Google Test - undefined reference to testing::internal::AssertHelper::AssertHelper

Question

I built Google Test from source on Windows 10. Now I'm trying to create an application that uses the library. Building the program with CMake fails for some reason.

EDIT // It seems that CMake is not linking Google Test properly. I get the same results when I remove the target_link_libraries(tests GTest::GTest) line from the tests folder CMakeLists.txt.

Here's my code (the program fails at the call to EXPECT_EQ):

#include "gtest/gtest.h"

namespace {
    class CanTest: public ::testing::Test {};

    TEST_F(CanTest, CanReallyTest) {
        EXPECT_EQ(0, 0);
    }
}

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

Here's the tests subfolder CMakeLists.txt:

include(GoogleTest)
add_executable(tests CanTest.cpp)
target_link_libraries(tests GTest::GTest)
gtest_discover_tests(tests)

Here's the project CMakeLists.txt:

cmake_minimum_required(VERSION 3.10.0)

project(CxxTemplate
  VERSION 0.1.0.0
  LANGUAGES C CXX
  DESCRIPTION "A project containing the essentials for other projects"
)
set(CxxTemplate_VENDOR "Aron Rubin")
set(PROJECT_VENDOR "${CxxTemplate_VENDOR}")


set(CMAKE_DEBUG_POSTFIX d)

set(CMAKE_CXX_STANDARD 17)
set(CMAKE_C_STANDARD 11)

list(APPEND CMAKE_MODULE_PATH "${PROJECT_SOURCE_DIR}/cmake/modules")


if(POLICY CMP0074)
  cmake_policy(SET CMP0074 NEW)
endif()

find_package(GTest)
if(GTEST_FOUND)
set(Gtest_FOUND TRUE)
endif()
if(GTest_FOUND)
include(GoogleTest)
endif()

enable_testing()
add_subdirectory(tests)

include(CheckIncludeFiles)
CHECK_INCLUDE_FILES(sys/prctl.h HAVE_SYS_PRCTL_H)

find_package(Threads REQUIRED)

add_executable(CxxTemplate
  src/CxxTemplate.cpp  
)

target_link_libraries(CxxTemplate
  PUBLIC Threads::Threads
)

include(FeatureSummary)
feature_summary(WHAT ALL)

# include(DumpProps)
# print_target_properties(diva)
# include(DumpVariables)
# dump_all_variables()

Here are the error messages:

