From: Fokkema DOT DBRA AT delorie DOT com, 1043730 <dfokkema AT cs DOT vu DOT nl>
Newsgroups: comp.os.msdos.djgpp
Subject: Re: struct problem
Date: Fri, 22 Oct 1999 07:25:38 GMT
Organization: Fac. Wiskunde & Informatica, VU, Amsterdam
Message-ID: <7up3hi$nk7@cs.vu.nl>
References: <7umn1a$q3o AT cs DOT vu DOT nl> <380F206B DOT 8AE AT erols DOT com>
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To: djgpp AT delorie DOT com
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Reply-To: djgpp AT delorie DOT com

John S. Fine (johnfine AT erols DOT com) wrote:
:   I couldn't follow most of what you said, and the <snip>'ed parts
: of your code contain the parts that are the problem, so I can't
: give you an exact answer.

Sorry for that.

:   You may know that the entire value fits in 24-bits (maybe even
: 16) but there is no way for the compiler to communicate that to
: the linker in COFF format.

Ah, I see. Never suspected that that could be the problem. Now I see why
an other pointer (to a function) I used did work: it fitted nicely in
a 32bits variable.

:   One kludge I used before I wrote that linker was to have a version
: of the descriptor structure in which the middle dword is defined
: as a single value.  (Make sure you use __attribute__((packed)) so
: that a long can be placed at offset 2 in a struct).  I then init
: it with address+(attributes<<24).  Since attributes is a compile
: time constant, it is no problem;  And since the field is a long,
: COFF format handles not knowing the address until link time.  (You
: still need to make sure the address fits in 24-bits.)

Thanks! It works, now.

: BTW, the descriptor needs a linear address.  The linker will give
: you an offset.  If there is a difference between those, you must
: handle that as well.

Had that handled, already.


Thank you very much for your help. Sometimes I just don't know what these
djgpp error messages are about. Anyway, it works fine now.

David