Testing with google and cmake [duplicate] - c++

Question

Similar issue here.
This is my CMakeLists.txt:
cmake_minimum_required(VERSION 2.6)
# Locate GTest
find_package(GTest REQUIRED)
include_directories(${GTEST_INCLUDE_DIRS})
# Add test cpp file
add_executable(foo foo.cpp)
# Link test executable against gtest & gtest_main
target_link_libraries(foo ${GTEST_LIBRARIES} ${GTEST_MAIN_LIBRARIES} pthread)
And my foo.cpp:
#include <gtest/gtest.h>
TEST(sample_test_case, sample_test)
{
EXPECT_EQ(1, 1);
}
int main(int argc, char **argv)
{
testing::InitGoogleTest(&argc, argv);
return RUN_ALL_TESTS();
}
Now, all works fine when using the g++ compiler. However, when attempting to use QNX's compiler, ntox86-c++, I run into this problem:
CMake Error at /usr/share/cmake-2.8/Modules/FindPackageHandleStandardArgs.cmake:97 (MESSAGE):
Could NOT find GTest (missing: GTEST_LIBRARY GTEST_INCLUDE_DIR
GTEST_MAIN_LIBRARY)
I am on Ubuntu using the ntox86-c++ compiler, googletest, and cmake-gui.
What gives?

Answer 1

Google test was probably not properly installed (libgtest-dev may install only source files that needed to be compiled). I had the same problem and I followed the instructions from http://www.eriksmistad.no/getting-started-with-google-test-on-ubuntu/
sudo apt-get install libgtest-dev
sudo apt-get install cmake # install cmake
cd /usr/src/gtest
sudo cmake CMakeLists.txt
sudo make
#copy or symlink libgtest.a and libgtest_main.a to your /usr/lib folder
sudo cp *.a /usr/lib
This worked for me.

Answer 2

As explained by #detrick, the Ubuntu package libgtest-dev only installs sources, so you need to build and install the libraries yourself.
However, there is a much simpler way for building and installing since Ubuntu 18.04 than the manual commands in other answers:
sudo apt install libgtest-dev build-essential cmake
cd /usr/src/googletest
sudo cmake .
sudo cmake --build . --target install

Answer 3

ntox86-c++ looks like a cross-compiler, libgtest-dev package does not provide compiled library for the target platform (QNX).
Since year 2014 compiled libraries was dropped from libgtest-dev and has been added again in Ubuntu-20.04 focal, so find_package(GTest REQUIRED) does not work on Ubuntu-16.04 xenial and Ubuntu-18.04 bionic. The reason is given in /usr/share/doc/googletest/README.Debian (/usr/share/doc/libgtest-dev/README.Debian) and in e.g. in /usr/src/googletest/googletest/docs/V1_7_FAQ.md "Why is it not recommended to install a pre-compiled copy of Google Test (for example, into /usr/local)" section. Difference in compiler flags for the library and for a test could generate incompatible executable code. The problem with 18.04 and 16.04 is the reason why I have decided to add another answer to the old question.
add_subdirectory could be used to compile gtest provided by system package
set(GTest_ROOT /usr/src/googletest/googletest)
add_subdirectory(${GTest_ROOT}
"${CMAKE_CURRENT_BINARY_DIR}/googletest" EXCLUDE_FROM_ALL)
add_executable(test test.cpp)
target_link_libraries(test gtest_main)
# or just gtest if main function is defined
Instead of using system package for googletest sources there are at least 2 variants how to obtain particular version from git (besides obvious submodule), see
https://cmake.org/cmake/help/latest/module/FetchContent.html
https://github.com/google/googletest/blob/master/googletest/README.md

Answer 4

Some time ago I created a dockerfile and it helps me to keep a kind of recipe for installing later on google test on my systems:
apt-get install -y git g++ make cmake
git clone https://github.com/google/googletest.git
cd googletest
mkdir gbuild && cd gbuild && cmake .. && make
cp -r googletest/include/gtest /usr/local/include
cp gbuild/googlemock/gtest/lib*.a /usr/local/lib
cp gbuild/googlemock/lib*.a /usr/local/lib
I hope it helps :)