How to set up googleTest as a shared library on Linux

Question

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?

Solution 1

Before you start make sure your have read and understood this note from Google! This tutorial makes using gtest easy, but may introduce nasty bugs.

1. Get the googletest framework

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

Or get it by hand. I won't maintain this little How-to, so if you stumbled upon it and the links are outdated, feel free to edit it.

2. Unpack and build google test

tar xf release-1.8.0.tar.gz
cd googletest-release-1.8.0
cmake -DBUILD_SHARED_LIBS=ON .
make

3. "Install" the headers and libs on your system.

This step might differ from distro to distro, so make sure you copy the headers and libs in the correct directory. I accomplished this by checking where Debians former gtest libs were located. But I'm sure there are better ways to do this.

sudo cp -a googletest/include/gtest /usr/include
sudo cp -a googlemock/gtest/libgtest_main.so googlemock/gtest/libgtest.so /usr/lib/

# The easiest/best way:
make install  # Note: before v1.11 this can be dangerous and is not supported

4. Update the cache of the linker

... and check if the GNU Linker knows the libs

sudo ldconfig -v | grep gtest

If the output looks like this:

libgtest.so.0 -> libgtest.so.0.0.0
libgtest_main.so.0 -> libgtest_main.so.0.0.0

then everything is fine.

gTestframework is now ready to use. Just don't forget to link your project against the library by setting -lgtest as linker flag and optionally, if you did not write your own test mainroutine, the explicit -lgtest_main flag.

From here on you might want to go to Googles documentation, and the old docs about the framework to learn how it works. Happy coding!

Edit: This works for OS X too! See "How to properly setup googleTest on OS X"

Solution 2

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.

Solution 3

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 

Solution 4

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.

Solution 5

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.

View more solutions

Comments

[Shawn Chin]

Is there no make install target that you can use instead of manually copying the library and headers?

[ManuelSchneid3r]

Cite of the output of the makefile: 'make install' is dangerous and not supported. Instead, see README for how to integrate Google Test into your build system.

[ddelnano]

Your package gives me errors when I try to compile. Any reason why?? here is my log test.cpp:(.text+0x57): undefined reference to testing::Message::Message()' test.cpp:(.text+0x84): undefined reference to testing::internal::AssertHelper::AssertHelper(testing::TestP‌​artResult::Type, char const*, int, char const*)' test.cpp:(.text+0x97): undefined reference to `testing::internal::AssertHelper::operator=(testing::Message const&) const' ... its so long that I can't post the entire thing. I did this in a brand new Ubuntu 14.04 VM so nothing else was installed except the necessary dependencies.

[Nick Weedon]

@ddelnano Yeah i ran into this little google test gem too. Apparently the order of the shared libraries is important. When linking gtest to your unit test, try including gtest before other libraries. When i hit this problem, this link solved it for me: bbs.archlinux.org/viewtopic.php?id=156639

[Nick Weedon]

@ddelnano, also if your test suite does not have a 'main' defined then don't forget to link against 'gtest_main'.

[ddelnano]

I didn't include any other libraries. this is all i had in my file #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(); }

[ddelnano]

nevermind I didn't read the blog post until after I posted that comment. It is now finally working!

[user9869932]

With the last line I get error: /usr/bin/ld: /tmp/cczG727X.o: undefined reference to symbol '_ZN7testing4TestC2Ev'. I fixed this placing test.cpp before the libraries. i.e: g++ test.cpp -I $GTEST_HOME/include -L $GTEST_HOME/lib -lgtest -lgtest_main -lpthread

[jotadepicas]

Hmm, no, I think this only installs googlemock, but it does not install googletest (gtest). At least that's what happened to me.

[Alexander Zinovyev]

Actually you don't have to copy libraries manually, there is a target for that in Makefile. You can just do it like that: sudo apt-get install cmake # install cmake cd /usr/src/gtest sudo cmake CMakeLists.txt sudo make install That should be built and copy /usr/local/lib/

[m4l490n]

@AlexanderZinovyev I get "make: *** No rule to make target 'install'. Stop." when I execute the "sudo make install"

[Nubcake]

Have the files been renamed in the 1.8.0 version? There is no include/gtest as far as I can tell.

[Ahmed Nassar]

"sudo make install" worked on Ubuntu 18.04, but didn't work on Ubuntu 16.04.

[amritkrs]

@AhmedNassar: "sudo make install" does just the same thing as "sudo cp *.a /usr/lib". So, if install option is not available in generated Makefile, you just copy them manually

[Schütze]

Your post is out-of-date. Please do not mislead people, sudo cp -a libgtest_main.so libgtest.so /usr/lib/ does not work anymore. The file isn't even there to begin with.

[Carlo Wood]

I'd also like to know why debian removed a pre-installed shared library (they did so as per upstreams recommendations: bugs.debian.org/cgi-bin/bugreport.cgi?bug=802587). The wiki link given there does no longer exist though. So why was this the case?

[ntg]

Its been a while that I wrote this answer, let me know what is the problem with it if you think it has no value / is invalid.

[lingjiankong]

There is no need to manually sudo cp *.a /usr/lib, just repalce it with sudo make install should be fine.

[Ibrahim Mohamed]

I had to compile with -lgtest -lgtest_main -lpthread to make it work.

[Gino Mempin]

If linking against gtest_main (lgtest_main), there is no need to define your own main in the test file.

[Maxxik CZ]

your solution didn't work for me. The correct output of ldconfig didn't show up. sudo make instal worked for me.

[jaques-sam]

Just run make install from 1.11 onward, this works on >=debian10