Re: [RFA]: Add declaration for `alloca' to stdlib.h

["J. Johnston" <jjohnstn at cygnus dot com>]

"J. Johnston" wrote:
> 
> Corinna Vinschen wrote:
> >
> > Hi,
> >
> > newlib omits a declaration for alloca() in stdlib.h as it's described
> > e.g. in the Linux man pages.
> >
> > The following patch to libc/include/stdlib.h does that.  It declares
> > alloca() as external unless __GNUC__ is defined.  In that case alloca()
> > is defined as __builtin_alloca().
> >
> > Another way to implement that would be to include <alloca.h> if the
> > system has that file (as e.g. for linux in libc/sys/linux/include).
> >
> > If you prefer that, I will propose another patch which only includes
> > alloca.h for Linux and Cygwin and add a alloca.h file to libc/sys/cygwin.
> >
> 
> This is a BSD-extension, it is not ANSI, POSIX, nor Single Unix.
> It should be protected from __STRICT_ANSI__ applications.
> 
> IMO, the file from libc/sys/linux/include could be copied to the common
> include directory with an added __GNUC__ check.  There is no reason that
> other platforms couldn't use this functionality as well.
> 
> The stdlib.h directory should include <alloca.h> only if not

              ^ replace "directory" with "header file"
> __STRICT_ANSI__.
> 
> -- Jeff J.
> 
> > Corinna
> >
> > 2001-11-12  Corinna Vinschen  <vinschen@redhat.com>
> >
> >         * libc/include/stdlib.h: Add declaration for alloca().
> >
> > Index: libc/include/stdlib.h
> > ===================================================================
> > RCS file: /cvs/src/src/newlib/libc/include/stdlib.h,v
> > retrieving revision 1.11
> > diff -u -p -r1.11 stdlib.h
> > --- stdlib.h    2001/10/01 18:05:09     1.11
> > +++ stdlib.h    2001/11/12 12:50:04
> > @@ -45,6 +45,12 @@ extern __IMPORT int __mb_cur_max;
> >
> >  _VOID  _EXFUN(abort,(_VOID) _ATTRIBUTE ((noreturn)));
> >  int    _EXFUN(abs,(int));
> > +#ifdef __GNUC__
> > +#define alloca(size) __builtin_alloca(size)
> > +#else
> > +void * _EXFUN(alloca,(size_t));
> > +#endif
> > +
> >  int    _EXFUN(atexit,(_VOID (*__func)(_VOID)));
> >  double _EXFUN(atof,(const char *__nptr));
> >  #ifndef __STRICT_ANSI__
> >
> > --
> > Corinna Vinschen
> > Cygwin Developer
> > Red Hat, Inc.
> > mailto:vinschen@redhat.com