Re: RFC: implement DW_OP_bit_piece

[Stan Shebs <stanshebs@earthlink.net>]

Tom Tromey wrote:
> Stan> the dwarf2_tracepoint_var_ref code to compile to bytecodes, and
> Stan> human-readable description in locexpr_describe_location_1.
>
> Stan> (Yes it's onerous, but we did want to revive tracepoints, right?)
>
> Tom> I will update locexpr_describe_location_1.
>
> I am actually just going to commit what I have, because it definitely
> improves the situation, and then work on the remaining pieces as
> separate patches.  I did not see a clean way to make
> locexpr_describe_location_1 nicer, so I am going to rewrite it as
> discussed elsewhere in the thread.
>   

Which rewrite is that?  I can see switching to opcode disassembly for 
heinously-complicated location expressions, but multiple pieces and 
reg/offset seem reasonable to describe verbally - if nothing else, it 
conveys to the user that a local has a nontrivial liveness range and 
lives in different places at different times, so the user needs to be 
cautious when a register or stack location seems to have a wrong value 
in it.

Stan