Hier der Beispiel Code
MyClass.h

#ifndef MYCLASS_H_
#define MYCLASS_H_

class MyClass {

	public:
	int method1( int a, int b );

};

#endif /* MYCLASS_H_ */

MyClass.cpp

#include "MyClass.h"

int MyClass::method1( int a, int b )
{
	return 7;
}

MyClassTest.cpp

#include "MyClass.h"
#include "gtest/gtest.h"

namespace {

// The fixture for testing class Foo.
class MyClassTest : public ::testing::Test {
protected:
	// You can remove any or all of the following functions if its body
	// is empty.

	MyClassTest() {
		// You can do set-up work for each test here.
	}

	virtual ~MyClassTest() {
		// You can do clean-up work that doesn't throw exceptions here.
	}

	// If the constructor and destructor are not enough for setting up
	// and cleaning up each test, you can define the following methods:

	virtual void SetUp() {
		// Code here will be called immediately after the constructor (right
		// before each test).
	}

	virtual void TearDown() {
		// Code here will be called immediately after each test (right
		// before the destructor).
	}

	// Objects declared here can be used by all tests in the test case for Foo.
};

TEST_F(MyClassTest, MethodBarDoesAbc) {
	MyClass myClass;
	EXPECT_EQ( 7, myClass.method1(1,1) );
}

}  // namespace

int main(int argc, char **argv) {
	::testing::InitGoogleTest(&argc, argv);
	return RUN_ALL_TESTS();
}

So sieht mein Makefile aus:

CXX = g++
CFLAGS =

GTEST_INCLUDE = /pfad/zu/gtest-1.6.0/include
GTEST_LIBS = /pfad/zu/gtest-1.6.0

LIBS = -L$(GTEST_LIBS) -lgtest INCLUDE = -I$(GTEST_INCLUDE)

TARGET = MyClassTest
OBJFILES = MyClass.o MyClassTest.o
FILES = MyClass.cpp MyClassTest.cpp

$(TARGET): $(OBJFILES)$(CXX) $(LIBS) -o $(TARGET) $^
rm *.o

$(OBJFILES): $(FILES)$(CXX) $(CFLAGS) $(INCLUDE) -c $^

all:$(TARGET)

clean:
rm *.o $(TARGET)

Die Pfade im Makefile sind korrekt gesetzt und auch die Bibliothek konnte ich korrekt übersetzen und es läuft auf meinem Mac einwandfrei. Auf der Linux-Maschine erhalte ich aber folgende Fehlerausgabe:

