* gdb.base/scope.exp problems and possible fix
@ 2003-03-25 16:29 Corinna Vinschen
2003-03-25 16:39 ` Daniel Jacobowitz
0 siblings, 1 reply; 6+ messages in thread
From: Corinna Vinschen @ 2003-03-25 16:29 UTC (permalink / raw)
To: gdb
Hi,
I have a problem with the gdb.base/scope.exp test. I'm getting 100 errors
when running this test now for xstormy16-elf while the same test was no
problem when I tested xstormy the last time (well, more than 12 months ago).
Basically the problem is that:
1 bar() {}
2
3 foo()
4 {
5 int local = 0;
6
7 {
8 int local = 1;
9 bar();
10 }
11 }
When stepping to the call to bar(), `print local' prints correctly "1".
When stepping into bar(), then changing the frame with `up' and then
calling `print local', it incorrectly prints "0".
I've set a breakpoint to dwarf2_evaluate_loc_desc() to see which variable
it tries to access:
When in the outer block of foo(), var->line is 5, so the correct
variable is accessed, frame->frame is 292. The value returned is 0.
When in the inner block of foo(), var->line is 8, still the correct
variable is accessed, frame->frame is 292. The value returned is 1.
After stepping into bar() and calling "up", var->line is 8. So
apparently it still thinks it accesses the right variable, frame->frame
is still 292... but the returned value is nevertheless 0.
Further debugging showed the following difference:
While in foo(), the value of the FP register is obviously taken from
the register itself. When in the bar(),"up" situation, the FP register
is in saved_regs of the next frame. Now, what happens is in
execute_stack_op(), when evaluating the content of the FP register,
the call to
result = (ctx->read_reg) (ctx->baton, op - DW_OP_reg0, &expr_lval,
&memaddr);
(which is a call to dwarf_expr_read_reg()) returns in both cases the
correct result 292 but when in foo(), expr_lval is lval_register, while
when in bar(), expr_lval is lval_memory. In the latter case, the correct
value in result is ignored and overwritten with the wrong value from
memaddr, which is 296. Then, in the calling function (which is the
DW_OP_fbreg part of execute_stack_op(), `result' is totally differently
handled, with result becoming an illegal value. The 0 printed for
`local' isn't actually the 0 from the outer `local' variable but only
0 coincidentally.
If in that situation the result value would have been used and treated
like a lval_register, everything would have been fine! But as it is
now, result is wrongly tweaked twice in execute_stack_op().
I did the following as workaround:
Index: dwarf2expr.c
===================================================================
RCS file: /cvs/cvsfiles/devo/gdb/dwarf2expr.c,v
retrieving revision 2.1
diff -u -p -r2.1 dwarf2expr.c
--- dwarf2expr.c 2003/03/19 23:00:23 2.1
+++ dwarf2expr.c 2003/03/25 14:13:55
@@ -367,6 +367,7 @@ execute_stack_op (struct dwarf_expr_cont
result = (ctx->read_reg) (ctx->baton, op - DW_OP_reg0, &expr_lval,
&memaddr);
+#if 0
if (expr_lval == lval_register)
{
ctx->regnum = op - DW_OP_reg0;
@@ -374,6 +375,10 @@ execute_stack_op (struct dwarf_expr_cont
}
else
result = memaddr;
+#else
+ ctx->regnum = op - DW_OP_reg0;
+ ctx->in_reg = 1;
+#endif
This solved the scope problem totally *and* solved various other FAILs,
too, even in gdb.c++. This one change dropped the overall FAIL count
in my local sandbox from 249 to 95!
But is that workaround a valid fix?
Corinna
--
Corinna Vinschen
Cygwin Developer
Red Hat, Inc.
mailto:vinschen@redhat.com
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: gdb.base/scope.exp problems and possible fix
2003-03-25 16:29 gdb.base/scope.exp problems and possible fix Corinna Vinschen
@ 2003-03-25 16:39 ` Daniel Jacobowitz
2003-03-25 16:51 ` Corinna Vinschen
2003-03-31 6:11 ` Andrew Cagney
0 siblings, 2 replies; 6+ messages in thread
From: Daniel Jacobowitz @ 2003-03-25 16:39 UTC (permalink / raw)
To: gdb
On Tue, Mar 25, 2003 at 05:29:29PM +0100, Corinna Vinschen wrote:
> But is that workaround a valid fix?
I don't think it's completely right, but I have good news for you - I
do have a patch that I think _is_ right. I submitted it for review two
weeks ago. Would you please try the patch in:
http://sources.redhat.com/ml/gdb-patches/2003-03/msg00286.html
and tell me whether it works as well for you?
--
Daniel Jacobowitz
MontaVista Software Debian GNU/Linux Developer
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: gdb.base/scope.exp problems and possible fix
2003-03-25 16:39 ` Daniel Jacobowitz
@ 2003-03-25 16:51 ` Corinna Vinschen
2003-03-25 17:30 ` Corinna Vinschen
2003-03-31 6:11 ` Andrew Cagney
1 sibling, 1 reply; 6+ messages in thread
From: Corinna Vinschen @ 2003-03-25 16:51 UTC (permalink / raw)
To: gdb
Hi Daniel,
On Tue, Mar 25, 2003 at 11:39:31AM -0500, Daniel Jacobowitz wrote:
> On Tue, Mar 25, 2003 at 05:29:29PM +0100, Corinna Vinschen wrote:
> > But is that workaround a valid fix?
