Re: [patch/mips] Use unwind in mips_get_saved_register

[Andrew Cagney <ac131313@ges.redhat.com>]

> On Sep 13,  1:55pm, Andrew Cagney wrote:
> 
> 
>> The attached is ``two steps forward, one step back'' patch.
>> 
>> It modifies mips_get_saved_register() so that it uses the new unwind 
>> code.  The new unwind code automatically handles the fetching of 
>> registers in dummy-frames.  Unfortunatly, the change doesn't fix the 
>> problem of the MIPS fiddling memory register reads dependant on the 
>> current ABI.
> 
> 
> I posted a similar patch last month:
> 
>     http://sources.redhat.com/ml/gdb-patches/2002-08/msg00198.html
> 
> At that time you rejected it for the reasons given in:
> 
>     http://sources.redhat.com/ml/gdb-patches/2002-08/msg00214.html
>     http://sources.redhat.com/ml/gdb-patches/2002-08/msg00235.html
> 
> Please explain what has changed between then and now which makes it
> acceptable to now use frame_register_unwind()?

I know.  See:
http://sources.redhat.com/ml/gdb-patches/2002-09/msg00223.html

At the time of your original patch, the only motivation was the 
elimination of frame_register_unwind() --- on its own, I don't see any 
benefit.  Since then, as part of converting the MIPS to generic dummy 
frames (a needed and huge forward step), I've found that I need to use 
the generic unwind code to at least keep things working.  You'll note 
that the code includes some very blunt comments that make it clear where 
any bugs are.

enjoy,
Andrew