svn commit: r307756 - in head: include sys/sys

[John Baldwin]

On Saturday, October 22, 2016 12:00:56 AM Brooks Davis wrote:
> On Fri, Oct 21, 2016 at 11:50:02PM +0000, John Baldwin wrote:
> > Author: jhb
> > Date: Fri Oct 21 23:50:02 2016
> > New Revision: 307756
> > URL: https://svnweb.freebsd.org/changeset/base/307756
> > 
> > Log:
> >   Define max_align_t for C11.
> >   
> >   libc++'s stddef.h includes an existing definition of max_align_t for
> >   C++11, but it is only defined for C++, not for C.  In addition, GCC and
> >   clang both define an alternate version of max_align_t that uses a
> >   union of multiple types rather than a plain long double as in libc++.
> >   This adds a __max_align_t to <sys/_types.h> that matches the GCC and
> >   clang definition that is mapped to max_align_t in <stddef.h>.
> >   
> >   PR:		210890
> >   Reviewed by:	dim
> >   MFC after:	1 month
> >   Differential Revision:	https://reviews.freebsd.org/D8194
> > 
> > Modified:
> >   head/include/stddef.h
> >   head/sys/sys/_types.h
> > 
> > Modified: head/include/stddef.h
> > ==============================================================================
> > --- head/include/stddef.h	Fri Oct 21 21:55:50 2016	(r307755)
> > +++ head/include/stddef.h	Fri Oct 21 23:50:02 2016	(r307756)
> > @@ -62,6 +62,14 @@ typedef	___wchar_t	wchar_t;
> >  #endif
> >  #endif
> >  
> > +#if __STDC_VERSION__ >= 201112L || __cplusplus >= 201103L
> > +#ifndef __CLANG_MAX_ALIGN_T_DEFINED
> > +typedef	__max_align_t	max_align_t;
> > +#define __CLANG_MAX_ALIGN_T_DEFINED
> > +#define __GCC_MAX_ALIGN_T
> > +#endif
> > +#endif
> > +
> >  #define	offsetof(type, member)	__offsetof(type, member)
> >  
> >  #endif /* _STDDEF_H_ */
> > 
> > Modified: head/sys/sys/_types.h
> > ==============================================================================
> > --- head/sys/sys/_types.h	Fri Oct 21 21:55:50 2016	(r307755)
> > +++ head/sys/sys/_types.h	Fri Oct 21 23:50:02 2016	(r307756)
> > @@ -100,6 +100,11 @@ typedef	__uint_least32_t __char32_t;
> >  #define	_CHAR32_T_DECLARED
> >  #endif
> >  
> > +typedef struct {
> 
> Should this be union per the commit message?

Dimitry's response is correct of course.  I think my brain had "fixed" this
when I read it to be a union instead of a struct since a struct seems so
obviously wrong.

-- 
John Baldwin