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From: Vladimir Prus <ghost@cs.msu.su>
To: Johan Rydberg <jrydberg@virtutech.com>
Subject: Re: read watchpoints ignored?
Date: Mon, 14 Nov 2005 14:10:00 -0000
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Cc: Daniel Jacobowitz <drow@false.org>,
 Eli Zaretskii <eliz@gnu.org>,
 gdb@sources.redhat.com
References: <200511111622.01337.ghost@cs.msu.su> <200511141642.22179.ghost@cs.msu.su> <43789851.7080608@virtutech.com>
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On Monday 14 November 2005 16:59, you wrote:
> Vladimir Prus wrote:
> > This essentially disables read watchpoints. What's the point in first
> > implementing read watchpoints in a target, and then disabling them
> > completely in gdb? Should be then disallow "read watchpoint" packet in
> > the remote protocol?
>
> I wouldn't say it disables read watchpoints, since the functionality GDB
> provides is exactly that; read watchpoints.  The difference is that it
> uses access watchpoints to accomplish this, because a large set of targets
> does not support true read watchpoints.
>
> Which is more important; providing the functionality, or providing some
> functionality for some targets, but using hardware read watchpoints instead
> of hardware access watchpoints?

I hope we can have both. The only thing needed is a way to detect that remote 
targets supports read watchpoints. Using 

   remote_protocol_Z[Z_PACKET_READ_WP].support

from remote.c (under cover of new target operation) is such a way, and I think 
it should work fine. But comments from more knowledgable persons are welcome.

- Volodya