Re: [PATCH v7 13/16] qemu-iotests: insert valgrind command line as wrapper for qemu binary

[Eric Blake <eblake@redhat.com>]

On Mon, Jun 28, 2021 at 02:31:47PM +0200, Emanuele Giuseppe Esposito wrote:
> If -gdb and -valgrind are both defined, return an error.
> 
> Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
> ---
>  tests/qemu-iotests/iotests.py | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/tests/qemu-iotests/iotests.py b/tests/qemu-iotests/iotests.py
> index 85d8c0abbb..7aa6707032 100644
> --- a/tests/qemu-iotests/iotests.py
> +++ b/tests/qemu-iotests/iotests.py
> @@ -591,7 +591,11 @@ class VM(qtest.QEMUQtestMachine):
>      def __init__(self, path_suffix=''):
>          name = "qemu%s-%d" % (path_suffix, os.getpid())
>          timer = 15.0 if not (qemu_gdb or qemu_valgrind) else None
> -        super().__init__(qemu_prog, qemu_opts, wrapper=qemu_gdb,
> +        if qemu_gdb and qemu_valgrind:
> +            sys.stderr.write('Either use gdb or valgrind, not together\n')

Perhaps:

'gdb and valgrind are mutually exclusive'

gets the same message across in a more idiomatic manner.

(It _is_ possible to use both gdb and valgrind at the same time - but
that tends to be for developers of one of those two programs: either
using gdb to debug how valgrind is working, or using valgrind to check
gdb itself for bad memory behavior. You're correct that you can't
expect sane results by using both together on a program under test)

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
Virtualization:  qemu.org | libvirt.org