Workaround for virtual function/dllimport bug, also patch guidance request

[Mumit Khan]

Jason Merrill <jason@cygnus.com> writes:
> >>>>> Mumit Khan <khan@nanotech.wisc.edu> writes:
> 
>  > The fix is simple -- just import the vtables from the DLL. Currently,
>  > config/winnt.c:associated_type returns a NULL context for a vtable,
>  > and I don't know how to get to it, so it's not imported correctly. 
> 
> That's odd; DECL_CONTEXT for the vtable should give the right answer.

I thought so too, but see how the context is assigned *after* calling
cp_finish_decl in class.c:finish_vtbls(). The context for symbols must
be set before any call to make_decl_rtl for the backend to pick the 
needed bits in the attributes. That bit about saving the context and
then assigning it again is a bit too deep for me. 

>  > Re check_override, I've moved it to grokclassfn, and it looks ok so far.
>  > Note that I haven't removed it from finish_struct_1 since I'm not sure
>  > where else it needs to be added, other than the current one in 
>  > add_implicitly_declared_members.
> 
> Please try removing it from everywhere but grokclassfn and see how that
> works.

Are you sure? Removing it from add_implicitly_declared_members will not
do the right thing, right? I'll submit a patch later.

Regards,
Mumit