Re: [libvirt] [PATCH] add an assert, to avoid a false-positive NULL-deref warning from clang

1 Mar 2010


      Eric Blake wrote:
...
According to Jim Meyering on 3/1/2010 10:13 AM:
...
Here's a case in which using an assertion appears to be the only
way to tell clang that "client" really is non-NULL at that point.
I'm sure clang's analyzers will eventually improve, and hence avoid
this sort of false positive, so have marked this with a FIXME comment,
to help ensure we eventually remove this otherwise unnecessary assertion.
...
On the other hand, perhaps a more invasive rewrite would also work while
also avoiding assert(), by hoisting the worker->quitRequest into the while
loop, something like:
while ((client = qemudPendingJob(server)) == NULL) {
         if (worker->quitRequest
             || virCondWait(&server->job, &server->lock) < 0) {
             virMutexUnlock(&server->lock);
             return NULL;
         }
     }
     if (worker->quitRequest) {
         virMutexUnlock(&client->lock);
         virMutexUnlock(&server->lock);
         return NULL;
     }
Should I write that into patch format?
Yes, please.
That is equivalent, placates clang, and is more readable.
Thanks!