mclow.lists added a comment. In https://reviews.llvm.org/D25403#573104, @jlebar wrote:
> Likewise, should I update the documentation to indicate that check-cxx may > fail with a clang built from tip of tree, due to c++17 support being > experimental? Or do you all want to change the target so that it doesn't run > the c++17 tests by default? This burned about an hour of developer time > yesterday, I guess because we couldn't believe that check-cxx would be > intentionally broken like that, so it would be nice to have some sort of fix. Yesterday and today is the first time in a while that clang has been seriously broken for more than an hour or so. I'm not inclined to worry about it yet. >> I don't see how this can possibly be constexpr. >> it calls isfinite(), which is hoisted from ::isfinite(), which comes from >> the C library. >> Since C knows nothing about constexpr, we're stuck. > > Functions that call non-constexpr things can be marked constexpr; you just > can't evaluate them in a constexpr context (as you demonstrated). > > All I need is for the function to be marked as constexpr; I do not need the > function be constexpr-evaluatable. Then what's the point? How can you test if it is correct? > I think the implications of this change would be that, if you evaluated this > function in a constexpr context, before the change would be a compile error > when calling __libcpp_isnan, and after this change it would be a compile > error at calling ::isnan. Since the function should not be called outside of > libc++ anyway, I was hoping that wouldn't make a difference to anyone. I guess I don't understand the motivation for this change. https://reviews.llvm.org/D25403 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
