https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66970
--- Comment #11 from Jonathan Wakely <redi at gcc dot gnu.org> --- (In reply to felix from comment #7) > I made the feature closely mimic The Other Compiler's behaviour: only > function built-ins are recognised. This includes generic functions like > __builtin_add_overflow and C library functions specially handled by the > front-end like printf (unless -fno-builtin is used), but excludes types like > __builtin_va_list and function-like constructs (implemented as keywords) > like __builtin_offsetof and __builtin_types_compatible_p. This is not so > much of a problem for them, since they also provide __has_feature(), > __has_extension() and __is_identifier() macros. I hate that behaviour. Having to use !__is_identifier(__builtin_launder) is confusing (and not just to me, but to developers of LLVM's own libc++, who I've had to explain the problem to). But consistency with Clang is probably more important than making __has_builtin behave sanely.
