Re: [PATCH] gdb: prevent the use of the clear command to remove the internal breakpoint (PR cli/7161)

[Enze Li <lienze2010@hotmail.com>]

Hi Pedro, Tom

Thanks to both of you for the code review.  I have sent the v2 of the
patch to the list, adding a testcase dedicated to testing PR7161.

Thanks,
Enze

On Mon, 2022-03-14 at 13:53 +0000, Pedro Alves wrote:
> Hi!
> 
> On 2022-03-14 12:24, Enze Li via Gdb-patches wrote:
> > This patch fixes the PR cli/7161 - "clear command removes internal
> > breakpoints".
> > 
> > In this patch, a new function "internal_breakpoint" is added to
> > determine whether the breakpoint is internal or not.  If the
> > breakpoint is internal when using the clear command, no action will
> > be taken, thus preventing the use of the clear command to remove
> > the interal breakpoint.
> > 
> > Tested on x86_64-linux.
> > 
> > Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=7161
> > ---
> >  gdb/breakpoint.c | 10 +++++++++-
> >  gdb/breakpoint.h |  3 +++
> >  2 files changed, 12 insertions(+), 1 deletion(-)
> > 
> > diff --git a/gdb/breakpoint.c b/gdb/breakpoint.c
> > index a3cfeea6989..08628d885e7 100644
> > --- a/gdb/breakpoint.c
> > +++ b/gdb/breakpoint.c
> > @@ -6477,6 +6477,13 @@ pending_breakpoint_p (struct breakpoint *b)
> >    return b->loc == NULL;
> >  }
> >  
> > +/* See breakpoint.h.  */
> > +bool
> > +internal_breakpoint (struct breakpoint *b)
> > +{
> > +  return b->ops == &internal_breakpoint_ops;
> > +}
> > +
> 
> The clear command shouldn't delete momentary breakpoints either
> (those have bp num == 0),
> nor internal breakpoints created via Python's gdb.Breakpoint, I
> think.  Neither of these
> use internal_breakpoint_ops. 
> 
> I think we should check the existing user_breakpoint_p instead.
> 
> This should really have a testcase in the gdb testsuite.
> 
> Pedro Alves