blob: dab0af4026df98eb3d0b74d1039202206aa171cc (
plain)
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
|
// RUN: %clang_cc1 -fsyntax-only %s -verify -fblocks
// test for block type safety.
@interface Super @end
@interface Sub : Super @end
void f2(void(^f)(Super *)) {
Super *o;
f(o);
}
void f3(void(^f)(Sub *)) {
Sub *o;
f(o);
}
void r0(Super* (^f)()) {
Super *o = f();
}
void r1(Sub* (^f)()) {
Sub *o = f();
}
@protocol NSObject;
void r2 (id<NSObject> (^f) (void)) {
id o = f();
}
void test1() {
f2(^(Sub *o) { }); // expected-error {{incompatible block pointer types passing 'void (^)(Sub *)', expected 'void (^)(Super *)'}}
f3(^(Super *o) { }); // OK, block taking Super* may be called with a Sub*
r0(^Super* () { return 0; }); // OK
r0(^Sub* () { return 0; }); // OK, variable of type Super* gets return value of type Sub*
r0(^id () { return 0; }); // expected-error {{incompatible block pointer types passing 'id (^)(void)', expected 'Super *(^)()'}}
r1(^Super* () { return 0; }); // expected-error {{incompatible block pointer types passing 'Super *(^)(void)', expected 'Sub *(^)()'}}
r1(^Sub* () { return 0; }); // OK
r1(^id () { return 0; }); // expected-error {{incompatible block pointer types passing 'id (^)(void)', expected 'Sub *(^)()'}}
r2(^id<NSObject>() { return 0; });
}
@interface A @end
@interface B @end
void f0(void (^f)(A* x)) {
A* a;
f(a);
}
void f1(void (^f)(id x)) {
B *b;
f(b);
}
void test2(void)
{
f0(^(id a) { }); // OK
f1(^(A* a) { }); // expected-error {{incompatible block pointer types passing 'void (^)(A *)', expected 'void (^)(id)'}}
f1(^(id<NSObject> a) { }); // OK
}
@interface NSArray
// Calls block() with every object in the array
-enumerateObjectsWithBlock:(void (^)(id obj))block;
@end
@interface MyThing
-(void) printThing;
@end
@implementation MyThing
static NSArray* myThings; // array of MyThing*
-(void) printThing { }
// programmer wants to write this:
-printMyThings1 {
[myThings enumerateObjectsWithBlock: ^(MyThing *obj) { // expected-error {{incompatible block pointer types sending 'void (^)(MyThing *)', expected 'void (^)(id)'}}
[obj printThing];
}];
}
// strict type safety requires this:
-printMyThings {
[myThings enumerateObjectsWithBlock: ^(id obj) {
MyThing *obj2 = (MyThing *)obj;
[obj2 printThing];
}];
}
@end
|
