Re: [libvirt PATCH] All pointers to virXMLPropString() use g_autofree.

On Thu, Jul 09, 2020 at 02:40:34PM -0300, Nicolás Brignone wrote: > On Thu, Jul 9, 2020 at 5:15 AM Daniel P. Berrangé <berrange(a)redhat.com&gt; wrote: > > > > On Wed, Jul 08, 2020 at 11:15:27PM -0400, Laine Stump wrote: > > > On 7/8/20 4:19 PM, Nicolas Brignone wrote: > > > > All pointers to virXMLPropString() use g_autofree. > > > > > > > > > I changed the summary line like this, to be more precise: > > > > > > > > > conf: use g_autofree for all pointers to virXMLPropString() in device_conf.c > > > > > > > > > > All modified functions are similar, in all cases "cleanup" label is removed, > > > > along with all the "goto" calls. > > > > > > > > > I've been advised in the recent past to put the g_autofree additions and > > > corresponding removals of free functions into one patch, then do the removal > > > of the extra labels (in favor of directly returning) in a separate patch to > > > make it easier to hand-verify / review. Here's a couple recent examples: > > > > > > > > > https://www.redhat.com/archives/libvir-list/2020-July/msg00317.html > > > > > > > > > In your case the changes are few enough that I'm okay with it a single > > > patch, except... > > > > > > > > > > > > > > Signed-off-by: Nicolas Brignone <nmbrignone(a)gmail.com&gt; > > > > --- > > > > src/conf/device_conf.c | 183 +++++++++++++---------------------------- > > > > 1 file changed, 56 insertions(+), 127 deletions(-) > > > > > > > > diff --git a/src/conf/device_conf.c b/src/conf/device_conf.c > > > > index 7d48a3f..9fa6141 100644 > > > > --- a/src/conf/device_conf.c > > > > +++ b/src/conf/device_conf.c > > > > @@ -208,45 +208,43 @@ int > > > > virPCIDeviceAddressParseXML(xmlNodePtr node, > > > > virPCIDeviceAddressPtr addr) > > > > { > > > > - char *domain, *slot, *bus, *function, *multi; > > > > xmlNodePtr cur; > > > > xmlNodePtr zpci = NULL; > > > > - int ret = -1; > > > > memset(addr, 0, sizeof(*addr)); > > > > - domain = virXMLPropString(node, "domain"); > > > > - bus = virXMLPropString(node, "bus"); > > > > - slot = virXMLPropString(node, "slot"); > > > > - function = virXMLPropString(node, "function"); > > > > - multi = virXMLPropString(node, "multifunction"); > > > > + g_autofree char *domain = virXMLPropString(node, "domain"); > > > > + g_autofree char *bus = virXMLPropString(node, "bus"); > > > > + g_autofree char *slot = virXMLPropString(node, "slot"); > > > > + g_autofree char *function = virXMLPropString(node, "function"); > > > > + g_autofree char *multi = virXMLPropString(node, "multifunction"); > > > > > > > > > ... you've modified it so that local variables are being declared *below* a > > > line of executable code rather than at the top of the block. Although I > > > don't see anything in the coding style document > > > (https://libvirt.org/coding-style.html) about it, and it may just be > > > leftover from a time when we supported a compiler that required all > > > declarations to be at top of scope, I think pretty much all of libvirts code > > > declares all local variables at the top of the scope. > > > > We should really document it, and even enforce it at compile time. > > I think you are asking for enabling: > > -Wdeclaration-after-statement (C and Objective-C only) > Warn when a declaration is found after a statement in a > block. This construct, known from C++, was introduced > with ISO C99 and is by default allowed in GCC. It is not > supported by ISO C90. Yes, but.... > Will take a look. ..don't spend your time on enabling -Wdeclaration-after-statement unless you are strongly motivated to do a lot of tedious work. I took at stab at it about 12 months ago, but didn't complete it as there are a surprising amount of subtle edge cases to deal with, so I never got as far as sending a patch proposal. FWIW, WIP is here https://gitlab.com/berrange/libvirt/-/tree/c99-vars but this is based against ancient version, not current git master, so I doubt it will rebase cleanly at all Regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|