SjoerdMeijer added inline comments.
================ Comment at: lib/Headers/float.h:137 +#ifdef __STDC_WANT_IEC_60559_TYPES_EXT__ +# define FLT16_MANT_DIG __FLT16_MANT_DIG__ ---------------- scanon wrote: > rogfer01 wrote: > > scanon wrote: > > > rogfer01 wrote: > > > > My understanding is that, given that we support TS18661-2 by default, > > > > this macro should be predefined by clang and then there is no need to > > > > protect these macros. > > > > > > > > You may want to add a test for this in `test/Preprocessor/init.c`. > > > Where do you see that the `__STDC_WANT_IEC_60559_TYPES_EXT__` macro > > > should be predefined by clang? > > Hi Steve, > > > > certainly you're right, the TS says > > > > > The new identifiers added to C11 library headers by this part of ISO/IEC > > > TS-18661 are defined or declared by their respective headers only if > > > `__STDC_WANT_IEC_60559_TYPES_EXT__` is defined as a macro at the point in > > > the source file where the appropriate header is first included. > > > > so (if I read this right) these identifiers are only available if such > > macro is defined when including `float.h`. > > > > Can I assume from your comment that someone else should define it? Perhaps > > the `float.h` header itself, some other file in the C-library > > implementation or the user of the compiler via some > > `-D__STDC_WANT_IEC_60559_TYPES_EXT__`, but not be predefined by the > > compiler? If this is the case, then the macros still have to be guarded > > conditionally (as they were in the original patch). > > > > Does this make sense? Thanks. > I think we could justify defining it ourselves under non-strict compilation > modes; alternatively, system headers might define it for users in non-strict > modes. > > My reading of the TS is that in strict mode, these types and macros should be > hidden unless the user explicitly requests them by defining > `__STDC_WANT_IEC_60559_TYPES_EXT__` themselves. Thanks, very useful discussion and clarification. I will add some tests for this, which I indeed forgot. Cheers. https://reviews.llvm.org/D34695 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
