In case you don't prefer installing the libgmock.a and libgtest.a static library files and the respective header files on common system folders, then there is yet another way to build the Google test framework.
The following command will create three object files, as shown in Figure 7.4:
g++ -c googletest/googletest/src/gtest-all.cc googletest/googlemock/src/gmock-all.cc googletest/googlemock/src/gmock_main.cc -I googletest/googletest/ -I googletest/googletest/include -I googletest/googlemock -I googletest/googlemock/include -lpthread -
The next step is to combine all the object files into a single static library with the following command:
ar crf libgtest.a gmock-all.o gmock_main.o gtest-all.o
If all goes well, your folder should have the brand new libgtest.a static library, as shown in Figure 7.5. Let's understand the following command instructions:
g++ -c googletest/googletest/src/gtest-all.cc googletest/googlemock/src/gmock-all.cc googletest/googlemock/src/gmock_main.cc -I googletest/googletest/ -I googletest/googletest/include
-I googletest/googlemock -I googletest/googlemock/include -lpthread -std=c++14
The preceding command will help us create three object files: gtest-all.o, gmock-all.o, and gmock_main.o. The googletest framework makes use of some C++11 features, and I have purposefully used c++14 to be on the safer side. The gmock_main.cc source file has a main function that will initialize the Google mock framework, which in turn will internally initialize the Google test framework. The best part about this approach is that we don't have to supply the main function for our unit test application. Please note the compilation command includes the following include paths to help the g++ compiler locate the necessary header files in the Google test and Google mock frameworks:
-I googletest/googletest -I googletest/googletest/include -I googletest/googlemock -I googletest/googlemock/include
Now the next step is to create our libgtest.a static library that will bundle both gtest and gmock frameworks into one single static library. As the Google test framework makes use of multiple threads, it is mandatory to link the pthread library as part of our static library:
ar crv libgtest.a gtest-all.o gmock_main.o gmock-all.o
The ar archive command helps combine all the object files into a single static library.
The following image demonstrates the discussed procedure practically in a terminal:
