Re: [RFC] varobj deletion after the binary has changed

[Denis PILAT <denis.pilat@st.com>]

Daniel Jacobowitz wrote:
> On Tue, Jan 23, 2007 at 01:32:22PM +0100, Denis PILAT wrote:
>   
>> Hi,
>>
>> We have a bug in one of our gdb target, when the binary changed while 
>> beeing debugged it appears that some of our varobj refers to invalid 
>> symbols or type.
>>
>> I propose a patch that delete all varobj when symbols are reloaded. May 
>> be there is a better place to do that but I think we must do that 
>> somewhere, don't you ?
>>     
>
> The right thing to do is probably to figure out where the
> invalid references come from and fix them - probably by re-evaluating
> expressions at the next -var-update.  Deleting things behind the front
> end's back is a bad policy.
>
>
>   
Deleting all is a little bit radical, I can understand that.
Re-evaluating expression would give the expected thing for globale 
variables, but for varobj that has been set on local variable (so within 
a "valid_block"), it should have side effects: the evaluation of the 
expression might tied the varobj to a variable different than the one 
the user originally decided.

I propose to distinguish 2 cases
- varobj on global variable (valid_block == null) must have their 
expression re-evaluated.
- other one must be put in a kind of invalid state that will gives 
"in_scope="false" to the user.
This last point will involve a new field in varobj structure, I haven't 
seen something to mark varobj as invalid.

Denis