>
> I don't think it's completely right, but I have good news for you - I
> do have a patch that I think _is_ right. I submitted it for review two
> weeks ago. Would you please try the patch in:
> http://sources.redhat.com/ml/gdb-patches/2003-03/msg00286.html
> and tell me whether it works as well for you?
I tested it on scope.exp and it works fine. Another test on store.exp
which had related errors is running fine, too.
I've just started a full testsuite run to see if it has any regressions
in comparison to my patch. I'll report back in an hour or so.
Thanks,
Corinna
--
Corinna Vinschen
Cygwin Developer
Red Hat, Inc.
mailto:vinschen@redhat.com
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: gdb.base/scope.exp problems and possible fix
2003-03-25 16:51 ` Corinna Vinschen
@ 2003-03-25 17:30 ` Corinna Vinschen
2003-03-25 18:28 ` Daniel Jacobowitz
0 siblings, 1 reply; 6+ messages in thread
From: Corinna Vinschen @ 2003-03-25 17:30 UTC (permalink / raw)
To: gdb
On Tue, Mar 25, 2003 at 05:51:39PM +0100, Corinna Vinschen wrote:
> Hi Daniel,
>
> On Tue, Mar 25, 2003 at 11:39:31AM -0500, Daniel Jacobowitz wrote:
> > On Tue, Mar 25, 2003 at 05:29:29PM +0100, Corinna Vinschen wrote:
> > > But is that workaround a valid fix?
> >
> > I don't think it's completely right, but I have good news for you - I
> > do have a patch that I think _is_ right. I submitted it for review two
> > weeks ago. Would you please try the patch in:
> > http://sources.redhat.com/ml/gdb-patches/2003-03/msg00286.html
> > and tell me whether it works as well for you?
>
> I tested it on scope.exp and it works fine. Another test on store.exp
> which had related errors is running fine, too.
>
> I've just started a full testsuite run to see if it has any regressions
> in comparison to my patch. I'll report back in an hour or so.
No regressions!
Thanks,
Corinna
--
Corinna Vinschen
Cygwin Developer
Red Hat, Inc.
mailto:vinschen@redhat.com
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: gdb.base/scope.exp problems and possible fix
2003-03-25 17:30 ` Corinna Vinschen
@ 2003-03-25 18:28 ` Daniel Jacobowitz
0 siblings, 0 replies; 6+ messages in thread
From: Daniel Jacobowitz @ 2003-03-25 18:28 UTC (permalink / raw)
To: gdb; +Cc: jimb
On Tue, Mar 25, 2003 at 06:30:38PM +0100, Corinna Vinschen wrote:
> On Tue, Mar 25, 2003 at 05:51:39PM +0100, Corinna Vinschen wrote:
> > Hi Daniel,
> >
> > On Tue, Mar 25, 2003 at 11:39:31AM -0500, Daniel Jacobowitz wrote:
> > > On Tue, Mar 25, 2003 at 05:29:29PM +0100, Corinna Vinschen wrote:
> > > > But is that workaround a valid fix?
> > >
> > > I don't think it's completely right, but I have good news for you - I
> > > do have a patch that I think _is_ right. I submitted it for review two
> > > weeks ago. Would you please try the patch in:
> > > http://sources.redhat.com/ml/gdb-patches/2003-03/msg00286.html
> > > and tell me whether it works as well for you?
> >
> > I tested it on scope.exp and it works fine. Another test on store.exp
> > which had related errors is running fine, too.
> >
> > I've just started a full testsuite run to see if it has any regressions
> > in comparison to my patch. I'll report back in an hour or so.
>
> No regressions!
Thanks for testing it! Jim?
--
Daniel Jacobowitz
MontaVista Software Debian GNU/Linux Developer
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: gdb.base/scope.exp problems and possible fix
2003-03-25 16:39 ` Daniel Jacobowitz
2003-03-25 16:51 ` Corinna Vinschen
@ 2003-03-31 6:11 ` Andrew Cagney
1 sibling, 0 replies; 6+ messages in thread
From: Andrew Cagney @ 2003-03-31 6:11 UTC (permalink / raw)
To: Jim Blandy; +Cc: Daniel Jacobowitz, gdb
Jim,
> On Tue, Mar 25, 2003 at 05:29:29PM +0100, Corinna Vinschen wrote:
>
>> But is that workaround a valid fix?
>
>
> I don't think it's completely right, but I have good news for you - I
> do have a patch that I think _is_ right. I submitted it for review two
> weeks ago. Would you please try the patch in:
> http://sources.redhat.com/ml/gdb-patches/2003-03/msg00286.html
> and tell me whether it works as well for you?
Can you please look at this. It's been identified as a serious problem:
http://sources.redhat.com/ml/gdb/2003-03/msg00193.html
Andrew
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2003-03-31 6:11 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2003-03-25 16:29 gdb.base/scope.exp problems and possible fix Corinna Vinschen
2003-03-25 16:39 ` Daniel Jacobowitz
2003-03-25 16:51 ` Corinna Vinschen
2003-03-25 17:30 ` Corinna Vinschen
2003-03-25 18:28 ` Daniel Jacobowitz
2003-03-31 6:11 ` Andrew Cagney
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).