Re: [PATCH v4 08/15] docs/devel/testing: add -gdb option to the debugging section of QEMU iotests

[Vladimir Sementsov-Ogievskiy]

20.05.2021 10:52, Emanuele Giuseppe Esposito wrote:
> Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>

Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>

> ---
>   docs/devel/testing.rst | 11 +++++++++++
>   1 file changed, 11 insertions(+)
>
> diff --git a/docs/devel/testing.rst b/docs/devel/testing.rst
> index 8144e316a4..a746cab745 100644
> --- a/docs/devel/testing.rst
> +++ b/docs/devel/testing.rst
> @@ -229,6 +229,17 @@ Debugging a test case
>   The following options to the ``check`` script can be useful when debugging
>   a failing test:
>   
> +* ``-gdb`` wraps every QEMU invocation in a ``gdbserver``, which waits for a
> +  connection from a gdb client.  The options given to ``gdbserver`` (e.g. the
> +  address on which to listen for connections) are taken from the 
> ``$GDB_OPTIONS``
> +  environment variable.  By default (if ``$GDB_OPTIONS`` is empty), it listens 
> on
> +  ``localhost:12345``.
> +  It is possible to connect to it for example with
> +  ``gdb -iex "target remote $addr"``, where ``$addr`` is the address
> +  ``gdbserver`` listens on.
> +  If the ``-gdb`` option is not used, ``$GDB_OPTIONS`` is ignored,
> +  regardless on whether it is set or not.
> +
>   * ``-d`` (debug) just increases the logging verbosity, showing
>     for example the QMP commands and answers.
>   

Didn't you think of an interface as simple as just wrap qemu binary by "gdb --args" 
and redirect stdin and stdout directly to the terminal where test is running? Wouldn't it more 
convenient? So, you just start ./check -gdb <test>, and you are in gdb. Or you need 
exactly gdb server, to attach from another machine?

Keeping this possibility in mind, it's probably better to call you option 
"-gdbserver"... But we can rename later if needed, finally, it's only a test 
framework.


--
Best regards,
Vladimir