thakis added inline comments.
================ Comment at: clang/test/Parser/objc-static-assert.mm:1 +// RUN: %clang_cc1 -fsyntax-only -verify -Wno-objc-root-class %s + ---------------- aaron.ballman wrote: > thakis wrote: > > aaron.ballman wrote: > > > Can you try explicitly specifying C++98 as the underlying language > > > standard mode? I feel like `_Static_assert()` will continue to work there > > > (because we made it a language extension in all modes) but > > > `static_assert()` may fail (because that's gated on C++11 support). If > > > that turns out to be the case, then I think `objc_static_assert` should > > > be more complex than expanding to `true`, or we should talk about > > > supporting `static_assert()` in all C++ language modes like we do for > > > `_Static_assert()`. > > Correct, with -std=c++98 static_assert isn't available but _Static_assert > > still is. If you want, I can add a test for this, but this is covered by > > regular c++ tests already. > > > > I think the has_feature() should stay as-is though: Else you have no way to > > know if _Static_assert works in obj-c mode, and you can check if > > static_assert works by checkout has_feature && __cplusplus >= 201103L if > > you still care about c++98. > > > > (And adding one feature each for static_assert and _Static_assert seems > > like overkill.) > > Correct, with -std=c++98 static_assert isn't available but _Static_assert > > still is. If you want, I can add a test for this, but this is covered by > > regular c++ tests already. > > Please do (if we don't change the availability of `static_assert()`), because > the test currently relies on the unwritten -std option in order to pass. > > > I think the has_feature() should stay as-is though: Else you have no way to > > know if _Static_assert works in obj-c mode, and you can check if > > static_assert works by checkout has_feature && __cplusplus >= 201103L if > > you still care about c++98. > > I don't think this is the correct approach. Testing for `static_assert()` > support should not leave the user guessing at what the correct spelling is. > > > (And adding one feature each for static_assert and _Static_assert seems > > like overkill.) > > Definitely agreed there. > > I think the correct way forward is to support `static_assert()` in all > language modes like we already do for `_Static_assert()`, then > `objc_static_assert` becomes useful as-is. I cannot think of a reason why we > would want to allow `_Static_assert()` in C++ but not allow `static_assert()`. I updated the test. Accepting `static_assert()` independent of language mode seems pretty unrelated to this patch here, so I don't want to do this. If you don't like the current has_feature approach, I'm all ears for other approaches. The current approach allows you to detect if clang can handle static_assert in objc objects, and codebases that still care about c++98 will have a static_assert wrapping macro keyed off __cplusplus already, so that part will transparently just work as well. And codebases that are c++11 and newer are in a good position too. I think the current setup is pretty good. (But I'm happy to hear better suggestions.) CHANGES SINCE LAST ACTION https://reviews.llvm.org/D59223/new/ https://reviews.llvm.org/D59223 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
