Re: [PATCH] Remove useless if-before-free tests.

From: Jim Meyering <jim@meyering.net>
Date: Feb 18, 2008, 09:01 UTC
Message-ID: <87ve4my6y2.fsf@rho.meyering.net>
In-Reply-To: <alpine.LSU.1.00.0802172210470.30505@racer.site>

Johannes Schindelin <Johannes.Schindelin@gmx.de> wrote:

Show 11 quoted lines

> On Sun, 17 Feb 2008, Jim Meyering wrote:
>
>> It is equivalent not just because POSIX has required free(NULL) to work
>> for a long time, but simply because it has worked for so long that no
>> reasonable porting target fails the test. Here's some evidence from
>> nearly 1.5 years ago:
>>
>>     http://www.winehq.org/pipermail/wine-patches/2006-October/031544.html
>
>>From this mail, we see that there is at least one target where this leads
> to a crash (remember, git should run on more platforms than Wine).

Hi,

Thanks for the feedback.

FYI, you don't have to go back 20+ years to 3BSD to find a system on which free(NULL) fails :-) SunOS4's did, too. So if that is a reasonable porting target for git, then you will need the wrapper. With references to "SunOS" in Makefile and configure, I did wonder about that. Let me know and I'll adjust the proposed patch.

Show 14 quoted lines

> However, such a crash is pretty obvious in our test-suite, I guess, and
> thus we could easily introduce something like this into git-compat-util.h
> should the need ever arise:
>
> #ifdef FREE_NULL_CRASHES
> inline void gitfree(void *ptr)
> {
> 	if (ptr)
> 		free(ptr);
> }
> #define free gitfree
> #endif
>
> IOW I like that type of cleanup.

:-)