Re: Understanding GDB frames

[Ross Morley <ross@tensilica.com>]

Marc Gauthier wrote:

>Ross Morley wrote:
>  
>
>>Associating them with the function has problems with recursion. 
>>It seems to
>>me the ideal is to recreate vars that have gone out of scope (they really
>>are new vars). Use of a scope breakpoint can better detect that than the
>>current methods. However, are there implementation or performance issues?
>>    
>>
>
>As we discussed offline yesterday, this has performance implications
>on the GUI, which would have to recreate the varobjs every time which
>is time consuming.  
>

> And (a) being optional, could be fully supported
>like watchpoints by setting a breakpoint at the return PC, even though
>it has a performance hit (especially in the presence of recursion).
>
>  
>

I believe the performance implication comes mainly from the MI client
having to recreate the MI vars, not so much from the scope breakpoint.
If I recall correctly, the scope breakpoint would disappear the first
time the var went out of scope, and would not exist subsequent times
until the target stops and is resumed again (however it's been a while
since I looked at scope breakpoints).

Ross