vsk added a comment. In https://reviews.llvm.org/D21695#513723, @filcab wrote:
> In https://reviews.llvm.org/D21695#510788, @vsk wrote: > > > After reading through the discussion in https://reviews.llvm.org/D19668, I > > don't think I understood the pros/cons of using a single ABI check (like > > asan does) versus adding version numbers to each handler routine. With the > > latter approach, wouldn't users only be able to link old object files with > > new runtimes if we never delete old checks? If that's the case, and > > assuming that we'd like to delete old checks, a single version symbol check > > would accomplish the same thing. > > > With ASan it's very easy to add a single symbol for all of it, since it's a > single pass, and when it runs, instrumentation is added. For UBSan it depends > on it being enabled and you hitting a place where it checks for it. We can > emit the version check symbol in emitCheckHandlerCall, though. Ah, yeah, I can see how this might be cumbersome. > With split versioning, as long as the checks you enable don't get different > versions (it's rare that we change checks, too), they'll still work (arguably > this is not as valuable as I think it is, but things like Android frameworks > enabling UBSan checks in production might make it more valuable). Running sanitized programs in production sounds strange to me. But, if there isn't really a cost to supporting this, I suppose it's fine. ================ Comment at: lib/CodeGen/CGExpr.cpp:2473 @@ +2472,3 @@ + ("__ubsan_handle_" + CheckName + + (CheckInfo.Version ? "_v" + std::to_string(CheckInfo.Version) : "") + + (NeedsAbortSuffix ? "_abort" : "")) ---------------- filcab wrote: > vsk wrote: > > Wdyt of dropping the "_vN" component if the version is 0? That's one less > > compiler-rt change that we'd need. > That's what it's doing: > (CheckInfo.Version ? "_v" + std::to_string(CheckInfo.Version) : "") > Of course! My mistake. https://reviews.llvm.org/D21695 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