C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.3.0/../../../../x86_64-w64-mingw32/bin/ld.exe: tests\CanTest.o:C:\Users\mkkek\Documents\koodi\cppkirja\Advanced-CPlusPlus\Lesson1\Exercise01\project\CxxTemplate\Debug/../tests/CanTest.cpp:18: multiple definition of `main'; src\CxxTemplate.o:C:\Users\mkkek\Documents\koodi\cppkirja\Advanced-CPlusPlus\Lesson1\Exercise01\project\CxxTemplate\Debug/../src/CxxTemplate.cpp:32: first defined here
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.3.0/../../../../x86_64-w64-mingw32/bin/ld.exe: tests\CanTest.o:C:\Users\mkkek\Documents\koodi\cppkirja\Advanced-CPlusPlus\Lesson1\Exercise01\project\CxxTemplate\Debug/../tests/CanTest.cpp:11: undefined reference to `testing::Test::Test()'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.3.0/../../../../x86_64-w64-mingw32/bin/ld.exe: tests\CanTest.o:C:\Users\mkkek\Documents\koodi\cppkirja\Advanced-CPlusPlus\Lesson1\Exercise01\project\CxxTemplate\Debug/../tests/CanTest.cpp:11: undefined reference to `testing::Test::~Test()'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.3.0/../../../../x86_64-w64-mingw32/bin/ld.exe: tests\CanTest.o:C:\Users\mkkek\Documents\koodi\cppkirja\Advanced-CPlusPlus\Lesson1\Exercise01\project\CxxTemplate\Debug/../tests/CanTest.cpp:14: undefined reference to `testing::Message::Message()'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.3.0/../../../../x86_64-w64-mingw32/bin/ld.exe: tests\CanTest.o: in function `TestBody':
C:\Users\mkkek\Documents\koodi\cppkirja\Advanced-CPlusPlus\Lesson1\Exercise01\project\CxxTemplate\Debug/../tests/CanTest.cpp:14: undefined reference to `testing::internal::AssertHelper::AssertHelper(testing::TestPartResult::Type, char const*, int, char const*)'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.3.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:\Users\mkkek\Documents\koodi\cppkirja\Advanced-CPlusPlus\Lesson1\Exercise01\project\CxxTemplate\Debug/../tests/CanTest.cpp:14: undefined reference to `testing::internal::AssertHelper::operator=(testing::Message const&) const'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.3.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:\Users\mkkek\Documents\koodi\cppkirja\Advanced-CPlusPlus\Lesson1\Exercise01\project\CxxTemplate\Debug/../tests/CanTest.cpp:14: undefined reference to `testing::internal::AssertHelper::~AssertHelper()'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.3.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:\Users\mkkek\Documents\koodi\cppkirja\Advanced-CPlusPlus\Lesson1\Exercise01\project\CxxTemplate\Debug/../tests/CanTest.cpp:14: undefined reference to `testing::internal::AssertHelper::~AssertHelper()'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.3.0/../../../../x86_64-w64-mingw32/bin/ld.exe: tests\CanTest.o:C:\Users\mkkek\Documents\koodi\cppkirja\Advanced-CPlusPlus\Lesson1\Exercise01\project\CxxTemplate\Debug/../tests/CanTest.cpp:19: undefined reference to `testing::InitGoogleTest(int*, char**)'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.3.0/../../../../x86_64-w64-mingw32/bin/ld.exe: tests\CanTest.o:C:/msys64/mingw64/include/gtest/internal/gtest-internal.h:516: undefined reference to `testing::internal::IsTrue(bool)'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.3.0/../../../../x86_64-w64-mingw32/bin/ld.exe: tests\CanTest.o: in function `GetSetUpCaseOrSuite':
C:/msys64/mingw64/include/gtest/internal/gtest-internal.h:516: undefined reference to `testing::internal::GTestLog::GTestLog(testing::internal::GTestLogSeverity, char const*, int)'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.3.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:/msys64/mingw64/include/gtest/internal/gtest-internal.h:516: undefined reference to `testing::internal::GTestLog::~GTestLog()'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.3.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:/msys64/mingw64/include/gtest/internal/gtest-internal.h:516: undefined reference to `testing::internal::GTestLog::~GTestLog()'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.3.0/../../../../x86_64-w64-mingw32/bin/ld.exe: tests\CanTest.o:C:/msys64/mingw64/include/gtest/internal/gtest-internal.h:531: undefined reference to `testing::internal::IsTrue(bool)'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.3.0/../../../../x86_64-w64-mingw32/bin/ld.exe: tests\CanTest.o: in function `GetTearDownCaseOrSuite':
C:/msys64/mingw64/include/gtest/internal/gtest-internal.h:531: undefined reference to `testing::internal::GTestLog::GTestLog(testing::internal::GTestLogSeverity, char const*, int)'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.3.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:/msys64/mingw64/include/gtest/internal/gtest-internal.h:531: undefined reference to `testing::internal::GTestLog::~GTestLog()'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.3.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:/msys64/mingw64/include/gtest/internal/gtest-internal.h:531: undefined reference to `testing::internal::GTestLog::~GTestLog()'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.3.0/../../../../x86_64-w64-mingw32/bin/ld.exe: tests\CanTest.o:C:\Users\mkkek\Documents\koodi\cppkirja\Advanced-CPlusPlus\Lesson1\Exercise01\project\CxxTemplate\Debug/../tests/CanTest.cpp:13: undefined reference to `testing::internal::MakeAndRegisterTestInfo(char const*, char const*, char const*, char const*, testing::internal::CodeLocation, void const*, void (*)(), void (*)(), testing::internal::TestFactoryBase*)'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.3.0/../../../../x86_64-w64-mingw32/bin/ld.exe: tests\CanTest.o:CanTest.cpp:(.rdata+0x210): undefined reference to `testing::Test::SetUp()'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.3.0/../../../../x86_64-w64-mingw32/bin/ld.exe: tests\CanTest.o:CanTest.cpp:(.rdata+0x218): undefined reference to `testing::Test::TearDown()'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.3.0/../../../../x86_64-w64-mingw32/bin/ld.exe: tests\CanTest.o:CanTest.cpp:(.rdata+0x278): undefined reference to `testing::Test::SetUp()'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.3.0/../../../../x86_64-w64-mingw32/bin/ld.exe: tests\CanTest.o:CanTest.cpp:(.rdata+0x280): undefined reference to `testing::Test::TearDown()'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.3.0/../../../../x86_64-w64-mingw32/bin/ld.exe: tests\CanTest.o: in function `RUN_ALL_TESTS()':
C:/msys64/mingw64/include/gtest/gtest.h:2473: undefined reference to `testing::UnitTest::GetInstance()'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.3.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:/msys64/mingw64/include/gtest/gtest.h:2473: undefined reference to `testing::UnitTest::Run()'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.3.0/../../../../x86_64-w64-mingw32/bin/ld.exe: tests\CanTest.o: in function `testing::AssertionResult testing::internal::CmpHelperEQ<int, int>(char const*, char const*, int const&, int const&)':
C:/msys64/mingw64/include/gtest/gtest.h:1528: undefined reference to `testing::AssertionSuccess()'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/9.3.0/../../../../x86_64-w64-mingw32/bin/ld.exe: tests\CanTest.o: in function `testing::AssertionResult testing::internal::CmpHelperEQFailure<int, int>(char const*, char const*, int const&, int const&)':
C:/msys64/mingw64/include/gtest/gtest.h:1511: undefined reference to `testing::internal::EqFailure(char const*, char const*, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, bool)'

