On 3/28/19 2:40 AM, Bjoern Walk wrote:
+/* Take all children of @from and convert them into children of @to. */ +void +virDomainSnapshotMoveChildren(virDomainSnapshotObjPtr from, + virDomainSnapshotObjPtr to) +{ + virDomainSnapshotObjPtr child; + virDomainSnapshotObjPtr last; + + for (child = from->first_child; child; child = child->sibling) { + child->parent = to; + if (!child->sibling) + last = child; + } + to->nchildren += from->nchildren; + last->sibling = to->first_child;
Silly Coverity compiler gets quite confused thinking that @last couldn't be set while not considering the above loop couldn't end without it unless of course from->first_child == NULL I suppose, which would be a different issue. Still if before the for loop we check "if (!from->first_child) return;", then coverity is happy.
Good find from Coverity. If there are no children to move, I do need the early exit, so I'll squash that in.
Did you forget this? Function is pushed in this (broken?) version and I get a warning/error on GCC 8.0.1.
Sorry, no morning coffee yet, the fix is in, but I still get a GCC warning:
CC conf/libvirt_conf_la-virdomainmomentobjlist.lo ../../src/conf/virdomainmomentobjlist.c: In function 'virDomainMomentMoveChildren': ../../src/conf/virdomainmomentobjlist.c:178:19: error: 'last' may be used uninitialized in this function [-Werror=maybe-uninitialized] last->sibling = to->first_child; ~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~ cc1: all warnings being treated as errors make[5]: *** [Makefile:9650: conf/libvirt_conf_la-virdomainmomentobjlist.lo] Error 1
So gcc isn't as smart as Coverity at seeing that it will always be initialized.
This fixes it:
diff --git a/src/conf/virdomainmomentobjlist.c b/src/conf/virdomainmomentobjlist.c index 92cf52dd..2e9343ff 100644 --- a/src/conf/virdomainmomentobjlist.c +++ b/src/conf/virdomainmomentobjlist.c @@ -165,7 +165,7 @@ virDomainMomentMoveChildren(virDomainMomentObjPtr from, virDomainMomentObjPtr to) { virDomainMomentObjPtr child; - virDomainMomentObjPtr last; + virDomainMomentObjPtr last = NULL;
Yep, will push shortly as a build-fixer. I'm assuming you're okay if I push it in your name, as you reported and posted the fix, even though it wasn't the usual git format. -- Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3226 Virtualization: qemu.org | libvirt.org