https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80130
Eric Gallager <egallager at gcc dot gnu.org> changed:
What |Removed |Added
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CC| |jakub at gcc dot gnu.org
--- Comment #4 from Eric Gallager <egallager at gcc dot gnu.org> ---
(In reply to Richard Biener from comment #3)
> (In reply to Eric Gallager from comment #2)
> > I only get 1 warning on (1) and only with -Wstrict-aliasing=1.
> > -Wstrict-aliasing=2 and -Wstrict-aliasing=3 are both silent.
> >
> > (In reply to Richard Biener from comment #1)
> > > The warning implementation is incredibly stupid, don't use it. It doesn't
> > > have any context (so the two stmt variant is different from the single
> > > stmt
> > > one).
> >
> > It'd still be nice if it could be improved though. Although, maybe it
> > already has been?
>
> I don't see how it can be improved. Iff the compiler can detect an
> aliasing violation it may as well try to be conservative (which in
> fact we do later during optimization).
>
> Jakub has attempted to do a TBAA sanitizer, not sure how far that went though,
> it is quite meta-data heavy to do "correctly". Still tracking the dynamic
> type of storage at runtime and then instrumenting each access is the only
> way to reliably detect TBAA violations (without false positives).
cc-ing Jakub then to see how far he got with it
