On Sun, 2021-06-13 at 23:30 +0100, 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.
>
> #include <stdlib.h>
>
> #include <cstddef>
> void f(int * g)
> {
> *g = 1;
>
> if(NULL == g)
> {
> exit(1);
> }
> }
>
> Best regards Jonny
It was explained by Chris Lattner at
http://blog.llvm.org/2011/05/what-every-c-programmer-should-know_21.html
GCC (<= 4.4) had -Wunreachable-code which might work for this case. But
it was too unreliable (as Chris said, generally there is no reliable way
to do this) and removed in later releases.
--
Xi Ruoyao <xry111@xxxxxxxxxxxxxxxx>
School of Aerospace Science and Technology, Xidian University
