On Tue, Aug 26, 2014 at 2:31 AM, Evgeniy Stepanov <[email protected] > wrote:
> As Chandler said, disabling extern templates may help with some simple > tests, but the only reliable way to get rid of MSan false positives is > linking with instrumented libc++. > > We should concentrate on making is easier to build and use > instrumented libc++ instead. > Yes, please! > > On Mon, Aug 18, 2014 at 6:30 AM, Eric Fiselier <[email protected]> wrote: > >> FWIW, I don't think that MSan was *ever* intended to not have false > >> positives with an uninstrumented standard library. So I really don't > >> understand why this is an interesting thing to dig into. > > > > That is new information to me so I'll have to take that into > consideration. > > What I was trying to avoid was breaking MSAN usability for end users of > > libc++. > > Since its unlikely that they have a instrumented standard library it > would > > be nice if their system libc++ didn't always cause the first MSAN > failure. > > > > Since __attribute__((__always_inline__)) seems to cause a lot of these > > failures I imagine it is possible to reduce the FP's without removing the > > extern template declarations. > > In that case it might still be work putting time into. > > > > /Eric > > > > > > On Sun, Aug 17, 2014 at 8:24 PM, Howard Hinnant < > [email protected]> > > wrote: > >> > >> On Aug 17, 2014, at 9:26 PM, Justin Bogner <[email protected]> > wrote: > >> > >> > Howard Hinnant <[email protected]> writes: > >> >> On Aug 17, 2014, at 9:06 PM, Justin Bogner <[email protected]> > >> >> wrote: > >> >> > >> >>> I really don't think it's worth the cost of insantiating these very > >> >>> fundamental templates in *every single user* to work around a > >> >>> limitation > >> >>> in the memory sanitizer. This is an unreasonable amount of overhead > >> >>> for > >> >>> standard library types. > >> >> > >> >> Always measure. I’m not saying you’re wrong. I’m saying you’re > >> >> stating a performance conclusion without measurements (which should > >> >> never be acceptable). > >> > > >> > I did measure :) Though, I sent it to llvm-dev and it probably > should've > >> > been cfe-dev. Sorry about that. > >> > > >> > http://lists.cs.uiuc.edu/pipermail/llvmdev/2014-August/075793.html > >> > >> Ah, I have not been monitoring llvm-dev. Thank you for the link. > >> > >> Howard > >> > > > > > > _______________________________________________ > > cfe-commits mailing list > > [email protected] > > http://lists.cs.uiuc.edu/mailman/listinfo/cfe-commits > > > > _______________________________________________ > cfe-commits mailing list > [email protected] > http://lists.cs.uiuc.edu/mailman/listinfo/cfe-commits >
_______________________________________________ cfe-commits mailing list [email protected] http://lists.cs.uiuc.edu/mailman/listinfo/cfe-commits
