Re: [PATCH] Makefile: add NO_CLOCK_GETTIME check

From: Junio C Hamano <gitster@pobox.com>
Date: Sep 3, 2014, 19:45 UTC
Message-ID: <xmqqwq9kwkrg.fsf@gitster.dls.corp.google.com>
In-Reply-To: <1409771687-5597-1-git-send-email-reubenhwk@gmail.com>

Reuben Hawkins <reubenhwk@gmail.com> writes:

Show 18 quoted lines

> Some really old platforms, rhel3, which don't define CLOCK_MONOTONIC, still
> need a way to build git.  Some high resolution timer code was added Jul 12,
> 2014 to aid debugging performance issues.  That code uses clock_gettime and
> CLOCK_MONOTONIC.  That change breaks building git on ancient platforms which
> don't support CLOCK_MONOTONIC, so a way to disable that code is needed.
>
> To use this feature...
>
> $ make NO_CLOCK_GETTIME=1
>
> This change amends the commit...
>
>  commit 148d6771bf5e00aa1d7fa2221507a3dfe4c1e37f
>  Author: Karsten Blees <karsten.blees@gmail.com>
>  Date:   Sat Jul 12 02:05:42 2014 +0200
>
>   trace: add high resolution timer function to debug performance issues
> ---

Show 17 quoted lines

>  Makefile | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/Makefile b/Makefile
> index 9f984a9..0c1c8cf 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -1502,10 +1502,12 @@ ifdef GMTIME_UNRELIABLE_ERRORS
>  	BASIC_CFLAGS += -DGMTIME_UNRELIABLE_ERRORS
>  endif
>  
> +ifndef NO_CLOCK_GETTIME
>  ifdef HAVE_CLOCK_GETTIME
>  	BASIC_CFLAGS += -DHAVE_CLOCK_GETTIME
>  	EXTLIBS += -lrt
>  endif
> +endif

I am not sure why you even need this change. Wouldn't you get exactly the same result if you did not define HAVE_CLOCK_GETTIME when building?

>  
>  ifeq ($(TCLTK_PATH),)
>  NO_TCLTK = NoThanks