null-deref-ps.c revision f6e5ec45950df60555ee96c62b728b485394e34e 
1// RUN: clang -checker-simple -verify %s
2
3#include<stdint.h>
4#include <assert.h>
5
6void f1(int *p) {
7  if (p) *p = 1;
8  else *p = 0; // expected-warning{{ereference}}
9}
10
11struct foo_struct {
12  int x;
13};
14
15int f2(struct foo_struct* p) {
16
17  if (p)
18    p->x = 1;
19
20  return p->x++; // expected-warning{{Dereference of null pointer.}}
21}
22
23int f3(char* x) {
24
25  int i = 2;
26
27  if (x)
28    return x[i - 1];
29
30  return x[i+1]; // expected-warning{{Dereference of null pointer.}}
31}
32
33int f3_b(char* x) {
34
35  int i = 2;
36
37  if (x)
38    return x[i - 1];
39
40  return x[i+1]++; // expected-warning{{Dereference of null pointer.}}
41}
42
43int f4(int *p) {
44
45  uintptr_t x = (uintptr_t) p;
46
47  if (x)
48    return 1;
49
50  int *q = (int*) x;
51  return *q; // expected-warning{{Dereference of null pointer.}}
52}
53
54int f5() {
55
56  char *s = "hello world";
57  return s[0]; // no-warning
58}
59
60int bar(int* p, int q) __attribute__((nonnull));
61
62int f6(int *p) {
63  return !p ? bar(p, 1) // expected-warning {{Null pointer passed as an argument to a 'nonnull' parameter}}
64         : bar(p, 0);   // no-warning
65}
66
67int* qux();
68
69int f7(int x) {
70
71  int* p = 0;
72
73  if (0 == x)
74    p = qux();
75
76  if (0 == x)
77    *p = 1; // no-warning
78
79  return x;
80}
81
82int f8(int *p, int *q) {
83  if (!p)
84    if (p)
85      *p = 1; // no-warning
86
87  if (q)
88    if (!q)
89      *q = 1; // no-warning
90}
91
92int* qux();
93
94int f9(int len) {
95  assert (len != 0);
96  int *p = 0;
97
98  for (int i = 0; i < len; ++i)
99   p = qux(i);
100
101  return *p++; // no-warning
102}
103
104int f9b(int len) {
105  assert (len > 0);  // note use of '>'
106  int *p = 0;
107
108  for (int i = 0; i < len; ++i)
109   p = qux(i);
110
111  return *p++; // no-warning
112}
113
114