From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.org/gmane.linux.lib.musl.general/6700 Path: news.gmane.org!not-for-mail From: Rich Felker Newsgroups: gmane.linux.lib.musl.general Subject: Re: pthread_equal Date: Mon, 8 Dec 2014 11:25:09 -0500 Message-ID: <20141208162509.GI4574@brightrain.aerifal.cx> References: <1418049745.15892.10.camel@posteo.de> <20141208145604.GC4574@brightrain.aerifal.cx> <1418055521.15892.16.camel@posteo.de> Reply-To: musl@lists.openwall.com NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Trace: ger.gmane.org 1418055929 11136 80.91.229.3 (8 Dec 2014 16:25:29 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Mon, 8 Dec 2014 16:25:29 +0000 (UTC) To: musl@lists.openwall.com Original-X-From: musl-return-6713-gllmg-musl=m.gmane.org@lists.openwall.com Mon Dec 08 17:25:23 2014 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 1Xy17j-0003Ki-7Q for gllmg-musl@m.gmane.org; Mon, 08 Dec 2014 17:25:23 +0100 Original-Received: (qmail 26250 invoked by uid 550); 8 Dec 2014 16:25:22 -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 26233 invoked from network); 8 Dec 2014 16:25:21 -0000 Content-Disposition: inline In-Reply-To: <1418055521.15892.16.camel@posteo.de> User-Agent: Mutt/1.5.21 (2010-09-15) Original-Sender: Rich Felker Xref: news.gmane.org gmane.linux.lib.musl.general:6700 Archived-At: On Mon, Dec 08, 2014 at 05:18:41PM +0100, Jörg Krause wrote: > On Mo, 2014-12-08 at 09:56 -0500, Rich Felker wrote: > > On Mon, Dec 08, 2014 at 03:42:25PM +0100, Jörg Krause wrote: > > > Why does musl declares pthread_equal both as macro and as function? > > > > C and POSIX allow any of their standard functions to be provided as > > macros too, but the function definition must always be provided. The > > reason I put the macro in musl is simply that it's easy to do and > > gives better code (trivial inline comparison rather than spilling all > > registers and making a function call) and it's not something where the > > implementation could change or need to change. > > I see! The problem was, that MPD (Music Player Daemon, implemented in C > ++) for instance used ::pthread_equal(id, other_id) which did not build > with musl because of the macro expansion. > > The maintainer removed the namespace operator to get it work with musl: > http://git.musicpd.org/cgit/master/mpd.git/commit/?h=v0.18.x&id=d8fc2db910a11dbbba53ba7ecf96d0e32a081076 I see. For the standard C headers, the C++ versions are supposed to omit the macros that the C versions might offer. However, there's no such rule for POSIX headers since there's no formal spec for interaction of C++ and POSIX at all. Perhaps it would be useful to take the same approach and suppress such macros if __cplusplus is defined, even in the POSIX headers? But I think from an application portability perspective, they should either use #undef or parens, i.e. (::pthread_equal)(id1,id2), instead of assuming there is no macro. Rich