[cfe-dev] LibC++ v3.8 - Problems with ISO C wrapper headers

[David Chisnall via cfe-dev]

On 26 Jan 2016, at 20:09, Martin J. O'Riordan via cfe-dev <cfe-dev at lists.llvm.org> wrote:
> 
> And C++ also requires that some parts of the interfaces from C are presented to C++ as functions - examples being ‘fpclassify’, ‘signbit’ etc.  These have to be handled differently, and I think that the current LibC++ approach to these is good and maintains semantic compatibility with C.
>  
> I had intended to build a patch file of my changes today in case anyone is interested, but other things got me busy.  I’ll do that tomorrow and attach it to this thread.
>  
> I think that it is a good idea to have LibC++ provide its own wrapper headers for the C headers.  It is a logical place to deal with portability issues that arise when referring to C headers provided by newlib, uclibc or glibc (and other less well known implementations).  The handling of these portability issues will mean that the ‘c’ prefixed C++ headers will need little or no alteration and just maintain the ‘std’ namespace.
> 

I note that none of your listed libc implementations are the defaults on the operating systems that ship libc++ as the default C++ standard library implementation…

It would be very helpful for people who are working on this to provide a set of recommendations for C library maintainers to make C++ interoperability easier.  That way, those of us who do have control over the libc headers can work from the other end to improve the situation.

David