Daniel Jacobowitz wrote:

>> >                 } else {
>> > 
>> > It wants to show the value in its variables window, not the reference.
>> > So this patch would break it.
>> > 
>> > So, should we change common_val_print, do you think?
>> 
>> Short-term, this might be a solution. But note again that depending on
>> textual "value" field is bad idea in any case.
> 
> That's not actually what I meant - I'm not thinking of MI here.
> common_val_print gets called from a number of places:
> 
> - varobj c_value_of_variable, used by Insight and MI
>   (-var-list-children, -var-evaluate-expression, -var-assign,
>    -var-update).
> 
> - print_frame_args, where it is used to deliberately print
>   only the address of a reference.  I'm not entirely sure why.
> 
> - Languages, to implement value_print - not relevant right now.

It appears that 'common_val_print' has 'deref_ref' parameter which can be
used to get back the old behaviour. However, then we'll again get no output
if there's any undereferencable reference.

I attach a patch that addresses this issue -- now, undereferencable
references don't throw. For dereferencable references the value is printed
after ":" as it is now.

Changelog:

2006-04-04 Vladimir Prus <ghost@cs.msu.su>

    * c-valprint.c (c_val_print): Explicitly check if a reference
      is dereferencable.
    * valops.c (value_at_maybe): New function
    * value.h (value_at_maybe): Export.
    * mi/mi-cmd-stack.c (list_args_or_locals): Use 'common_val_print',
     instead of 'print_value_value'. Remove code duplication.

Patch is attached.

- Volodya