Re: [PATCH] -var-update [was Re: Variable objects: references formatting]

[Daniel Jacobowitz <drow at false dot org>]

On Wed, May 17, 2006 at 11:52:31AM +1200, Nick Roberts wrote:
>  >                             For instance:
>  > 
>  >   /* The contents of VAL1 are supposed to be known.  */
>  >   gdb_assert (!value_lazy (val1));
>  > 
>  > If val1 is the reference at this point, then we haven't checked what we
>  > think we have.
> 
> Trying to interpret the code, given that val1 doesn't hold the value I
> wonder why this assertion is true i.e why is value->lazy=0 even though
> the value isn't in the contents field.

I am not sure what you mean.

!value_lazy (val1) means the contents of val1 have already been read
from the target.  At this point, val1 is the _reference_.  Nothing is
arranging to cache the value pointed to; that's what needs to happen.

>  > Every time my_value_equal is called its first argument comes from a
>  > varobj's ->value.  It seems to me that if we want to properly know
>  > whether the varobj has changed, we'd better have read its value into
>  > GDB.
> 
> Could it not doing that because GDB's value mechanism isn't working properly
> for references?

The value mechanism is working fine; it's varobj that does not support
references.

-- 
Daniel Jacobowitz
CodeSourcery