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

// RUN: %clang_cc1 -analyze -analyzer-checker=core,unix.Malloc -analyzer-store=region -verify %s

typedef unsigned int UInt32;
typedef signed long CFIndex;
typedef signed char BOOL;
typedef unsigned long NSUInteger;
@class NSString, Protocol;
extern void NSLog(NSString *format, ...) __attribute__((format(__NSString__, 1, 2)));
typedef struct _NSZone NSZone;
@class NSInvocation, NSMethodSignature, NSCoder, NSString, NSEnumerator;
@protocol NSObject
- (BOOL)isEqual:(id)object;
- (id)retain;
- (oneway void)release;
- (id)autorelease;
- (id)init;
@end  @protocol NSCopying  - (id)copyWithZone:(NSZone *)zone;
@end  @protocol NSMutableCopying  - (id)mutableCopyWithZone:(NSZone *)zone;
@end  @protocol NSCoding  - (void)encodeWithCoder:(NSCoder *)aCoder;
@end
@interface NSObject <NSObject> {}
+ (id)allocWithZone:(NSZone *)zone;
+ (id)alloc;
- (void)dealloc;
@end
@interface NSObject (NSCoderMethods)
- (id)awakeAfterUsingCoder:(NSCoder *)aDecoder;
@end
extern id NSAllocateObject(Class aClass, NSUInteger extraBytes, NSZone *zone);
typedef struct {
}
NSFastEnumerationState;
@protocol NSFastEnumeration  - (NSUInteger)countByEnumeratingWithState:(NSFastEnumerationState *)state objects:(id *)stackbuf count:(NSUInteger)len;
@end           @class NSString, NSDictionary;
@interface NSValue : NSObject <NSCopying, NSCoding>  - (void)getValue:(void *)value;
@end  @interface NSNumber : NSValue  - (char)charValue;
- (id)initWithInt:(int)value;
@end   @class NSString;
@interface NSArray : NSObject <NSCopying, NSMutableCopying, NSCoding, NSFastEnumeration>  - (NSUInteger)count;
@end  @interface NSArray (NSArrayCreation)  + (id)array;
@end       @interface NSAutoreleasePool : NSObject {
}
- (void)drain;
@end extern NSString * const NSBundleDidLoadNotification;
typedef double NSTimeInterval;
@interface NSDate : NSObject <NSCopying, NSCoding>  - (NSTimeInterval)timeIntervalSinceReferenceDate;
@end            typedef unsigned short unichar;
@interface NSString : NSObject <NSCopying, NSMutableCopying, NSCoding>
- (NSUInteger)length;
- (NSString *)stringByAppendingString:(NSString *)aString;
- ( const char *)UTF8String;
- (id)initWithUTF8String:(const char *)nullTerminatedCString;
+ (id)stringWithUTF8String:(const char *)nullTerminatedCString;
@end        @class NSString, NSURL, NSError;
@interface NSData : NSObject <NSCopying, NSMutableCopying, NSCoding>  - (NSUInteger)length;
+ (id)dataWithBytesNoCopy:(void *)bytes length:(NSUInteger)length;
+ (id)dataWithBytesNoCopy:(void *)bytes length:(NSUInteger)length freeWhenDone:(BOOL)b;
@end 

typedef __typeof(sizeof(int)) size_t;
void *malloc(size_t);
void free(void *);

// Done with headers. Start testing.
void testNSDatafFreeWhenDoneNoError(NSUInteger dataLength) {
  unsigned char *data = (unsigned char *)malloc(42);
  NSData *nsdata = [NSData dataWithBytesNoCopy:data length:dataLength];
  free(data); // no warning
}

// False Negative
void testNSDatafFreeWhenDone(NSUInteger dataLength) {
  unsigned char *data = (unsigned char *)malloc(42);
  NSData *nsdata = [NSData dataWithBytesNoCopy:data length:dataLength freeWhenDone:1];
  free(data); // false negative
}