Re: [PATCH] dissect: add support for _Generic

[Oleg Nesterov <oleg@redhat.com>]

On 07/29, Luc Van Oostenryck wrote:
>
> > +	break; case EXPR_GENERIC: {
> > +		struct type_expression *map;
> > +
> > +		do_expression(U_VOID, expr->control);
> > +
> > +		for (map = expr->map; map; map = map->next)
> > +			ret = do_expression(mode, map->expr);
> > +		if (expr->def)
> > +			ret = do_expression(mode, expr->def);
> > +	}
> > +
> >  	break; case EXPR_SYMBOL:
> >  		ret = report_symbol(mode, expr);
> >  	}
>
> Yes, that should do the 'walking'.

OK, I am sending this stupid patch. Better than nothing.

> The returned type will just be
> quite arbitrary, but I don't know how much it matters.

Of course. And this is not good. For example:

	void func(void)
	{
		struct B *b; struct C *c; struct D *d;
		_Generic(a,
			int:		b,
			void*:		c,
			default:	d
		) ->mem++;
	}

output:

   1:6                    def   f func                             void ( ... )
   3:18  func             def . v b                                struct B *
   3:31  func             def . v c                                struct C *
   3:44  func             def . v d                                struct D *
   4:18  func             ---   v a                                bad type
   5:33  func             --m . v b                                struct B *
   6:33  func             --m . v c                                struct C *
   7:33  func             --m . v d                                struct D *
   8:11  func             -m-   m D.mem                            bad type

But I do not know how to improve it without serious complications, and
(so far) I think it doesn't worth the effort.

Oleg.