These messages are probably about building instrumented libc++ for asan/tsan/msan testing from compiler-rt build system.
On Tue, Aug 26, 2014 at 10:27 PM, Eric Fiselier <[email protected]> wrote: > I added support for "LLVM_USE_SANITIZER" when building and testing last > week. > > I've also noticed that when I use cmake to build libc++ in tree there are > already some existing messages about > building different instrumented libc++ versions. I'm not quite sure what > those are about though. They are not coming from libc++. > > /Eric > > > On Tue, Aug 26, 2014 at 10:44 AM, Kostya Serebryany <[email protected]> wrote: >> >> >> >> >> 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
