Hello This isn't real code, just an example to show. I've tried with: -Wall -Wextra -O2 and some other warnings, but couldn't get this to generate a warning that *g was possibly de-referenced. May I ask, does GCC have a way to get warnings when pointers are not checked? I had a look but -Wnull-dereference didn't help. #include <stdlib.h> #include <cstddef> void f(int * g) { *g = 1; if(NULL == g) { exit(1); } } Best regards Jonny