[Bug c/91918] New: Const pointer argument to atomic_compare_exchange doesn't cause an error.

[mq at ucw dot cz]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91918

            Bug ID: 91918
           Summary: Const pointer argument to atomic_compare_exchange
                    doesn't cause an error.
           Product: gcc
           Version: 8.3.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: mq at ucw dot cz
  Target Milestone: ---

Passing second argument (desired) to atomic_compare_exchange as const pointer
doesn'ŧ cause an error and silently segfaults, as in this code.

#include <stdatomic.h>
static const int desired = 42;
static _Atomic int data = 0;

int main(void) {
  atomic_compare_exchange_weak(&data, &desired, 64);
}