[PATCH] Fix libstdc++ usage of __ctype_b/__ctype_to*

[Benjamin Kosnik]

> > > -#if _GLIBCPP_USE_SHADOW_HEADERS
> > > +#if _GLIBCPP_C_LOCALE_GNU
> > > +  const ctype_base::mask*
> > > +  ctype<char>::classic_table() throw()
> > > +  {
> > > +    if (!_S_c_locale)
> > > +      _S_create_c_locale(_S_c_locale, "C");
> > > +    return _S_c_locale->__ctype_b;
> > > +  }
> > > +#else
> > 
> > _S_c_locale should be created before this. I suppose this is safer.
> 
> Most probably yes, but as it is a static method I wanted to be sure.
> Should I leave it in?

Sure.

> > > +# if _GLIBCPP_USE_SHADOW_HEADERS
> > >    using _C_legacy::__ctype_toupper;
> > >    using _C_legacy::__ctype_tolower;
> > >    using _C_legacy::__ctype_b;
> > > -#endif
> > 
> > Just remove all this _GLIBCPP_USE_SHADOW_HEADERS cruft.
> 
> You mean the using lines too?

Yep.

> > >    const ctype_base::mask*
> > >    ctype<char>::classic_table() throw()
> > > -  { return __ctype_b; }  
> > 
> > Why not just _S_c_locale->__ctype_b?
> 
> Well, I use _S_c_locale->__ctype_b #ifdef _GLIBCPP_C_LOCALE_GNU,
> otherwise _S_c_locale is NULL (config/locale/generic/c_locale.cc has:
>   void
>   locale::facet::_S_create_c_locale(__c_locale& __cloc, const char*,
>                                     __c_locale)
>   { __cloc = NULL; }
> ) and it is a bad idea to dereference it...

Whoops. Right. This is ok then.

> 
> > 
> > > -  
> > > +  {
> > > +    const ctype_base::mask* __ret;
> > > +    char* __old = strdup(setlocale(LC_CTYPE, NULL));
> > > +    setlocale(LC_CTYPE, "C");
> > > +    __ret = __ctype_b;
> 
> BTW: This will have the effect that --enable-clocale=generic will no longer
> work with glibc 2.3+. Although for everything but checking the generic
> clocale gnu it makes no sense to use anything but --enable-clocale=gnu
> with glibc 2.3+, we might as well consider using:
> 
> #if __GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ > 2)
> 	__ret = *__ctype_b_loc();
> #else
> 	__ret = __ctype_b;
> #endif
> here (and similarly with __ctype_tolower and __ctype_toupper).

Sounds good.

-benjamin