1// RUN: %clang_cc1 -triple i386-apple-darwin10 -analyze -analyzer-checker=core,deadcode,alpha.core -std=gnu99 -analyzer-store=region -analyzer-constraints=range -analyzer-purge=none -verify %s -Wno-error=return-type
2// RUN: %clang_cc1 -triple i386-apple-darwin10 -analyze -analyzer-checker=core,deadcode,alpha.core -std=gnu99 -analyzer-store=region -analyzer-constraints=range -verify %s -Wno-error=return-type
3
4typedef unsigned uintptr_t;
5
6extern void __assert_fail (__const char *__assertion, __const char *__file,
7    unsigned int __line, __const char *__function)
8     __attribute__ ((__noreturn__));
9
10#define assert(expr) \
11  ((expr)  ? (void)(0)  : __assert_fail (#expr, __FILE__, __LINE__, __func__))
12
13void f1(int *p) {
14  if (p) *p = 1;
15  else *p = 0; // expected-warning{{ereference}}
16}
17
18struct foo_struct {
19  int x;
20};
21
22int f2(struct foo_struct* p) {
23
24  if (p)
25    p->x = 1;
26
27  return p->x++; // expected-warning{{Access to field 'x' results in a dereference of a null pointer (loaded from variable 'p')}}
28}
29
30int f3(char* x) {
31
32  int i = 2;
33
34  if (x)
35    return x[i - 1];
36
37  return x[i+1]; // expected-warning{{Array access (from variable 'x') results in a null pointer dereference}}
38}
39
40int f3_b(char* x) {
41
42  int i = 2;
43
44  if (x)
45    return x[i - 1];
46
47  return x[i+1]++; // expected-warning{{Array access (from variable 'x') results in a null pointer dereference}}
48}
49
50int f4(int *p) {
51
52  uintptr_t x = (uintptr_t) p;
53
54  if (x)
55    return 1;
56
57  int *q = (int*) x;
58  return *q; // expected-warning{{Dereference of null pointer (loaded from variable 'q')}}
59}
60
61int f4_b() {
62  short array[2];
63  uintptr_t x = array; // expected-warning{{incompatible pointer to integer conversion}}
64  short *p = x; // expected-warning{{incompatible integer to pointer conversion}}
65
66  // The following branch should be infeasible.
67  if (!(p == &array[0])) {
68    p = 0;
69    *p = 1; // no-warning
70  }
71
72  if (p) {
73    *p = 5; // no-warning
74    p = 0;
75  }
76  else return; // expected-warning {{non-void function 'f4_b' should return a value}}
77
78  *p += 10; // expected-warning{{Dereference of null pointer}}
79  return 0;
80}
81
82int f5() {
83
84  char *s = "hello world";
85  return s[0]; // no-warning
86}
87
88int bar(int* p, int q) __attribute__((nonnull));
89
90int f6(int *p) {
91  return !p ? bar(p, 1) // expected-warning {{Null pointer passed as an argument to a 'nonnull' parameter}}
92         : bar(p, 0);   // no-warning
93}
94
95int bar2(int* p, int q) __attribute__((nonnull(1)));
96
97int f6b(int *p) {
98  return !p ? bar2(p, 1) // expected-warning {{Null pointer passed as an argument to a 'nonnull' parameter}}
99         : bar2(p, 0);   // no-warning
100}
101
102int bar3(int*p, int q, int *r) __attribute__((nonnull(1,3)));
103
104int f6c(int *p, int *q) {
105   return !p ? bar3(q, 2, p) // expected-warning {{Null pointer passed as an argument to a 'nonnull' parameter}}
106             : bar3(p, 2, q); // no-warning
107}
108
109void f6d(int *p) {
110  bar(p, 0);
111  // At this point, 'p' cannot be null.
112  if (!p) {
113    int *q = 0;
114    *q = 0xDEADBEEF; // no-warning
115  }
116}
117
118void f6e(int *p, int offset) {
119  // PR7406 - crash from treating an UnknownVal as defined, to see if it's 0.
120  bar((p+offset)+1, 0); // not crash
121}
122
123int* qux();
124
125int f7(int x) {
126
127  int* p = 0;
128
129  if (0 == x)
130    p = qux();
131
132  if (0 == x)
133    *p = 1; // no-warning
134
135  return x;
136}
137
138int* f7b(int *x) {
139
140  int* p = 0;
141
142  if (((void*)0) == x)
143    p = qux();
144
145  if (((void*)0) == x)
146    *p = 1; // no-warning
147
148  return x;
149}
150
151int* f7c(int *x) {
152
153  int* p = 0;
154
155  if (((void*)0) == x)
156    p = qux();
157
158  if (((void*)0) != x)
159    return x;
160
161  // If we reach here then 'p' is not null.
