On Tue, 15 Sep 2020 13:58:53 +0300 Vladimir Sementsov-Ogievskiy <vsement...@virtuozzo.com> wrote:
> 14.09.2020 15:35, Greg Kurz wrote: > > As recommended in "qapi/error.h", add a bool return value to > > spapr_add_lmbs() and spapr_add_nvdimm(), and use them instead > > of local_err in spapr_memory_plug(). > > > > Since object_property_get_uint() only returns 0 on failure, use > > that as well. > > Why are you sure? Can't the property be 0 itself? > Hmmm... I've based this assumption on the header: * Returns: the value of the property, converted to an unsigned integer, or 0 * an error occurs (including when the property value is not an integer). but looking at the implementation, I don't see any check that a property cannot be 0 indeed... It's a bit misleading to mention this in the header though. I understand that the function should return something, which should have a some explicitly assigned value to avoid compilers or static analyzers to yell, but the written contract should be that the value is _undefined_ IMHO. In its present form, the only way to know if the property is valid is to pass a non-NULL errp actually. I'd rather even see that in the contract, and an assert() in the code. An alternative would be to convert it to have a bool return value and get the actual uint result with a pointer argument. > > > > Also call ERRP_GUARD() to be able to check the status of void > > function pc_dimm_plug() with *errp. > > > > I'm now hesitating to either check *errp for object_property_get_uint() too or simply drop this patch...
