Date: Tue, 30 Sep 2003 13:14:34 -0400 (EDT) From: John Baldwin <jhb@FreeBSD.org> To: Bruce Evans <bde@zeta.org.au> Cc: net@freebsd.org Subject: Re: finishing the if.h/if_var.h split Message-ID: <XFMail.20030930131434.jhb@FreeBSD.org> In-Reply-To: <20031001011119.U1245@gamplex.bde.org>
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On 30-Sep-2003 Bruce Evans wrote: > On Tue, 30 Sep 2003, John Baldwin wrote: > >> On 30-Sep-2003 Bruce Evans wrote: >> > On Mon, 29 Sep 2003, Brooks Davis wrote: >> >> Unfortunately, "soon" hasn't happened yet and it is now tripping me >> >> up. To add the if_dev member to struct ifnet (see the forthcoming >> >> post on that subject), it is necessary for sys/bus.h to be included in >> >> net/if_var.h >> > >> > That would be namespace pollution, so it is not permitted :-). Requiring >> > all files that include <sys/if_var.h> (and especially <sys/if.h> to >> > include <sys/bus.h> would be interface breakage so it is even less >> > permitted. >> >> Well, if if.h stops including if_var.h, then only kernel files that >> include net/if_var.h would need sys/bus.h. I think that's manageable. > > All userland files that include net/if_var.h would also need it (except > they would only need device_t). Is struct ifnet exposed to userland? Ugh, why do we export such things? I guess because ifconfig grovels around in the kernel due to a lack of APIs between the kernel and userland. *sigh* >> >> which in turn requires that if_var.h NOT be included in >> >> genassym.c. >> > >> > Do you mean in userland? There don't seem to be any immediate problems >> > for genassym.c or any other file in the kernel from including <sys/bus.h> >> > unconditionally in <net/if_var.h>. However, the pollution may be harmful >> ... >> The problem is that the newbus foo_if.h files don't exist when genassym >> is compiled and used. sys/bus.h needs bus_if.h and device_if.h, hence >> the breakage. > > I see. This is a bug in the dependencies for genassym.o and .depend. > "make depend" creates *_if.h but it also creates genassym.o. There aren't > enough dependencies so the order is mostly accidental. genassym.o happens > to get created first, so it doesn't compile unless *_if.h already exist. I think that genassym shouldn't need anything that includes *_if.h headers, and that if we find ourselves in that situation, perhaps some huge header needs to be split up instead. :) We shouldn't be going near new-bus or kobj in assembly files. -- John Baldwin <jhb@FreeBSD.org> <>< http://www.FreeBSD.org/~jhb/ "Power Users Use the Power to Serve!" - http://www.FreeBSD.org/
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