----- On Jun 3, 2020, at 8:31 AM, Florian Weimer fweimer@xxxxxxxxxx wrote: > * Mathieu Desnoyers: > >> ----- On Jun 3, 2020, at 8:05 AM, Florian Weimer fweimer@xxxxxxxxxx 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) I think I found the culprit: it should be: __rseq_alignas (32) uint32_t version; rather than the other way around. > >>> 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, so I just remove the __rseq_alignas for now and use "aligned()" instead like the UAPI header. I plan to keep the other macros for now. >> >> 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. OK, Thanks! Mathieu > > Thanks, > Florian -- Mathieu Desnoyers EfficiOS Inc. http://www.efficios.com
