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Article #807Re: Alignment (padding) of derived classes, Mach-O vs. CFM
From: Stefan Haller
Date: Wed, 25 Jun 2003 19:06
Date: Wed, 25 Jun 2003 19:06
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Miro Jurisic <macdev@meeroh.org> wrote: > In article <1fwrc5z.1wbucc58vha4aN%stk@snafu.de>, stk@snafu.de (Stefan Haller) > wrote: > > > We need to pass objects between a Mach-O application and a CFM shared > > library, built from the same source code. > > You are doomed. Well, fortunately we are not. We call virtual functions only from the Mach-O side, and we don't use dynamic_cast on the CFM side. With these restrictions everything works well, except for the padding-between-base- and-derived problem. We were able to solve that problem by adding compile-time assertions to make sure that the offset of the first member of every derived class is equal to sizeof(base). It turned out that we had to add manual padding only in two classes (out of some 400). -- Stefan Haller Berlin, Germany http://home.snafu.de/stk/
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X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 10bcce,98e56c06675247cc X-Google-Attributes: gid10bcce,public X-Google-Thread: f635e,98e56c06675247cc X-Google-Attributes: gidf635e,public X-Google-ArrivalTime: 2003-06-25 12:06:37 PST Path: arc1-ca.pugleaf.net!archiver1.google.com!news1.google.com!newsfeed.stanford.edu!lnsnews.lns.cornell.edu!newsstand.cit.cornell.edu!news.stealth.net news.stealth.net!news.stealth.net!newsfeed.icl.net!newsfeed.fjserv.net!newsfeed.freenet.de!eusc.inter.net!news.eusc.inter.net!stk From: stk@snafu.de (Stefan Haller) Newsgroups: comp.sys.mac.programmer.codewarrior,codewarrior.mac Subject: Re: Alignment (padding) of derived classes, Mach-O vs. CFM Date: Wed, 25 Jun 2003 21:06:14 +0200 Organization: none Lines: 25 Message-ID: <1fx4n9b.yw82xo18155hpN%stk@snafu.de> References: <1fwrc5z.1wbucc58vha4aN%stk@snafu.de> <macdev-7428E9.22150424062003@senator-bedfellow.mit.edu> X-Trace: news.eusc.inter.net 1056567996 14737 213.23.144.7 (25 Jun 2003 19:06:36 GMT) X-Complaints-To: abuse@eusc.inter.net Mail-Copies-To: never User-Agent: MacSOUP/2.5b3 (Mac OS X version 10.2.6)