Re: [PATCH v4 05/28] Add to_value method to dwarf_location class

[Zoran Zaric <zoran.zaric@amd.com>]

> 
> Zoran> Currently, we only know how to convert from a memory location
> Zoran> description into a value, but it is resonable to expect a set
> Zoran> of target hooks that would let the target decide on how to do
> Zoran> other conversions in the future.
> 
> When would this be useful?
> 
> Anyway, this patch looks ok.
> 
> Tom
> 

This is a bit difficult question to answer.

 From the class design point, it is useful to have an unified interface 
for all DWARF stack elements.

Having the generality and flexibility of a location description being on 
the stack and using that in conjunction with DW_OP_call like operations 
(for refactoring), one could have a need to convert a resulting implicit 
location description into a value.

Also, there were some suggestions of operations that would use the value 
on the top of the stack as a register number or an index to a register 
bank. In that world, the expression could push a register location 
description (as a base of indexing), convert it to some kind of value 
representation, apply index calculation to it and then use that new 
operation on the result.

In reality, we (AMD) don't need that flexibility, but it made sense to 
me to not be over restrictive where I didn't needed to be.

Zoran