From owner-freebsd-hackers@FreeBSD.ORG Tue Mar 4 15:38:40 2008 Return-Path: Delivered-To: hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 0BAE61065674 for ; Tue, 4 Mar 2008 15:38:40 +0000 (UTC) (envelope-from rwatson@FreeBSD.org) Received: from cyrus.watson.org (cyrus.watson.org [209.31.154.42]) by mx1.freebsd.org (Postfix) with ESMTP id D952F8FC1D for ; Tue, 4 Mar 2008 15:38:39 +0000 (UTC) (envelope-from rwatson@FreeBSD.org) Received: from fledge.watson.org (fledge.watson.org [209.31.154.41]) by cyrus.watson.org (Postfix) with ESMTP id 7473046C30; Tue, 4 Mar 2008 10:38:39 -0500 (EST) Date: Tue, 4 Mar 2008 15:38:39 +0000 (GMT) From: Robert Watson X-X-Sender: robert@fledge.watson.org To: "M. Warner Losh" In-Reply-To: <20080304.083350.1661915009.imp@bsdimp.com> Message-ID: <20080304153651.I41184@fledge.watson.org> References: <20080303.224256.635730757.imp@bsdimp.com> <20080304151326.J41184@fledge.watson.org> <20080304.083350.1661915009.imp@bsdimp.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Cc: hackers@freebsd.org Subject: Re: Comments on pmake diffs for building on Linux X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 04 Mar 2008 15:38:40 -0000 On Tue, 4 Mar 2008, M. Warner Losh wrote: > : In most ports of FreeBSD parts to Linux that I've seen, the preferred solution > : has to been to bring the entire FreeBSD queue.h with you rather than relying > : on the native Linux queue.h. This is what we do for OpenBSM, for example; > : this also helps out when you get to Mac OS X, Solaris, etc, where all the > : queue.h's continue to vary in subtle ways. This depends a fair amount on a > : lack of header pollution in the OS's own include files, of course... > > I was rather hoping for something that could be used without any of that > nonsense... Sadly, nonsense seems to be the name of the game in software portability. Here's the broken autoconf garbage I use to pick out adequate queue.h's from inadequate ones: # sys/queue.h exists on most systems, but its capabilities vary a great deal. # test for LIST_FIRST and TAILQ_FOREACH_SAFE, which appears to not exist in # all of them, and are necessary for OpenBSM. AC_TRY_LINK([ #include ], [ #ifndef LIST_FIRST #error LIST_FIRST missing #endif #ifndef TAILQ_FOREACH_SAFE #error TAILQ_FOREACH_SAFE #endif ], [ AC_DEFINE(HAVE_FULL_QUEUE_H,, Define if queue.h includes LIST_FIRST) ]) Note that there are at least a couple of mostly stylistic bugs there (could use compile rather than link, definition description is poor, errors are inconsistent). :-) I found that on both Linux and Mac OS X, the queue.h's didn't have everything I wanted. Robert N M Watson Computer Laboratory University of Cambridge