On Thu, 31 Aug 2023 at 13:33, Ken Matsui <kmat...@cs.washington.edu> wrote: > > On Tue, Aug 8, 2023 at 1:23 PM Jonathan Wakely <jwak...@redhat.com> wrote: > > > > > > > > On Wed, 19 Jul 2023 at 20:33, Ken Matsui via Libstdc++ > > <libstd...@gcc.gnu.org> wrote: > >> > >> This patch defines _GLIBCXX_HAS_BUILTIN_TRAIT macro, which will be used > >> as a flag to toggle the use of built-in traits in the type_traits header > >> through _GLIBCXX_NO_BUILTIN_TRAITS macro, without needing to modify the > >> source code. > >> > >> libstdc++-v3/ChangeLog: > >> > >> * include/bits/c++config (_GLIBCXX_HAS_BUILTIN_TRAIT): Define. > >> (_GLIBCXX_HAS_BUILTIN): Keep defined. > > > > > > I think this would be a little better as: > > > > * include/bits/c++config (_GLIBCXX_HAS_BUILTIN): Do not undef. > > (_GLIBCXX_HAS_BUILTIN_TRAIT): Define. > > > > OK for trunk with that change, thanks. > > > Thank you for your review! Patrick and I were discussing the naming > conventions for the macros _GLIBCXX_HAS_BUILTIN_TRAIT and > _GLIBCXX_NO_BUILTIN_TRAITS. It was brought to our attention that these > namings might be ambiguous, as there are implementations that have > corresponding built-ins but do not have fallback. Therefore, we > believe that using _GLIBCXX_USE_BUILTIN_TRAIT instead of > _GLIBCXX_HAS_BUILTIN_TRAIT would be more appropriate. Similarly, we > think that _GLIBCXX_AVOID_BUILTIN_TRAITS would be a better choice than > _GLIBCXX_NO_BUILTIN_TRAITS, as the latter implies that there are no > built-ins, when in fact it is meant to express that the use of > built-ins should be avoided when defining this macro. Could you please > let me know your thoughts on these updated namings?
Yes, I agree that makes sense. I think personally I'd go with "DISABLE" instead of "AVOID", or even "DO_NOT_USE" (to mirror "USE" in the macro for individual traits), but either is OK. > > > >> > >> > >> Signed-off-by: Ken Matsui <kmat...@gcc.gnu.org> > >> --- > >> libstdc++-v3/include/bits/c++config | 10 +++++++++- > >> 1 file changed, 9 insertions(+), 1 deletion(-) > >> > >> diff --git a/libstdc++-v3/include/bits/c++config > >> b/libstdc++-v3/include/bits/c++config > >> index dd47f274d5f..984985d6fff 100644 > >> --- a/libstdc++-v3/include/bits/c++config > >> +++ b/libstdc++-v3/include/bits/c++config > >> @@ -854,7 +854,15 @@ namespace __gnu_cxx > >> # define _GLIBCXX_HAVE_BUILTIN_LAUNDER 1 > >> #endif > >> > >> -#undef _GLIBCXX_HAS_BUILTIN > >> +// Returns 1 if _GLIBCXX_NO_BUILTIN_TRAITS is not defined and the compiler > >> +// has a corresponding built-in type trait, 0 otherwise. > >> +// _GLIBCXX_NO_BUILTIN_TRAITS can be defined to disable the use of > >> built-in > >> +// traits. > >> +#ifndef _GLIBCXX_NO_BUILTIN_TRAITS > >> +# define _GLIBCXX_HAS_BUILTIN_TRAIT(BT) _GLIBCXX_HAS_BUILTIN(BT) > >> +#else > >> +# define _GLIBCXX_HAS_BUILTIN_TRAIT(BT) 0 > >> +#endif > >> > >> // Mark code that should be ignored by the compiler, but seen by Doxygen. > >> #define _GLIBCXX_DOXYGEN_ONLY(X) > >> -- > >> 2.41.0 > >> >
