Re: MI: frozen variable objects

[Vladimir Prus <ghost@cs.msu.su>]

Frederic RISS wrote:

> On Thu, 2006-11-16 at 06:58 -0700, Greg Watson wrote:
>> I don't really understand the motivation for putting this kind of
>> functionality into gdb. Any GUI that is more than just a front-end
>> for gdb will most likely have an internal data structure representing
>> the value of the variable, and can retain or manage access to the
>> value if required. It seems to me that adding functionality like this
>> to gdb just adds to bloat when it is really a GUI function anyway.
> 
> The interesting part seems to be the one that hasn't been submited yet
> about GDB auto-freezing some values due to archtectural requirements.
> The debugger has architectural knowledge and it shouldn't be necessary
> to duplicate it in the GUI.
> I agree with your general point though. Maybe the functionality
> shouldn't be in the debugger, but the information should be available to
> the GUI... through varobj properties maybe? Of course this means that
> the GUIs have to known about and respect this information.

Since GUI typically rely to -var-update to read and report which values have
changed, it's best to change -var-update not to implicitly read
read-sensitive values. Doing this in GUI requires that GUI never
issues -var-update for a variable object that contains read-sensitive
children. That would be quite a drastic change in GUI architecture.

With frozen variable object as implemented in the patch, GUI need only
localized straight-forward changes.

- Volodya