On Sat, Jun 30, 2018 at 02:30:05PM +0530, Sukrit Bhatnagar wrote:
> New macros are introduced which help in adding GNU C's cleanup
> attribute to variable declarations. Variables declared with these
> macros will have their allocated memory freed automatically when
> they go out of scope.
>
> Signed-off-by: Sukrit Bhatnagar <skrtbhtngr@xxxxxxxxx>
> ---
> src/util/viralloc.h | 44 ++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 44 insertions(+)
>
> diff --git a/src/util/viralloc.h b/src/util/viralloc.h
> index 69d0f90..5c1d0d5 100644
> --- a/src/util/viralloc.h
> +++ b/src/util/viralloc.h
> @@ -596,4 +596,48 @@ void virAllocTestInit(void);
> int virAllocTestCount(void);
> void virAllocTestOOM(int n, int m);
> void virAllocTestHook(void (*func)(int, void*), void *data);
> +
> +# define VIR_AUTOPTR_TYPE_NAME(type) type##AutoPtr
> +# define VIR_AUTOPTR_FUNC_NAME(type) type##AutoPtrFree
> +
> +/**
> + * VIR_DEFINE_AUTOPTR_FUNC:
> + * @type: type of the variable to be freed automatically
> + * @func: cleanup function to be automatically called
> + *
> + * This macro defines a function for automatic freeing of
> + * resources allocated to a variable of type @type. This newly
> + * defined function works as a necessary wrapper around @func.
> + */
> +# define VIR_DEFINE_AUTOPTR_FUNC(type, func) \
> + typedef type *VIR_AUTOPTR_TYPE_NAME(type); \
So, it's not visible at first glance how ^this typedef is used...
> + static inline void VIR_AUTOPTR_FUNC_NAME(type)(type **_ptr) \
> + { \
> + if (*_ptr) \
> + (func)(*_ptr); \
> + *_ptr = NULL; \
> + } \
...therefore I'd write it explicitly as
VIR_AUTOPTR_FUNC_NAME(type)(VIR_AUTOPTR_TYPE_NAME(type) *_ptr)
> +
> +# define VIR_AUTOPTR(type) \
> + __attribute__((cleanup(VIR_AUTOPTR_FUNC_NAME(type)))) VIR_AUTOPTR_TYPE_NAME(type)
> +
Also, since we're going to use it like this:
VIR_AUTOPTR(virDomainDef) foo
instead of this:
VIR_AUTOPTR(virDomainDefPtr) foo
why do we need VIR_AUTOPTR_TYPE_NAME anyway, since you could just use
"type *" in the VIR_AUTOPTR macro definition and that should work for external
types as well.
Erik
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