162  *p = 1; // no-warning
163  return x;
164}
165
166int* f7c2(int *x) {
167
168  int* p = 0;
169
170  if (((void*)0) == x)
171    p = qux();
172
173  if (((void*)0) == x)
174    return x;
175
176  *p = 1; // expected-warning{{null}}
177  return x;
178}
179
180
181void f8(int *p, int *q) {
182  if (!p)
183    if (p)
184      *p = 1; // no-warning
185
186  if (q)
187    if (!q)
188      *q = 1; // no-warning
189}
190
191int* qux();
192
193int f9(unsigned len) {
194  assert (len != 0);
195  int *p = 0;
196  unsigned i;
197
198  for (i = 0; i < len; ++i)
199   p = qux(i);
200
201  return *p++; // no-warning
202}
203
204int f9b(unsigned len) {
205  assert (len > 0);  // note use of '>'
206  int *p = 0;
207  unsigned i;
208
209  for (i = 0; i < len; ++i)
210   p = qux(i);
211
212  return *p++; // no-warning
213}
214
215int* f10(int* p, signed char x, int y) {
216  // This line tests symbolication with compound assignments where the
217  // LHS and RHS have different bitwidths.  The new symbolic value
218  // for 'x' should have a bitwidth of 8.
219  x &= y;
220
221  // This tests that our symbolication worked, and that we correctly test
222  // x against 0 (with the same bitwidth).
223  if (!x) {
224    if (!p) return 0;
225    *p = 10;
226  }
227  else p = 0;
228
229  if (!x)
230    *p = 5; // no-warning
231
232  return p;
233}
234
235// Test case from <rdar://problem/6407949>
236void f11(unsigned i) {
237  int *x = 0;
238  if (i >= 0) { // expected-warning{{always true}}
239    // always true
240  } else {
241    *x = 42; // no-warning
242  }
243}
244
245void f11b(unsigned i) {
246  int *x = 0;
247  if (i <= ~(unsigned)0) {
248    // always true
249  } else {
250    *x = 42; // no-warning
251  }
252}
253
254// Test case for switch statements with weird case arms.
255typedef int     BOOL, *PBOOL, *LPBOOL;
256typedef long    LONG_PTR, *PLONG_PTR;
257typedef unsigned long ULONG_PTR, *PULONG_PTR;
258typedef ULONG_PTR DWORD_PTR, *PDWORD_PTR;
259typedef LONG_PTR LRESULT;
260typedef struct _F12ITEM *HF12ITEM;
261
262void f12(HF12ITEM i, char *q) {
263  char *p = 0;
264  switch ((DWORD_PTR) i) {
265  case 0 ... 10:
266    p = q;
267    break;
268  case (DWORD_PTR) ((HF12ITEM) - 65535):
269    return;
270  default:
271    return;
272  }
273
274  *p = 1; // no-warning
275}
276
277// Test handling of translating between integer "pointers" and back.
278void f13() {
279  int *x = 0;
280  if (((((int) x) << 2) + 1) >> 1) *x = 1;
281}
282
283// PR 4759 - Attribute non-null checking by the analyzer was not correctly
284// handling pointer values that were undefined.
285void pr4759_aux(int *p) __attribute__((nonnull));
286
287void pr4759() {
288  int *p;
289  pr4759_aux(p); // expected-warning{{Function call argument is an uninitialized value}}
290}
291
292// Relax function call arguments invalidation to be aware of const
293// arguments. Test with function pointers. radar://10595327
294void ttt(const int *nptr);
295void ttt2(const int *nptr);
296typedef void (*NoConstType)(int*);
297int foo10595327(int b) {
298  void (*fp)(int *);
299  // We use path sensitivity to get the function declaration. Even when the
300  // function pointer is cast to non-pointer-to-const parameter type, we can
301  // find the right function declaration.
302  if (b > 5)
303    fp = (NoConstType)ttt2;
304  else
305    fp = (NoConstType)ttt;
306  int x = 3;
307  int y = x + 1;
308  int *p = 0;
309  fp(&y);
310  if (x == y)
311      return *p; // no-warning
312  return 0;
313}
314