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From: dewar@merv.cs.nyu.edu (Robert Dewar)
Subject: Re: Urgent question: malloc and ada...
Date: 1998/05/03
Message-ID: <dewar.894232573@merv>#1/1
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Newsgroups: comp.lang.ada
Date: 1998-05-03T00:00:00+00:00
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Jonathan said

<<On many systems, the calling convention is carved in stone.  Unfortunately,
on every C compiler that I know well, it is possible to adjust the
alignment of the fields in structs on a case-by-case basis.  Those alignments
do not have to correspond to any system convention or even make any
sense.  Of course, most of the compilers I know well are for Intel
processors, but it's in the GCC documentation.  In fact GNU C allows a
lot more leeway in how you specify the alignment of the fields in a struct
than the MS-DOS/Windows compilers I've used.
>>

Following up on my previous message .... the above makes no sense. The
calling sequence includes the specifications for how structs are passed
by reference, and thus how they are layed out and aligned. A calling
sequence that is "carved in stone" must include these issues in the carving!

Obviously if you use other than the default layout, by the use of the
equiavelnt of pragmas or rep clauses, then no Ada compiler can 
telephaythically guess what you have done. 

However, every Ada compiler wlil implement sufficient flexibility so that
you can use analogous statements in your Ada program to align and lay out
your data in a compatible manner.

Jonathan, I don't see any problem here at all. If you see one, let me make
the same request I make of Joe, please give us an example of what you
think is a problem case.