Is it possible to use gdb Tracepoint facility with sparc-rtems-gdb?

Is it possible to use gdb Tracepoint facility with sparc-rtems-gdb?

[jreiver]

Hello,

I've found in the GDB User Manual a very interesting feature:
"In some applications, it is not feasible for the debugger to interrupt the
program's execution long enough for the developer to learn anything helpful
about its behavior. If the program's correctness depends on its real-time
behavior, delays introduced by a debugger might cause the program to change its
behavior drastically, or perhaps fail, even when the code itself is correct. It
is useful to be able to observe the program's behavior without interrupting it."

But the GDB user manual also says:
"The tracepoint facility is currently available only for remote targets. See
section Specifying a Debugging Target. In addition, your remote target must know
how to collect trace data. This functionality is implemented in the remote stub;
however, none of the stubs distributed with GDB support tracepoints as of this
writing."

I'm not sure, but does that mean that the Tracepoint feature is not completely
supported by all targets?

I have tried to test it by debugging my program with sparc-rtems-gdb, connected
to tsim-leon3 simulator from Gaisler Research:
- I have been able to add tracepoints, enable and disable tracepoints, or make
Tracepoint Action Lists, as specified in GDB user manual
- However, I couldn't start the "Trace experiment" with the "tstart" command,
which returned me this error:
===========================================
(gdb) tstart
Trace can only be run on remote targets.
===========================================

Has anyone ever tried Tracepoint Feature with sparc-rtems-gdb?
Any explanation would be appreciated.

Thanks.

JR

Re: Is it possible to use gdb Tracepoint facility with sparc-rtems-gdb?

[Michael Snyder]

Hi,

The tracepoint debugging feature depends on support from
the remote target side (in this case, tsim-leon3 simulator.
The target (simulator) has to be able to interpret certain
extra commands and queries from gdb.

You would need to ask the suppliers of this simulator
whether it knows about these messages.

jreiver@free.fr wrote:
> Hello,
> 
> I've found in the GDB User Manual a very interesting feature:
> "In some applications, it is not feasible for the debugger to interrupt the
> program's execution long enough for the developer to learn anything helpful
> about its behavior. If the program's correctness depends on its real-time
> behavior, delays introduced by a debugger might cause the program to change its
> behavior drastically, or perhaps fail, even when the code itself is correct. It
> is useful to be able to observe the program's behavior without interrupting it."
> 
> But the GDB user manual also says:
> "The tracepoint facility is currently available only for remote targets. See
> section Specifying a Debugging Target. In addition, your remote target must know
> how to collect trace data. This functionality is implemented in the remote stub;
> however, none of the stubs distributed with GDB support tracepoints as of this
> writing."
> 
> I'm not sure, but does that mean that the Tracepoint feature is not completely
> supported by all targets?
> 
> I have tried to test it by debugging my program with sparc-rtems-gdb, connected
> to tsim-leon3 simulator from Gaisler Research:
> - I have been able to add tracepoints, enable and disable tracepoints, or make
> Tracepoint Action Lists, as specified in GDB user manual
> - However, I couldn't start the "Trace experiment" with the "tstart" command,
> which returned me this error:
> ===========================================
> (gdb) tstart
> Trace can only be run on remote targets.
> ===========================================
> 
> Has anyone ever tried Tracepoint Feature with sparc-rtems-gdb?
> Any explanation would be appreciated.
> 
> Thanks.
> 
> JR