[Bug bootstrap/51705] FreeBSD uses unsupported C++11 features when __cplusplus == 201103L

["sgk at troutmask dot apl.washington.edu" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51705

--- Comment #20 from Steve Kargl <sgk at troutmask dot apl.washington.edu> 2011-12-30 17:26:30 UTC ---
On Fri, Dec 30, 2011 at 10:45:38AM +0000, andreast at gcc dot gnu.org wrote:
> With the below 'hack' I'm able to bootstrap on x86_64-*-freebsd10.0.
> I'm not sure why my system does not like the original four escape backslashes
> in the select and sed line.
> 
> The diff between the sys/cdefs.h and the fixed sys/cdefs.h looks like this:
> 
> -#define        _Noreturn               [[noreturn]]
> +#define        _Noreturn               __dead2
> 
> + * g++ -std=c++11 defines __cplusplus to 201103L, which lies about
> + * the level of support g++ has for the C++11 standard.
> + */
> +fix = {
> +    hackname  = cdef_cplusplus;
> +    mach      = "*-*-freebsd10.*";
> +    files     = sys/cdefs.h;
> +    select    = "\\[\\[noreturn\\]\\]";
> +    sed       = "s/\\[\\[noreturn\\]\\]/__dead2/";

Are you using bash and GNU sed instead of FreeBSD's sh
and sed?  When I used the above patterns, the changed
file contained

#define        _Noreturn               [[noreturn__dead2]