MI questions from eclipse.org

[Andrew Cagney]

> * Variable notification
>>   - assignment: Doing a -var-assign follow by a
>>     -var-update does not show any variables been change.
>>     Is this the behaviour?
> 
> 
> Yes. (Didn't I get back to you on this already? I thought I had.) Any, the 
> way varobj works, it saves a copy of GDB's internal representation for a 
> variable. When one updates the root (-var-update), it computes a new 
> "value" and compares against the old one.
> 
> When you assign a new value to a variable (and it succeeds), this new 
> "value" is saved and used for subsequent comparisons (of whether anything 
> has changed). This contrasts to how registers work, but the register stuff 
> is wrong, IMO. :-) (This happens because MI doesn't modify its "value" for 
> the register like varobj does.)
> 
> 
>>   - And on a more complex note, doing -data-write-memory
>>     to some memory and the memory was a variable object
>>     should -var-update notice this?
> 
> 
> Yes. In HEAD sources it certainly does. [Aside: In mi2, this will trigger
> an event telling you that something has changed. Unfortunately, we cannot 
> tell you WHAT changed. Only that the state of the target has changed. This 
> is necessary because there are some really goofy systems out there, like 
> those with memory-mapped registers.]

Yes.

The upper bound on the performance is the same as single step.

Andrew