Unit testing Objective-C++ frameworks with Xcode 4.x

Question

I'm writing a framework using Objective C++ and I am having trouble setting up unit tests for it.

Compiling just the framework target works fine.

But when I tell Xcode to compile and run the test bundle I get:

Ld ~/Library/Developer/Xcode/DerivedData/TestFramework-axdefcbatoubjbbfqiyxildilobl/Build/Products/Debug/TestFrameworkTests.octest/Contents/MacOS/TestFrameworkTests normal x86_64
    cd "~/Projects/TestFramework"
    setenv MACOSX_DEPLOYMENT_TARGET 10.7
    "/Applications/Xcode 4.5.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang++" -arch x86_64 -bundle -isysroot "/Applications/Xcode 4.5.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.8.sdk" -L~/Library/Developer/Xcode/DerivedData/TestFramework-axdefcbatoubjbbfqiyxildilobl/Build/Products/Debug -L/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/usr/lib -F~/Library/Developer/Xcode/DerivedData/TestFramework-axdefcbatoubjbbfqiyxildilobl/Build/Products/Debug "-F/Applications/Xcode 4.5.app/Contents/Developer/Library/Frameworks" -filelist ~/Library/Developer/Xcode/DerivedData/TestFramework-axdefcbatoubjbbfqiyxildilobl/Build/Intermediates/TestFramework.build/Debug/TestFrameworkTests.build/Objects-normal/x86_64/TestFrameworkTests.LinkFileList -mmacosx-version-min=10.7 -v -fobjc-arc -fobjc-link-runtime -fprofile-arcs -stdlib=libc++ -framework SenTestingKit -framework Cocoa -framework TestFramework -o ~/Library/Developer/Xcode/DerivedData/TestFramework-axdefcbatoubjbbfqiyxildilobl/Build/Products/Debug/TestFrameworkTests.octest/Contents/MacOS/TestFrameworkTests

Apple clang version 4.0 (tags/Apple/clang-421.10.48) (based on LLVM 3.1svn)
Target: x86_64-apple-darwin11.4.0
Thread model: posix
 "/Applications/Xcode 4.5.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/ld" -demangle -dynamic -arch x86_64 -bundle -macosx_version_min 10.7.0 -syslibroot "/Applications/Xcode 4.5.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.8.sdk" -o ~/Library/Developer/Xcode/DerivedData/TestFramework-axdefcbatoubjbbfqiyxildilobl/Build/Products/Debug/TestFrameworkTests.octest/Contents/MacOS/TestFrameworkTests -L~/Library/Developer/Xcode/DerivedData/TestFramework-axdefcbatoubjbbfqiyxildilobl/Build/Products/Debug -L/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/usr/lib -filelist ~/Library/Developer/Xcode/DerivedData/TestFramework-axdefcbatoubjbbfqiyxildilobl/Build/Intermediates/TestFramework.build/Debug/TestFrameworkTests.build/Objects-normal/x86_64/TestFrameworkTests.LinkFileList -framework SenTestingKit -framework Cocoa -framework TestFramework -force_load "/Applications/Xcode 4.5.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/arc/libarclite_macosx.a" -framework Foundation -lobjc -lc++ "/Applications/Xcode 4.5.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../lib/clang/4.0/lib/darwin/libclang_rt.profile_osx.a" -lSystem "/Applications/Xcode 4.5.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../lib/clang/4.0/lib/darwin/libclang_rt.osx.a" -F~/Library/Developer/Xcode/DerivedData/TestFramework-axdefcbatoubjbbfqiyxildilobl/Build/Products/Debug "-F/Applications/Xcode 4.5.app/Contents/Developer/Library/Frameworks"
Undefined symbols for architecture x86_64:
  "Foo::Bar::Bar()", referenced from:
      -[FooBar_Tests testBaz] in FooBar_Tests.o
  "Foo::Bar::baz() const", referenced from:
      -[FooBar_Tests testBaz] in FooBar_Tests.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)

I have:

C++ Language Dialect: c++11
C++ Standard Library: libc++

set on both build targets (framework & test bundle).
And I am of course linking against the framework in my test bundle target.
Furthermore, all framework headers are marked public.
I also tried adding the framework files to the test bundle's target and leaving them out. None of these fixed the problem.

I am a bit puzzled as to what's going wrong here, right now. Any ideas?

---

This is how my C++ class looks like (kind of):

//FooBar.hh
namespace Foo {
    class Bar {
    public:
        bool baz() const;
    }
}

//FooBar.mm
#import "FooBar.hh"
namespace Foo {
    bool Bar::baz() const {
        return true;
    }
}

And this my test case:

//FooBar_Tests.hh
#import <SenTestingKit/SenTestingKit.h>

@interface FooBar_Tests : SenTestCase

@end

//FooBar_Tests.mm
#import "FooBar_Tests.hh"
#import <TestFramework/FooBar.hh>
//this one fails as well (compiles fine, fails one linkage):
//#import "FooBar.hh"

@implementation FooBar_Tests

- (void)testBaz {
    Foo::Bar bar();
    STAssertEquals(bar.baz(), true, nil);
}

Edit: Split code up into .hh&.mm files. Still getting the same errors though.

Answer 1

I eventually added a new unit test target to my project, enabled C++11 and tried compiling/running it. Success.
Somehow my original unit test target must have gone bad in regards to C++11. Had compiled just fine before.

Now it's time to migrate my test cases to the new test bundle, I guess.

…and I thought I was going mad. Oh well…

Answer 2

One possible problem is that your unit tests are in the header file. Header files do not do much in OCUnit. You can even get rid of the header file and put all your test case code in the implementation file. Add an Objective-C unit test class to your project, give it the extension .mm, and move your test case code there. Does that fix the problem?

When I unit test C++ code with OCUnit, I find I have to add the C++ files in my app to the unit test target to avoid link errors. I'm not sure if it applies to Objective-C++ code, but it's something to look into.