This is the mail archive of the
gcc@gcc.gnu.org
mailing list for the GCC project.
Re: gcc visibility used by moz
Hi,
On Sat, 15 Jul 2006, Gabriel Dos Reis wrote:
> | I don't see how they get past this issue. I've had some claim, but
> | it's a feature, not a bug.
> |
> | The basic question is, are two unrelated types in different dlls the
> | same, just because they have the same name? How do you prevent them
> | from being the same?
>
> it has been a kind of implicit garantee that two classes with external
> linkage and with same mangled names refers to the same type.
> Implementations have used that property -- which "leaks" into user codes
> via type_info::operator== and type_info::before.
>
> My primary concern is to what extent that guarantee continues to hold
> with the visibility stuff and without alienating coding patterns.
That's one concern. But what also need to be considered is what if you
don't need that guarantee. For instance in an ecosystem where you don't
rely on C++ RTTI at all, and instead have your own system (like mozilla
seems to have, and KDE has for sure). For those a possibility for Doing
The Right thing should be provided without having to care for C++ RTTI (or
ideally by providing a working but slow RTTI).
Ciao,
Michael.