Re: [libvirt] [PATCH v2 4/4] util: alloc: Note that VIR_AUTOPTR/VIR_AUTOCLEAN must not be used with vectors

On Wed, Feb 27, 2019 at 15:05:18 +0100, Erik Skultety wrote: > On Tue, Feb 26, 2019 at 04:48:26PM +0100, Peter Krempa wrote: > > We'd free only the first element of the vector leaking the rest. > > > > Signed-off-by: Peter Krempa <pkrempa(a)redhat.com&gt; > > --- > > src/util/viralloc.h | 6 ++++++ > > 1 file changed, 6 insertions(+) > > > > diff --git a/src/util/viralloc.h b/src/util/viralloc.h > > index 15451d4673..572b7d1c1c 100644 > > --- a/src/util/viralloc.h > > +++ b/src/util/viralloc.h > > @@ -650,6 +650,9 @@ void virAllocTestHook(void (*func)(int, void*), void *data); > > * the variable declared with it by calling the function > > * defined by VIR_DEFINE_AUTOPTR_FUNC when the variable > > * goes out of scope. > > + * > > + * Note that this macro must NOT be used with vectors! The cleaning function > > + * will not free any elements beyond the first. > > s/cleaning/freeing/ > > I understand, but if you have happen to have a dedicated list type, then you'd > have a dedicated destructor, so both of these would be okay with vectors. On Note that the function registered via __attribute(cleanup ... gets only the pointer to the stack'd variable as an argument. This means that you can do only 'value-terminated' (NULL, -1, ... ) lists. Anything requiring count of elements will need to be encapsulated in a struct which makes it a container. Thus the comment does not apply.