Message-ID:	<8D53104ECD0CD211AF4000A0C9D60AE337C6ED@probe-2.Acclaim-Euro.net>
From:	Shawn Hargreaves <ShawnH AT Probe DOT co DOT uk>
To:	djgpp AT delorie DOT com
Subject:	Re: The DXE mechanism - has anybody used it effectively?
Date:	Tue, 22 Dec 1998 17:07:44 -0000
MIME-Version:	1.0
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Reply-To:	djgpp AT delorie DOT com

Laurence Withers writes:
> 1 - can I create a large module, using several different input files? 

Yes.

> 2 - if I pass a pointer to a function in my C++ code, can the DXE call 
>     that function?

Yes. All the DXE interface provides is a single pointer to some item 
that is exported by the DXE module, which your C or C++ program gets 
as the return value from _dxe_load(). It is up to you to decide what 
you want this pointer to represent: it could be just one function 
provided by the DXE module which your main program can call, or more 
usually it will be an interface structure that the DXE routine fills 
in, containing pointers to lots of different functions. This can work 
in either direction: the DXE can provide a structure containing NULL 
pointers, the main program can fill these in with the addresses of 
actual functions from itself or from libc, and then the DXE routines 
can call these functions via the pointers. This gets very boring if 
you want to call large numbers of libc routines from the DXE code 
(a lot of typing to export them all) but it is quite simple to do.

> 3 - will I be able to call the DXE from C++ code (as opposed to C 
>     code)? Connected with this, will I be able to write the DXE in C++?

I've no idea: try it and see! Making a wild guess, probably the code 
will compile ok, but some things like global objects won't be 
initialised properly.


	Shawn Hargreaves.

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