[Bug c++/94753] -undef, c++20 and feature-test macros
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94753 --- Comment #5 from Andrew Pinski --- I will change the testcase's comment to be: ``` For C++11+ __cpp_constexpr and __cpp_static_assert GCC define these even with -undef. ``` The feature macros as mentioned by Jonathan, we want them defined almost everywhere including in older versions of C++, my patch still implements that. The comment in the testcase might be confusing since feature macros were not in C++11 but we should still define them for C++11.
[Bug c++/94753] -undef, c++20 and feature-test macros
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94753 --- Comment #4 from Jonathan Wakely --- Maybe I've misunderstood you, but the feature test macros for C++11 features should definitely be defined for C++11. They're not "system-specific" or "GCC-specific". Just because they weren't in the standard prior to C++20 doesn't mean they shouldn't be defined when the corresponding feature is supported.
[Bug c++/94753] -undef, c++20 and feature-test macros
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94753 --- Comment #3 from r_new at rambler dot ru --- Don't know gcc code, but /* For C++11+ __cpp_constexpr and __cpp_static_assert should be defined. */ #if __cplusplus >= 201103L is not true. All standard predefined macros listed in chapter "16.8 Predefined macro names" C++11 standard. But for C++20 it's true.
[Bug c++/94753] -undef, c++20 and feature-test macros
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94753 --- Comment #2 from Andrew Pinski --- Created attachment 58030 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=58030&action=edit Patch which I am testing I am testing this patch and will be submitting it for GCC 15.
[Bug c++/94753] -undef, c++20 and feature-test macros
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94753 Andrew Pinski changed: What|Removed |Added Status|NEW |ASSIGNED Assignee|unassigned at gcc dot gnu.org |pinskia at gcc dot gnu.org --- Comment #1 from Andrew Pinski --- I am going to fix this for GCC 15. The check for -undef is done way to early it seems in c_cpp_builtins . Basically the code to define the feature macros need to be moved to before that check. The reason why __cplusplus works is because that is done via libcpp rather than from the front-end.
