summaryrefslogtreecommitdiffstats
path: root/clang/test/Analysis/null-deref-ps.c
blob: 68937bec9f09d8ca461569e386bde4648dfbca8c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
// RUN: clang -analyze -std=gnu99 -checker-simple -verify %s &&
// RUN: clang -analyze -std=gnu99 -checker-simple -verify %s   -analyzer-range-constraints &&
// RUN: clang -analyze -std=gnu99 -checker-simple -analyzer-store-region -analyzer-purge-dead=false -verify %s &&
// RUN: clang -analyze -std=gnu99 -checker-cfref -analyzer-store-region -verify %s

#include<stdint.h>
#include <assert.h>

void f1(int *p) {  
  if (p) *p = 1;
  else *p = 0; // expected-warning{{ereference}}
}

struct foo_struct {
  int x;
};

int f2(struct foo_struct* p) {
  
  if (p)
    p->x = 1;
    
  return p->x++; // expected-warning{{Dereference of null pointer.}}
}

int f3(char* x) {
  
  int i = 2;
  
  if (x)
    return x[i - 1];
  
  return x[i+1]; // expected-warning{{Dereference of null pointer.}}
}

int f3_b(char* x) {
  
  int i = 2;
  
  if (x)
    return x[i - 1];
  
  return x[i+1]++; // expected-warning{{Dereference of null pointer.}}
}

int f4(int *p) {
  
  uintptr_t x = (uintptr_t) p;
  
  if (x)
    return 1;
    
  int *q = (int*) x;
  return *q; // expected-warning{{Dereference of null pointer.}}
}

int f4_b() {
  short array[2];
  uintptr_t x = array; // expected-warning{{incompatible pointer to integer conversion initializing}}
  short *p = x; // expected-warning{{incompatible integer to pointer conversion initializing}}
  
  // The following branch should be infeasible.
  if (!(p = &array[0])) {
    p = 0;
    *p = 1; // no-warning
  }
  
  if (p) {
    *p = 5; // no-warning
    p = 0;
  }
  else return;

  *p += 10; // expected-warning{{Dereference of null pointer}}
}


int f5() {
  
  char *s = "hello world";
  return s[0]; // no-warning
}

int bar(int* p, int q) __attribute__((nonnull));

int f6(int *p) { 
  return !p ? bar(p, 1) // expected-warning {{Null pointer passed as an argument to a 'nonnull' parameter}}
         : bar(p, 0);   // no-warning
}

int bar2(int* p, int q) __attribute__((nonnull(1)));

int f6b(int *p) { 
  return !p ? bar2(p, 1) // expected-warning {{Null pointer passed as an argument to a 'nonnull' parameter}}
         : bar2(p, 0);   // no-warning
}

int bar3(int*p, int q, int *r) __attribute__((nonnull(1,3)));

int f6c(int *p, int *q) {
   return !p ? bar3(q, 2, p) // expected-warning {{Null pointer passed as an argument to a 'nonnull' parameter}}
             : bar3(p, 2, q); // no-warning
}

int* qux();

int f7(int x) {
  
  int* p = 0;
  
  if (0 == x)
    p = qux();
  
  if (0 == x)
    *p = 1; // no-warning
    
  return x;
}

int f8(int *p, int *q) {
  if (!p)
    if (p)
      *p = 1; // no-warning
  
  if (q)
    if (!q)
      *q = 1; // no-warning
}

int* qux();

int f9(unsigned len) {
  assert (len != 0);
  int *p = 0;
  unsigned i;

  for (i = 0; i < len; ++i)
   p = qux(i);

  return *p++; // no-warning
}

int f9b(unsigned len) {
  assert (len > 0);  // note use of '>'
  int *p = 0;
  unsigned i;

  for (i = 0; i < len; ++i)
   p = qux(i);

  return *p++; // no-warning
}

int* f10(int* p, signed char x, int y) {
  // This line tests symbolication with compound assignments where the
  // LHS and RHS have different bitwidths.  The new symbolic value
  // for 'x' should have a bitwidth of 8.
  x &= y;
  
  // This tests that our symbolication worked, and that we correctly test
  // x against 0 (with the same bitwidth).
  if (!x) {
    if (!p) return;
    *p = 10;
  }
  else p = 0;

  if (!x)
    *p = 5; // no-warning

  return p;
}

// Test case from <rdar://problem/6407949>
void f11(unsigned i) {
  int *x = 0;
  if (i >= 0) {
    // always true
  } else {
    *x = 42; // no-warning
  }
}

void f11b(unsigned i) {
  int *x = 0;
  if (i <= ~(unsigned)0) {
    // always true
  } else {
    *x = 42; // no-warning
  }
}

// Test case for switch statements with weird case arms.
typedef int     BOOL, *PBOOL, *LPBOOL;
typedef long    LONG_PTR, *PLONG_PTR;
typedef unsigned long ULONG_PTR, *PULONG_PTR;
typedef ULONG_PTR DWORD_PTR, *PDWORD_PTR;
typedef LONG_PTR LRESULT;
typedef struct _F12ITEM *HF12ITEM;

void f12(HF12ITEM i, char *q) {
  char *p = 0;
  switch ((DWORD_PTR) i) {
  case 0 ... 10:
    p = q;
    break;
  case (DWORD_PTR) ((HF12ITEM) - 65535):
    return;
  default:
    return;
  }
  
  *p = 1; // no-warning
}

OpenPOWER on IntegriCloud