Re: [PATCH] tests/unit/test-io-channel-command: Silence GCC error "maybe-uninitialized"

["Michael S. Tsirkin" <mst@redhat.com>]

On Tue, Nov 01, 2022 at 10:39:36PM +0100, Bernhard Beschow wrote:
> GCC issues a false positive warning, resulting in build failure with -Werror:
> 
>   In file included from /usr/lib/glib-2.0/include/glibconfig.h:9,
>                    from /usr/include/glib-2.0/glib/gtypes.h:34,
>                    from /usr/include/glib-2.0/glib/galloca.h:34,
>                    from /usr/include/glib-2.0/glib.h:32,
>                    from ../src/include/glib-compat.h:32,
>                    from ../src/include/qemu/osdep.h:144,
>                    from ../src/tests/unit/test-io-channel-command.c:21:
>   /usr/include/glib-2.0/glib/gmacros.h: In function ‘test_io_channel_command_fifo’:
>   /usr/include/glib-2.0/glib/gmacros.h:1333:105: error: ‘dstargv’ may be used uninitialized [-Werror=maybe-uninitialized]
>    1333 |   static G_GNUC_UNUSED inline void _GLIB_AUTO_FUNC_NAME(TypeName) (TypeName *_ptr) { if (*_ptr != none) (func) (*_ptr); }     \
>         |                                                                                                         ^
>   ../src/tests/unit/test-io-channel-command.c:39:19: note: ‘dstargv’ was declared here
>      39 |     g_auto(GStrv) dstargv;
>         |                   ^~~~~~~
>   /usr/include/glib-2.0/glib/gmacros.h:1333:105: error: ‘srcargv’ may be used uninitialized [-Werror=maybe-uninitialized]
>    1333 |   static G_GNUC_UNUSED inline void _GLIB_AUTO_FUNC_NAME(TypeName) (TypeName *_ptr) { if (*_ptr != none) (func) (*_ptr); }     \
>         |                                                                                                         ^
>   ../src/tests/unit/test-io-channel-command.c:38:19: note: ‘srcargv’ was declared here
>      38 |     g_auto(GStrv) srcargv;
>         |                   ^~~~~~~
>   cc1: all warnings being treated as errors
> 
> GCC version:
> 
>   $ gcc --version
>   gcc (GCC) 12.2.0
> 
> Fixes: 68406d10859385c88da73d0106254a7f47e6652e ('tests/unit: cleanups for test-io-channel-command')
> Signed-off-by: Bernhard Beschow <shentey@gmail.com>

It's a game of whac-a-mole for sure but what are you gonnu do.

Acked-by: Michael S. Tsirkin <mst@redhat.com>

> ---
>  tests/unit/test-io-channel-command.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/tests/unit/test-io-channel-command.c b/tests/unit/test-io-channel-command.c
> index 43e29c8cfb..ba0717d3c3 100644
> --- a/tests/unit/test-io-channel-command.c
> +++ b/tests/unit/test-io-channel-command.c
> @@ -35,8 +35,8 @@ static void test_io_channel_command_fifo(bool async)
>      g_autofree gchar *fifo = g_strdup_printf("%s/%s", tmpdir, TEST_FIFO);
>      g_autoptr(GString) srcargs = g_string_new(socat);
>      g_autoptr(GString) dstargs = g_string_new(socat);
> -    g_auto(GStrv) srcargv;
> -    g_auto(GStrv) dstargv;
> +    g_auto(GStrv) srcargv = NULL;
> +    g_auto(GStrv) dstargv = NULL;
>      QIOChannel *src, *dst;
>      QIOChannelTest *test;
>  
> -- 
> 2.38.1