llvm-project/clang/test/Analysis/nullability.mm

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// RUN: %clang_cc1 -fblocks -analyze -analyzer-checker=core,nullability -DNOSYSTEMHEADERS=0 -verify %s
// RUN: %clang_cc1 -fblocks -analyze -analyzer-checker=core,nullability -analyzer-config nullability:NoDiagnoseCallsToSystemHeaders=true -DNOSYSTEMHEADERS=1 -verify %s
#include "Inputs/system-header-simulator-for-nullability.h"
@interface TestObject : NSObject
- (int *_Nonnull)returnsNonnull;
- (int *_Nullable)returnsNullable;
- (int *)returnsUnspecified;
- (void)takesNonnull:(int *_Nonnull)p;
- (void)takesNullable:(int *_Nullable)p;
- (void)takesUnspecified:(int *)p;
@property(readonly, strong) NSString *stuff;
@end
TestObject * getUnspecifiedTestObject();
TestObject *_Nonnull getNonnullTestObject();
TestObject *_Nullable getNullableTestObject();
int getRandom();
typedef struct Dummy { int val; } Dummy;
void takesNullable(Dummy *_Nullable);
void takesNonnull(Dummy *_Nonnull);
void takesUnspecified(Dummy *);
Dummy *_Nullable returnsNullable();
Dummy *_Nonnull returnsNonnull();
Dummy *returnsUnspecified();
int *_Nullable returnsNullableInt();
template <typename T> T *eraseNullab(T *p) { return p; }
void takesAttrNonnull(Dummy *p) __attribute((nonnull(1)));
void testBasicRules() {
Dummy *p = returnsNullable();
int *ptr = returnsNullableInt();
// Make every dereference a different path to avoid sinks after errors.
switch (getRandom()) {
case 0: {
Dummy &r = *p; // expected-warning {{Nullable pointer is dereferenced}}
} break;
case 1: {
int b = p->val; // expected-warning {{Nullable pointer is dereferenced}}
} break;
case 2: {
int stuff = *ptr; // expected-warning {{Nullable pointer is dereferenced}}
} break;
case 3:
takesNonnull(p); // expected-warning {{Nullable pointer is passed to a callee that requires a non-null 1st parameter}}
break;
case 4: {
Dummy d;
takesNullable(&d);
Dummy dd(d);
break;
}
case 5: takesAttrNonnull(p); break; // expected-warning {{Nullable pointer is passed to}}
default: { Dummy d = *p; } break; // expected-warning {{Nullable pointer is dereferenced}}
}
if (p) {
takesNonnull(p);
if (getRandom()) {
Dummy &r = *p;
} else {
int b = p->val;
}
}
Dummy *q = 0;
if (getRandom()) {
takesNullable(q);
takesNonnull(q); // expected-warning {{Null passed to a callee that requires a non-null 1st parameter}}
}
Dummy a;
Dummy *_Nonnull nonnull = &a;
nonnull = q; // expected-warning {{Null is assigned to a pointer which is expected to have non-null value}}
q = &a;
takesNullable(q);
takesNonnull(q);
}
void testMultiParamChecking(Dummy *_Nonnull a, Dummy *_Nullable b,
Dummy *_Nonnull c);
void testArgumentTracking(Dummy *_Nonnull nonnull, Dummy *_Nullable nullable) {
Dummy *p = nullable;
Dummy *q = nonnull;
switch(getRandom()) {
case 1: nonnull = p; break; // expected-warning {{Nullable pointer is assigned to a pointer which is expected to have non-null value}}
case 2: p = 0; break;
case 3: q = p; break;
case 4: testMultiParamChecking(nonnull, nullable, nonnull); break;
case 5: testMultiParamChecking(nonnull, nonnull, nonnull); break;
case 6: testMultiParamChecking(nonnull, nullable, nullable); break; // expected-warning {{Nullable pointer is passed to a callee that requires a non-null 3rd parameter}}
case 7: testMultiParamChecking(nullable, nullable, nonnull); // expected-warning {{Nullable pointer is passed to a callee that requires a non-null 1st parameter}}
case 8: testMultiParamChecking(nullable, nullable, nullable); // expected-warning {{Nullable pointer is passed to a callee that requires a non-null 1st parameter}}
case 9: testMultiParamChecking((Dummy *_Nonnull)0, nullable, nonnull); break;
}
}
Dummy *_Nonnull testNullableReturn(Dummy *_Nullable a) {
Dummy *p = a;
return p; // expected-warning {{Nullable pointer is returned from a function that is expected to return a non-null value}}
}
Dummy *_Nonnull testNullReturn() {
Dummy *p = 0;
return p; // expected-warning {{Null is returned from a function that is expected to return a non-null value}}
}
void testObjCMessageResultNullability() {
// The expected result: the most nullable of self and method return type.
