From mboxrd@z Thu Jan 1 00:00:00 1970 From: Julien Grall Subject: Re: [PATCH for-4.6] xen/public: arm: Use __typeof__ rather than typeof Date: Fri, 23 Oct 2015 15:44:01 +0100 Message-ID: <562A47B1.7030400@citrix.com> References: <1443986642-24392-1-git-send-email-julien.grall@citrix.com> <562A3295.6010901@citrix.com> <1445607059.2374.165.camel@citrix.com> <562A57D902000078000AE2A2@prv-mh.provo.novell.com> <562A3D0D.3000806@citrix.com> <562A5D4402000078000AE310@prv-mh.provo.novell.com> <1445610702.2374.199.camel@citrix.com> <562A625102000078000AE347@prv-mh.provo.novell.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail6.bemta5.messagelabs.com ([195.245.231.135]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1Zpdax-0004hX-BK for xen-devel@lists.xenproject.org; Fri, 23 Oct 2015 14:45:27 +0000 In-Reply-To: <562A625102000078000AE347@prv-mh.provo.novell.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Jan Beulich , Ian Campbell Cc: Ian Jackson , Tim Deegan , Keir Fraser , Wei.Liu2@citrix.com, xen-devel@lists.xenproject.org List-Id: xen-devel@lists.xenproject.org On 23/10/15 15:37, Jan Beulich wrote: >>>> On 23.10.15 at 16:31, wrote: >> On Fri, 2015-10-23 at 08:16 -0600, Jan Beulich wrote: >>> No, the validating script is a nice-to-have, but nothing more. What >>> I was referring to was a patch to drop the use of this gcc extension. >> >> Then I'm confused. This patch turns a typeof into a __typeof__. In < >> 56126D8702000078000A80AC@prv-mh.provo.novell.com> you said "typeof() is a >> gcc extension". >> >> Are you now saying that __typeof__ also a gcc extension too? >> >> I was under the impression that __typeof__ was standard (by some cxx at >> least) and your mail reinforced that (possibly wrong) impression. > > There's no typeof or __typeof__ in C11 or any earlier standard. > I'm sorry if earlier replies of mine gave a different impression. > >> https://gcc.gnu.org/onlinedocs/gcc/Typeof.html also says that "If you are >> writing a header file that must work when included in ISO C programs, write >> __typeof__ instead of typeof", which also lead me to believe __typeof__ was >> OK from this PoV. > > That's solely to prevent name space issues - __typeof__ is a > reserved name, while typeof isn't. Thank you for the explanation. I think we can do the same as x86 does i.e: #define set_xen_guest_handle_raw(hnd, val) \ do { if ( sizeof(hnd) == 8 ) *(uint64_t *)&(hnd) = 0; \ (hnd).p = val; \ } while ( 0 ) I will send a new version of this patch. Regards, -- Julien Grall