From e67c757c7cdd1837008e573295e87e3ebec5382d Mon Sep 17 00:00:00 2001
From: Ian Anderson <iana@apple.com>
Date: Tue, 26 Mar 2024 16:19:38 -0700
Subject: [PATCH] [Headers] Don't declare unreachable() from stddef.h in C++
Even if __need_unreachable is set, stddef.h should not declare unreachable() in C++ because it conflicts with the declaration in <utility>.
---
clang/lib/Headers/__stddef_unreachable.h | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/clang/lib/Headers/__stddef_unreachable.h b/clang/lib/Headers/__stddef_unreachable.h
index 518580c92d3f5..61df43e9732f8 100644
--- a/clang/lib/Headers/__stddef_unreachable.h
+++ b/clang/lib/Headers/__stddef_unreachable.h
@@ -7,6 +7,8 @@
*===-----------------------------------------------------------------------===
*/
+#ifndef __cplusplus
+
/*
* When -fbuiltin-headers-in-system-modules is set this is a non-modular header
* and needs to behave as if it was textual.
@@ -15,3 +17,5 @@
(__has_feature(modules) && !__building_module(_Builtin_stddef))
#define unreachable() __builtin_unreachable()
#endif
+
+#endif