Re: Concurrency has landed

[Stefan Monnier <monnier@iro.umontreal.ca>]

> The problem with -fcheck-pointer-bounds does not occur when the program
> computes p1 - p2, as the program still gets a valid integer. The problem
> occurs later, when Emacs computes q + (p1 - p2), where q is a dangling
> pointer into the old object.

Hmm... can you show in the code where we do that?  I'd expect the code
would do something like "newp2 = newp1 + (oldp2 - oldp1)", whereas you
seem to say that we do something more like "oldp2 = oldp1 + (newp2 -
newp1)", which would indeed be more risky (tho if oldp2 did exist before
the free, it should still work just fine even on odd architectures, but
at least I can see where an eager bounds-checker could complain).


        Stefan