Objective-C "Cannot find interface declaration for Object" - iphone

Question

Been programming an iOS/objective-c/cocos2d app. Things have been going fine up until this snag... I should note that it's Objective-C++, ie. .mm files, compiling for the iOS 5.0 simulator.
Basically, I'm only trying to subclass an interface. The error is produced on the #interface line: "Cannot find interface declaration for GameObject"
#import <Foundation/Foundation.h>
#import "CCSprite.h"
#import "cocos2d.h"
#import "Box2D.h"
#import "GameObject.h"
#interface AvalancheBlock : GameObject
{
}
#end
Here's the code for GameObject.h:
#import <UIKit/UIKit.h>
#import "cocos2d.h"
#import "Box2D.h"
#import "b2Body.h"
#import "OhSnowGame.h"
#interface GameObject : CCNode {
#public
b2Body *body;
b2BodyDef *bodyDef;
b2FixtureDef *fixtureDef;
b2PolygonShape *polygonShape;
b2CircleShape *circleShape;
CCSprite *sprite;
int typeTag;
bool markedForDestruction;
}
#property (readwrite, assign) b2Body *body;
#property (nonatomic, assign) b2BodyDef *bodyDef;
#property (nonatomic, assign) b2FixtureDef *fixtureDef;
#property (nonatomic, assign) b2PolygonShape *polygonShape;
#property (nonatomic, assign) b2CircleShape *circleShape;
#property (nonatomic, retain) CCSprite *sprite;
#property (readwrite, assign) int typeTag;
#property (readwrite, assign) bool markedForDestruction;
#property (readonly) int type;
-(id) init;
-(void) initBox2D;
-(int) type;
#end
And GameObject.mm:
#import "GameObject.h"
#implementation GameObject
#synthesize body, bodyDef, fixtureDef, polygonShape, circleShape, sprite, type, typeTag, markedForDestruction;
-(id) init {
if( (self=[super init]) ) {
[self initBox2D];
markedForDestruction = NO;
}
return self;
}
-(void) initBox2D {
bodyDef = new b2BodyDef();
fixtureDef = new b2FixtureDef();
//Initial fixture settings
fixtureDef->density = 1.0f;
fixtureDef->friction = 0.5f;
fixtureDef->restitution = 0.3f;
bodyDef->userData = self;
}
-(int) type {
return 0;
}
#end
If the correct file is being included... then why the error?
Thanks!
SOLVED:
Figured it out... there WAS a circular reference, but I still needed the reference. The solution was to remove the #import "OhSnowGame.h" from GameObject.h, and instead add the directive:
#class OhSnowGame
Learn something new every day.
SECOND UPDATE:
New issue, but very much related.
I have OhSnowGame.mm which includes a "AvalancheGrid.h".
AvalancheGrid.h includes AvalancheParams.h.
In OhSnowGame, I'm referencing both AvalancheGrid and AvalancheParams.
The compiler is throwing a linker error:
"Duplicate symbol AvalancheParams in OhSnowGame.o and AvalancheGrid.o"
But really it doesn't seem like there's any circular reference to me.
If I replace the #import "AvalancheGrid.h" in OhSnowGame.mm with just
#class AvalancheGrid; (and also #class AvalancheParams.h;)
then it doesn't let me reference the properties of those objects like I need to, ie:
avParams.severity = 3; //nope
avParams->severity = 3; //nope
[avParams setSeverity:3]; //nope (with #property severity exposed and synthesized)
I don't understand. How can I avoid the linker error and still access those properties?