Re: internal-error: insert_step_resume_breakpoint_at_sal

Andrew Cagney
2005-01-24T21:59:52Z

Nick Roberts wrote:
> > What's at $pc (where PC is 0x4012e7e9 or 0x80850d5), symtab==0 indicates
> > a symtab lookup failure.
>
> See my earlier message to Dave Korn.
>
> > > > Can you capture the output from "set debug infrun 1"? It should help.
> > >
> > > See below. I can send the full transcript if necessary.
> >
> > How much more?
>
> Well its only the stuff before I type "next" i.e. Emacs starting up and
> lots of:
>
> ...
> infrun: TARGET_WAITKIND_STOPPED
> infrun: stop_pc = 0x4012e7e9
> infrun: random signal 20
> infrun: resume (step=0, signal=20)
> infrun: prepare_to_wait
> infrun: infwait_normal_state
> infrun: TARGET_WAITKIND_STOPPED
> infrun: stop_pc = 0x4012e7e9
> infrun: random signal 20
> ...
>
> > There appears to be stuff missing here, the output should contain
> > something like:
> >
> > resume(step=1, signal=0)
> > resume(step=0, signal=0)
> >
> > as GDB single-steps the thread off breakpoint 3. The PC should be near
> > or at 0x80850d5 found in the below.
>
> Thats much earlier. I attach the full transcript below.
>
> Maybe its too hard to debug over the Internet as I don't understand the
> internals well enough. It doesn't seem to be causing a problem for anybody
> else and I can get round it in the way I suggested in my first message.

Tracking down these sorts of bugs is really important - it makes the
difference between a toy and a real debugger, and I think your efforts
have paid off :-)

With the log you provided I've been able to identify one bug -
back-to-back signals (where the inferior was receiving the next signal
just as the previous handler returned) would lead to a panic.

I'm about to commit a testcase and fix.

thanks,
Andrew