From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.org/gmane.linux.lib.musl.general/7406 Path: news.gmane.org!not-for-mail From: Szabolcs Nagy Newsgroups: gmane.linux.lib.musl.general Subject: Re: Explicit casts in ctype.h suppress compiler warnings Date: Fri, 17 Apr 2015 20:35:12 +0200 Message-ID: <20150417183511.GJ2875@port70.net> References: <1429289394.7038.3.camel@inria.fr> <20150417165238.GA6817@brightrain.aerifal.cx> Reply-To: musl@lists.openwall.com NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: ger.gmane.org 1429295726 5975 80.91.229.3 (17 Apr 2015 18:35:26 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Fri, 17 Apr 2015 18:35:26 +0000 (UTC) To: musl@lists.openwall.com Original-X-From: musl-return-7419-gllmg-musl=m.gmane.org@lists.openwall.com Fri Apr 17 20:35:26 2015 Return-path: Envelope-to: gllmg-musl@m.gmane.org Original-Received: from mother.openwall.net ([195.42.179.200]) by plane.gmane.org with smtp (Exim 4.69) (envelope-from ) id 1YjB6s-0003hI-2O for gllmg-musl@m.gmane.org; Fri, 17 Apr 2015 20:35:26 +0200 Original-Received: (qmail 27738 invoked by uid 550); 17 Apr 2015 18:35:24 -0000 Mailing-List: contact musl-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: Original-Received: (qmail 27711 invoked from network); 17 Apr 2015 18:35:24 -0000 Mail-Followup-To: musl@lists.openwall.com Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.23 (2014-03-12) Xref: news.gmane.org gmane.linux.lib.musl.general:7406 Archived-At: * Alexander Monakov [2015-04-17 21:24:09 +0300]: > > I confirm that the idea works, and as Rich said it causes a warning with > -pedantic -std=c89 with gcc-4.5..4.7 (but not 4.8, 4.9). > i assume we could use compound literals in c89 with __extension__ > > Do you have an idea in mind for how we could achieve that? I suspect > > the macros are still better optimizable than the inline function > > approach, so I'd lean towards doing a macro that avoids evaluating c > > and just checks its type, which would involve using ?: I think. > > I admit I was thinking of doing isspace-style inlines everywhere, but thanks > to your suggestion I was able to come up with this: > > static __inline void __is_int(int a) {} > #define isdigit(a) (__is_int(0?(a):0), ((unsigned)(a)-'0') < 10) > i think using :0 there is not useful because null pointer constants are special in ?: i think rich meant something like #define isdigit(a) (((0?1U:(a))-'0') < 10) which works when the conversion rank of a is <= unsigned