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
| // RUN: %clang_cc1 -fsyntax-only -verify -Wno-sizeof-array-argument %s
//
extern "C" void *bzero(void *, unsigned);
extern "C" void *memset(void *, int, unsigned);
extern "C" void *memmove(void *s1, const void *s2, unsigned n);
extern "C" void *memcpy(void *s1, const void *s2, unsigned n);
extern "C" void *memcmp(void *s1, const void *s2, unsigned n);
struct S {int a, b, c, d;};
typedef S* PS;
struct Foo {};
typedef const Foo& CFooRef;
typedef const Foo CFoo;
typedef volatile Foo VFoo;
typedef const volatile Foo CVFoo;
typedef double Mat[4][4];
template <class Dest, class Source>
inline Dest bit_cast(const Source& source) {
Dest dest;
memcpy(&dest, &source, sizeof(dest));
return dest;
}
// http://www.lysator.liu.se/c/c-faq/c-2.html#2-6
void f(Mat m, const Foo& const_foo, char *buffer) {
S s;
S* ps = &s;
PS ps2 = &s;
char arr[5];
char* parr[5];
Foo foo;
char* heap_buffer = new char[42];
/* Should warn */
memset(&s, 0, sizeof(&s)); // \
// expected-warning {{'memset' call operates on objects of type 'S' while the size is based on a different type 'S *'}} expected-note{{did you mean to remove the addressof in the argument to 'sizeof' (and multiply it by the number of elements)?}}
memset(ps, 0, sizeof(ps)); // \
// expected-warning {{'memset' call operates on objects of type 'S' while the size is based on a different type 'S *'}} expected-note{{did you mean to dereference the argument to 'sizeof' (and multiply it by the number of elements)?}}
memset(ps2, 0, sizeof(ps2)); // \
// expected-warning {{'memset' call operates on objects of type 'S' while the size is based on a different type 'PS' (aka 'S *')}} expected-note{{did you mean to dereference the argument to 'sizeof' (and multiply it by the number of elements)?}}
memset(ps2, 0, sizeof(typeof(ps2))); // \
// expected-warning {{argument to 'sizeof' in 'memset' call is the same pointer type}}
memset(ps2, 0, sizeof(PS)); // \
// expected-warning {{argument to 'sizeof' in 'memset' call is the same pointer type}}
memset(heap_buffer, 0, sizeof(heap_buffer)); // \
// expected-warning {{'memset' call operates on objects of type 'char' while the size is based on a different type 'char *'}} expected-note{{did you mean to provide an explicit length?}}
bzero(&s, sizeof(&s)); // \
// expected-warning {{'bzero' call operates on objects of type 'S' while the size is based on a different type 'S *'}} expected-note{{did you mean to remove the addressof in the argument to 'sizeof' (and multiply it by the number of elements)?}}
bzero(ps, sizeof(ps)); // \
// expected-warning {{'bzero' call operates on objects of type 'S' while the size is based on a different type 'S *'}} expected-note{{did you mean to dereference the argument to 'sizeof' (and multiply it by the number of elements)?}}
bzero(ps2, sizeof(ps2)); // \
// expected-warning {{'bzero' call operates on objects of type 'S' while the size is based on a different type 'PS' (aka 'S *')}} expected-note{{did you mean to dereference the argument to 'sizeof' (and multiply it by the number of elements)?}}
bzero(ps2, sizeof(typeof(ps2))); // \
// expected-warning {{argument to 'sizeof' in 'bzero' call is the same pointer type}}
bzero(ps2, sizeof(PS)); // \
// expected-warning {{argument to 'sizeof' in 'bzero' call is the same pointer type}}
bzero(heap_buffer, sizeof(heap_buffer)); // \
// expected-warning {{'bzero' call operates on objects of type 'char' while the size is based on a different type 'char *'}} expected-note{{did you mean to provide an explicit length?}}
memcpy(&s, 0, sizeof(&s)); // \
// expected-warning {{'memcpy' call operates on objects of type 'S' while the size is based on a different type 'S *'}} expected-note{{did you mean to remove the addressof in the argument to 'sizeof' (and multiply it by the number of elements)?}}
memcpy(0, &s, sizeof(&s)); // \
// expected-warning {{'memcpy' call operates on objects of type 'S' while the size is based on a different type 'S *'}} expected-note{{did you mean to remove the addressof in the argument to 'sizeof' (and multiply it by the number of elements)?}}
