From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.org/gmane.linux.lib.musl.general/2761 Path: news.gmane.org!not-for-mail From: Rich Felker Newsgroups: gmane.linux.lib.musl.general Subject: Re: printf warning with uintmax_t Date: Sat, 9 Feb 2013 08:24:00 -0500 Message-ID: <20130209132400.GO20323@brightrain.aerifal.cx> References: <1360361439.23424.95.camel@eris.loria.fr> <20130208221408.GN20323@brightrain.aerifal.cx> <1360398900.23424.151.camel@eris.loria.fr> <20130209120318.GY6181@port70.net> 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 1360416251 14447 80.91.229.3 (9 Feb 2013 13:24:11 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Sat, 9 Feb 2013 13:24:11 +0000 (UTC) To: musl@lists.openwall.com Original-X-From: musl-return-2762-gllmg-musl=m.gmane.org@lists.openwall.com Sat Feb 09 14:24:33 2013 Return-path: Envelope-to: gllmg-musl@plane.gmane.org Original-Received: from mother.openwall.net ([195.42.179.200]) by plane.gmane.org with smtp (Exim 4.69) (envelope-from ) id 1U4APx-0003pV-31 for gllmg-musl@plane.gmane.org; Sat, 09 Feb 2013 14:24:33 +0100 Original-Received: (qmail 9387 invoked by uid 550); 9 Feb 2013 13:24:13 -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 9379 invoked from network); 9 Feb 2013 13:24:13 -0000 Content-Disposition: inline In-Reply-To: <20130209120318.GY6181@port70.net> User-Agent: Mutt/1.5.21 (2010-09-15) Xref: news.gmane.org gmane.linux.lib.musl.general:2761 Archived-At: On Sat, Feb 09, 2013 at 01:03:19PM +0100, Szabolcs Nagy wrote: > * Jens Gustedt [2013-02-09 09:35:00 +0100]: > > Am Freitag, den 08.02.2013, 17:14 -0500 schrieb Rich Felker: > > > It looks like we're not matching the ABI convention gcc expects, where > > > [u]intmax_t is the lowest-rank type capable of storing the full > > > integer range (i.e. long on 64-bit systems). > > > > I didn't check how you do this in musl, but for me gcc without any > > includes has > > > > #define __INTMAX_TYPE__ long int > > > > so I guess that macro is just what should be taken to match its > > expectations for printf formats. You still could have a fallback for > > compilers that don't provide this. I checked for clang and it does, > > BTW. > > tcc, pcc, cparse (the firm frontend) does not define __INTMAX_TYPE__ > and clang blindly follows gcc > > there may be various possible definitions for intmax_t, assuming > a given abi, and the compiler has no business knowing which one is > choosen by the libc > > of course printf format checking, c++ and c11 generics with builtin > intmax_t functions change that Indeed. The underlying type of all typedefs is part of the ABI if you're considering C++. > i think it's better if the intmax_t definition is fixed for a given > abi (so libc can define it without consulting the compiler), but > just like with __WCHAR_TYPE__ it may be ifdefed: if __INTMAX_TYPE__ Actually I believe the current treatment of __WCHAR_TYPE__ is wrong, isn't it? It should not vary between compilers on a given arch/abi combination. I suspect the code in i386 alltypes.h now is leftover cruft from when the type was first fixed, when I didn't understand the ABI requirements well. > is defined then use that otherwise a default (however that adds an > extra branch in the preprocessor for no good reason: it may change > from compiler to compiler but it should not, the compilers should > agree on something here) > > once this is sorted out inttypes.h should be fixed as well I think [u]intmax_t should just be moved back to alltypes.h with the correct per-arch definitions. A related issue is the limit values. Right now, UINTMAX_MAX is just defined as UINT64_MAX, but the type of the latter is wrong (always ULL). We could either move them to bits, use some #ifdef magic to get them right based on the assumption that all archs use the lowest-rank type of the needed size (is this correct?), or if that assumption is incorrect we could just omit the suffixes like ULL and let the compiler choose the appropriate type for the hex constants. This may generate warnings with some bogus gcc versions or modes, though... Rich