TestObject *o = getUnspecifiedTestObject();
int *shouldBeNullable = [eraseNullab(getNullableTestObject()) returnsNonnull];
switch (getRandom()) {
case 0:
// The core analyzer assumes that the receiver is non-null after a message
// send. This is to avoid some false positives, and increase performance
// but it also reduces the coverage and makes this checker unable to reason
// about the nullness of the receiver.
[o takesNonnull:shouldBeNullable]; // No warning expected.
break;
case 1:
shouldBeNullable =
[eraseNullab(getNullableTestObject()) returnsUnspecified];
[o takesNonnull:shouldBeNullable]; // No warning expected.
break;
case 3:
shouldBeNullable = [eraseNullab(getNullableTestObject()) returnsNullable];
[o takesNonnull:shouldBeNullable]; // expected-warning {{Nullable pointer is passed to a callee that requires a non-null 1st parameter}}
break;
case 4:
shouldBeNullable = [eraseNullab(getNonnullTestObject()) returnsNullable];
[o takesNonnull:shouldBeNullable]; // expected-warning {{Nullable pointer is passed to a callee that requires a non-null 1st parameter}}
break;
case 5:
shouldBeNullable =
[eraseNullab(getUnspecifiedTestObject()) returnsNullable];
[o takesNonnull:shouldBeNullable]; // expected-warning {{Nullable pointer is passed to a callee that requires a non-null 1st parameter}}
break;
case 6:
shouldBeNullable = [eraseNullab(getNullableTestObject()) returnsNullable];
[o takesNonnull:shouldBeNullable]; // expected-warning {{Nullable pointer is passed to a callee that requires a non-null 1st parameter}}
break;
case 7: {
int *shouldBeNonnull = [eraseNullab(getNonnullTestObject()) returnsNonnull];
[o takesNonnull:shouldBeNonnull];
} break;
}
}
Dummy * _Nonnull testDirectCastNullableToNonnull() {
Dummy *p = returnsNullable();
takesNonnull((Dummy * _Nonnull)p); // no-warning
return (Dummy * _Nonnull)p; // no-warning
}
Dummy * _Nonnull testIndirectCastNullableToNonnull() {
Dummy *p = (Dummy * _Nonnull)returnsNullable();
takesNonnull(p); // no-warning
return p; // no-warning
}
Dummy * _Nonnull testDirectCastNilToNonnull() {
takesNonnull((Dummy * _Nonnull)0); // no-warning
return (Dummy * _Nonnull)0; // no-warning
}
void testIndirectCastNilToNonnullAndPass() {
Dummy *p = (Dummy * _Nonnull)0;
// FIXME: Ideally the cast above would suppress this warning.
takesNonnull(p); // expected-warning {{Null passed to a callee that requires a non-null 1st parameter}}
}
void testIndirectNilPassToNonnull() {
Dummy *p = 0;
takesNonnull(p); // expected-warning {{Null passed to a callee that requires a non-null 1st parameter}}
}
void testConditionalNilPassToNonnull(Dummy *p) {
if (!p) {
takesNonnull(p); // expected-warning {{Null passed to a callee that requires a non-null 1st parameter}}
}
}
Dummy * _Nonnull testIndirectCastNilToNonnullAndReturn() {
Dummy *p = (Dummy * _Nonnull)0;
// FIXME: Ideally the cast above would suppress this warning.
return p; // expected-warning {{Null is returned from a function that is expected to return a non-null value}}
}
void testInvalidPropagation() {
Dummy *p = returnsUnspecified();
takesNullable(p);
takesNonnull(p);
}
void onlyReportFirstPreconditionViolationOnPath() {
Dummy *p = returnsNullable();
takesNonnull(p); // expected-warning {{Nullable pointer is passed to a callee that requires a non-null 1st parameter}}
takesNonnull(p); // No warning.
// The first warning was not a sink. The analysis expected to continue.
int i = 0;
i = 5 / i; // expected-warning {{Division by zero}}
(void)i;
}
Dummy *_Nonnull doNotWarnWhenPreconditionIsViolatedInTopFunc(
Dummy *_Nonnull p) {
if (!p) {
Dummy *ret =
0; // avoid compiler warning (which is not generated by the analyzer)
if (getRandom())
return ret; // no warning
else
return p; // no warning
} else {
return p;
}
}
Dummy *_Nonnull doNotWarnWhenPreconditionIsViolated(Dummy *_Nonnull p) {
if (!p) {
Dummy *ret =
0; // avoid compiler warning (which is not generated by the analyzer)
if (getRandom())
return ret; // no warning
else
return p; // no warning
} else {
return p;
}
}
void testPreconditionViolationInInlinedFunction(Dummy *p) {
doNotWarnWhenPreconditionIsViolated(p);
}
void inlinedNullable(Dummy *_Nullable p) {
if (p) return;
}
void inlinedNonnull(Dummy *_Nonnull p) {
if (p) return;
}
void inlinedUnspecified(Dummy *p) {
if (p) return;
}
void testNilReturnWithBlock(Dummy *p) {
p = 0;
Dummy *_Nonnull (^myblock)(void) = ^Dummy *_Nonnull(void) {
return p; // TODO: We should warn in blocks.
