clang/test/Analysis/pointer-arithmetic.c

   1 // RUN: %clang_analyze_cc1 -analyzer-checker=core -verify %s
   2
   3 int test1(void) {
   4   int *p = (int *)sizeof(int);
   5   p -= 1;
   6   return *p; // expected-warning {{Dereference of null pointer}}
   7 }
   8
   9 int test2(void) {
  10   int *p = (int *)sizeof(int);
  11   p -= 2;
  12   p += 1;
  13   return *p; // expected-warning {{Dereference of null pointer}}
  14 }
  15
  16 int test3(void) {
  17   int *p = (int *)sizeof(int);
  18   p++;
  19   p--;
  20   p--;
  21   return *p; // expected-warning {{Dereference of null pointer}}
  22 }
  23
  24 int test4(void) {
  25   // This is a special case where pointer arithmetic is not calculated to
  26   // preserve useful warnings on dereferences of null pointers.
  27   int *p = 0;
  28   p += 1;
  29   return *p; // expected-warning {{Dereference of null pointer}}
  30 }