[testsuite & dwarf2] How to handle store.exp failure on AMD64?

[Richard Henderson]

> >Moreover, the algorithm I suggested that you use -- assume saved --
> >is also completely independant of the ABI, so its' not like GDB 
> >needs to hard code ABI specific information either.
> 
> It doesn't work in general.
> On a register window machine, it could use a fairly complex starting 
> state vis:
> 	globals: same
> 	locals: where saved on stack
> 	input: undefined
> 	output: in input
> (register windows give me a headache so don't assume this one is correct :-)

This has to be handled with the same magic that handles register windows
in the first place.  I.e. DW_CFA_GNU_window_save.  Dwarf2 doesn't handle
windows itself at all.

You could also do it with explicit dw2 operations, but that's no different
than a non-windowed system than starts with all DW_CFA_same_value and
adds DW_CFA_undefined, DW_CFA_register and DW_CFA_offset notes as needed.

> [perhaphs I should have cross posted this with dwarf2 :-)]

Probably.


r~