From: B <shentey@gmail.com>
To: qemu-devel@nongnu.org
Cc: qemu-trivial@nongnu.org, "Michael S. Tsirkin" <mst@redhat.com>
Subject: Re: [PATCH v2] hw/virtio/vhost-shadow-virtqueue: Silence GCC error "maybe-uninitialized"
Date: Tue, 27 Sep 2022 22:08:06 +0000 [thread overview]
Message-ID: <3565DD2F-D779-4EEA-9273-EC11963BC3C0@gmail.com> (raw)
In-Reply-To: <D1ED14E5-CFF9-4525-96C5-60262DB17309@gmail.com>
Am 20. September 2022 05:29:25 UTC schrieb Bernhard Beschow <shentey@gmail.com>:
>Am 10. September 2022 15:11:17 UTC schrieb Bernhard Beschow <shentey@gmail.com>:
>>GCC issues a false positive warning, resulting in build failure with -Werror:
>>
>> In file included from /usr/include/glib-2.0/glib.h:114,
>> from src/include/glib-compat.h:32,
>> from src/include/qemu/osdep.h:144,
>> from ../src/hw/virtio/vhost-shadow-virtqueue.c:10:
>> In function ‘g_autoptr_cleanup_generic_gfree’,
>> inlined from ‘vhost_handle_guest_kick’ at ../src/hw/virtio/vhost-shadow-virtqueue.c:292:42:
>> /usr/include/glib-2.0/glib/glib-autocleanups.h:28:3: error: ‘elem’ may be used uninitialized [-Werror=maybe-uninitialized]
>> 28 | g_free (*pp);
>> | ^~~~~~~~~~~~
>> ../src/hw/virtio/vhost-shadow-virtqueue.c: In function ‘vhost_handle_guest_kick’:
>> ../src/hw/virtio/vhost-shadow-virtqueue.c:292:42: note: ‘elem’ was declared here
>> 292 | g_autofree VirtQueueElement *elem;
>> | ^~~~
>> cc1: all warnings being treated as errors
>>
>>There is actually no problem since "elem" is initialized in both branches.
>>Silence the warning by initializig it with "NULL".
>>
>>$ gcc --version
>>gcc (GCC) 12.2.0
>>
>>Fixes: 9c2ab2f1ec333be8614cc12272d4b91960704dbe ("vhost: stop transfer elem ownership in vhost_handle_guest_kick")
>>Signed-off-by: Bernhard Beschow <shentey@gmail.com>
>>---
>
>Ping
Ping2
>
>> hw/virtio/vhost-shadow-virtqueue.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>>diff --git a/hw/virtio/vhost-shadow-virtqueue.c b/hw/virtio/vhost-shadow-virtqueue.c
>>index e8e5bbc368..596d4434d2 100644
>>--- a/hw/virtio/vhost-shadow-virtqueue.c
>>+++ b/hw/virtio/vhost-shadow-virtqueue.c
>>@@ -289,7 +289,7 @@ static void vhost_handle_guest_kick(VhostShadowVirtqueue *svq)
>> virtio_queue_set_notification(svq->vq, false);
>>
>> while (true) {
>>- g_autofree VirtQueueElement *elem;
>>+ g_autofree VirtQueueElement *elem = NULL;
>> int r;
>>
>> if (svq->next_guest_avail_elem) {
>
next prev parent reply other threads:[~2022-09-27 22:10 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-10 15:11 [PATCH v2] hw/virtio/vhost-shadow-virtqueue: Silence GCC error "maybe-uninitialized" Bernhard Beschow
2022-09-10 16:05 ` Richard Henderson
2022-09-10 20:20 ` Bernhard Beschow
2022-09-20 5:29 ` Bernhard Beschow
2022-09-27 22:08 ` B [this message]
2022-09-29 19:08 ` Laurent Vivier
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