Re: [AD] END_OF_MAIN removal patch for msvc

[Evert Glebbeek <eglebbk@xxxxxxxxxx>]

On 17 Nov 2008, at 20:36, Peter Wang wrote:
> It might be best just to expose the boilerplate to the user.
> For any program which wants to be portable to Mac OS X, you'd write:
>
>     int real_main(int argc, const char *argv)
>     {
> 	al_init();
> 	...
>     }
>
>     int main(int argc, const char *argv)
>     {
> 	return al_run_in_main_thread(real_main, argc, argv);
>     }
>
> Nothing up the sleeves.
>
> We might need three different versions of al_run_in_main_thread,
> for zero arguments, two arguments, and three arguments.  Of course,  
> we'd
> probably get sick of writing that and end up providing a macro:
>
>     ALLEGRO_MAIN_WRAPPER(real_main, argc, argv);
>
> which looks suspiciously like END_OF_MAIN().  *But* it doesn't require
> the symbol `_mangled_main_address' to exist, which causes problems  
> when
> people try to load the Allegro shared object at run-time, and there is
> no name mangling.

My main concern would be the number of people who forget to do that,  
inadvertently creating platform-dependent code. My secondary concern  
would be how that would interact with other libraries (probably no  
worse than END_OF_MAIN(), but the thought occured). My third concern  
would be that I actually think that looks uglier than END_OF_MAIN() ;)

I think it makes sense to split the problem in two: requiring a copy  
of argv[] and having a non-standard main/main requirement.
The former can be solved by providing a function to pass it (we need  
some sensible default if a user forgets to do this), assuming we  
really want it still.
The latter was never needed on *nix and now isn't needed on Windows  
anymore either. That leaves OS X.

If OS X is the only platform that needs a magic main at the moment,  
we should again look for a way to get rid of it there too. The  
ucontext stuff Peter [Hull] mentioned would be what I'd look into,  
assuming there's a way to make it work in Tiger (Leopard and up  
shouldn't be a problem if I understand correctly). Maybe (optionally)  
not in debug mode though, but then we'd still need END_OF_MAIN() just  
for that. Some sort of progress...

Evert