gdb/469: replace flush_cached_frames() and registers_changed() with target_changed()

[ac131313 at redhat dot com]

>Number:         469
>Category:       gdb
>Synopsis:       replace flush_cached_frames() and registers_changed() with target_changed()
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    unassigned
>State:          open
>Class:          change-request
>Submitter-Id:   net
>Arrival-Date:   Sat Apr 06 07:08:00 PST 2002
>Closed-Date:
>Last-Modified:
>Originator:     ac131313@redhat.com
>Release:        2002-04-05
>Organization:
>Environment:

>Description:
At present GDB tries to be smart over what needs to be rebuilt when - if the registers are changed, it is assumed that memory didn't change for instance.  In general that isn't true.  A single byte change has the potential of invaliding everything.  There are edge conditions that are not correctly handled: modifying a register can corrupt the entire stack frame; writing to memory can modify a register / stack frame; some h/w has dual ported memory - also a register; ...

Instead of trying to be smart (and failing), be stupid.  If the target is modified (memory write, register write, continue), invalidate everything.

Then concentrate on the most important case - recovering from a stop / continue / inferior function call.
>How-To-Repeat:

>Fix:

>Release-Note:
>Audit-Trail:
>Unformatted: