GNAT 2008 GPL pragma import VC++

GNAT 2008 GPL pragma import VC++

[JJ]

I have an Ada program that has a pragma import to a Visual C++
procedure.  I have tried several combination's of External_Name (all
uppercase, all lowercase, mixed...) to no avail.  I continue to get an
"undefined reference" error during the link.

Anyone have any experience with this?

Re: GNAT 2008 GPL pragma import VC++

[sjw]

On Jan 27, 7:30 pm, JJ <jayson.prich...@ngc.com> wrote:
> I have an Ada program that has a pragma import to a Visual C++
> procedure.  I have tried several combination's of External_Name (all
> uppercase, all lowercase, mixed...) to no avail.  I continue to get an
> "undefined reference" error during the link.
>
> Anyone have any experience with this?

No experience with VC++; but you might be having problems with name
mangling? (ie, the c++ compiler decorates the object name of the
function with inscrutable encoding of the parameter/result profile,
thus supporting overloading and possibly other features).

You might try
extern "C" {
int foo(int *bar);
}

which (in GCC at any rate) will generate the symbol foo (or _foo, but
at any rate something easier to manage).

Re: GNAT 2008 GPL pragma import VC++

[Per Sandberg]

I Have been working with VC and GNAT and are using the following setup.

Rules for the C/C++ code (VC).
* Always build DLL:s
* use external C convention
* use plain C in the interface.

Then my experience is that it almost always works.

/Per

If you post a sniped with the C code and corresponding Ada code along 
with the error log, maybe i could pinpoint the problem.


JJ wrote:
> I have an Ada program that has a pragma import to a Visual C++
> procedure.  I have tried several combination's of External_Name (all
> uppercase, all lowercase, mixed...) to no avail.  I continue to get an
> "undefined reference" error during the link.
> 
> Anyone have any experience with this?

Re: GNAT 2008 GPL pragma import VC++

[JJ]

On Jan 27, 3:28 pm, sjw <simon.j.wri...@mac.com> wrote:
> On Jan 27, 7:30 pm, JJ <jayson.prich...@ngc.com> wrote:
>
> > I have an Ada program that has a pragma import to a Visual C++
> > procedure.  I have tried several combination's of External_Name (all
> > uppercase, all lowercase, mixed...) to no avail.  I continue to get an
> > "undefined reference" error during the link.
>
> > Anyone have any experience with this?
>
> No experience with VC++; but you might be having problems with name
> mangling? (ie, the c++ compiler decorates the object name of the
> function with inscrutable encoding of the parameter/result profile,
> thus supporting overloading and possibly other features).
>
> You might try
> extern "C" {
> int foo(int *bar);
>
> }
>
> which (in GCC at any rate) will generate the symbol foo (or _foo, but
> at any rate something easier to manage).

Thanks.  I suspected a mangling problem.  I had heard that sometimes
the case of the procedure name has to be different than what is in the
C/C++ code.

I was just trying the extern "C" when I read your post.  Still not
success.  I even did an created a symbol table and inserted that
symbol into the Ada pragma import.  Still getting an "undefined
reference" error on linking.

Re: GNAT 2008 GPL pragma import VC++

[JJ]

On Jan 27, 3:28 pm, sjw <simon.j.wri...@mac.com> wrote:
> On Jan 27, 7:30 pm, JJ <jayson.prich...@ngc.com> wrote:
>
> > I have an Ada program that has a pragma import to a Visual C++
> > procedure.  I have tried several combination's of External_Name (all
> > uppercase, all lowercase, mixed...) to no avail.  I continue to get an
> > "undefined reference" error during the link.
>
> > Anyone have any experience with this?
>
> No experience with VC++; but you might be having problems with name
> mangling? (ie, the c++ compiler decorates the object name of the
> function with inscrutable encoding of the parameter/result profile,
> thus supporting overloading and possibly other features).
>
> You might try
> extern "C" {
> int foo(int *bar);
>
> }
>
> which (in GCC at any rate) will generate the symbol foo (or _foo, but
> at any rate something easier to manage).

One other thought... I am using GPS (Gnat Programming Studio) as my
IDE.  Right now I am using the -Idir_to_the_obj_file switch.  This
points to the VC++ object file created.  Is there something else that
I need in the build process?

Re: GNAT 2008 GPL pragma import VC++

[Manuel Gomez]

On 27 ene, 20:30, JJ <jayson.prich...@ngc.com> wrote:
> I have an Ada program that has a pragma import to a Visual C++
> procedure.  I have tried several combination's of External_Name (all
> uppercase, all lowercase, mixed...) to no avail.  I continue to get an
> "undefined reference" error during the link.
>
> Anyone have any experience with this?

Take a look at this Ada wikibook page:

http://en.wikibooks.org/wiki/Ada_Programming/Platform/Windows/Visual_C%2B%2B_-_GNAT_interface