Re: [PATCH] powerpc: Fix unitialized variable

[Stefan Liebler <stli at linux dot vnet dot ibm dot com>]

Hi Adhemerval,

i get the warning: ‘resplen’ may be used uninitialized in this function 
[-Wmaybe-uninitialized] on s390, too.

This patch disables Wmaybe-uninitialized warning on s390x with gcc 4.8, 
4.9 and gcc from today, but not on power.

Please test if it fixes your warnings too.

Bye Stefan

---
2014-12-11  Stefan Liebler  <stli@linux.vnet.ibm.com>

	resolv/res_send.c (send_vc): Disable warning resplen may
	be used uninitialized.

On 12/11/2014 12:42 AM, Adhemerval Zanella wrote:
> On 10-12-2014 19:22, Joseph Myers wrote:
> > On Wed, 10 Dec 2014, Adhemerval Zanella wrote:
> >
> > > The 'resolv/res_send.c' build with _STRING_ARCH_unaligned not defined
> > > may utilize the local resplen uninitialized.  This patch sets it to 0.
> > Do you have an actual path through the function that can result in it
> > being used uninitialized, and where a value of 0 is correct?
>
> I do not, I used as default just to avoid the warning.
>
> > My understanding, as described in
> > <https://sourceware.org/ml/libc-alpha/2014-11/msg00693.html>, was that
> > this is a false positive warning - the variable is never actually used
> > uninitialized, but determining that requires considering the values other
> > variables can have on the paths leading to resplen being used.  And since
> > we don't want to add initializations (to installed code as opposed to
> > testcases) that actually require code to be generated simply in order to
> > avoid warnings, that may indicate disabling -Wmaybe-uninitialized around
> > the code that generates the warning.
> I understand the idea of avoid such warning, I will the compiler directives.

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