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
|
/* Verify -Wuse-after-free=1 triggers only for unconditional uses and
not for equality expressions.
{ dg-do compile }
{ dg-options "-O0 -Wall -Wuse-after-free=1" } */
#if __cplusplus
# define EXTERN_C extern "C"
#else
# define EXTERN_C extern
#endif
EXTERN_C void free (void*);
void sink (void*);
void warn_double_free (void *p)
{
free (p);
free (p); // { dg-warning "pointer 'p' used" }
}
void nowarn_cond_double_free (void *p, int c)
{
free (p);
if (c)
free (p);
}
void warn_call_after_free (void *p)
{
free (p);
sink (p); // { dg-warning "pointer 'p' used" }
}
void nowarn_cond_call_after_free (void *p, int c)
{
free (p);
if (c)
sink (p);
}
void* warn_return_after_free (void *p)
{
free (p);
return p; // { dg-warning "pointer 'p' used" }
}
void* nowarn_cond_return_after_free (void *p, int c)
{
free (p);
if (c)
return p;
return 0;
}
void warn_relational_after_free (char *p, char *q[])
{
free (p);
int a[] =
{
p < q[0], // { dg-warning "pointer 'p' used" }
p <= q[1], // { dg-warning "pointer 'p' used" }
p > q[2], // { dg-warning "pointer 'p' used" }
p >= q[3], // { dg-warning "pointer 'p' used" }
p == q[4],
p != q[5]
};
sink (a);
}
void nowarn_cond_relational_after_free (char *p, char *q[], int c)
{
free (p);
int a[] =
{
c ? p < q[0] : q[0][0],
c ? p <= q[1] : q[1][1],
c ? p > q[2] : q[2][2],
c ? p >= q[3] : q[3][3],
c ? p == q[4] : q[4][4],
c ? p != q[5] : q[5][5],
};
sink (a);
}
// Verify no warning for the example in the manual.
struct A { int refcount; void *data; };
void release (struct A *p)
{
int refcount = --p->refcount;
free (p);
if (refcount == 0)
free (p->data); // no warning at level 1
}
|
