[libcxx-commits] [libcxx] [libc++] stddef.h needs to #include_next for the new clang __need_ macros (PR #86252)

[Ian Anderson via libcxx-commits]

https://github.com/ian-twilightcoder created https://github.com/llvm/llvm-project/pull/86252

clang added several __need_ macros to stddef.h that need to be added to the libc++ version as well. clang will also re-enter stddef.h to define rsize_t if __STDC_WANT_LIB_EXT1__ is set, do that in the libc++ one too.

>From 9ac771904c89338af99dda13ee24a91cb30296bc Mon Sep 17 00:00:00 2001
From: Ian Anderson <iana at apple.com>
Date: Thu, 21 Mar 2024 23:45:55 -0700
Subject: [PATCH] [libc++] stddef.h needs to #include_next for the new clang
 __need_ macros

clang added several __need_ macros to stddef.h that need to be added to the libc++ version as well. clang will also re-enter stddef.h to define rsize_t if __STDC_WANT_LIB_EXT1__ is set, do that in the libc++ one too.
---
 libcxx/include/stddef.h | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/libcxx/include/stddef.h b/libcxx/include/stddef.h
index 887776b150e49d..a3acf0ff10d1b6 100644
--- a/libcxx/include/stddef.h
+++ b/libcxx/include/stddef.h
@@ -7,8 +7,9 @@
 //
 //===----------------------------------------------------------------------===//
 
-#if defined(__need_ptrdiff_t) || defined(__need_size_t) || defined(__need_wchar_t) || defined(__need_NULL) ||          \
-    defined(__need_wint_t)
+#if defined(__need_ptrdiff_t) || defined(__need_size_t) || defined(__need_rsize_t) || defined(__need_wchar_t) ||       \
+    defined(__need_NULL) || defined(__need_nullptr_t) || defined(__need_unreachable) || defined(__need_max_align_t) || \
+    defined(__need_offsetof) || defined(__need_wint_t)
 
 #  if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #    pragma GCC system_header
@@ -16,7 +17,7 @@
 
 #  include_next <stddef.h>
 
-#elif !defined(_LIBCPP_STDDEF_H)
+#elif !defined(_LIBCPP_STDDEF_H) || (defined(__STDC_WANT_LIB_EXT1__) && __STDC_WANT_LIB_EXT1__ >= 1)
 #  define _LIBCPP_STDDEF_H
 
 /*