};
myblock();
}
Dummy *_Nonnull testDefensiveInlineChecks(Dummy * p) {
switch (getRandom()) {
case 1: inlinedNullable(p); break;
case 2: inlinedNonnull(p); break;
case 3: inlinedUnspecified(p); break;
}
if (getRandom())
takesNonnull(p); // no-warning
if (getRandom()) {
Dummy *_Nonnull varWithInitializer = p; // no-warning
Dummy *_Nonnull var1WithInitializer = p, // no-warning
*_Nonnull var2WithInitializer = p; // no-warning
}
if (getRandom()) {
Dummy *_Nonnull varWithoutInitializer;
varWithoutInitializer = p; // no-warning
}
return p;
}
@interface SomeClass : NSObject {
int instanceVar;
}
@end
@implementation SomeClass (MethodReturn)
- (id)initWithSomething:(int)i {
if (self = [super init]) {
instanceVar = i;
}
return self;
}
- (TestObject * _Nonnull)testReturnsNullableInNonnullIndirectly {
TestObject *local = getNullableTestObject();
return local; // expected-warning {{Nullable pointer is returned from a method that is expected to return a non-null value}}
}
- (TestObject * _Nonnull)testReturnsCastSuppressedNullableInNonnullIndirectly {
TestObject *local = getNullableTestObject();
return (TestObject * _Nonnull)local; // no-warning
}
- (TestObject * _Nonnull)testReturnsNullableInNonnullWhenPreconditionViolated:(TestObject * _Nonnull) p {
TestObject *local = getNullableTestObject();
if (!p) // Pre-condition violated here.
return local; // no-warning
else
return p; // no-warning
}
@end
@interface ClassWithInitializers : NSObject
@end
@implementation ClassWithInitializers
- (instancetype _Nonnull)initWithNonnullReturnAndSelfCheckingIdiom {
// This defensive check is a common-enough idiom that we filter don't want
// to issue a diagnostic for it,
if (self = [super init]) {
}
return self; // no-warning
}
- (instancetype _Nonnull)initWithNonnullReturnAndNilReturnViaLocal {
self = [super init];
// This leaks, but we're not checking for that here.
ClassWithInitializers *other = nil;
// False negative. Once we have more subtle suppression of defensive checks in
// initializers we should warn here.
return other;
}
@end
@interface SubClassWithInitializers : ClassWithInitializers
@end
@implementation SubClassWithInitializers
// Note: Because this is overridding
// -[ClassWithInitializers initWithNonnullReturnAndSelfCheckingIdiom],
// the return type of this method becomes implicitly id _Nonnull.
- (id)initWithNonnullReturnAndSelfCheckingIdiom {
if (self = [super initWithNonnullReturnAndSelfCheckingIdiom]) {
}
return self; // no-warning
}
- (id _Nonnull)initWithNonnullReturnAndSelfCheckingIdiomV2; {
// Another common return-checking idiom
self = [super initWithNonnullReturnAndSelfCheckingIdiom];
if (!self) {
return nil; // no-warning
}
return self;
}
@end
@interface ClassWithCopyWithZone : NSObject<NSCopying,NSMutableCopying> {
id i;
}
@end
@implementation ClassWithCopyWithZone
-(id)copyWithZone:(NSZone *)zone {
ClassWithCopyWithZone *newInstance = [[ClassWithCopyWithZone alloc] init];
if (!newInstance)
return nil;
newInstance->i = i;
return newInstance;
}
-(id)mutableCopyWithZone:(NSZone *)zone {
ClassWithCopyWithZone *newInstance = [[ClassWithCopyWithZone alloc] init];
if (newInstance) {
newInstance->i = i;
}
return newInstance;
}
@end
NSString * _Nullable returnsNullableString();
void callFunctionInSystemHeader() {
NSString *s = returnsNullableString();
NSSystemFunctionTakingNonnull(s);
#if !NOSYSTEMHEADERS
// expected-warning@-2{{Nullable pointer is passed to a callee that requires a non-null 1st parameter}}
#endif
}
void callMethodInSystemHeader() {
NSString *s = returnsNullableString();
NSSystemClass *sc = [[NSSystemClass alloc] init];
[sc takesNonnull:s];
#if !NOSYSTEMHEADERS
// expected-warning@-2{{Nullable pointer is passed to a callee that requires a non-null 1st parameter}}
#endif
}