On 10/12/2021 16.06, Olivier Hainque wrote: > Hello, > > The attached patch for libstdc++ / VxWorks helps building > the library for old versions of the OS, as witnessed with > VxWorks 6.9 in particular. > > It explicitly requests C99 features from old system headers, > on which libstc++ relies since at least c++98. The specific > issue that exposed this was a failure to compile > > libstdc++-v3/src/c++17/floating_to_chars.cc > > for VxWorks 6.9 with a batch of errors such as: > > error: 'FP_NAN' was not declared in this scope > > The missing definitions are provided by the > system headers with guards on _HAS_C9X, which gets > internally defined when _C99 is. > > Ok to commit?
Yes, we've observed that error as well. We have just patched our vxworks 5.5 headers to provide FP_NAN et al. There's no test of definedness or other uses of a _C99 macro anywhere, so ok by me, as it shouldn't change anything on our end. Rasmus
