Re: [Xen-devel] [PATCH 1/1] hvm.c: Prevent gcc uninitialised var warning

[Ian Murray <murrayie@xxxxxxxxxxx>]

----- Original Message -----
> From: Jan Beulich <JBeulich@xxxxxxxx>
> To: Don Slutz <dslutz@xxxxxxxxxxx>
> Cc: Ian Murray <murrayie@xxxxxxxxxxx>; Andrew Cooper 
> <andrew.cooper3@xxxxxxxxxx>; Keir Fraser <keir@xxxxxxx>; Ian Campbell 
> <ian.campbell@xxxxxxxxxx>; xen-devel@xxxxxxxxxxxxx
> Sent: Thursday, 26 March 2015, 7:48
> Subject: Re: [Xen-devel] [PATCH 1/1] hvm.c: Prevent gcc uninitialised var     
> warning
> 
>>>>  On 25.03.15 at 21:03, <dslutz@xxxxxxxxxxx> wrote:
>>  On 03/25/15 11:48, Jan Beulich wrote:
>>>>>>  On 25.03.15 at 16:02, <andrew.cooper3@xxxxxxxxxx> 
> wrote:
>>>>  As an aside, the compiler is in a very easy position to spot this.  
> The
>>>>  error means that GCC has positively identified a basic block which 
> does
>>>>  use bufioreq_pfn before it has been initialised.
>>>> 
>> 
>>  If the compiler is right, how come the messages says:
>> 
>>  may be used
>> 
>>  which to me says that it's determination is not 100%
> 
> No, that's a wrong interpretation of the wording - it instead means
> that there is at least one path where the variable gets initialized,
> and at least one where that's not provably the case. As opposed
> to a variable being used uninitialized no matter what path leads to
> the use site.

> 


FWIW, I upgraded one of the boxes with the issue to Ubuntu 14.04.2 and gcc no 
longer complained.


# gcc --version
gcc-4.8.real (Ubuntu 4.8.2-19ubuntu1) 4.8.2



> 
> Jan
> 
> 
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@xxxxxxxxxxxxx
> http://lists.xen.org/xen-devel
> 

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel