On 6/13/21 4:30 PM, Jonny Grant wrote:
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.
The pointer test is eliminated before -Wnull-dereference runs so it
can't do anything in this case. -fno-delete-null-pointer-checks
disables the optimization and retains the test so -Wnull-dereference
could in theory detect it but it isn't designed to do it. But if
it did, I suspect it would be quite noisy as a result of other
transformations like inlining and constant propagation. So making
it work with an acceptable S/R ratio would take more work than just
enhancing -Wnull-dereference.
Martin
#include <stdlib.h>
#include <cstddef>
void f(int * g)
{
*g = 1;
if(NULL == g)
{
exit(1);
}
}
Best regards Jonny
