[libcxx-commits] [libcxx] [libc++] Fix -Wgnu-include-next in stddef.h (PR #88214)

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llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-libcxx

Author: Louis Dionne (ldionne)

<details>
<summary>Changes</summary>

As reported in #<!-- -->86843, we must have #pragma GCC system_header before we use #include_next, otherwise the compiler may not understand that we're in a system header and may issue a diagnostic for our usage of

---
Full diff: https://github.com/llvm/llvm-project/pull/88214.diff


1 Files Affected:

- (modified) libcxx/include/stddef.h (+4-4) 


``````````diff
diff --git a/libcxx/include/stddef.h b/libcxx/include/stddef.h
index 470b5408336c6d..1583e78e3739ba 100644
--- a/libcxx/include/stddef.h
+++ b/libcxx/include/stddef.h
@@ -26,6 +26,10 @@
 
 #include <__config>
 
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
 // Note: This include is outside of header guards because we sometimes get included multiple times
 //       with different defines and the underlying <stddef.h> will know how to deal with that.
 #include_next <stddef.h>
@@ -33,10 +37,6 @@
 #ifndef _LIBCPP_STDDEF_H
 #  define _LIBCPP_STDDEF_H
 
-#  if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#    pragma GCC system_header
-#  endif
-
 #  ifdef __cplusplus
 typedef decltype(nullptr) nullptr_t;
 #  endif

``````````

</details>


https://github.com/llvm/llvm-project/pull/88214