Re: parisc: unwind tables and backtraces broken?

[Helge Deller <deller@gmx.de>]

On 07/07/2009 04:07 PM, Carlos O'Donell wrote:
> On Tue, Jul 7, 2009 at 12:42 AM, Kyle McMartin<kyle@mcmartin.ca>  wrote:
>> indeed, it very briefly had a dwarf unwinder, but linus turned it off
>> again because it turned out to generate worse backtraces than just
>> chunking through stack frames with frame pointers enabled did. although,
>> there is talk of it growing one again now.
>
> It will definitely need to grow a dwarf2 unwinder.
>
> Any sane ABI should drop the hard frame pointer requirement in order
> to get better code generation. For example on ARM under the EABI there
> is no hard fp, you get that register back for other uses and it
> simplifies prologue and epilogues. If you need an offset from the fp
> the compiler synthesizes it for you, and reuses it appropriately after
> the use is dead.
>
> I thought bfd, and therefore readelf and objdump could read parisc
> unwind info, if so, then what do those tools say about this broken
> unwind info?

Any hint what I should do to give you the input you need?

Helge