Subject: Re: Xnest on NetBSD/Alpha?
To: David Seifert <seifert@sequent.com>
From: Chris G. Demetriou <cgd@pa.dec.com>
List: port-alpha
Date: 07/28/1997 10:15:48
> Has anyone gotten Xnest working on NetBSD/Alpha?
> It brings up a window, but that's about it.

I seem to recall that Xnest is (or was; it may have been fixed) a
victim of gross mis-design.  The story goes something like this:

X servers use <data type A> to implement <X type T>.
X client libraries use <data type B> to implement <X type T>.

On 64-bit systems, A != B.

Xnest is both a server and a client.  "D'oh!"

Last time i looked at this (probably about a year ago), there were
significant problems of this nature, and they weren't easily fixable.
The sources you're looking at may have been improved from that state.


> I'm currently wading through the gcc warnings.  Most if not
> all of these are LP64 issues.  (Dispite lots of obvious
> attention to 64 bit issues in the code, #ifdef _alpha,
> DEC copyrights, etc. which would lead one to think that
> it ought to run on an alpha.)

DEC copyrights != 64-bit safe code.  How many years of 32-bit systems
did DEC have before the Alpha?  8-)

"_alpha" isn't defined by NetBSD/alpha, btw, __alpha__ is.  However,
even if you fix the #defines, the presence of those #ifdefs indicates
that somebody _tried_ to get it working, not that that person or group
_succeeded_.  8-)

You might try fixing up the #ifdefs so that they work properly on
NetBSD/alpha.  That has at least a _chance_ of doing the right thing
for you.


> I believe Xnest is new in X11R6.3.

Actually, Xnest and Xvfb have been around for a while -- at least
since R6(.0 8-), if i recall.  (Maybe since R6.1, though; i'm not sure
what all the dates on the version X11 releases are.)

The original sources I started hacking around in to provide the
existing rudimentary X support in NetBSD/alpha -- which were from
around Fall '95 -- included Xnest and Xvfb, and Xnest had the problem
that I described above.



cgd