On Mon, Jul 31, 2017 at 10:53 AM, Jonathan Wakely <jwak...@redhat.com> wrote: > On 27/07/17 16:27 +0900, Katsuhiko Nishimra wrote: >> >> From 56c4a18d0d8c8ce7aa1239880138775e4db06645 Mon Sep 17 00:00:00 2001 >> From: Katsuhiko Nishimra <ktns...@gmail.com> >> Date: Thu, 27 Jul 2017 16:03:54 +0900 >> Subject: [PATCH] libstdc++: Support std::is_aggregate on clang++ >> >> Currently, libstdc++ tries to detect __is_aggregate built-in macro using >> __has_builtin, but this fails on clang++ because __has_builtin on >> clang++ detects only built-in functions, not built-in macros. This patch >> adds a test using __is_identifier. Tested on clang++ >> 5.0.0-svn308422-1~exp1 and g++ 7.1.0-10 from Debian unstable. >> --- >> libstdc++-v3/include/std/type_traits | 5 +++++ >> 1 file changed, 5 insertions(+) >> >> diff --git a/libstdc++-v3/include/std/type_traits >> b/libstdc++-v3/include/std/type_traits >> index 390b6f40a..e7ec402fb 100644 >> --- a/libstdc++-v3/include/std/type_traits >> +++ b/libstdc++-v3/include/std/type_traits >> @@ -2894,6 +2894,11 @@ template <typename _From, typename _To> >> >> #if __GNUC__ >= 7 >> # define _GLIBCXX_HAVE_BUILTIN_IS_AGGREGATE 1 >> +#elif defined(__is_identifier) >> +// For clang >> +# if ! __is_identifier(__is_aggregate) >> +# define _GLIBCXX_HAVE_BUILTIN_IS_AGGREGATE 1 >> +# endif >> #elif defined __has_builtin >> // For non-GNU compilers: >> # if __has_builtin(__is_aggregate) > > > This __has_bultin check only exists for Clang, so should be replaced > by the correct __is_identifier check, not left there in addition to > it. > >
https://clang.llvm.org/docs/LanguageExtensions.html#checks-for-type-trait-primitives seems to suggest using __has_extension instead.
