[patch] Use --enable-libstdcxx-time=yes on DragonFly BSD

[Jonathan Wakely]

On 13 March 2015 at 08:50, John Marino wrote:
> Hi Jonathan,
> Today I build gcc5 and looked at the config.h contained in
> libstdc++-v3's build directory and none of those variables are enabled.
>
> The code that is patched doesn't seem to do anything.  I grepped the
> entire build directory for "libstdcxx_time" and got no results.
>
> I don't have "--enable-libstdcxx-time" set as a configure argument.  So
> I am thinking somehow this configuration check got skipped completely.

Hi John,

The variables cause additional checks to be run in configure, which
then result in these macros in c++config.h


/* Defined if clock_gettime has monotonic clock support. */
#define _GLIBCXX_USE_CLOCK_MONOTONIC 1

/* Defined if clock_gettime has realtime clock support. */
#define _GLIBCXX_USE_CLOCK_REALTIME 1

and

/* Defined if nanosleep is available. */
#define _GLIBCXX_USE_NANOSLEEP 1

and

/* Defined if sched_yield is available. */
#define _GLIBCXX_USE_SCHED_YIELD 1

I see these defined in
include/x86_64-unknown-dragonfly3.6/bits/c++config.h and I also see
previously UNSUPPORTED tests now PASS, so I think it's working.