I have an iOS app and am using XCode Version 6.3.1 (6D1002).
I have a m file in which I define
#interface CustomObject:NSObject {} #end
and I try to use in viewDidLoad as
CustomObject* obj = [[CustomObject alloc]init];
When I run this, I get linkage errors saying
Undefined symbols for architecture x86_64:
"_OBJC_CLASS_$_CustomObject", referenced from:
objc-class-ref in ChooseAlbumViewController.o
ld: symbol(s) not found for architecture x86_64
I have similar interfaces defined for other objects and those continue to build, link and run fine. Any new interfaces I'm defining are failing with these linkage errors. I could use some help to figure out what's causing this. I'm new to iOS development so if I'm missing information crucial to figure this out please let me know and I'll add it.
Few flags from my Build Settings that might help -
Build Active Architecture Only = YES
Architectures = Standard Architecture armv7 armv64
Valid Architectures = arm64 armv7 armv7s
Here is the code in which I define the interface and try to use it
#interface CustomAlbum : NSObject {
}
#end
#implementation ChooseAlbumViewController
{
}
- (void)viewDidLoad {
[super viewDidLoad];
CustomAlbum* a = [[CustomAlbum alloc] init];
}
Figured it out, the problem was that I had only defined an interface but had not defined an implementation. Adding
#implementation User
#end
to the .m file solved the linkage issues.
Thanks for the help guys
Most of the time, this happens when your class isn't being compiled into the target you want. Select the .m file that CustomObject is in and check the right sidebar. In the first tab, there should be a list of targets. Check ✔️ your current target so that Xcode compiles it.
while compiling the source file ChooseAlbumViewController looks for a corresponding header. The header named CustomAlbum doesn't match. This causes the error message.
Related
I just started porting an Android app to iOS, and am hitting a major roadblock that I can't figure out despite scouring many similar questions.
I am attempting to follow the pattern implemented in the CastVideos sample where the GoogleCast API is encapsulated in a singleton class which I've called CastManager. To use my singleton class, I #import "CastManager.h" in AppDelegate.m. Then in CastManager.h, I #import <GoogleCast/GoogleCast.h> so that I can use classes and protocols from it as part of CastManager's public interface. However, because I'm importing CastManager.h in both CastManager.m and AppDelegate.m, the linker is finding duplicate symbols from the GoogleCast framework.
This is my CastManager.h:
#import <GoogleCast/GoogleCast.h>
#import <Foundation/Foundation.h>
#interface CastManager : NSObject
#property(nonatomic, strong) GCKDeviceScanner *deviceScanner;
+ (instancetype)sharedCastManager;
#end
And corresponding CastManager.m:
#import "CastManager.h"
#implementation CastManager
+ (instancetype)sharedCastManager {
NSLog(#"sharedCastManager");
static CastManager *singleton = nil;
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
singleton = [[self alloc] init];
});
return singleton;
}
- (instancetype)init {
NSLog(#"init()");
if (self = [super init]) {
self.deviceScanner = [[GCKDeviceScanner alloc] init];
}
return self;
}
#end
And this is the main part of my AppDelegate.m:
#import "AppDelegate.h"
#import "CastManager.h"
#implementation AppDelegate
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
CastManager *castManager = [CastManager sharedCastManager];
return YES;
}
However, this results in the following error from the linker when attempting to build the project:
duplicate symbol _kGCKDeviceCapabilityVideoOut in:
/Users/nate/Library/Developer/Xcode/DerivedData/MyCastApp-ezrgxdnlvywpanerezulnarzknno/Build/Intermediates/MyCastApp.build/Debug-iphonesimulator/MyCastApp.build/Objects-normal/x86_64/AppDelegate.o
/Users/nate/Library/Developer/Xcode/DerivedData/MyCastApp-ezrgxdnlvywpanerezulnarzknno/Build/Intermediates/MyCastApp.build/Debug-iphonesimulator/MyCastApp.build/Objects-normal/x86_64/CastManager.o
... many similar errors ommitted for brevity ...
