Re: Python API - nested pretty printers MI implications

Pedro Alves
2011-08-15T13:26:07Z

On Monday 15 August 2011 13:36:50, André Pönitz wrote:

> I am not sure how partial updates on MI varobjs with phony levels
> would work at all.
>
> Imagine a data structure containing a char m[1000000][10], and a
> "phony level pretty printer" that displays all the m[i] with m[i][0] == 'A'.
> Suppose initially that would be the items m[1] and m[10000], so we
> get a display like
>
> m --
> m[1] "A...."
> m[1000] "A...."
>
> Now the user steps over m[5000][0] = 'A'. Assuming there is no dummy
> varobj for every _potential_ child, what mechanism would trigger the
> varobj's update to produce the display
>
> m --
> m[1] "A...."
> m[5000] "A...."
> m[10000] "A...."
>
> eventually?

AFAIK, frontends do:

-var-update 2 *

and that should yield (but doesn't):

^done,changelist=[{name="var1.m",value="",in_scope="true",type_changed="false",new_num_children="1",has_more="0",new_children=[{name="var1.m.5000",exp="5000",numchild="1",value="A....",type="foo"}]}]
(gdb)

Note new_num_children. This should trigger the frontend re-fetching
the children of var1.m.

I think the issue here is that dynamic varobj's code doesn't
handle new children appearing before existing ones. I got a
patch to address that though, needed for supporting varobj's
that hide "<unavailable>" children.

--
Pedro Alves