# read-cache-v5.c: compiler warnings

3 messages from 2012-08-19 to 2012-08-21. Participants: Ramsay Jones, Thomas Gummerer.
Thread: https://gitlist.dev/t/31285

## Ramsay Jones, 2012-08-19 19:13

Subject: read-cache-v5.c: compiler warnings
Message-ID: <50313AEC.1060700@ramsay1.demon.co.uk>
URL: https://gitlist.dev/e/50313AEC.1060700%40ramsay1.demon.co.uk

```
Hi Thomas,

Just an FYI; two out of the three gcc compilers I use (Linux, cygwin
but not MingW), issue the following warnings:

        CC read-cache-v5.o
    read-cache-v5.c: In function `write_index_v5':
    read-cache-v5.c:1011: warning: 'dir' might be used uninitialized in this function
    read-cache-v5.c:1012: warning: 'search' might be used uninitialized in this function
    read-cache-v5.c:1012: warning: 'found' might be used uninitialized in this function

[commit d2537158 ("Write index-v5", 16-08-2012)]

Normally I would take a look and offer a patch, but I haven't found time
to do so in the last 10 days. So, I'm just giving you a heads up ... ;-P

HTH

ATB,
Ramsay Jones

```

## Thomas Gummerer, 2012-08-20 08:29

Subject: Re: read-cache-v5.c: compiler warnings
Message-ID: <20120820082854.GA10909@tommy-fedora>
URL: https://gitlist.dev/e/20120820082854.GA10909%40tommy-fedora
In-Reply-To: <50313AEC.1060700@ramsay1.demon.co.uk>

```
On 08/19, Ramsay Jones wrote:
> Hi Thomas,
> 
> Just an FYI; two out of the three gcc compilers I use (Linux, cygwin
> but not MingW), issue the following warnings:
> 
>         CC read-cache-v5.o
>     read-cache-v5.c: In function `write_index_v5':
>     read-cache-v5.c:1011: warning: 'dir' might be used uninitialized in this function
>     read-cache-v5.c:1012: warning: 'search' might be used uninitialized in this function
>     read-cache-v5.c:1012: warning: 'found' might be used uninitialized in this function
> 
> [commit d2537158 ("Write index-v5", 16-08-2012)]
> 
> Normally I would take a look and offer a patch, but I haven't found time
> to do so in the last 10 days. So, I'm just giving you a heads up ... ;-P

Thanks for noticing.  This warnings only seem to be issued by older
versions of gcc, which is probably why two compilers give the warnings
while one doesn't.

The variables can never be uninitialized, because they are guarded by
ifs and older versions don't seem to recognize that.  I'll fix them
in a re-roll though (or a separate patch if that's preferred), just
waiting for some feedback for v4 of my series.

> 
> HTH
> 
> ATB,
> Ramsay Jones
> 

Thomas

```

## Ramsay Jones, 2012-08-21 19:04

Subject: Re: read-cache-v5.c: compiler warnings
Message-ID: <5033DBC9.7010707@ramsay1.demon.co.uk>
URL: https://gitlist.dev/e/5033DBC9.7010707%40ramsay1.demon.co.uk
In-Reply-To: <20120820082854.GA10909@tommy-fedora>

```
Thomas Gummerer wrote:
> On 08/19, Ramsay Jones wrote:
>> Hi Thomas,
>>
>> Just an FYI; two out of the three gcc compilers I use (Linux, cygwin
>> but not MingW), issue the following warnings:
>>
>>         CC read-cache-v5.o
>>     read-cache-v5.c: In function `write_index_v5':
>>     read-cache-v5.c:1011: warning: 'dir' might be used uninitialized in this function
>>     read-cache-v5.c:1012: warning: 'search' might be used uninitialized in this function
>>     read-cache-v5.c:1012: warning: 'found' might be used uninitialized in this function
>>
>> [commit d2537158 ("Write index-v5", 16-08-2012)]
>>
>> Normally I would take a look and offer a patch, but I haven't found time
>> to do so in the last 10 days. So, I'm just giving you a heads up ... ;-P
> 
> Thanks for noticing.  This warnings only seem to be issued by older
> versions of gcc, which is probably why two compilers give the warnings
> while one doesn't.

You would hope that was true, but I would not bet on it! I've seen these types
of warnings (which rely heavily on analysis performed primarily for optimisation)
come and go several times in gcc.

> The variables can never be uninitialized, because they are guarded by
> ifs and older versions don't seem to recognize that.  I'll fix them
> in a re-roll though (or a separate patch if that's preferred), just
> waiting for some feedback for v4 of my series.

Thanks!

ATB,
Ramsay Jones

```