Memory leak in obj-c/c++ code - c++

Question

I'm using instruments and I have a lot of memory being leaked by this method. It is used everywhere in my app, and when I built it, I used some c++ (i think).
Please let me know where the leak is happening if possible?
Instruments just says Malloc 16 bytes and has about 60 MB worth of these guys...
/*
Parses a dicionary into an object
*/
+(id)makeObject:(id)object fromDictionary:(NSDictionary *)dict{
#autoreleasepool {
NSArray *keys = #[#"#\"NSMutableArray\""];
//Init result
id result = object;
//Iterate every key
for (id key in [dict allKeys]) {
//Convert key to const char
const char * c = [key cStringUsingEncoding:NSASCIIStringEncoding];
//Use c to see if the class has this property
if (class_getProperty([object class], c)) {
//get the property
objc_property_t property = class_getProperty([result class], c);
//Get the property name and type
const char *name = property_getName(property);
const char *type = property_copyAttributeValue(property, "T");
//Cast const char to string
NSString *pNameString = [NSString stringWithFormat:#"%s",name];
NSString *typeString = [NSString stringWithFormat:#"%s",type];
//Add relationships
if ([keys containsObject:typeString]) {
//Get array of objects
NSArray *relationship = [dict objectForKey:pNameString];
NSMutableArray *allSubObjects = [[NSMutableArray alloc]init];
//Parse each individual object
for (NSDictionary *relationshipObj in relationship) {
//Create class from relationship
Class class = NSClassFromString(pNameString);
//Create object
id sub = [self makeObject:[[class alloc]init] fromDictionary:relationshipObj];
[allSubObjects addObject:sub];
}
[result setValue:allSubObjects forKey:pNameString];
}else{
//If so set the property for the key
[result setValue:[dict objectForKey:key] forKey:key];
}
}else{
//NSLog(#"%# did not respond to : %#", result, key);
}
}
//Return result
return result;
}
}
EDIT:
Instruments shows these two items most likely the culprits. What's the best way to fix this?
//Cast const char to string
NSString *pNameString = [NSString stringWithFormat:#"%s",name];
NSString *typeString = [NSString stringWithFormat:#"%s",type];

Answer 1

1) [NSString cStringUsingEncoding]
This allocate some memory internally which will not freed until the NSString object is deallocated. I don't know exactly but could it be possible repeatedly sending cStringUsingEncoding incur unused memory building up?
2) property_copyAttributeValue
Documentation says,
Return Value A C array of pointers of type objc_property_t describing
the properties declared by proto. Any properties declared by other
protocols adopted by this protocol are not included. The array
contains *outCount pointers followed by a NULL terminator. You must
free the array with free().
You need to free const char *type.
3) NSMutableArray *allSubObjects = [[NSMutableArray alloc]init]
It should be NSMutableArray *allSubObjects = [NSMutableArray array].
4) Object creation
Class class = NSClassFromString(pNameString);
//Create object
id sub = [self makeObject:[[class alloc]init] fromDictionary:relationshipObj];
I'd put this code block in its own autorelease pool.
[class alloc]init] is also suspicious.