Re: proposed PATCH: make watchpoints work correctly

[Paul Koning <pkoning at equallogic dot com>]

>>>>> "Eli" == Eli Zaretskii <eliz@elta.co.il> writes:

 >> Date: Wed, 28 May 2003 16:27:33 -0400 From: Paul Koning
 >> <pkoning@equallogic.com>
 >> 
 Eli> The above description made me nervous: it almost sounds like the
 Eli> current watchpoint support is pretty much dysfunctional, as most
 Eli> of the changes you suggest are not specific neither to remote.c
 Eli> nor to HAVE_NONSTEPPABLE_WATCHPOINT.  So could you please
 Eli> explain how, given those deficiencies, watchpoints do work for
 Eli> native targets such as x86, but did not work for your target?
 >> I'm not sure. I just built a gdb for x86 on NetBSD, and all I get
 >> is software write watchpoints, no hardware watch support seems to
 >> be present.

 Eli> That's strange: I thought hardware-assisted watchpoints were
 Eli> supported for all native x86 platforms.  Mark, could you please
 Eli> help us out here? is NetBSD an exception?

I built 5.3 for Linux and did the experiment there.  Hardware
watchpoints do work there.

 Eli> I don't have time right now to read the parts of breakpoint.c
 Eli> that you describe, but I promise to do that later today.  Thanks
 Eli> for taking time to explain your reasoning.

 >> The purpose of this patch submission is to get input from experts
 >> -- not necessarily to claim that the fix I submitted is the best
 >> way to solve the problem...

 Eli> Certainly, I understand that.  I just was surprised that your
 Eli> description of the problem was so different from my recollection
 Eli> of how watchpoints work.

I just ran a small test case on the x86 Linux native build of gdb 5.3,
and the problem (step works as if it were stepi, falsely reported as a
watchpoint hit) occurs there as well -- just as expected.

     paul