CODEWITHSUNDEEP
iphoneiosfacebook
zhyr28
zhyr28

Reputation: 27

Duplicate symbol _OBJC_METACLASS_$_SBJsonParser

I just included AWSIOSSDK.framework and Facebook SDK together in my project, then got a build error:

ld: duplicate symbol _OBJC_METACLASS_$_SBJsonParser in /Users/tom8/Desktop/site1/site1/facebook-ios-sdk/libfacebook_ios_sdk.a(SBJsonParser.o) and /Users/tom8/Desktop/AWSiOSSDK.framework/AWSiOSSDK(SBJsonParser.o) for architecture i386

I use iOS Facebook SDK Static Library, so i could not simply delete sbjson files in facebooksdk folder. I also tried to delete sbjson files in AWSIOSSDK folder, but it also did not work. Could someone give me some advice?

Upvotes: 0

Views: 1882

Answers (2)

user1609146
user1609146

Reputation: 26

I had the same problem too. You can delete the files from the Facebook Project itself, but you cannot delete from the framework.

So click:

facebook-ios-sdk.xcodeproj (to open up file contents) -> FBConnect (to view folder contents) -> JSON (to view folder contents) -> remove SBJsonWriter and SBJsonParser.

Try compiling. You should be good to go!

Eva

Upvotes: 0

Chris Trahey
Chris Trahey

Reputation: 18290

Almost without exception, when I get duplicate symbol build errors, it's because I was #include-ing .h files too prolifically from other .h files. The solution is almost always these two simple steps:

  1. move as many #include directives into .m files as possible
  2. use @protocol and @class forward-declarations in .h files.

The only cases where you need to #include an .h from an .h is when you actually extend a class or implement a protocol. If you just need to use a class name or protocol name in a signature, use forward declarations and move the #include to the .m file.

Example:

foo.h

#include "Bar.h"
#include "BazProtocol.h"
#include "BarDelegateProtocol.h"
@interface Foo:NSObject <BarDelegate>
@property (strong, nonatomic) id<Baz> myBaz;
@property (strong, nonatomic) Bar *myBar;
@end

becomes

#include "BarDelegateProtocol.h"
@class Bar;
@protocol Baz;

@interface Foo:NSObject
@property (strong, nonatomic) id<Baz> myBaz;
@property (strong, nonatomic) Bar *myBar;
@end

Upvotes: 1

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