Re: [PATCH] Always create a new value object in valpy_do_cast

[Simon Marchi <simark@simark.ca>]

On 1/22/23 15:50, Tom Tromey wrote:
>>>>>> "Hannes" == Hannes Domani <ssbssa@yahoo.de> writes:
> 
> Hannes> The problem isn't the value that's reference by gdb.Value, instead
> Hannes> one of the other values in all_values before it.
> 
> Hannes> But release_value removes it from all_values, and it was the exact value
> Hannes> that the scoped_value_mark free_values instance was using as the mark point,
> Hannes> and since it was then missing, all_values was cleared completely.
> Hannes> And one of those earlier values is still used by the printing later on.
> 
> OMG.  I think this is a latent bug in the value-mark API that's been
> there since... well I don't know exactly when, maybe forever.  So, nice
> find!
> 
> I think what we probably need is to change how the value_mark API works,
> so that it isn't relying on a value pointer being in all_values, but
> rather return some other type/object that isn't invalidated in the same
> way.

Is there an advantage of that value chain thing vs using value_ref_ptr
throughout?  Not replace all `value *` with value_ref_ptr, but have
functions return and accept value_ref_ptr where that makes sense.

Simon