1// RUN: %clang_analyze_cc1 -analyzer-checker=core,nullability -verify %s
2
3#define nil 0
4
5@protocol NSObject
6+ (id)alloc;
7- (id)init;
8- (instancetype)autorelease;
9- (void)release;
10@end
11
12__attribute__((objc_root_class))
13@interface
14NSObject<NSObject>
15@end
16
17@interface TestObject : NSObject
18@end
19
20TestObject *_Nonnull returnsNilObjCInstanceIndirectly() {
21  TestObject *local = nil;
22  return local; // expected-warning {{nil returned from a function that is expected to return a non-null value}}
23}
24
25TestObject * _Nonnull returnsNilObjCInstanceIndirectlyWithSupressingCast() {
26  TestObject *local = nil;
27  return (TestObject * _Nonnull)local; // no-warning
28}
29
30TestObject * _Nonnull returnsNilObjCInstanceDirectly() {
31  // The first warning is from Sema. The second is from the static analyzer.
32  return nil; // expected-warning {{null returned from function that requires a non-null return value}}
33              // expected-warning@-1 {{nil returned from a function that is expected to return a non-null value}}
34}
35
36TestObject * _Nonnull returnsNilObjCInstanceDirectlyWithSuppressingCast() {
37  return (TestObject * _Nonnull)nil; // no-warning
38}
39
40void testObjCNonARCNoInitialization(TestObject * _Nonnull p) {
41  TestObject * _Nonnull implicitlyZeroInitialized; // no-warning
42  implicitlyZeroInitialized = p;
43}
44
45void testObjCNonARCExplicitZeroInitialization() {
46  TestObject * _Nonnull explicitlyZeroInitialized = nil; // expected-warning {{nil assigned to a pointer which is expected to have non-null value}}
47}
48
49@interface ClassWithInitializers : NSObject
50@end
51
52@implementation ClassWithInitializers
53- (instancetype _Nonnull)initWithNonnullReturnAndSelfCheckingIdiom {
54  // This defensive check is a common-enough idiom that we don't want
55  // to issue a diagnostic for it.
56  if (self = [super init]) {
57  }
58
59  return self; // no-warning
60}
61
62- (instancetype _Nonnull)initWithNonnullReturnAndNilReturnViaLocal {
63  self = [super init];
64  // This leaks, but we're not checking for that here.
65
66  ClassWithInitializers *other = nil;
67  // False negative. Once we have more subtle suppression of defensive checks in
68  // initializers we should warn here.
69  return other;
70}
71
72- (instancetype _Nonnull)initWithPreconditionViolation:(int)p {
73  self = [super init];
74  if (p < 0) {
75    [self release];
76    return (ClassWithInitializers * _Nonnull)nil;
77  }
78  return self;
79}
80
81+ (instancetype _Nonnull)factoryCallingInitWithNonnullReturnAndSelfCheckingIdiom {
82  return [[[self alloc] initWithNonnullReturnAndSelfCheckingIdiom] autorelease]; // no-warning
83}
84
85+ (instancetype _Nonnull)factoryCallingInitWithNonnullReturnAndNilReturnViaLocal {
86  return [[[self alloc] initWithNonnullReturnAndNilReturnViaLocal] autorelease]; // no-warning
87}
88
89+ (instancetype _Nonnull)initWithPreconditionViolation:(int) p {
90  return [[[self alloc] initWithPreconditionViolation:p] autorelease]; // no-warning
91}
92
93- (TestObject * _Nonnull) returnsNil {
94  return (TestObject * _Nonnull)nil;
95}
96- (TestObject * _Nonnull) inlineOfReturnsNilObjCInstanceDirectlyWithSuppressingCast {
97  TestObject *o = [self returnsNil];
98  return o;
99}
100@end
101