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: 103376,1360213b539060b5
X-Google-Attributes: gid103376,public
X-Google-ArrivalTime: 2002-10-10 14:00:15 PST
Path: 
 archiver1.google.com!news1.google.com!newsfeed.stanford.edu!newsfeed.berkeley.edu!ucberkeley!hammer.uoregon.edu!skates!not-for-mail
From: Stephen Leake <stephen.a.leake.1@gsfc.nasa.gov>
Newsgroups: comp.lang.ada
Subject: Re: Linking an Ada DLL with MSVC++
Date: 10 Oct 2002 16:50:31 -0400
Organization: NASA Goddard Space Flight Center (skates.gsfc.nasa.gov)
Message-ID: <u1y6yqaqw.fsf@gsfc.nasa.gov>
References: <254c16a.0210101206.34540dda@posting.google.com>
NNTP-Posting-Host: anarres.gsfc.nasa.gov
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
X-Trace: skates.gsfc.nasa.gov 1034283677 24600 128.183.220.71 (10 Oct 2002
 21:01:17 GMT)
X-Complaints-To: usenet@news.gsfc.nasa.gov
NNTP-Posting-Date: 10 Oct 2002 21:01:17 GMT
User-Agent: Gnus/5.09 (Gnus v5.9.0) Emacs/21.2
Xref: archiver1.google.com comp.lang.ada:29693
Date: 2002-10-10T21:01:17+00:00
List-Id: <comp.lang.ada>

mcq95@earthlink.net (Marc A. Criley) writes:

> I've meticulously followed the instructions in the GNAT User Manual
> for building a DLL, along with a Microsoft-style import library (i.e.,
> the .lib and .exp files).
> 
> <snip>
> 
>    procedure Initialize_Vmf_API;
>    pragma Export(C, Initialize_VMF_API, "Initialize_VMF_API");
> 
> The header file is wrapped with 'extern "C" {' so as to avoid name
> mangling.
> 
> But when I finally link, I get a message stating that there is an
> "unresolved external symbol _Initialize_VMF_API", i.e., the function
> name with a leading underscore.

Back when I was doing this with GNAT 3.12 and Borland C++, I added the
underscore in the external name:

pragma Export (C, Initialize_VMF_API, "_Initialize_VMF_API");

That worked.

There is also the problem of which C calling convention the C++
compiler is using; Cdecl or stdcall. That can influence which link
name it looks for.

-- 
-- Stephe