Re: [Swig-devel] Re: New modules discussion

[John L. <le...@cs...>]

On Wed, April 5, 2006 8:09 am, Olly Betts said:
> On 2006-04-05, John Lenz <le...@cs...> wrote:
>> "You should be aware that your application will not work on some
>> platforms--most notably, Windows and AIX---if you rely on a
>> back-linking."
>>
>> From reading that, the only way to get modules working on Windows would
>> be
>> to factor out all the functions inside the SWIG core.
>
> There's an easy workaround for this:
>
> SWIG puts pointers to all the functions which a module is allowed to
> call into a struct, and the module provides a call which accepts such a
> struct which is called before anything else by SWIG.  Then the module
> can call back into SWIG using these function pointers.
>
> It requires that struct to be updated when new functions get added,
> but that shouldn't be a frequent occurence.  Note that if you never
> delete or reorder entries you can pass sizeof(struct) to avoid
> versioning issues.

Well, problem is the modules use a massive amount of functions from all
over the SWIG core... all the functions in DOH, and most of the functions
inside Source/Swig... We are talking about probably over 1000 functions. 
Now, some of the functions in DOH are already used through pointers, but
there still are a huge number of functions.

Getting all those functions into some struct is a lot of work... and one
which is balanced against the fact that loadable language modules aren't
that benificial.

On the other hand, I was searching around (just type back-linking into
google you get a lot of hacks which say it is possible) just found this
project, which supposedly allows backlinking using MinGW (which I think is
what SWIG uses to compile on windows?)

http://edll.sourceforge.net/

Not so sure about the license, becuase it is LGPL... maybe someone could
look into using that instead?

John