Hello,

Attached is a jumbo patch that is the results of me trialing changes to 
"trad-frame" and a new "tramp-frame" (better name?) that are ment to 
make the problem of writing a traditional unwinder easier.

I've committed this to the new (but effectively still born) 
cagney_tramp-20040309-branch.  Over comming weeks I'll be pulling out 
various ideas ideas in this patch and running them past people for 
integration into the mainline (I've already done the first -- pre_init 
data) in particular:

-- pre_init data
Already posted.  Simplifies the handling of gdbarch_data allocated 
before the architecture has been fully initialized.

-- trad-frame
A generic "trad_frame_cache", the idea has already been posted to gdb@.

-- [sig]tramp-frame
For those signal trampolines that rely on magic instructions at a random 
address.  Pass it a cache builder and the trampolines instruction 
sequence and it does the rest!

In doing this I've made some interface changes, namely:

-- make frame-unwind and frame-base more OO
In particular pass their vector as a parameter

-- add "const struct frame_data" to frame-* objects
so that multiple variants can be created

More in a few weeks (after 6.1 as this is pretty intrusive).

Andrew