RFC: Make dllimport/dllexport imply default visibility

[Andrew Pinski]

On 6/15/07, Mark Mitchell <mark@codesourcery.com> wrote:
>
> I don't think there's a contradiction.  The declaration on the structure
> is the default for the members and applies to the vtable and other class
> data.  There's no reason the members shouldn't be implemented elsewhere,
> and there's certainly existing code (in Windows, SymbianOS, and other
> DLL-based operating systems, whether or not there is on GNU/Linux) that
> implements different class members in different DLLs, while still not
> exporting the class from its home DLL.  One situation where this is
> useful is when the class members are actually shared between multiple
> classes, or are also callable as C functions, etc.

Well this allows for easier violating of ODR.  I guess I am just a bit
off of what is going on here but I agree with Chris in that this
really should be rejected as you have stuff which is hidden and then
you call a non hidden member function.  How can the vtable be hidden
while the member functions not be?  I think if you try to throw that
class across boundaries, it will never be caught as the typeinfos are
different.

So really I think this is just bad pratice and should at least get a
warning, even though code in real life exists, the code is broken to
say the least.

-- Pinski