clang/test/Analysis/builtin_overflow_notes.c

   1 // RUN: %clang_analyze_cc1 -analyzer-checker=core -analyzer-output text \
   2 // RUN:   -verify %s
   3
   4 void test_no_overflow_note(int a, int b)
   5 {
   6    int res;
   7
   8    if (__builtin_add_overflow(a, b, &res)) // expected-note {{Assuming no overflow}}
   9                                            // expected-note@-1 {{Taking false branch}}
  10      return;
  11
  12    if (res) { // expected-note {{Assuming 'res' is not equal to 0}}
  13               // expected-note@-1 {{Taking true branch}}
  14      int *ptr = 0; // expected-note {{'ptr' initialized to a null pointer value}}
  15      int var = *(int *) ptr; //expected-warning {{Dereference of null pointer}}
  16                              //expected-note@-1 {{Dereference of null pointer}}
  17    }
  18 }
  19
  20 void test_overflow_note(int a, int b)
  21 {
  22    int res; // expected-note{{'res' declared without an initial value}}
  23
  24    if (__builtin_add_overflow(a, b, &res)) { // expected-note {{Assuming overflow}}
  25                                              // expected-note@-1 {{Taking true branch}}
  26      int var = res; // expected-warning{{Assigned value is garbage or undefined}}
  27                     // expected-note@-1 {{Assigned value is garbage or undefined}}
  28      return;
  29    }
  30 }