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Newsgroups: comp.lang.ada
Subject: Re: Ada to C Interface: Passing Pointers Via System.Address
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From: Mark Lorenzen <mark.lorenzen@ofir.dk>
Date: 12 Jan 2005 16:50:46 +0100
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Date: 2005-01-12T16:50:46+01:00
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tmoran@acm.org writes:

> > struct_ptr : system.address;
> >
> > struct_ptr := ada_cfunct1(input1, input2);
> >
> > cfunct2(struct_ptr, input3);
> > ...
> > at the value of the memory of the struct_ptr after it has gone to ada and
> > back to c it says that it is null.  I must not be using the system.address
>   Could you please post a small, but complete (ie, compiles, but fails to
> run) program?  I'm very confused by the above, not knowing which of the
> functions are in Ada, which are imported from C, how is struct_ptr's value
> created, what are the declarations of ada_cfunct1 and cfunct2, etc.  I'm
> guessing that both ada_cfunct1 and cfunct2 are imported C functions.  How
> about putting printout inside ada_cfunct1 just before it returns
> struct_ptr, another printout just after the "struct_ptr := ...", and a
> third printout at the beginning of cfunct2, showing the value passed in
> for struct_ptr.

And please post the C prototype for the function you want to call from Ada.

- Mark Lorenzen