Build error for wcwidth and gcvt

[Kota Uchida]

I got understand about wchar_t data sizes.
I fixed my patch and sent it:
https://sourceware.org/ml/newlib/2019/msg00322.html

> The header should be kept untouched, of course.

The header file (wchar.h) must be fixed in order to
match types between the header and .c file.

On Mon, Jul 22, 2019 at 7:51 PM Corinna Vinschen <vinschen@redhat.com> wrote:
>
> On Jul 22 11:46, Thomas Wolff wrote:
> > On 22.07.2019 11:04, Corinna Vinschen wrote:
> > > On Jul 20 17:50, Kota Uchida wrote:
> > > > Hi All,
> > > >
> > > > This is my first mail to newlib community.
> > > > I've send this mail because I found some build errors
> > > > on newlib's master branch.
> > > >
> > > > Cygwin: unbreak the build with GCC 7
> > > > 6b7723a83032bd355d3c529d957fe209cb35b4d9
> > > >
> > > > I encountered 2 errors about wcwidth and gcvt.
> > > > I've pushed simple patches to forked repository:
> > > > https://github.com/uchan-nos/newlib-cygwin/commits/fix-build
> > The first patch is not correct:
> > - wcwidth (const wint_t wc)
> > + wcwidth (const wchar_t wc)
> >
> > Note the manual page.
> > Even if you see the wchar_t definition for Linux/POSIX, note that wchar_t
> > has 32 bits there.
> > On cygwin, however, wchar_t was defined to have only 16 bits, corresponding
> > to the Windows UTF-16 encoding.
> > The wcwidth parameter type wint_t is needed to support width enquiries for
> > non-BMP characters;
> > changing it would seriously deprive the function of part of its
> > capabilities.
> > Thomas
>
> We might need a generic and a Cygwin-specific definition in the source, i.e.
>
>   #ifdef __CYGWIN__
>   use wint_t
>   #else
>   use wchar_t
>   #endif
>
> The header should be kept untouched, of course.
>
>
> Corinna
>
> --
> Corinna Vinschen
> Cygwin Maintainer
> Red Hat