Re: [Qemu-devel] [PATCH v2 0/3] require newer glib2 to enable autofree'ing of stack variables exiting scope

["Alex Bennée" <alex.bennee@linaro.org>]

Daniel P. Berrangé <berrange@redhat.com> writes:

> Both GCC and CLang support a C extension attribute((cleanup)) which
> allows you to define a function that is invoked when a stack variable
> exits scope. This typically used to free the memory allocated to it,
> though you're not restricted to this. For example it could be used to
> unlock a mutex.
<snip>
>
>     GOOD:
>         g_autofree char *wibble = g_strdup("wibble")
> 	...
> 	return g_steal_pointer(wibble);
>
>     g_steal_pointer is an inline function which simply copies
>     the pointer to a new variable, and sets the original variable
>     to NULL, thus avoiding cleanup.

Surely this is a particular use case where you wouldn't use g_autofree
to declare the variable as you intending to return it to the outer scope?

--
Alex Bennée