Re: [RFA] remote.c: adjust Z packet addr using BREAKPOINT_FROM_PC

[Nick Duffek <nsd at redhat dot com>]

On 8-Jan-2001, J . T . Conklin wrote:

>The GDB internals manual indicates that BREAKPOINT_FROM_PC() may
>adjust the address.

Yes, and that's exactly why I want to move it: so that the target
architecture can adjust the address.

(Specifically, I want to convert the address from a byte address to an
instruction space pointer.  This entails (a) removing the IMEM_START bit
added by the harvard architecture mechanism and (b) dividing the address
by 8.)

>I think the reason that BREAKPOINT_FROM_PC() is called is to get the
>size of the breakpoint.

That's all it does prior to my patch.  But elsewhere in GDB, namely in
mem-break.c, BREAKPOINT_FROM_PC serves as a generic way for target
architectures to modify the address and other attributes of a breakpoint
before it hits the hardware.

Maybe that's an argument for replacing target_insert_breakpoint() with a
wrapper that calls BREAKPOINT_FROM_PC.

>but it would seem that the debug agent could then install the break in
>the wrong location.

I don't think that's a problem.  BREAKPOINT_FROM_PC doesn't modify the
address unless the target architecture author explicitly causes it to do
so, in which case it's presumably the right thing to do.

Nick