From: Jonathan Wakely <jwakely@redhat.com>
Date: Thu, 8 Feb 2024 15:38:35 +0000 (+0000)
Subject: libstdc++: Guard tr2::bases and tr2::direct_bases with __has_builtin
X-Git-Tag: basepoints/gcc-15~1251
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=5fb204aaf34b68c427f5b2bfb933fed72fe3eafb;p=thirdparty%2Fgcc.git

libstdc++: Guard tr2::bases and tr2::direct_bases with __has_builtin

These non-standard extensions use GCC-specific built-ins. Use
__has_builtin to avoid errors when Clang compiles this header.

See https://github.com/llvm/llvm-project/issues/24289

libstdc++-v3/ChangeLog:

	* include/tr2/type_traits (bases, direct_bases): Use
	__has_builtin to check if required built-ins are supported.
---

diff --git a/libstdc++-v3/include/tr2/type_traits b/libstdc++-v3/include/tr2/type_traits
index a7ebaf669471..603039de8947 100644
--- a/libstdc++-v3/include/tr2/type_traits
+++ b/libstdc++-v3/include/tr2/type_traits
@@ -82,20 +82,23 @@ namespace tr2
   /// Sequence abstraction metafunctions for manipulating a typelist.
 
 
-
+#if __has_builtin(__bases)
   /// Enumerate all the base classes of a class. Form of a typelist.
   template<typename _Tp>
     struct bases
     {
       typedef __reflection_typelist<__bases(_Tp)...>		type;
     };
+#endif
 
+#if __has_builtin(__direct_bases)
   /// Enumerate all the direct base classes of a class. Form of a typelist.
   template<typename _Tp>
     struct direct_bases
     {
       typedef __reflection_typelist<__direct_bases(_Tp)...>	type;
     };
+#endif
 
   /// @} group metaprogramming
 }