ahatanak added a comment. In https://reviews.llvm.org/D29908#676589, @ahatanak wrote:
> Posting John's review comment, which was sent to the review I abandoned: > > "Hmm. The behavior I think we actually want here is that we should move out > of the __block variable but not perform NRVO, essentially like we would if > the variable were a parameter. I think that's what's happening. Because of the changes made in r274291, NRVO isn't performed, but the move constructor instead of the copy constructor is called to return the shared_ptr. The shared_ptr in the heap is moved to returned shared_ptr (%agg.result), so when the block function passed to dispatch_async is executed, it segfaults because the object "ret" used to point to has been destructed. If that's the case, should we conclude that clang is behaving as expected? > The block byref copy helper should always be doing a move if it can, > regardless of whether the function is returned. That's independent of this, > though." https://reviews.llvm.org/D29908 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
