Re: [libvirt] [PATCH] daemon: Don't try to free an unsigned int in error paths

On 04/22/2011 10:31 AM, Christophe Fergeau wrote: > On Fri, Apr 22, 2011 at 10:17:01AM -0600, Eric Blake wrote: >> On 04/22/2011 10:11 AM, Matthias Bolte wrote: >>>          remoteDispatchError(rerr); >>> -        VIR_FREE(ret->names.names_len); >>> +        VIR_FREE(ret->names.names_val); >> >> And to think I missed those in the huge patch.  Oops. > > Maybe VIR_FREE should be changed to something like > > -# define VIR_FREE(ptr) virFree(&(ptr)) > +# define VIR_FREE(ptr) \ > +    do { void *check_type = (ptr); virFree(&(check_type)); } while (0) Not quite.  That assigns check_type to NULL, rather than the intended assignment of ptr. But the idea has merit; I'll see if I can come up with a variant that still evaluates ptr only once, by wrapping the type check in a sizeof hack. > I also get more warnings about casting from const to non-const, this can > be avoided by making check_type const void *, but maybe these warnings > indicate that something that shouldn't be freed is freed. How many warnings?  If it's only a handful, we should start investigating; if it's lots, then I'm not sure how much it buys us.