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// RUN: %clang_analyze_cc1 -triple x86_64-apple-darwin10 -analyzer-checker=core,alpha.core.StackAddressAsyncEscape -fblocks -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);
extern dispatch_queue_t queue;
void f(int);
void test_block_inside_block_async_no_leak() {
int x = 123;
int *p = &x;
void (^inner)(void) = ^void(void) {
int y = x;
++y;
};
// Block_copy(...) copies the captured block ("inner") too,
// there is no leak in this case.
dispatch_async(queue, ^void(void) {
int z = x;
++z;
inner();
}); // no-warning
}
dispatch_block_t test_block_inside_block_async_leak() {
int x = 123;
void (^inner)(void) = ^void(void) {
int y = x;
++y;
};
void (^outer)(void) = ^void(void) {
int z = x;
++z;
inner();
};
return outer; // expected-warning-re{{Address of stack-allocated block declared on line {{.+}} is captured by a returned block}}
}
// The block literal defined in this function could leak once being
// called.
void output_block(dispatch_block_t * blk) {
int x = 0;
*blk = ^{ f(x); }; // expected-warning {{Address of stack-allocated block declared on line 43 is still referred to by the caller variable 'blk' upon returning to the caller. This will be a dangling reference [core.StackAddressEscape]}}
}
// The block literal captures nothing thus is treated as a constant.
void output_constant_block(dispatch_block_t * blk) {
*blk = ^{ };
}
// A block can leak if it captures at least one variable and is not
// under ARC when its' stack frame expires.
void test_block_leak() {
__block dispatch_block_t blk;
int x = 0;
dispatch_block_t p = ^{
blk = ^{ // expected-warning {{Address of stack-allocated block declared on line 57 is still referred to by the caller variable 'blk' upon returning to the caller. This will be a dangling reference [core.StackAddressEscape]}}
f(x);
};
};
p();
blk();
output_block(&blk);
blk();
}
// A block captures nothing is a constant thus never leaks.
void test_constant_block_no_leak() {
__block dispatch_block_t blk;
dispatch_block_t p = ^{
blk = ^{
f(0);
};
};
p();
blk();
output_constant_block(&blk);
blk();
}
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