memmove(ps, 0, sizeof(ps)); // \
// expected-warning {{'memmove' call operates on objects of type 'S' while the size is based on a different type 'S *'}} expected-note{{did you mean to dereference the argument to 'sizeof' (and multiply it by the number of elements)?}}
memcmp(ps, 0, sizeof(ps)); // \
// expected-warning {{'memcmp' call operates on objects of type 'S' while the size is based on a different type 'S *'}} expected-note{{did you mean to dereference the argument to 'sizeof' (and multiply it by the number of elements)?}}
/* Shouldn't warn */
memset((void*)&s, 0, sizeof(&s));
memset(&s, 0, sizeof(s));
memset(&s, 0, sizeof(S));
memset(&s, 0, sizeof(const S));
memset(&s, 0, sizeof(volatile S));
memset(&s, 0, sizeof(volatile const S));
memset(&foo, 0, sizeof(CFoo));
memset(&foo, 0, sizeof(VFoo));
memset(&foo, 0, sizeof(CVFoo));
memset(ps, 0, sizeof(*ps));
memset(ps2, 0, sizeof(*ps2));
memset(ps2, 0, sizeof(typeof(*ps2)));
memset(arr, 0, sizeof(arr));
memset(parr, 0, sizeof(parr));
bzero((void*)&s, sizeof(&s));
bzero(&s, sizeof(s));
bzero(&s, sizeof(S));
bzero(&s, sizeof(const S));
bzero(&s, sizeof(volatile S));
bzero(&s, sizeof(volatile const S));
bzero(&foo, sizeof(CFoo));
bzero(&foo, sizeof(VFoo));
bzero(&foo, sizeof(CVFoo));
bzero(ps, sizeof(*ps));
bzero(ps2, sizeof(*ps2));
bzero(ps2, sizeof(typeof(*ps2)));
bzero(arr, sizeof(arr));
bzero(parr, sizeof(parr));
memcpy(&foo, &const_foo, sizeof(Foo));
memcpy((void*)&s, 0, sizeof(&s));
memcpy(0, (void*)&s, sizeof(&s));
char *cptr;
memcpy(&cptr, buffer, sizeof(cptr));
memcpy((char*)&cptr, buffer, sizeof(cptr));
CFooRef cfoo = foo;
memcpy(&foo, &cfoo, sizeof(Foo));
memcpy(0, &arr, sizeof(arr));
typedef char Buff[8];
memcpy(0, &arr, sizeof(Buff));
unsigned char* puc;
bit_cast<char*>(puc);
float* pf;
bit_cast<int*>(pf);
int iarr[14];
memset(&iarr[0], 0, sizeof iarr);
memset(iarr, 0, sizeof iarr);
bzero(&iarr[0], sizeof iarr);
bzero(iarr, sizeof iarr);
int* iparr[14];
memset(&iparr[0], 0, sizeof iparr);
memset(iparr, 0, sizeof iparr);
bzero(&iparr[0], sizeof iparr);
bzero(iparr, sizeof iparr);
memset(m, 0, sizeof(Mat));
bzero(m, sizeof(Mat));
// Copy to raw buffer shouldn't warn either
memcpy(&foo, &arr, sizeof(Foo));
memcpy(&arr, &foo, sizeof(Foo));
// Shouldn't warn, and shouldn't crash either.
memset(({
if (0) {}
while (0) {}
for (;;) {}
&s;
}), 0, sizeof(s));
bzero(({
if (0) {}
while (0) {}
for (;;) {}
&s;
}), sizeof(s));
}
namespace ns {
void memset(void* s, char c, int n);
void bzero(void* s, int n);
void f(int* i) {
memset(i, 0, sizeof(i));
bzero(i, sizeof(i));
}
}
extern "C" int strncmp(const char *s1, const char *s2, unsigned n);
extern "C" int strncasecmp(const char *s1, const char *s2, unsigned n);
extern "C" char *strncpy(char *det, const char *src, unsigned n);
extern "C" char *strncat(char *dst, const char *src, unsigned n);
extern "C" char *strndup(const char *src, unsigned n);
void strcpy_and_friends() {
const char* FOO = "<- should be an array instead";
const char* BAR = "<- this, too";
strncmp(FOO, BAR, sizeof(FOO)); // \
// expected-warning {{'strncmp' call operates on objects of type 'const char' while the size is based on a different type 'const char *'}} expected-note{{did you mean to provide an explicit length?}}
strncasecmp(FOO, BAR, sizeof(FOO)); // \
// expected-warning {{'strncasecmp' call operates on objects of type 'const char' while the size is based on a different type 'const char *'}} expected-note{{did you mean to provide an explicit length?}}
char buff[80];
strncpy(buff, BAR, sizeof(BAR)); // \
// expected-warning {{'strncpy' call operates on objects of type 'const char' while the size is based on a different type 'const char *'}} expected-note{{did you mean to provide an explicit length?}}
strndup(FOO, sizeof(FOO)); // \
// expected-warning {{'strndup' call operates on objects of type 'const char' while the size is based on a different type 'const char *'}} expected-note{{did you mean to provide an explicit length?}}
}
|