I'd appreciate any help, as I'm not a C++ expert.

Answer 1

I encountered this same issue using eclipse. Mine was due to not linking the google test libraries which can be found in the lib folder of google test build directory.

Image Description

Answer 2

You can incorporate the building of the GTest library (from source) directly into your CMake configuration, as suggested by the official Google documentation: https://github.com/google/googletest/tree/master/googletest#incorporating-into-an-existing-cmake-project.

In other words, create a new file called CMakeLists.txt.in:

cmake_minimum_required(VERSION 2.8.2)

project(googletest-download NONE)

include(ExternalProject)
ExternalProject_Add(googletest
  GIT_REPOSITORY    https://github.com/google/googletest.git
  GIT_TAG           master
  SOURCE_DIR        "${CMAKE_CURRENT_BINARY_DIR}/googletest-src"
  BINARY_DIR        "${CMAKE_CURRENT_BINARY_DIR}/googletest-build"
  CONFIGURE_COMMAND ""
  BUILD_COMMAND     ""
  INSTALL_COMMAND   ""
  TEST_COMMAND      ""
)

And then in your existing CMakeLists.txt file, include this snippet:

# Download and unpack googletest at configure time
configure_file(CMakeLists.txt.in googletest-download/CMakeLists.txt)
execute_process(COMMAND ${CMAKE_COMMAND} -G "${CMAKE_GENERATOR}" .
  RESULT_VARIABLE result
  WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/googletest-download )
if(result)
  message(FATAL_ERROR "CMake step for googletest failed: ${result}")
endif()
execute_process(COMMAND ${CMAKE_COMMAND} --build .
  RESULT_VARIABLE result
  WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/googletest-download )
if(result)
  message(FATAL_ERROR "Build step for googletest failed: ${result}")
endif()

# Prevent overriding the parent project's compiler/linker
# settings on Windows
set(gtest_force_shared_crt ON CACHE BOOL "" FORCE)

# Add googletest directly to our build. This defines
# the gtest and gtest_main targets.
add_subdirectory(${CMAKE_CURRENT_BINARY_DIR}/googletest-src
                 ${CMAKE_CURRENT_BINARY_DIR}/googletest-build
                 EXCLUDE_FROM_ALL)

# The gtest/gtest_main targets carry header search path
# dependencies automatically when using CMake 2.8.11 or
# later. Otherwise we have to add them here ourselves.
if (CMAKE_VERSION VERSION_LESS 2.8.11)
  include_directories("${gtest_SOURCE_DIR}/include")
endif()

# Now simply link against gtest or gtest_main as needed. Eg
add_executable(example example.cpp)
target_link_libraries(example gtest_main)
add_test(NAME example_test COMMAND example)

## Remainder of your project config...

Placing your test code in example.cpp should make them executable via example.exe once built.

Answer 3

I use Eclipse as the IDE. I had simply forgotten to specify the builder in the project settings, so Eclipse tried to build the project with g++.

This helped: