This content originally appeared on DEV Community and was authored by Adam.S
Objective
This is a BAREBONES C++ template with Google Test support using CMake. It is setup to allow for the building of a static library using TDD principles; but could be adapted for building a small program. This is in no way the ideal solution.
This template was created to allow for programming under Mac OS. But the files should work under other systems.
Directory Structure
This is the structure that we start with. It should be noted that the build directory will be generated in the root of this structure under VSCode. This appears, to generally be discouraged and can be changed with some configuration options that I will not go into here.
❯ tree .
.
├── CMakeLists.txt
├── README.md
├── src
│ ├── CMakeLists.txt
│ ├── Example.cpp
│ └── Example.hpp
└── tests
├── CMakeLists.txt
└── lib-tester.cpp
Requirements
You will require the following items to be installed. Note that I have used homebrew in order to source the requirements. If you are not using Mac OS you should be able to find other ways to install the requirements. Google Search will be your friend in this.
CMake
Installation
brew install cmake
Google Test
Installation
brew install googletest
Example Execution
Let's build the code in and Out of Source build folder.
❯ cmake -B /tmp/testing -S .
-- The CXX compiler identification is AppleClang 13.0.0.13000029
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Check for working CXX compiler: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/c++ - skipped
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Found GTest: /usr/local/lib/cmake/GTest/GTestConfig.cmake (found version "1.11.0")
-- Configuring done
-- Generating done
-- Build files have been written to: /tmp/testing
Let's compile the code
❯ cd /tmp/testing
❯ ls
CMakeCache.txt CTestTestfile.cmake cmake_install.cmake tests
CMakeFiles Makefile src
❯ make
[ 25%] Building CXX object src/CMakeFiles/mylib.dir/EXample.cpp.o
[ 50%] Linking CXX static library libmylib.a
[ 50%] Built target mylib
[ 75%] Building CXX object tests/CMakeFiles/Test1Tester.dir/lib-tester.cpp.o
[100%] Linking CXX executable Test1Tester
[100%] Built target Test1Tester
Things to note: The generated static library will be called libmylib.a and its name comes from the project variable in the top level CMakeList.txt file.
CMakeList.txt Contents
Root
cmake_minimum_required(VERSION 3.22)
project(mylib
VERSION 0.1.0.0
DESCRIPTION "What does it do?"
LANGUAGES CXX
)
set(CMAKE_CXX_STANDARD 14)
set(CMAKE_CXX_STANDARD_REQUIRED true)
set(CMAKE_POSTION_INDEPENDENT_CODE ON)
enable_testing()
add_subdirectory(src)
add_subdirectory(tests)
The project label here is being used to set several variables.
-
mylib
This is used to set the library's name ->libmylib.a
-
enable_testing()
This is used to enable to testing within the IDE -
add_subdirectory()
This makes the top level aware of the sub-directories.src
is the code source of the library. Andtests
is where the source code for the testing code will be written.
src
set(LIB_BINARY ${CMAKE_PROJECT_NAME})
set(headers
Example.hpp)
set(sources
EXample.cpp)
set(SOURCES ${headers} ${sources})
add_library(${LIB_BINARY} STATIC ${SOURCES})
target_include_directories( ${LIB_BINARY} PUBLIC ${CMAKE_CURRENT_SOURCE_DIR})
-
LIB_BINARY
This stores the name of the library to be generated. Coming from project which was set in the previous CMakeList.txt covered earlier. -
headers
This will contain references to any and all header files that are need to compile the library. -
sources
This will contain references to any source files that are needed. -
SOURCES
This combinesheaders
andsources
-
add_library
This tells cmake that we are declaring we want to generate a library file and not an executable. We also specifiy that it is to be a Static and not dynamic library. -
target_include_directories
this tells cmake that we should:- build a library named
lib{LIB_BINARY}.a
- This directory's contents should be made available to other directories in the main project. This means we will be able to build the test programs using this new library.
- build a library named
tests
cmake_minimum_required(VERSION 3.22)
set(CMAKE_CXX_STANDARD 14)
set(CMAKE_CXX_STANDARD_REQUIRED true)
set(CMAKE_POSTION_INDEPENDENT_CODE ON)
file(GLOB_RECURSE TEST_SOURCES LIST_DIRECTORIES false *.hpp *.cpp)
set(test1 Test1Tester)
set(test1src lib-tester.cpp)
# Specify second test program and source files
#set(test2 Test2Tester)
#set(test2src lib-tester2.cpp)
add_executable(${test1} ${test1src})
# Specify executable for second tester
#add_executable(${test2} ${test2src})
find_package( GTest REQUIRED )
# adds the gtest include directory
include_directories( ${GTEST_INCLUDE_DIRS} )
# links gtest
target_link_libraries( ${test1} LINK_PUBLIC ${GTEST_LIBRARIES} ${CMAKE_PROJECT_NAME})
# Specify target for second test program
#target_link_libraries( ${test2} LINK_PUBLIC ${GTEST_LIBRARIES} ${CMAKE_PROJECT_NAME})
enable_testing()
add_test(
NAME ${test1}}
COMMAND ${test1}
)
-
file
This another way to get gather the files for compiling. Though it is discouraged. -
test1
This will hold the name of the testing executable. -
test1src
This holds the name of the source file to be used to build the test executable. -
add_executable
This is the executable to be compiled as the test program
We also need to ensure that we can link in the GTest library. We do that with the following commands.
find_package( GTest REQUIRED )
# adds the gtest include directory
include_directories( ${GTEST_INCLUDE_DIRS} )
- This locates the Google Test libraries that were installed earlier.
Linking the everything together so we have an executable that tests our code.
target_link_libraries( ${test1} LINK_PUBLIC ${GTEST_LIBRARIES} ${CMAKE_PROJECT_NAME})
- This creates the executable, linking the GTEST library and the
mylib
library
If you look through you will see that I have commented out a second source and executable. It is possible to build several test programs. This allows you to build different tests programs instead of having one single monalithic test application.
Screen Capture
Github Repo
You can get the source here
This content originally appeared on DEV Community and was authored by Adam.S
Adam.S | Sciencx (2021-12-10T07:53:06+00:00) A barebones C++ library template using CMake and Google Test. Retrieved from https://www.scien.cx/2021/12/10/a-barebones-c-library-template-using-cmake-and-google-test/
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