Re: [PATCH v3 08/15] docs/devel/testing: add -gdb option to the debugging section of QEMU iotests

[Max Reitz]

On 14.04.21 19:03, Emanuele Giuseppe Esposito wrote:
> Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
> ---
>   docs/devel/testing.rst | 7 +++++++
>   1 file changed, 7 insertions(+)
>
> diff --git a/docs/devel/testing.rst b/docs/devel/testing.rst
> index b7e2370e7e..2ee77a057b 100644
> --- a/docs/devel/testing.rst
> +++ b/docs/devel/testing.rst
> @@ -229,6 +229,13 @@ Debugging a test case
>   QEMU iotests offers some options to debug a failing test, that can be
>   given as options to the ``check`` script:
>   
> +* ``-gdb`` wraps ``gdbsever`` to the QEMU binary,
> +  so it is possible to connect to it via gdb.
> +  One way to do so is via ``gdb -iex "target remote $GDB_QEMU"``
> +  The default address is ``localhost:12345``, and can be changed
> +  by setting the ``$GDB_QEMU`` environmental variable.

*environment variable

> +  The final command line will be ``gdbserver $GDB_QEMU $QEMU ...``
> +

I think the order in this explanation is ordered not quite right, 
because it uses $GDB_QEMU before explaining what it is.  (Also, I 
suppose $GDB_QEMU might contain other options than the socket address, 
so "target remote $GDB_QEMU" does not necessarily work.)  I’d 
reorder/change it to:

``-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 
``$GDB_QEMU`` environment variable.  By default (if ``$GDB_QEMU`` is 
empty), it listens on ``localhost:12345``.
You can connect to it for example with ``gdb -iex "target remote 
$addr"``, where ``$addr`` is the address ``gdbserver`` listens on.

Max

>   * ``-d`` (debug) just increases the logging verbosity, showing
>     for example the QMP commands and answers.
>