/C++/GTestDemo> make
g++ -I/pfad/zu/gtest-1.6.0/include -c MyClass.cpp MyClassTest.cpp
g++ -L/pfad/zu/gtest-1.6.0 -lgtest -o MyClassTest MyClass.o MyClassTest.o
MyClassTest.o: In function (anonymous namespace)::MyClassTest::MyClassTest()': MyClassTest.cpp:(.text+0x14): undefined reference totesting::Test::Test()'
MyClassTest.o: In function (anonymous namespace)::MyClassTest::~MyClassTest()': MyClassTest.cpp:(.text+0x45): undefined reference totesting::Test::~Test()'
MyClassTest.o: In function (anonymous namespace)::MyClassTest\_MethodBarDoesAbc\_Test::TestBody()': MyClassTest.cpp:(.text+0x180): undefined reference totesting::internal::AssertHelper::AssertHelper(testing::TestPartResult::Type, char const*, int, char const*)'
MyClassTest.cpp:(.text+0x193): undefined reference to testing::internal::AssertHelper::operator=(testing::Message const&) const' MyClassTest.cpp:(.text+0x19f): undefined reference totesting::internal::AssertHelper::~AssertHelper()'
MyClassTest.cpp:(.text+0x1d5): undefined reference to testing::internal::AssertHelper::~AssertHelper()' MyClassTest.o: In functionmain':
MyClassTest.cpp:(.text+0x224): undefined reference to testing::InitGoogleTest(int*, char**)' MyClassTest.cpp:(.text+0x229): undefined reference totesting::UnitTest::GetInstance()'
MyClassTest.cpp:(.text+0x231): undefined reference to testing::UnitTest::Run()' MyClassTest.o: In function__static_initialization_and_destruction_0(int, int)':
MyClassTest.cpp:(.text+0x39b): undefined reference to testing::internal::MakeAndRegisterTestInfo(char const*, char const*, char const*, char const*, void const*, void (*)(), void (*)(), testing::internal::TestFactoryBase*)' MyClassTest.o:(.rodata+0x170): undefined reference totypeinfo for testing::Test'
MyClassTest.o: In function testing::internal::scoped\_ptr<std::basic\_string<char, std::char\_traits<char>, std::allocator<char> > >::reset(std::basic\_string<char, std::char_traits<char>, std::allocator<char> >*)': MyClassTest.cpp:(.text.\_ZN7testing8internal10scoped\_ptrISsE5resetEPSs\[testing::internal::scoped\_ptr<std::basic\_string<char, std::char\_traits<char>, std::allocator<char> > >::reset(std::basic\_string<char, std::char_traits<char>, std::allocator<char> >*)\]+0x24): undefined reference totesting::internal::IsTrue(bool)'
MyClassTest.o: In function testing::internal::scoped\_ptr<std::basic\_stringstream<char, std::char\_traits<char>, std::allocator<char> > >::reset(std::basic\_stringstream<char, std::char_traits<char>, std::allocator<char> >*)': MyClassTest.cpp:(.text.\_ZN7testing8internal10scoped\_ptrISt18basic\_stringstreamIcSt11char\_traitsIcESaIcEEE5resetEPS6_\[testing::internal::scoped\_ptr<std::basic\_stringstream<char, std::char\_traits<char>, std::allocator<char> > >::reset(std::basic\_stringstream<char, std::char_traits<char>, std::allocator<char> >*)\]+0x23): undefined reference totesting::internal::IsTrue(bool)'
MyClassTest.o: In function testing::AssertionResult testing::internal::CmpHelperEQ<int, int>(char const*, char const*, int const&, int const&)': MyClassTest.cpp:(.text.\_ZN7testing8internal11CmpHelperEQIiiEENS\_15AssertionResultEPKcS4\_RKT\_RKT0_\[testing::AssertionResult testing::internal::CmpHelperEQ<int, int>(char const*, char const*, int const&, int const&)\]+0x35): undefined reference totesting::AssertionSuccess()'
MyClassTest.cpp:(.text._ZN7testing8internal11CmpHelperEQIiiEENS_15AssertionResultEPKcS4_RKT_RKT0_[testing::AssertionResult testing::internal::CmpHelperEQ<int, int>(char const*, char const*, int const&, int const&)]+0x8f): undefined reference to `testing::internal::EqFailure(char const*, char const*, testing::internal::String const&, testing::internal::String const&, bool)'
collect2: ld returned 1 exit status
make: *** [MyClassTest] Error 1

Was funktioniert hier denn nicht?

$(CXX) -o $(TARGET) $^ $(LIBS)

Jetzt sieht die Fehlermeldung etwas anders aus:

