Setting up googletest (or gtest, C++ unit testing library) can be tricky. When starting a new project, integrating googletest can be problematic, despite having no such issues with other libraries.

The following guide provides instructions on how to compile and add googletest to a C++ project. It uses pkg-config to obtain compiler flags and works with build systems such as cmake .

It was tested on Ubuntu but might work on other systems as well.

Download and compile googletest

Download the latest release from https://github.com/google/googletest/releases

1wget https://github.com/google/googletest/archive/release-1.8.0.tar.gz

and extract it:

1tar xzf release-1.8.0.tar.gz
2cd googletest-release-1.8.0

After that, we can compile it:

1mkdir build && cd build
2cmake ..
3make -j

Now, copy the headers to a directory where compilers can find them:

1sudo cp -r ../googletest/include /usr/local/include

Then, copy static libraries:

1sudo cp -r ./googlemock/gtest/libgtest*.a /usr/local/lib/

Additionally, you can also add googlemock library (C++ framework for mocking objects):

1sudo cp -r ./googlemock/libgmock*.a /usr/local/lib/

Find googletest with pkg-config

After compiling and installing library files, try to find the library with pkg-config :

1pkg-config --libs --cflags gtest

If you get a message about gtest not being found (“Package gtest was not found in the pkg-config search path”) then it means pkg-config cannot find gtest’s .pc file which provides the necessary configuration.

Run the following command to see the list of directories read by pkg-config:

1pkg-config --variable pc_path pkg-config

Choose one of them, e.g. /usr/lib/pkgconfig , and inside that directory create a file named gtest.pc which should like similar to this:

 1prefix=/usr/local
 2exec_prefix=${prefix}
 3libdir=${prefix}/lib
 4includedir=${prefix}/include
 6Name: gtest
 7Description: gtest
 8Version: 1.8.0
 9Libs: -L${libdir} -lgtest -lpthread
10Cflags: -I${includedir}

Having done that, the following command:

1pkg-config  --libs --cflags gtest

should produce valid output, i.e. similar to

1-I/usr/local/include -L/usr/local/lib -lgtest -lpthread

Integrating googletest with cmake

If you use cmake to build your program, you can use pkg-config to find correct compilation flags.

First, in order to add support for pkg-config in cmake, add the following in CMakeLists.txt :

1find_package(PkgConfig)

Then, find gtest with pkg-config :

1pkg_check_modules(GTEST "gtest" REQUIRED)

You can verify that it’s available by printing GTEST_FOUND variable

1message(STATUS "gtest found: " ${GTEST_FOUND})

and running cmake . on your project.

After you confirm cmake can find the library, just add a definition for your test executable, e.g.

1add_executable(test_1
2  tests/test_1.cpp

and then link gtest with it:

1target_link_libraries(test_1 ${GTEST_LIBRARIES})

Running build command e.g. cmake . && make should now successfully build the executable.

That concludes googletest installation. See the next section if you need to add googlemock (C++ mocking library).

Integrating googlemock with a C++ project

First, ensure you have copied libgmock*.a libraries to /usr/local/lib , i.e. by executing:

1sudo cp -r ./googlemock/libgmock*.a /usr/local/lib/

Create gmock.pc configuration file in /usr/lib/pkgconfig so that pkg-config can resolve compiler flags:

 1prefix=/usr/local
 2exec_prefix=${prefix}
 3libdir=${prefix}/lib
 4includedir=${prefix}/include
 6Name: gmock
 7Description: gmock
 8Version: 1.8.0
 9Libs: -L${libdir} -lgmock -lpthread
10Cflags: -I${includedir}

Then, find gmock in CMakeLists.txt :

1pkg_check_modules(GMOCK "gmock" REQUIRED)

Finally, link your tests with googlemock by adding ${GMOCK_LIBRARIES} variable:

1target_link_libraries(test_readdir ${GTEST_LIBRARIES} ${GMOCK_LIBRARIES})

After all those steps, tests using googletest/googlemock should compile correctly by executing standard commands ( cmake . && make )!