From: Iain Dooley <idoo4002@...>
Date: 2005-08-29T21:12:44+09:00
Subject: Re: catching segmentation faults from Ruby



ts wrote:
>>>>>>"I" == Iain Dooley <idoo4002@mail.usyd.edu.au> writes:
> 
> 
> I> but surely i can't call:
> 
> I> rb_protect(app.exec(),VALUE ?,RESULT ?);
> 
>   /* Something like this */
> 
>   static VALUE
>   call_exec_for_app(QApplication *app)
>   {
>       return app->exec();
>   }
> 
>   /* ... */
>   int status;
>   VALUE res;
>   /* ... */
>   
>   res = rb_protect(call_exec_for_app, (VALUE)&app, &status);
>   if (status) {
>      /* there is a ruby error */
>   }
>   /* ... */

it appears that i can't pass the name of a C function to rb_protect. 
i've tried these things:

/*** DEFINITION OF MY EXECUTE FUNCTION***/

VALUE executeApplication(void);

VALUE executeApplication()
{
     return app->exec();
}

1) passing the C function to rb_protect as follows:

         VALUE res = rb_protect(executeApplication, (VALUE)0, &status);

gives the following compile errors:

main.cpp:30: error: invalid conversion from `VALUE (*)()' to `VALUE 
(*)(VALUE)'
main.cpp:30: error:   initializing argument 1 of `VALUE rb_protect(VALUE 
(*)(VALUE), VALUE, int*)'

2) using rb_define_method to define the method in ruby and then using 
rb_const_get to get it out and then calling it:

     rb_define_method(rb_cObject,"executeApplication",executeApplication,0);

VALUE res;
VALUE func = rb_const_get(rb_cObject,rb_intern("executeApplication"));
res = rb_protect(func, (VALUE)0, &status);

gives the following compile errors:

main.cpp:24: error: invalid conversion from `VALUE (*)()' to `VALUE 
(*)(...)'
main.cpp:24: error:   initializing argument 3 of `void 
rb_define_method(VALUE, const char*, VALUE (*)(...), int)'
main.cpp:30: error: invalid conversion from `VALUE' to `VALUE (*)(VALUE)'
main.cpp:30: error:   initializing argument 1 of `VALUE rb_protect(VALUE 
(*)(VALUE), VALUE, int*)'

these types really confuse the hell out of me. what is VALUE(*)() ?!?! 
VALUE everywhere... this is the last tiny little thing that i have to do 
  for the summer of code ends in two days ... just need to protect the 
calls!

cheers

iain