1 // RUN: %clang_cc1 -std=c++11 -Wno-conversion-null -analyze -analyzer-checker=core -analyzer-store region -verify %s
2 
3 // test to see if nullptr is detected as a null pointer
4 void foo1(void) {
5   char  *np = nullptr;
6   *np = 0;  // expected-warning{{Dereference of null pointer}}
7 }
8 
9 // check if comparing nullptr to nullptr is detected properly
10 void foo2(void) {
11   char *np1 = nullptr;
12   char *np2 = np1;
13   char c;
14   if (np1 == np2)
15     np1 = &c;
16   *np1 = 0;  // no-warning
17 }
18 
19 // invoving a nullptr in a more complex operation should be cause a warning
20 void foo3(void) {
21   struct foo {
22     int a, f;
23   };
24   char *np = nullptr;
25   // casting a nullptr to anything should be caught eventually
26   int *ip = &(((struct foo *)np)->f);  // expected-warning{{Access to field 'f' results in a dereference of a null pointer (loaded from variable 'np')}}
27 
28   // Analysis stops at the first problem case, so we won't actually warn here.
29   *ip = 0;
30   *np = 0;
31 }
32 
33 // nullptr is implemented as a zero integer value, so should be able to compare
34 void foo4(void) {
35   char *np = nullptr;
36   if (np != 0)
37     *np = 0;  // no-warning
38   char  *cp = 0;
39   if (np != cp)
40     *np = 0;  // no-warning
41 }
42 
43 int pr10372(void *& x) {
44   // GNU null is a pointer-sized integer, not a pointer.
45   x = __null;
46   // This used to crash.
47   return __null;
48 }
49 
50 void zoo1() {
51   char **p = 0;
52   delete *(p + 0); // expected-warning{{Dereference of null pointer}}
53 }
54 
55 void zoo2() {
56   int **a = 0;
57   int **b = 0;
58   asm ("nop"
59       :"=r"(*a)
60       :"0"(*b) // expected-warning{{Dereference of null pointer}}
61       );
62 }
63 
64 int exprWithCleanups() {
65   struct S {
66     S(int a):a(a){}
67     ~S() {}
68 
69     int a;
70   };
71 
72   int *x = 0;
73   return S(*x).a; // expected-warning{{Dereference of null pointer}}
74 }
75 
76 int materializeTempExpr() {
77   int *n = 0;
78   struct S {
79     int a;
80     S(int i): a(i) {}
81   };
82   const S &s = S(*n); // expected-warning{{Dereference of null pointer}}
83   return s.a;
84 }
85