Re: Calling Ada from C++ (MS Visual C++)

[Stephen Leake <stephen.a.leake.1@gsfc.nasa.gov>]

julian_robbins@bigfoot.com (Julian Robbins) writes:

> Okay, so here is what I have done...
> 
> Compiled the original "mathutil.adb" into "mathutil.o". Then used
> "gnatbind -n mathutil" which produced the files "b~mathutil.adb" and
> ".ads". I then compiled these using gcc and renamed the resulting .o
> file "main.o".

I wouldn't call it "main", since it is _not_ your C "main". Call it
"ada_elab_stuff". Or at least "ada_main". Actually, there's nothing
wrong with "b~mathutil" :).

> Within my VC++ project I have then included the mathutil.o and
> main.o files, added calls to adainit() and adafinal() and then
> compiled/linked. This throws up various missing links, so I have
> included the following library files: libgnat.a libgcc.a
> libmingw32.a
> 
> Does this seem correct?? 

Yes, you've got it.

> It seems to compile and run, but I can't help thinking that this
> process seems a bit odd.

Welcome to the world of multi-language multi-vendor programming :).

You've got it easier than I did; I was using Borland C++, which has a
different object file format than GNAT on Win32. So I had GNAT build a
DLL to link with Borland. Reverse engineering the naming conventions
took a while!

Just out of curiosity, why are you using MS C++ instead of Gnu C++?
I'll assume it's to get MFC.

-- 
-- Stephe