Re: [libvirt] [PATCH 4/4] virFree: Check const correctness

Up to now it's possible to do something like this: const char *ptr; ptr = strdup("my example string"); VIR_FREE(ptr); The problem is, const char * pointers should not be modified (and freeing them is kind of modification). We should avoid this. A little trick is used: assigning a const pointer into 'void *' triggers compiler warning about discarding 'const' qualifier from pointer. So the virFree() function gains new dummy argument, that is not touched anyhow, just fulfills the const correctness check duty. Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com&gt; --- src/util/viralloc.c | 6 ++++-- src/util/viralloc.h | 20 ++++++++++++++++---- src/xenapi/xenapi_utils.c | 2 +- 3 files changed, 21 insertions(+), 7 deletions(-)

@@ -543,11 +543,23 @@ void virFree(void *ptrptr) ATTRIBUTE_NONNULL(1); * @ptr: pointer holding address to be freed * * Free the memory stored in 'ptr' and update to point - * to NULL. + * to NULL. Moreover, this macro has a side effect in + * form of evaluating passed argument multiple times.