duplicate symbol _kGCKDeviceCapabilityAudioIn in:
/Users/nate/Library/Developer/Xcode/DerivedData/MyCastApp-ezrgxdnlvywpanerezulnarzknno/Build/Intermediates/MyCastApp.build/Debug-iphonesimulator/MyCastApp.build/Objects-normal/x86_64/AppDelegate.o
/Users/nate/Projects/MyCastApp/GoogleCast.framework/GoogleCast(GCKDevice.o)
ld: 8 duplicate symbols for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
As far as I can tell, this exactly copies the pattern as defined in the CastVideos sample, but the sample compiles fine, and mine doesn't, and I've scoured through both projects trying to find what is different, but I just don't see it. Further, I don't see anything really wrong with doing this, and would expect it to work fine. I can't think of any other way to do it, really.
Here are the relevant files from the CastVideos sample for comparison:
ChromecastDeviceController.h
ChromecastDeviceController.m
AppDelegate.m
Other questions point to solutions that don't apply or don't fix it:
I'm not importing a .m file on accident.
I don't have duplicate references to any files in the project.
The "Compile Sources" section of the "Build Phases" project setting doesn't include any duplicates.
I've added the '-ObjC' linker flag as described by the GoogleCast API docs, though it has the same error with or without it.
I've tried deleting the delegate data and doing a clean before building.
This is with Xcode 6.3.1 running on OS X Yosemite 10.10.3 and the GoogleCastSDK-2.6.0 package from the SDK documentation page
I have checked in my sample project with the problem at https://github.com/nshafer/MyCastApp
Any help is greatly appreciated!
Edit: the duplicate is somewhat related, it's definitely about the same symbols, but the answers there didn't help, as I'm not using Object-C++, but rather just Objective-C. I don't have a .mm file, just a .m file.
For me it helped to switch the "No Common Blocks" compiler setting to NO:
It pretty much seems to make sense, the setting is explained here: What is GCC_NO_COMMON_BLOCKS used for?
The linker tells you that you have a variable named kGCKDeviceCapabilityVideoOut in two files, AppDelegate.m and CastManager.m. Since it's not in your source code, it's most likely in the GoogleCast code that you are including.
Either change the GoogleCast.h file, or make sure it is only included in one .m file. Including it from CastManager.h means it is indirectly included in every file that includes CastManager.h, so I would avoid that and only include it from CastManager.m. You'll probably have to add
#class GCKDeviceScanner;
in your CastManager.h file.
I found another fix, which is to edit GCKDevice.h in the GoogleCast.framework/Headers folder. Change the 4 constants from GCK_EXPORT to GCK_EXTERN near the top of the file.
/** Device capability flag for video out. */
GCK_EXTERN const NSInteger kGCKDeviceCapabilityVideoOut;
/** Device capability flag for video in. */
GCK_EXTERN const NSInteger kGCKDeviceCapabilityVideoIn;
/** Device capability flag for audio out. */
GCK_EXTERN const NSInteger kGCKDeviceCapabilityAudioOut;
/** Device capability flag for audio in. */
GCK_EXTERN const NSInteger kGCKDeviceCapabilityAudioIn;
I detailed this in a bug report I filed with Google's issue tracker, but it was marked as a duplicate of another somewhat related issue. Either way, it will perhaps get fixed in the next version. Until then, I would suggest going with changing the "No Common Blocks" setting as detailed in Joobik'com's answer, as that doesn't involve changing the 3rd party code.
I am getting this error for a single class from a static library, which I have compiled myself. It has all been working fine and I wanted to add another class as a simple data transfer object called PPClientData.
