[c++] How to set up googleTest as a shared library on Linux

Debian does not provide any precompiled packages for gTest anymore. They suggest you integrate the framework into your project's makefile. But I want to keep my makefile clean. How do I set up gTest like the former versions (<1.6.0), so that I can link against the library?

Just in case somebody else gets in the same situation like me yesterday (2016-06-22) and also does not succeed with the already posted approaches - on Lubuntu 14.04 it worked for me using the following chain of commands:

git clone https://github.com/google/googletest
cd googletest
cmake -DBUILD_SHARED_LIBS=ON .
make
cd googlemock
sudo cp ./libgmock_main.so ./gtest/libgtest.so gtest/libgtest_main.so ./libgmock.so /usr/lib/
sudo ldconfig

The following method avoids manually messing with the /usr/lib directory while also requiring minimal change in your CMakeLists.txt file. It also lets your package manager cleanly uninstall libgtest-dev.

The idea is that when you get the libgtest-dev package via

sudo apt install libgtest-dev

The source is stored in location /usr/src/googletest

You can simply point your CMakeLists.txt to that directory so that it can find the necessary dependencies

Simply replace FindGTest with add_subdirectory(/usr/src/googletest gtest)

At the end, it should look like this

add_subdirectory(/usr/src/googletest gtest)
target_link_libraries(your_executable gtest)

This will install google test and mock library in Ubuntu/Debian based system:

sudo apt-get install google-mock

Tested in google cloud in debian based image.

If you happen to be using CMake, you can use ExternalProject_Add as described here.

This avoids you having to keep gtest source code in your repository, or installing it anywhere. It is downloaded and built in your build tree automatically.

This answer from askubuntu is what worked for me. Seems simpler than other options an less error-prone, since it uses package libgtest-dev to get the sources and builds from there: https://askubuntu.com/questions/145887/why-no-library-files-installed-for-google-test?answertab=votes#tab-top

Please refer to that answer, but just as a shortcut I provide the steps here as well:

sudo apt-get install -y libgtest-dev
sudo apt-get install -y cmake
cd /usr/src/gtest
sudo cmake .
sudo make
sudo mv libg* /usr/lib/

After that, I could build my project which depends on gtest with no issues.

Update for Debian/Ubuntu

Google Mock (package: google-mock) and Google Test (package: libgtest-dev) have been merged. The new package is called googletest. Both old names are still available for backwards compatibility and now depend on the new package googletest.

So, to get your libraries from the package repository, you can do the following:

sudo apt-get install googletest -y
cd /usr/src/googletest
sudo mkdir build
cd build
sudo cmake ..
sudo make
sudo cp googlemock/*.a googlemock/gtest/*.a /usr/lib

After that, you can link against -lgmock (or against -lgmock_main if you do not use a custom main method) and -lpthread. This was sufficient for using Google Test in my cases at least.

If you want the most current version of Google Test, download it from github. After that, the steps are similar:

git clone https://github.com/google/googletest
cd googletest
sudo mkdir build
cd build
sudo cmake ..
sudo make
sudo cp lib/*.a /usr/lib

As you can see, the path where the libraries are created has changed. Keep in mind that the new path might be valid for the package repositories soon, too.

Instead of copying the libraries manually, you could use sudo make install. It "currently" works, but be aware that it did not always work in the past. Also, you don't have control over the target location when using this command and you might not want to pollute /usr/lib.

For 1.8.1 based on @ManuelSchneid3r 's answer I had to do:

wget github.com/google/googletar xf release-1.8.1.tar.gz 
tar xf release-1.8.1.tar.gz
cd googletest-release-1.8.1/
cmake -DBUILD_SHARED_LIBS=ON .
make

I then did make install which seemed to work for 1.8.1, but following @ManuelSchneid3r it would mean:

sudo cp -a googletest/include/gtest /usr/include
sudo cp -a googlemock/include/gmock /usr/include
sudo cp `find .|grep .so$` /usr/lib/

It took me a while to figure out this because the normal "make install" has been removed and I don't use cmake. Here is my experience to share. At work, I don't have root access on Linux, so I installed the Google test framework under my home directory: ~/usr/gtest/.

To install the package in ~/usr/gtest/ as shared libraries, together with sample build as well:

$ mkdir ~/temp
$ cd ~/temp
$ unzip gtest-1.7.0.zip 
$ cd gtest-1.7.0
$ mkdir mybuild
$ cd mybuild
$ cmake -DBUILD_SHARED_LIBS=ON -Dgtest_build_samples=ON -G"Unix Makefiles" ..
$ make
$ cp -r ../include/gtest ~/usr/gtest/include/
$ cp lib*.so ~/usr/gtest/lib

To validate the installation, use the following test.c as a simple test example:

    #include <gtest/gtest.h>
    TEST(MathTest, TwoPlusTwoEqualsFour) {
        EXPECT_EQ(2 + 2, 4);
    }

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

To compile:

    $ export GTEST_HOME=~/usr/gtest
    $ export LD_LIBRARY_PATH=$GTEST_HOME/lib:$LD_LIBRARY_PATH
    $ g++ -I $GTEST_HOME/include -L $GTEST_HOME/lib -lgtest -lgtest_main -lpthread test.cpp 

Let me answer this specifically for ubuntu users. First start by installing the gtest development package.

sudo apt-get install libgtest-dev

Note that this package only install source files. You have to compile the code yourself to create the necessary library files. These source files should be located at /usr/src/gtest. Browse to this folder and use cmake to compile the library:

sudo apt-get install cmake # install cmake
cd /usr/src/gtest
sudo mkdir build
cd build
sudo cmake ..
sudo make
sudo make install

Now to compile your programs that uses gtest, you have to link it with:

-lgtest -lgtest_main -lpthread

This worked perfectly for me on Ubuntu 14.04LTS.

This will build and install both gtest and gmock 1.7.0:

mkdir /tmp/googleTestMock
tar -xvf googletest-release-1.7.0.tar.gz -C /tmp/googleTestMock
tar -xvf googlemock-release-1.7.0.tar.gz -C /tmp/googleTestMock
cd /tmp/googleTestMock
mv googletest-release-1.7.0 gtest
cd googlemock-release-1.7.0
cmake -DBUILD_SHARED_LIBS=ON .
make -j$(nproc)
sudo cp -a include/gmock /usr/include
sudo cp -a libgmock.so libgmock_main.so /usr/lib/
sudo cp -a ../gtest/include/gtest /usr/include
sudo cp -a gtest/libgtest.so gtest/libgtest_main.so /usr/lib/
sudo ldconfig

I was similarly underwhelmed by this situation and ended up making my own Ubuntu source packages for this. These source packages allow you to easily produce a binary package. They are based on the latest gtest & gmock source as of this post.

Google Test DEB Source Package

Google Mock DEB Source Package

To build the binary package do this:

tar -xzvf gtest-1.7.0.tar.gz
cd gtest-1.7.0
dpkg-source -x gtest_1.7.0-1.dsc
cd gtest-1.7.0
dpkg-buildpackage

It may tell you that you need some pre-requisite packages in which case you just need to apt-get install them. Apart from that, the built .deb binary packages should then be sitting in the parent directory.

For GMock, the process is the same.

As a side note, while not specific to my source packages, when linking gtest to your unit test, ensure that gtest is included first (https://bbs.archlinux.org/viewtopic.php?id=156639) This seems like a common gotcha.