1 // RUN: %clang_cc1 -fsyntax-only -verify -Wno-sizeof-array-argument %s
2 //
3 extern "C" void *memset(void *, int, unsigned);
4 extern "C" void *memmove(void *s1, const void *s2, unsigned n);
5 extern "C" void *memcpy(void *s1, const void *s2, unsigned n);
6 extern "C" void *memcmp(void *s1, const void *s2, unsigned n);
7 
8 struct S {int a, b, c, d;};
9 typedef S* PS;
10 
11 struct Foo {};
12 typedef const Foo& CFooRef;
13 typedef const Foo CFoo;
14 typedef volatile Foo VFoo;
15 typedef const volatile Foo CVFoo;
16 
17 typedef double Mat[4][4];
18 
19 template <class Dest, class Source>
bit_cast(const Source & source)20 inline Dest bit_cast(const Source& source) {
21   Dest dest;
22   memcpy(&dest, &source, sizeof(dest));
23   return dest;
24 }
25 
26 // http://www.lysator.liu.se/c/c-faq/c-2.html#2-6
f(Mat m,const Foo & const_foo,char * buffer)27 void f(Mat m, const Foo& const_foo, char *buffer) {
28   S s;
29   S* ps = &s;
30   PS ps2 = &s;
31   char arr[5];
32   char* parr[5];
33   Foo foo;
34   char* heap_buffer = new char[42];
35 
36   /* Should warn */
37   memset(&s, 0, sizeof(&s));  // \
38       // 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)?}}
39   memset(ps, 0, sizeof(ps));  // \
40       // 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)?}}
41   memset(ps2, 0, sizeof(ps2));  // \
42       // 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)?}}
43   memset(ps2, 0, sizeof(typeof(ps2)));  // \
44       // expected-warning {{argument to 'sizeof' in 'memset' call is the same pointer type}}
45   memset(ps2, 0, sizeof(PS));  // \
46       // expected-warning {{argument to 'sizeof' in 'memset' call is the same pointer type}}
47   memset(heap_buffer, 0, sizeof(heap_buffer));  // \
48       // 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?}}
49 
50   memcpy(&s, 0, sizeof(&s));  // \
51       // 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)?}}
52   memcpy(0, &s, sizeof(&s));  // \
53       // 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)?}}
54 
55   memmove(ps, 0, sizeof(ps));  // \
56       // 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)?}}
57   memcmp(ps, 0, sizeof(ps));  // \
58       // 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)?}}
59 
60   /* Shouldn't warn */
61   memset((void*)&s, 0, sizeof(&s));
62   memset(&s, 0, sizeof(s));
63   memset(&s, 0, sizeof(S));
64   memset(&s, 0, sizeof(const S));
65   memset(&s, 0, sizeof(volatile S));
66   memset(&s, 0, sizeof(volatile const S));
67   memset(&foo, 0, sizeof(CFoo));
68   memset(&foo, 0, sizeof(VFoo));
69   memset(&foo, 0, sizeof(CVFoo));
70   memset(ps, 0, sizeof(*ps));
71   memset(ps2, 0, sizeof(*ps2));
72   memset(ps2, 0, sizeof(typeof(*ps2)));
73   memset(arr, 0, sizeof(arr));
74   memset(parr, 0, sizeof(parr));
75 
76   memcpy(&foo, &const_foo, sizeof(Foo));
77   memcpy((void*)&s, 0, sizeof(&s));
78   memcpy(0, (void*)&s, sizeof(&s));
79   char *cptr;
80   memcpy(&cptr, buffer, sizeof(cptr));
81   memcpy((char*)&cptr, buffer, sizeof(cptr));
82 
83   CFooRef cfoo = foo;
84   memcpy(&foo, &cfoo, sizeof(Foo));
85 
86   memcpy(0, &arr, sizeof(arr));
87   typedef char Buff[8];
88   memcpy(0, &arr, sizeof(Buff));
89 
90   unsigned char* puc;
91   bit_cast<char*>(puc);
92 
93   float* pf;
94   bit_cast<int*>(pf);
95 
96   int iarr[14];
97   memset(&iarr[0], 0, sizeof iarr);
98   memset(iarr, 0, sizeof iarr);
99 
100   int* iparr[14];
101   memset(&iparr[0], 0, sizeof iparr);
102   memset(iparr, 0, sizeof iparr);
103 
104   memset(m, 0, sizeof(Mat));
105 
106   // Copy to raw buffer shouldn't warn either
107   memcpy(&foo, &arr, sizeof(Foo));
108   memcpy(&arr, &foo, sizeof(Foo));
109 
110   // Shouldn't warn, and shouldn't crash either.
111   memset(({
112     if (0) {}
113     while (0) {}
114     for (;;) {}
115     &s;
116   }), 0, sizeof(s));
117 }
118 
119 namespace ns {
120 void memset(void* s, char c, int n);
f(int * i)121 void f(int* i) {
122   memset(i, 0, sizeof(i));
123 }
124 }
125 
126 extern "C" int strncmp(const char *s1, const char *s2, unsigned n);
127 extern "C" int strncasecmp(const char *s1, const char *s2, unsigned n);
128 extern "C" char *strncpy(char *det, const char *src, unsigned n);
129 extern "C" char *strncat(char *dst, const char *src, unsigned n);
130 extern "C" char *strndup(const  char *src, unsigned n);
131 
strcpy_and_friends()132 void strcpy_and_friends() {
133   const char* FOO = "<- should be an array instead";
134   const char* BAR = "<- this, too";
135 
136   strncmp(FOO, BAR, sizeof(FOO)); // \
137       // 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?}}
138   strncasecmp(FOO, BAR, sizeof(FOO));  // \
139       // 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?}}
140 
141   char buff[80];
142 
143   strncpy(buff, BAR, sizeof(BAR)); // \
144       // 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?}}
145   strndup(FOO, sizeof(FOO)); // \
146       // 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?}}
147 }
148