Re: RFA: Recognize 'x' in response to 'p' packet

[Steven Johnson <sjohnson at neurizon dot net>]

The PowerPC is such an example, where the Register response usually 
includes floating point registers, but say the MPC860 family doesnt have 
them.   I would imagine the reason to do it is so that, in future, GDB 
can remove from the users view registers that are non existent for a 
target, rather than show them as 0's.

If so, then this would be a necessary first step (identifying such from 
the target.)

Steven

Paul Schlie wrote:

> > Jim Blandy
> > * remote.c (fetch_register_using_p): Recognize 'x's for the value
> >  of the register as indicating that the register's value is not
> >  available.
>
>
> Out of curiosity, under what practical circumstances would the value of a
> register not be accessible? (and if not, shouldn't an error be returned, as
> opposed to an 'x' which is converted to a 0 anyway? Which I've noticed "g"
> packets also assume?)