From: Björn Steinbrink <b.steinbrink@gmx.de>
Date: Fri, 16 Nov 2007 12:55:27 GMT
Subject: Re: [PATCH] Fix "identifier redeclared" compilation error with SUN cc.
Message-ID: <20071116125527.GB14473@atjola.homenet>
In-Reply-To: <7vd4ua3hww.fsf@gitster.siamese.dyndns.org>

On 2007.11.15 20:58:55 -0800, Junio C Hamano wrote:
> How about doing it this way?
> 
>   # ifndef FLEX_ARRAY
>   #   if defined(__GNUC__)
>   #     if (__GNUC__ < 3)
>   #       define FLEX_ARRAY 0
>   #     else
>   #       define FLEX_ARRAY /* empty */
>   #     endif
>   #   else
>         /* more cases we know we can use 0 or empty can come here */
>   #   endif
>   # endif
> 
>   /* if still undefined, default to the safe, old fashioned way */
>   # ifndef FLEX_ARRAY
>   #   define FLEX_ARRAY 1
>   # endif

Yeah, looks a bit smarter.

> The basic idea is:
> 
>  * The user (from Makefile command line, config.mak, or you
>    could add autoconf test) can pass -DFLEX_ARRAY=... to specify
>    exactly what should happen;

Eeeek! He said autoconf! Waaah! ... Ehrm, sorry where was I?

>  * Otherwise, if we happen to know for sure that we can use "0"
>    or "/* empty */" with the compiler, we define FLEX_ARRAY;
>    currently we know such things for gcc.
> 
>  * For everybody else, we use safer default of "1".  IOW, if you
>    know your compiler does not grok "/* empty */" nor "0", you
>    do not have to do anything special but use the default case
>    as everybody else.

Yep, definitely better than my patch.

Björn