Fragile ABI

[R Grocott]

Hm. Come to think of it, I have another question for somebody 
knowledgeable about this stuff:

The blog post I linked only talks about rewriting vtables at 
dynamic-link-time. Would it be possible to implement something 
similar for the sizes of structs and scope-classes, and the 
relative address of member variables? dsimcha's post has led me 
to realize that without these additional features, the ABI would 
still be quite fragile.

I know very little about dynamic linking, but I guess it might be 
too expensive to justify? If nothing else, it would probably 
block a few compile-time optimisations (since offsets and sizes 
would have to be treated as unknown variables rather than integer 
constants).