[multi-arch] The frame as the global parameter (long, important)

[Jim Ingham]

Andrew,

>
>
>> So, yeah, it seems like this should work, provided you make sure you
>> don't assume that there is only one valid result of a backtrace, and
>> make switching the order fairly easy...
>
> Hmm, GDB currently assumes that, given a frame, there is only one
> possible next frame.  I'll be leaving that assumption alone :-)

I don't think this is really that much of a problem.  In the scheme I 
was sketching, given an ordering of the "frame recognizers" the previous 
frame will always be unique.  But if you switch the ordering, then the 
previous frame will change.  You will need this in your RPC example too, 
since I would definitely want the ability to turn off tracing across the 
RPC, and in this case the frame ordering will change as well.

This is a pretty heavyweight thing to do, however, so it is probably 
safe to blow away the frame cache and start all over if you do this...  
So as long as cleaning up all your state and starting over is easy to 
do, then this will fall out.

Jim
--
Jim Ingham                                   jingham@apple.com
Developer Tools - gdb
Apple Computer