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Re: Watchpoint segfaults
Hi Daniel,
On Sat, 2005-12-10 at 10:57 -0500, Daniel Jacobowitz wrote:
> On Sat, Dec 10, 2005 at 10:31:02AM +0200, Eli Zaretskii wrote:
> > > Date: Fri, 9 Dec 2005 14:58:11 -0500
> > > From: Daniel Jacobowitz <drow@false.org>
> > >
> > > I think we want to temporarily disable breakpoints whose expression can't be
> > > parsed
> >
> > I agree. But perhaps instead of just disabling it we should display
> > some warning the first time we find that we are unable to parse its
> > expression.
>
> That sounds like a good idea. We should also try to re-parse it at any
> available opportunity, e.g. when the symbol table changes. This'll
> take a little work to get right.
I am not too clear about this. Do you mean
observer_notify_executable_changed but that does not get called in case
of add-symbol-file where the symtab could change again and you have
potential cases there ? There used to be a file_changed_hook where we
might be able to do this but thats been deprecated here .
http://sources.redhat.com/ml/gdb-patches/2004-04/msg00271.html
>
> > > and print it as a string rather than using the expression printer.
> >
> > Print it where? in the table displayed by "info breakpoints" or
> > equivalent commands? Or do you have some other situation in mind?
>
> Sorry, yes, I was referring to the "info breakpoints" segfault.
> Basically someone's going to have to go through and audit the uses of
> ->exp.
This is a rather simplistic fix which does not yet disable the
watchpoint but prevents the segfault . I did on the 6.4 branch since
that is what I have handy . Also the other occurences of
print_expression with -->exp that I could find were in mention in which
case you do have a symbol table already created and if the symbol were
not there an automatic error would be raised much in advance.
Is there any other usecase you had in mind ?
cheers
Ramana
Index: breakpoint.c
===================================================================
RCS file: /cvs/src/src/gdb/breakpoint.c,v
retrieving revision 1.217
diff -a -u -r1.217 breakpoint.c
--- breakpoint.c 29 May 2005 03:13:17 -0000 1.217
+++ breakpoint.c 10 Dec 2005 19:38:54 -0000
@@ -3387,7 +3387,10 @@
if (addressprint)
ui_out_field_skip (uiout, "addr");
annotate_field (5);
- print_expression (b->exp, stb->stream);
+ if (b->exp)
+ print_expression (b->exp, stb->stream);
+ else
+ ui_out_field_string (uiout,"what", b->exp_string);
ui_out_field_stream (uiout, "what", stb);
break;