Re: [patch/rfc] Eliminate TARGET_HAS_HARDWARE_WATCHPOINTS

[Andrew Cagney <cagney@gnu.org>]

>>Date: Thu, 9 Sep 2004 08:47:56 -0400
>>> From: Daniel Jacobowitz <drow@false.org>
>>> Cc: cagney@gnu.org, gdb-patches@sources.redhat.com
>>> 
>>
>>>> > I understand the theory, I just don't know how to test for watchpoint
>>>> > support in a program by just compiling it.  If you can suggest a
>>>> > program whose compilation will reveal that, please do.
>>
>>> 
>>> There's nothing generic controlled by TARGET_HAS_HARDWARE_WATCHPOINTS.
>>> It controls an include of <sys/debugreg.h> in i386v-nat.c - that can be
>>> autoconf'd, and then checked for the appropriate DR_* constants if
>>> that's necessary.  It controls the use of prwatch_t in procfs.c,
>>> likewise.
> 
> 
> I'm not sure the mere presence of DR_* automatically means that
> hardware watchpoints are supported at run time.  I'd prefer to hear
> that from Mark or someone else who could tell for sure.
> 
> In any case, if the above is true, then there should be no problem to
> write an Autoconf test that would replace
> TARGET_HAS_HARDWARE_WATCHPOINTS.  As soon as that is posted here, I
> will withdraw all my objections to removing the old macro in favor of
> the new mechanism.

This assumes that we've access to machines to test it on, and the code 
being modified is even being used / worth retaining.  Resolving both of 
those takes this from a no-problem task to something best handled 
separatly, and something that should not block this current patch.

Andrew