Re: [RFA] regcache.c (register_fetched) + related changes

[Andrew Cagney <ac131313@cygnus.com>]

>     Can you give an example of where this is happening?  I'm currently aware
>     of two cases:
> 
>             [0 .. NUM_REGS)
>                     where supply_register() should be used
> 
> Not always.  See below.
> 
>             [NUM_REGS .. NUM_REGS + PSEUDO_NUM_REGS)
>                     I suspect your case.
> 
> I *clear* in the [NUM_REGS, NUM_REGS+PSEUDO_NUM_REGS) range and *set*
> in the [0, NUM_REGS) range.

The code that sets the valid bit in the range [0, NUM_REGS) should be
doing so using either of the functions:

	supply_register() - target side
or	write_register_gen() - core-gdb side

if it isn't it is doing something un-documented and so, in my opinion,
should use a function that makes the use of that un-documented behavour
very clear.

Hence, in your case, I think your code really should be using a function
called something like deprecated_raw_register_fetched().

If I commit a change that replaces register_valid[] with the pair:

	deprecated_raw_register_fetched()
	pseudo_register_fetched()

will this allow your existing code to work?

Looking to the future, when (not if) the frame code is re-vamped to have
register values bound to a frame, will it be possible to use that
mechanism to implement what you're trying to do how using the regcache?

	Andrew