Re: [rfc] Annotation level THREE

[Nick Roberts <nick@nick.uklinux.net>]

 > >  > Why do you need display-{begin,end}?  -display-insert has been made 
 > >  > redundant by the varobj stuff - it lets the GUI efficiently track its 
 > >  > display values outside of the CLI.  
 > > 
 > > Variable objects don't auto-display. You seem to have to type
 > > -var-evaluate-expression each time the program stops. 
 > 
 > Why do you need auto-display?  What are you using it for?
 > 
 > Remember, every time the target changes (e.g., from a user modifying a 
 > variable or register), the display needs to be updated.  This is because 
 > that variable/register has the potential to modify every single value 
 > being displayed.  Further, unless your using some sort of changes-only 
 > mechanism, such as provided by the varobj, the display windows are just 
 > not going to scale.

You're right. If the user assigns a value to a variable, using my code, the
display window for that variable won't update in Emacs until the next
statement is executed.

What do you mean by `not going to scale'? Currently if I display an array
slice, say just a few elements from a large array, I need to parse them from
output for the whole array. Could I arrange for GDB to just output the elements
I want using variable objects?

Can I get GDB to tell me what the current list of variable objects is? Can
I generate names for them automatically?

 > >  >  The testsuite is a good source of 
 > >  > varobj examples (unfortunatly lacking from the doco):
 > >  > http://sources.redhat.com/gdb/current/onlinedocs/gdb_25.html#SEC565
 > > 
 > > The lack of documentation for (and apparent completeness of) GDB/MI is part of
 > > the problem.
 > 
 > Um, the varobj is documented.  It just lacks a vew concrete examples. 
 > Those can be found by examining the testsuite.  Both Apple and Eclipse 
 > are using this part of the MI.

Its a question of resources. I'm one person doing things in my spare time.
Apple and Eclipse have full time teams dedicated to the task.

 > >  > The above list also contains thing like field-{begin,end}, 
 > >  > array-section-{begin,end} et.al.  Why are they needed.
 > > 
 > > I use them to parse the output. They could probably go, if necessary, but
 > > others that you plan to take out *are* needed.
 > 
 > Can you please be more specific?

Perhaps I could turn that question round. Which annotations are you planning
to keep?

Nick