thakis added inline comments. ================ Comment at: test/SemaCXX/auto-type-from-cxx.cpp:14 @@ +13,3 @@ + auto _ = [](__auto_type f) {}; // expected-error {{'__auto_type' not allowed in lambda parameter}} + __auto_type g = 2; + struct BitField { int field:2; }; ---------------- comex wrote: > thakis wrote: > > Shouldn't this say "warning: __auto_type is a gnu extension" (since this > > uses -std=c++14, not -std=gnu++14)? > Hmm... when I added `ext_auto_type` to the .td, I didn't notice the > difference between Extension and ExtWarn. Since the patch currently uses > Extension, it won't warn by default, but will with `-pedantic`, `-Wgnu`, or > `-Wgnu-auto-type`. The C test uses `-pedantic` so it gets the warning. > > Is there an explicit policy on which extensions should be ExtWarn? Looking > at the rest of that file, ExtWarns seem to be mostly either (a) standardized > extensions (which will warn if `-std` is too early) and (b) 'extensions' that > are more like "Clang will accept your buggy code" than features. Most GNU > extensions are just Extension, so I think it makes sense to do the same for > `__auto_type`. > > I could update the C++ test to add `-pedantic`, but arguably it makes more > sense to test the fact that the warning is not emitted by default. I'm not sure either. `typeof` warns with -std=c++14 but not with -std=gnu++14. From a user perspective, this makes sense to me: I want to write standard c++ and I want the compiler to help me with that, but I don't want to get all the pedantic warnings that -pedantic entails. For example, consider using clang-cl to build Windows code, and wanting MSVC to be able to build said Windows code too. (This can of course go wrong with standard C++ too, but in that case I'm running into MSVC bugs which will eventually be fixed.) So if it's possible to match how typeof works, I think that'd be good. If it's not possible, this wouldn't be the only GNU extension allowed in -std=c++14 mode though, so it's not a big thing.
http://reviews.llvm.org/D12686 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits