From: Marek Polacek <polacek@redhat.com>
To: Jonathan Wakely <jwakely@redhat.com>
Cc: libstdc++@gcc.gnu.org, gcc-patches@gcc.gnu.org,
Jason Merrill <jason@redhat.com>
Subject: Re: [PATCH] c++: Enable __has_builtin for new reference binding built-ins
Date: Tue, 19 Jul 2022 09:30:32 -0400 [thread overview]
Message-ID: <Ytax+P/2oPc8m9su@redhat.com> (raw)
In-Reply-To: <20220719131102.2469016-1-jwakely@redhat.com>
On Tue, Jul 19, 2022 at 02:11:02PM +0100, Jonathan Wakely wrote:
> Tested x86_64-linux, OK for trunk?
>
> -- >8 --
>
> The new built-ins need to be detectable using __has_builtin, and the
> library should use that to check for them.
>
> This fixes an error with Clang when C++23 is enabled.
LGTM but can't approve.
Thanks and sorry for missing this!
> gcc/cp/ChangeLog:
>
> * cp-objcp-common.cc (names_builtin_p): Return true for
> RID_REF_CONSTRUCTS_FROM_TEMPORARY and
> RID_REF_CONVERTS_FROM_TEMPORARY.
>
> libstdc++-v3/ChangeLog:
>
> * include/std/type_traits (__cpp_lib_reference_from_temporary)
> (reference_constructs_from_temporary)
> (reference_converts_from_temporary): Only define when the
> built-ins are available.
> ---
> gcc/cp/cp-objcp-common.cc | 2 ++
> libstdc++-v3/include/std/type_traits | 4 ++++
> 2 files changed, 6 insertions(+)
>
> diff --git a/gcc/cp/cp-objcp-common.cc b/gcc/cp/cp-objcp-common.cc
> index 0b70d5567e4..4079a4b4aec 100644
> --- a/gcc/cp/cp-objcp-common.cc
> +++ b/gcc/cp/cp-objcp-common.cc
> @@ -461,6 +461,8 @@ names_builtin_p (const char *name)
> case RID_IS_ASSIGNABLE:
> case RID_IS_CONSTRUCTIBLE:
> case RID_UNDERLYING_TYPE:
> + case RID_REF_CONSTRUCTS_FROM_TEMPORARY:
> + case RID_REF_CONVERTS_FROM_TEMPORARY:
> return true;
> default:
> break;
> diff --git a/libstdc++-v3/include/std/type_traits b/libstdc++-v3/include/std/type_traits
> index b1a1deecf66..14b029cec64 100644
> --- a/libstdc++-v3/include/std/type_traits
> +++ b/libstdc++-v3/include/std/type_traits
> @@ -3505,6 +3505,9 @@ template<typename _Ret, typename _Fn, typename... _Args>
> template<typename _Tp>
> inline constexpr bool is_scoped_enum_v = is_scoped_enum<_Tp>::value;
>
> +#if __has_builtin(__reference_constructs_from_temporary) \
> + && __has_builtin(__reference_converts_from_temporary)
> +
> #define __cpp_lib_reference_from_temporary 202202L
>
> /// True if _Tp is a reference type, a _Up value can be bound to _Tp in
> @@ -3544,6 +3547,7 @@ template<typename _Ret, typename _Fn, typename... _Args>
> template<typename _Tp, typename _Up>
> inline constexpr bool reference_converts_from_temporary_v
> = reference_converts_from_temporary<_Tp, _Up>::value;
> +#endif // __has_builtin for reference_from_temporary
> #endif // C++23
>
> #if _GLIBCXX_HAVE_IS_CONSTANT_EVALUATED
> --
> 2.34.3
>
Marek
next prev parent reply other threads:[~2022-07-19 13:30 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-07-19 13:11 Jonathan Wakely
2022-07-19 13:30 ` Marek Polacek [this message]
2022-07-19 14:05 ` Jason Merrill
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