Re: [PATCH 2/2] [PING]Testsuite for varobj updation after symbol removal

[Taimoor <tmirza@codesourcery.com>]

ping.

If there are no further comments, Can I push this change?

Thanks,
Taimoor

On 05/11/2015 06:49 PM, Taimoor wrote:
>
>
> On 04/27/2015 11:46 PM, Vladimir Prus wrote:
>>
>> thanks, so the issue is that removing a symbol file recreates
>> *all* global varobjs, and in the process clears any change of value
>> since the last update. I agree the patch is fixing that.
>>
>> There's a second change, it seems - to invalidate varobj that refers
>> to types in unloaded objfile - is there a test for that?
>>
>
> Hi Vladimir,
>
> Sorry for delayed response. There are no separate tests for invalidation
> of varobjs in unloaded objfile as it gets tested by existing varobj
> tests. If we don't invalidate varobjs in unloaded objfile, a lot GDB
> tests will fail. This is because while trying to retrieve old varobj
> value for already removed objfile (to compare with current value), it
> will try to access pointers that are no longer valid and that will
> result in failure.
> Marking varobjs that refers to types in unloaded objfile invalid makes
> sure we do not accidentally use dangling pointers to obtain varobj value
> for unloaded objfile.
>
> IMO, GDB should avoid using pointers whose target has been already freed
> and this change specifically marks var->type to NULL to make sure no
> dangling pointers remain after objfile is unloaded so any subsequent
> call to varobj_get_value does not result in segmentation fault.
>
>
> Thanks,
> Taimoor