On Thu, 12 Jul 2018 at 22:09, Erik Skultety <eskultet@redhat.com> wrote:
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@gmail.com> --- 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.
I agree. We don't really need it. Here is how the code will look after the changes you suggested: # define VIR_AUTOPTR_FUNC_NAME(type) type##AutoPtrFree # define VIR_DEFINE_AUTOPTR_FUNC(type, func) \ static inline void VIR_AUTOPTR_FUNC_NAME(type)(type **_ptr) \ { \ if (*_ptr) \ (func)(*_ptr); \ *_ptr = NULL; \ } \ # define VIR_AUTOFREE(type) __attribute__((cleanup(virFree))) type # define VIR_AUTOPTR(type) \ __attribute__((cleanup(VIR_AUTOPTR_FUNC_NAME(type)))) type * Shall I proceed to send the first series of patches?