The error is:
Undefined symbols for architecture armv7:
"_OBJC_CLASS_$_PPClientData", reference from: objc-class-ref in
CPPIntegrationDelegate.o
The relevant file is included in the library compile targets and I have used otool -d on the (fat) library and it shows
libPPIntegration.a(PPClientData.o) (architecture armv7):
(__DATA,--data) section
The header for the class (PPClientData.h), which is included in the app is like this:
#import <Foundation/Foundation.h>
#interface PPClientData : NSObject
#property(nonatomic, strong) NSString* clientId;
// 3 others identical to the above with different names
#end
and the .m file which should be compiled into the library looks like this:
#import "PPClientData.h"
#implementation PPClientData
#synthesize clientId;
//Synthesize others
-(id)init {
self = [super init];
return self;
}
#end
It is consumed in a single class in the app as follows. If this one function that consumes it is commented out, the linker error goes away (it links to other classes in the library) but with this in, it fails. This is a delegate function for the library.
#import "CPPIntegrationDelegate.h"
#import "PPClientData.h"
#implementation CPPIntegrationDelegate
// Various other functions that work fine
-(PPClientData*)clientData:(PPIntegration*)integration {
PPClientData* dict = [[PPClientData alloc]init]; // This is the line that causes the linker error
dict.clientId = #"whatever";
// set other properties of dict
return dict;
}
I understand what the linker is trying to do and what the error suggests but I don't see what I've missed. Can anyone help?
If you are on Xcode 5.1, try to remove arm64 from Valid Architectures (under Build Settings) and also change the Architectures from "Standard architectures" to just armv7 and armv7s. This might be relevant to you: how to stop xcode5.1 building for 64bit
Well, it wasn't the architectures causing the problem but in some way, xcode or whatever had been confused by the order of the forward declaration of the class I was using and then the definition itself. Initially, the broken code was something like:
BrokenClass.h
// Definitions etc.
GoodClass.h
#class BrokenClass;
- (BrokenClass*)someMethod:(SomeType*) param;
GoodClass.m
#import "BrokenClass.h"
- (BrokenClass*)someMethod:(SomeType*) param
{
}
Which was included into my App by including GoodClass.h into a header file, which forward declared BrokenClass and then included BrokenClass.h into an m file which should have completed the definition, where the class was used.
Anyway, to fix it, I changed the GoodClass code to:
GoodClass.h
#import "BrokenClass.h"
- (BrokenClass*)someMethod:(SomeType*) param;
Removed the #import in the m file and then only included the one GoodClass.h into my app (which brought in the BrokenClass).
Whether this is a bug somehow or more likely, I had too many forward declarations etc. I'm not sure.
I'm including the Layar SDK framework into my app (version 8.0) and everything works fine on a device.
However, I can't run the app on a simulator anymore - I don't mind Layar not working (there's no camera after all!) but I do need it to compile for continual integration, automated tests etc (not to mention developing on the train top/from work!)
The linker gives me these errors :
ld: warning: ignoring file /Users/username/Documents/appname/libs/MPOAuth/libMPOAuthMobile.a, missing required architecture i386 in file /Users/username/Documents/appname/libs/MPOAuth/libMPOAuthMobile.a (2 slices)
ld: warning: ignoring file local/LayarSDK/LayarSDK.framework/LayarSDK, missing required architecture i386 in file local/LayarSDK/LayarSDK.framework/LayarSDK (2 slices)
Undefined symbols for architecture i386:
"_OBJC_CLASS_$_LayarSDK", referenced from:
objc-class-ref in MYAppDelegate.o
ld: symbol(s) not found for architecture i386
Checking, the LayarSDK doesn't contain i386, it only contains armv7 and armv7s.
My solution is pretty clumsy - if anyone has a better idea, please let me know!
I compile this file (LayarSimulatorStub.m) into my app :
#if TARGET_IPHONE_SIMULATOR
#import <Foundation/Foundation.h>
#interface LayarSDK : NSObject
#end
#implementation LayarSDK
+ (id)layarSDKWithConsumerKey:(id)a andConsumerSecret:(id)b andDelegate:(id)c { return nil; }
- (id)init { return nil; }
- (id)initWithConsumerKey:(id)a andConsumerSecret:(id)b andDelegate:(id)c { return nil; }
#end
#endif
Now, there is an i386 symbol LayarSDK. It just returns nil from all it's constructors. The app now compiles with Layar disabled.
