https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109542
Xi Ruoyao <xry111 at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |xry111 at gcc dot gnu.org --- Comment #1 from Xi Ruoyao <xry111 at gcc dot gnu.org> --- Performing arithmetic on NULL pointer is an undefined behavior. The standard says you can only perform arithmetic on a pointer if it's a pointer to an array element (an object not in any array will be considered as the only element in an array with length 1), but NULL is not such a pointer.