/C++/GTestDemo> make
g++ -o MyClassTest MyClass.o MyClassTest.o -L/pfad/zu/gtest-1.6.0 -lgtest
/pfad/zu/gtest-1.6.0/libgtest.a(gtest-all.o): In function testing::internal::ThreadLocal<testing::TestPartResultReporterInterface*>::~ThreadLocal()': gtest-all.cc:(.text.\_ZN7testing8internal11ThreadLocalIPNS\_31TestPartResultReporterInterfaceEED2Ev\[\_ZN7testing8internal11ThreadLocalIPNS\_31TestPartResultReporterInterfaceEED5Ev\]+0x16): undefined reference topthread_getspecific'
gtest-all.cc:(.text._ZN7testing8internal11ThreadLocalIPNS_31TestPartResultReporterInterfaceEED2Ev[_ZN7testing8internal11ThreadLocalIPNS_31TestPartResultReporterInterfaceEED5Ev]+0x2b): undefined reference to pthread\_key\_delete' /pfad/zu/gtest-1.6.0/libgtest.a(gtest-all.o): In functiontesting::internal::ThreadLocal<std::vector<testing::internal::TraceInfo, std::allocatortesting::internal::TraceInfo > >::~ThreadLocal()':
gtest-all.cc:(.text._ZN7testing8internal11ThreadLocalISt6vectorINS0_9TraceInfoESaIS3_EEED2Ev[_ZN7testing8internal11ThreadLocalISt6vectorINS0_9TraceInfoESaIS3_EEED5Ev]+0x16): undefined reference to pthread_getspecific' gtest-all.cc:(.text.\_ZN7testing8internal11ThreadLocalISt6vectorINS0\_9TraceInfoESaIS3\_EEED2Ev\[\_ZN7testing8internal11ThreadLocalISt6vectorINS0\_9TraceInfoESaIS3\_EEED5Ev\]+0x2b): undefined reference topthread_key_delete'
/pfad/zu/gtest-1.6.0/libgtest.a(gtest-all.o): In function testing::internal::ThreadLocal<std::vector<testing::internal::TraceInfo, std::allocator<testing::internal::TraceInfo> > >::GetOrCreateValue() const': gtest-all.cc:(.text.\_ZNK7testing8internal11ThreadLocalISt6vectorINS0\_9TraceInfoESaIS3\_EEE16GetOrCreateValueEv\[testing::internal::ThreadLocal<std::vector<testing::internal::TraceInfo, std::allocator<testing::internal::TraceInfo> > >::GetOrCreateValue() const\]+0x18): undefined reference topthread_getspecific'
gtest-all.cc:(.text._ZNK7testing8internal11ThreadLocalISt6vectorINS0_9TraceInfoESaIS3_EEE16GetOrCreateValueEv[testing::internal::ThreadLocal<std::vector<testing::internal::TraceInfo, std::allocatortesting::internal::TraceInfo > >::GetOrCreateValue() const]+0x7f): undefined reference to pthread\_setspecific' /pfad/zu/gtest-1.6.0/libgtest.a(gtest-all.o): In functiontesting::internal::ThreadLocaltesting::TestPartResultReporterInterface*::CreateKey()':
gtest-all.cc:(.text._ZN7testing8internal11ThreadLocalIPNS_31TestPartResultReporterInterfaceEE9CreateKeyEv[testing::internal::ThreadLocaltesting::TestPartResultReporterInterface*::CreateKey()]+0x16): undefined reference to pthread\_key\_create' /pfad/zu/gtest-1.6.0/libgtest.a(gtest-all.o): In functiontesting::internal::ThreadLocal<std::vector<testing::internal::TraceInfo, std::allocatortesting::internal::TraceInfo > >::CreateKey()':
gtest-all.cc:(.text._ZN7testing8internal11ThreadLocalISt6vectorINS0_9TraceInfoESaIS3_EEE9CreateKeyEv[testing::internal::ThreadLocal<std::vector<testing::internal::TraceInfo, std::allocatortesting::internal::TraceInfo > >::CreateKey()]+0x16): undefined reference to pthread\_key_create' /pfad/zu/gtest-1.6.0/libgtest.a(gtest-all.o): In functiontesting::internal::ThreadLocaltesting::TestPartResultReporterInterface*::GetOrCreateValue() const':
gtest-all.cc:(.text._ZNK7testing8internal11ThreadLocalIPNS_31TestPartResultReporterInterfaceEE16GetOrCreateValueEv[testing::internal::ThreadLocaltesting::TestPartResultReporterInterface*::GetOrCreateValue() const]+0x16): undefined reference to pthread_getspecific' gtest-all.cc:(.text.\_ZNK7testing8internal11ThreadLocalIPNS\_31TestPartResultReporterInterfaceEE16GetOrCreateValueEv\[testing::internal::ThreadLocal<testing::TestPartResultReporterInterface*>::GetOrCreateValue() const\]+0x7d): undefined reference topthread_setspecific'
collect2: ld returned 1 exit status
make: *** [MyClassTest] Error 1