The conditional compilation means that it's not present for the device architectures so there are no linker errors.
When i try tests like
#interface My_Tests : XCTestCase
- (void)testExample {
XCTAssertTrue(#YES, #"has to be passed");
}
Everything is working fine. However when i try such pattern:
#import "NSString+Additions.h"
//...
- (void)testNameValidation {
NSString *string = #"Harry";
XCTAssertTrue([string stringIsValid], #"Name validation error");
}
I get:
file:///Users/username/project/ProjectTests/ProjectTest.m: test failure:
-[Project_test testNameValidation] failed: (([string stringIsValid]) is true)
failed: throwing "-[__NSCFConstantString stringIsValid]: unrecognized selector
sent to instance 0x2f58ae8" - Name validation error
I can also just do something like this:
#import "MyViewController.h"
//...
- (void)testSomething {
MyViewController *a = [[MyViewController alloc] init];
XCTAssertTrue(#YES, #"Impossible!");
}
I get 2 errors (first and last line):
Undefined symbols for architecture i386:
"_OBJC_CLASS_$_MyViewController", referenced from:
objc-class-ref in MyTest.o
ld: symbol(s) not found for architecture i386
clang: error: linker command failed with exit code 1 (use -v to see invocation)
Can someone explain me what am I doing wrong..? I can't do anything with my classes. It may be worth adding that i'm trying to test my custom static library and files included in it. I'm using CocoaPods and I've set environment basing on Kiwi description (only to be able to use CocoaPods files in my tests, I was also wondering whether to use Kiwi or XCTests).
PS. This is my first try with unit tests of any type, so please forgive eventual noobish question ;)
The unit tests aren't linked against the static library.
Add the library to the "Link Binary with Libraries" section of the build phases for the test target.
I want to use the http://getsharekit.com framework for future iOS projects. Hence I started testing out the framework.
But I already get the following error:
Undefined symbols for architecture i386:
"_OBJC_CLASS_$_SHKItem", referenced from:
objc-class-ref in ShareKitTestAppDelegate.o
"_OBJC_CLASS_$_SHKActionSheet", referenced from:
objc-class-ref in ShareKitTestAppDelegate.o
ld: symbol(s) not found for architecture i386
collect2: ld returned 1 exit status
Often, as far as I know, these problems arise if header files are wrongly imported. But I don't see any error here in the following code where the problem above occurs:
#import "ShareKitTestAppDelegate.h"
#import "SHK.h"
#import "SHKItem.h"
#import "SHKActionSheet.h"
- (IBAction) letshare:(id)sender
{
// Create the item to share (in this example, a url)
NSURL *url = [NSURL URLWithString:#"http://getsharekit.com"];
SHKItem *item = [SHKItem URL:url title:#"ShareKit is Awesome!"];
// Get the ShareKit action sheet
SHKActionSheet *actionSheet = [SHKActionSheet actionSheetForItem:item];
// Display the action sheet
[self.window addSubview:actionSheet];
}
I also included the ShareKit Headers Folder into HeaderSearchPath Build-Options, because of searching for all the headers.
But I don't see any error here or anything missed.
Can somebody help me?
With best regards,
Andreas
I had a similar problem with the following linker error:
Undefined symbols for architecture i386: "_OBJC_CLASS_$_SHK"
I resolved it by adding SHK.m to compiled sources under Project settings->Target->Build Phases. Not sure why SHK.m was not in the compiled sources list, and it was working previous to duplicating the Target. After the duplication I couldn't link any of the targets.
Adding SHKItem.m or SHK.m to compiled sources might help you if they aren't there already.
Read this http://getsharekit.com/install/.
Have you added the frameworks?