* Mathieu Desnoyers: > ----- On Jun 3, 2020, at 8:05 AM, Florian Weimer fwei...@redhat.com wrote: > >> * Mathieu Desnoyers: >> >>> +#ifdef __cplusplus >>> +# if __cplusplus >= 201103L >>> +# define __rseq_static_assert(expr, diagnostic) static_assert (expr, >>> diagnostic) >>> +# define __rseq_alignof(type) alignof (type) >>> +# define __rseq_alignas(x) alignas (x) >>> +# define __rseq_tls_storage_class thread_local >>> +# endif >>> +#elif (defined __STDC_VERSION__ ? __STDC_VERSION__ : 0) >= 201112L >>> +# define __rseq_static_assert(expr, diagnostic) _Static_assert (expr, >>> diagnostic) >>> +# define __rseq_alignof(type) _Alignof (type) >>> +# define __rseq_alignas(x) _Alignas (x) >>> +# define __rseq_tls_storage_class _Thread_local >>> +#endif >> >> This does not seem to work. I get this with GCC 9: >> >> In file included from /tmp/cih_test_gsrKbC.cc:8:0: >> ../sysdeps/unix/sysv/linux/sys/rseq.h:42:50: error: attribute ignored >> [-Werror=attributes] >> # define __rseq_alignas(x) alignas (x) >> ^ >> ../sysdeps/unix/sysv/linux/sys/rseq.h:122:14: note: in expansion of macro >> ‘__rseq_alignas’ >> uint32_t __rseq_alignas (32) version; >> ^ > > Is that when compiling C or C++ code ? If it's C code, I would expect > "_Alignas" to be used, not "alignas". > > Which exact version of gcc do you use ?
C++ code. CXX was set to this compiler at configure time: gcc version 9.3.1 20200408 (Red Hat 9.3.1-2) (GCC) >> In any case, these changes really have to go into the UAPI header first. >> Only the __thread handling should remain. Otherwise, we'll have a tough >> situation on our hands changing the UAPI header, without introducing >> macro definition conflicts. I'd suggest to stick to the aligned >> attribute for the time being, like the current UAPI headers. > > OK. Should I do that in a separate patch, or you do it on top of my patchset, > or should I re-spin another round of the series ? I think the initial commit should mirror the current UAPI header contents. Keep the macros for the UAPI patch though. 8-) We can pick up these changes once they have been merged into Linux. Thanks, Florian
