[libcxx-commits] [libcxx] [libcxxabi] [libc++] Simplify when the sized global deallocations overloads are available (PR #114667)

[Nikolas Klauser via libcxx-commits]

https://github.com/philnik777 updated https://github.com/llvm/llvm-project/pull/114667

>From 4895ef2a80b580285e2079a7df5c119de8f593fa Mon Sep 17 00:00:00 2001
From: Nikolas Klauser <nikolasklauser at berlin.de>
Date: Sat, 2 Nov 2024 14:41:22 +0100
Subject: [PATCH] [libc++] Simplify when the sized global deallocations
 overloads are available

---
 libcxx/include/new           | 20 ++++----------------
 libcxxabi/src/CMakeLists.txt |  8 ++++++++
 2 files changed, 12 insertions(+), 16 deletions(-)

diff --git a/libcxx/include/new b/libcxx/include/new
index 49e500809e158f..96d4c226a65e37 100644
--- a/libcxx/include/new
+++ b/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
diff --git a/libcxxabi/src/CMakeLists.txt b/libcxxabi/src/CMakeLists.txt
index 84fe2784bec5ca..c824e5c4a47f5f 100644
--- a/libcxxabi/src/CMakeLists.txt
+++ b/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