Re: Which MI behavior is correct ?

[Maxim Grigoriev <maxim@tensilica.com>]

Thanks !

I understand we're going to have to upgrade our GNU XT-GDB 6.5 to be able
to use the '@' syntax.

-- Maxim

Jim Blandy wrote:
> Maxim Grigoriev <maxim@tensilica.com> writes:
>   
>> This seems to be an answer to my question. The behavior has changed
>> probably since somewhere around 6.3. Now, variable objects are associated
>> with the frame, not with the function. As you can see in gdb 6.3 case
>> ( NATIVE.log ), variables "var1" and "var2" were successfully reused,
>> when new frame was allocated after hitting the breakpoint second time.
>> In 6.5+ (XTENSA.log), we have to recreate variable objects every time
>> we have a new frame because the old variables are out of scope.
>>     
>
> Just to connect this old thread with newer conversation:
>
> To avoid recreating variable objects, you probably want to pass '@' as
> your frame to -var-create.  This makes the varobj re-parse and
> re-evaluate the expression using the currently selected frame at each
> update.
>
> Old-style varobjs that use '*' or an address as their frame should
> never come back into scope once their frame is popped.  If they do,
> it's a fluke.
>
> The '@' syntax is undocumented; I posted a manual patch based on some
> experimentation and reading the code:
>
> http://sourceware.org/ml/gdb-patches/2007-05/msg00397.html
>