LIBRARY_SIZED_DEALLOCATION
+#    if _LIBCPP_HAS_SIZED_DEALLOCATION
 _LIBCPP_OVERRIDABLE_FUNC_VIS void operator delete[](void* __p, std::size_t __sz, std::align_val_t) _NOEXCEPT;
 #    endif
 #  endif

libcxxabi/src/CMakeLists.txt

@@ -184,6 +184,10 @@ if (CMAKE_POSITION_INDEPENDENT_CODE OR NOT DEFINED CMAKE_POSITION_INDEPENDENT_CO
 endif()
 target_compile_options(cxxabi_shared_objects PRIVATE "${LIBCXXABI_ADDITIONAL_COMPILE_FLAGS}")
 
+# Build with -fsized-deallocation, which is default in recent versions of Clang.
+# TODO(LLVM 21): This can be dropped once we only support Clang >= 19.
+target_add_compile_flags_if_supported(cxxabi_shared_objcts PRIVATE -fsized-deallocation)
+
 add_library(cxxabi_shared SHARED)
 set_target_properties(cxxabi_shared
   PROPERTIES
@@ -275,6 +279,10 @@ set_target_properties(cxxabi_static_objects
 )
 target_compile_options(cxxabi_static_objects PRIVATE "${LIBCXXABI_ADDITIONAL_COMPILE_FLAGS}")
 
+# Build with -fsized-deallocation, which is default in recent versions of Clang.
+# TODO(LLVM 21): This can be dropped once we only support Clang >= 19.
+target_add_compile_flags_if_supported(cxxabi_static_objcts PRIVATE -fsized-deallocation)
+
 if(LIBCXXABI_HERMETIC_STATIC_LIBRARY)
   target_add_compile_flags_if_supported(cxxabi_static_objects PRIVATE -fvisibility=hidden)
   # If the hermetic library doesn't define the operator new/delete functions