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

[Erik Skultety]

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 at redhat.com>
> ---
>  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
the other hand I'm not sure whether we have such a thing at the moment, so I
guess it's meaningful to document in the meantime.

Reviewed-by: Erik Skultety <eskultet at redhat.com>

>   */
>  # define VIR_AUTOPTR(type) \
>      __attribute__((cleanup(VIR_AUTOPTR_FUNC_NAME(type)))) type *
> @@ -662,6 +665,9 @@ void virAllocTestHook(void (*func)(int, void*), void *data);
>   * when the variable goes out of scope.
>   * The cleanup function is registered by VIR_DEFINE_AUTOCLEAN_FUNC macro for
>   * the given type.
> + *
> + * Note that this macro must NOT be used with vectors! The cleaning function
> + * will not free any elements beyond the first.
>   */
>  # define VIR_AUTOCLEAN(type) \
>      __attribute__((cleanup(VIR_AUTOCLEAN_FUNC_NAME(type)))) type
> --
> 2.20.1
>
> --
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