From mboxrd@z Thu Jan  1 00:00:00 1970
X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me
X-Spam-Level: 
X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00 autolearn=ham
	autolearn_force=no version=3.4.4
X-Google-Language: ENGLISH,ASCII-7-bit
X-Google-Thread: 103376,fd63afa4dc364b7e
X-Google-Attributes: gid103376,public
X-Google-ArrivalTime: 2001-03-26 10:46:06 PST
Path: 
 supernews.google.com!sn-xit-03!supernews.com!freenix!wanadoo.fr!not-for-mail
From: Pascal Obry <p.obry@wanadoo.fr>
Newsgroups: comp.lang.ada
Subject: Re: Implementing C/C++ style #include...
Date: 26 Mar 2001 20:44:00 +0200
Organization: Home - http://perso.wanadoo.fr/pascal.obry
Message-ID: <uu24g2wwf.fsf@wanadoo.fr>
References: <98m938$2iod0$1@ID-25716.news.dfncis.de>
 <OrZxgIisAHA.289@cpmsnbbsa09> <99alrr$itf$1@nh.pace.co.uk>
 <tbk5cb2rf5aef0@corp.supernews.com> <99d5dj$fi4$1@nh.pace.co.uk>
 <K$VNnBA+Jhv6Ewa4@zooks.demon.co.uk> <99nkte$157$1@nh.pace.co.uk>
 <u7l1cgzpa.fsf@gsfc.nasa.gov>
NNTP-Posting-Host: mix-velizy-106-2-189.abo.wanadoo.fr
X-Trace: wanadoo.fr 985631745 9588 193.249.121.189 (26 Mar 2001 18:35:46 GMT)
X-Complaints-To: abuse@wanadoo.fr
NNTP-Posting-Date: 26 Mar 2001 18:35:46 GMT
X-Newsreader: Gnus v5.7/Emacs 20.7
Xref: supernews.google.com comp.lang.ada:6066
Date: 2001-03-26T18:35:46+00:00
List-Id: <comp.lang.ada>


Stephen Leake <stephen.a.leake.1@gsfc.nasa.gov> writes:

> Not this one:
> 
>    function Ada_Size_Of_Input is new 
>       Interfaces_C_More.Storage_Unit_Size_Of (Input_Type);
> #if GNAT_Compiler
>    pragma Export (C, Ada_Size_Of_Input,
>                   "ball_ct633_ada_size_of_input",  
>                   "ball_ct633_ada_size_of_input");
> #elsif ObjectAda_Compiler
>    pragma Export (DLL_STDCALL, Ada_Size_Of_Input, 
>                   "ball_ct633_ada_size_of_input", 
>                   "ball_ct633_ada_size_of_input");
> #end if;

I agree with you that in such a case a preprocessor could be usefull. Anothe
way to handle this is by writing a template and have the right spec generated
by a script.

   function Ada_Size_Of_Input is new 
      Interfaces_C_More.Storage_Unit_Size_Of (Input_Type);
   pragma Export (<OS_CONVENTION>, Ada_Size_Of_Input,
                  "ball_ct633_ada_size_of_input",  
                  "ball_ct633_ada_size_of_input");

This is even easier to maintain. Only one Export pragma. And if you have to
change/add new convention for new compiler you just need to add one token into
your script.

You can even configure prefix if you need so:

   function Ada_Size_Of_Input is new 
      Interfaces_C_More.Storage_Unit_Size_Of (Input_Type);
   pragma Export (<OS_CONVENTION>, Ada_Size_Of_Input,
                  "<COMP_PREFIX>_ada_size_of_input",  
                  "<COMP_PREFIX>_ada_size_of_input");

> 
> The difference is in the name of the Convention. Preprocessing is, in
> this case, the best way to handle it. I believe the only alternative
> is to reproduce the entire package spec, and change this one value.
> Surely you do not claim that is better from a maintenance point of
> view? 

Agree, but see above.

> I can only assume you have not personally encountered a situation like
> this. Until you have, you need to be a little more open :).

I have but in that case I use script.

Pascal.

-- 

--|------------------------------------------------------
--| Pascal Obry                           Team-Ada Member
--| 45, rue Gabriel Peri - 78114 Magny Les Hameaux FRANCE
--|------------------------------------------------------
--|         http://perso.wanadoo.fr/pascal.obry
--|
--| "The best way to travel is by means of imagination"