Re: Moving C11 Functions from winsup to newlib

Hi Joel,

On Mar 14 11:53, Joel Sherrill wrote:
> Hi
> 
> In looking at what's missing from RTEMS for C11, I noticed that these from
> uchar.h are in winsup (as .cc) but not in newlib.
> 
> size_t c16rtomb(char *restrict, char16_t, mbstate_t *restrict);
> size_t c32rtomb(char *restrict, char32_t, mbstate_t *restrict);
> size_t mbrtoc16(char16_t *restrict, const char *restrict, size_t, mbstate_t
> *restrict);
> size_t mbrtoc32(char32_t *restrict, const char *restrict, size_t, mbstate_t
> *restrict);
> 
> Would it be ok to move them to the newlib side?

We can move the uchar.h header to newlib verbatim, it's target
independent.

It's not as easy for the actual implementation, because Cygwin's
implementation relies on char16_t being equivalent to wchar_t as Cygwin
uses the Windows UTF-16 as wchar_t type for simplicity.

A truly independent implementation must not rely on wchar_t being any
Unicode variation, be it UCS-2, UTF_16, or UTF-32.

Some systems have their own wchar_t, as with the historical
implementations of wchar_t in newlib/libc/ctype/jp2uc.c for japanese
codesets (S)JIS/EUCJP.
We should probably get rid of them in favor of true wchar_t == "Some
Unicode" for *all* targets.

> Add a uchar directory? Or where?

Either that, or in string.

> What about converting the implementation to C? Is that needed?

The Cygwin functions are plain C. They are just inside a C++ source.


Corinna