Re: RFC: partially fix empty DW_OP_piece

[Tom Tromey <tromey@redhat.com>]

>>>>> "Jan" == Jan Kratochvil <jan.kratochvil@redhat.com> writes:

We were talking on irc and Jan asked for more information about part of
my plan...

Tom> The other way is to simply remove val_print entirely and make all of
Tom> printing work using values.  I think this is the route I would prefer.

Jan> That could hopefully solve the problem of missing type-associated object
Jan> address for DW_OP_push_object_address for the VLA (variable length arrays)
Jan> patch.

I am curious to know what you need here.

I started by looking briefly at replacing val_print.  This looks pretty
big, though.  So I looked into other solutions.

I wrote a big patch to pass lval_funcs through all the val_print code.
However, it turns out that this is not sufficient: the code has to
handle value_offset() as well, which means either adding another
argument (the offset) or just passing the original value through.

So, currently I am thinking I will go through my existing patch and have
it pass a value instead of lval_funcs.  Of course this means a lot of
redundant info, which is ugly.

There are barriers to removing val_print.  I think the biggest one,
conceptually, is that recursion in val_print means making new values,
which means copying the value contents.  This can be expensive.  (Of
course there are solutions to that, reference counting the value
contents comes to mind.)

Tom