Re: Covariant returns

[Jim Dehnert <dehnert@xxxxxxxxxxxxxxxxxxxx>]

> From: Mark Mitchell <mark@xxxxxxxxxxxxxxxx>
> 
> Although the closed issues list discusses covariant returns, the ABI
> document itself does not.  It looks like we agreed on providing
> alternate entry points for non-trivial covariant returns.

Added a clause in 2.5.2 Category 2.

> In that
> case, we need to specify the order in the vtable in which such entries
> appear.

The same place where it would appear if it weren't overriding.  Is
there a specific place where the comment is required?

> Since we also provide a copy of a virtual function in the
> primary vtable when a derived class orverrides a virtual function from
> a secondary base, we need to know whether to make copies of all the
> entry points, or just the one with the same signature as that provided
> in the derived class.

Both.  See the addition to 2.5.2 Category 2.

> There also need to be vcall offsets for all of the covariant returns.

Added a clause in 2.5.2 Category 3.

> Other issues?

Anyone think of any?  Please look at my additions...

Jim

-	    Jim Dehnert		dehnert@xxxxxxx
				(650)933-4272