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
| // RUN: %clang_analyze_cc1 -triple x86_64-apple-darwin10 -analyzer-checker=core,alpha.core.StackAddressAsyncEscape -fblocks -fobjc-arc -verify %s
typedef struct dispatch_queue_s *dispatch_queue_t;
typedef void (^dispatch_block_t)(void);
void dispatch_async(dispatch_queue_t queue, dispatch_block_t block);
typedef long dispatch_once_t;
void dispatch_once(dispatch_once_t *predicate, dispatch_block_t block);
typedef long dispatch_time_t;
void dispatch_after(dispatch_time_t when, dispatch_queue_t queue, dispatch_block_t block);
void dispatch_barrier_sync(dispatch_queue_t queue, dispatch_block_t block);
extern dispatch_queue_t queue;
extern dispatch_once_t *predicate;
extern dispatch_time_t when;
void test_block_expr_async() {
int x = 123;
int *p = &x;
dispatch_async(queue, ^{
*p = 321;
});
// expected-warning@-3 {{Address of stack memory associated with local variable 'x' \
is captured by an asynchronously-executed block}}
}
void test_block_expr_once_no_leak() {
int x = 123;
int *p = &x;
// synchronous, no warning
dispatch_once(predicate, ^{
*p = 321;
});
}
void test_block_expr_after() {
int x = 123;
int *p = &x;
dispatch_after(when, queue, ^{
*p = 321;
});
// expected-warning@-3 {{Address of stack memory associated with local variable 'x' \
is captured by an asynchronously-executed block}}
}
void test_block_expr_async_no_leak() {
int x = 123;
int *p = &x;
// no leak
dispatch_async(queue, ^{
int y = x;
++y;
});
}
void test_block_var_async() {
int x = 123;
int *p = &x;
void (^b)(void) = ^void(void) {
*p = 1;
};
dispatch_async(queue, b);
// expected-warning@-1 {{Address of stack memory associated with local variable 'x' \
is captured by an asynchronously-executed block}}
}
void test_block_with_ref_async() {
int x = 123;
int &r = x;
void (^b)(void) = ^void(void) {
r = 1;
};
dispatch_async(queue, b);
// expected-warning@-1 {{Address of stack memory associated with local variable 'x' \
is captured by an asynchronously-executed block}}
}
dispatch_block_t get_leaking_block() {
int leaked_x = 791;
int *p = &leaked_x;
return ^void(void) {
*p = 1;
};
// expected-warning@-3 {{Address of stack memory associated with local variable 'leaked_x' \
is captured by a returned block}}
}
void test_returned_from_func_block_async() {
dispatch_async(queue, get_leaking_block());
// expected-warning@-1 {{Address of stack memory associated with local variable 'leaked_x' \
is captured by an asynchronously-executed block}}
}
// synchronous, no leak
void test_block_var_once() {
int x = 123;
int *p = &x;
void (^b)(void) = ^void(void) {
*p = 1;
};
dispatch_once(predicate, b); // no-warning
}
void test_block_var_after() {
int x = 123;
int *p = &x;
void (^b)(void) = ^void(void) {
*p = 1;
};
dispatch_after(when, queue, b);
// expected-warning@-1 {{Address of stack memory associated with local variable 'x' \
is captured by an asynchronously-executed block}}
}
void test_block_var_async_no_leak() {
int x = 123;
int *p = &x;
void (^b)(void) = ^void(void) {
int y = x;
++y;
};
dispatch_async(queue, b); // no-warning
}
void test_block_inside_block_async_no_leak() {
int x = 123;
int *p = &x;
void (^inner)(void) = ^void(void) {
int y = x;
++y;
};
void (^outer)(void) = ^void(void) {
int z = x;
++z;
inner();
};
dispatch_async(queue, outer); // no-warning
}
dispatch_block_t accept_and_pass_back_block(dispatch_block_t block) {
block();
return block; // no-warning
}
void test_passing_continuation_no_leak() {
int x = 123;
int *p = &x;
void (^cont)(void) = ^void(void) {
*p = 128;
};
accept_and_pass_back_block(cont); // no-warning
}
@interface NSObject
@end
@protocol OS_dispatch_semaphore
@end
typedef NSObject<OS_dispatch_semaphore> *dispatch_semaphore_t;
dispatch_semaphore_t dispatch_semaphore_create(long value);
long dispatch_semaphore_wait(dispatch_semaphore_t dsema, dispatch_time_t timeout);
long dispatch_semaphore_signal(dispatch_semaphore_t dsema);
void test_no_leaks_on_semaphore_pattern() {
int x = 0;
int *p = &x;
dispatch_semaphore_t semaphore = dispatch_semaphore_create(0);
dispatch_async(queue, ^{
*p = 1;
// Some work.
dispatch_semaphore_signal(semaphore);
}); // no-warning
// Do some other work concurrently with the asynchronous work
// Wait for the asynchronous work to finish
dispatch_semaphore_wait(semaphore, 1000);
}
void test_dispatch_barrier_sync() {
int buf[16];
for (int n = 0; n < 16; ++n) {
int *ptr = &buf[n];
// FIXME: Should not warn. The dispatch_barrier_sync() call ensures
// that the block does not outlive 'buf'.
dispatch_async(queue, ^{ // expected-warning{{Address of stack memory associated with local variable 'buf' is captured by an asynchronously-executed block}}
(void)ptr;
});
}
dispatch_barrier_sync(queue, ^{});
}
|