This project serves as an example of how to setup a cmake project in what is hopefully a straight forward way, vs some of the other cmake examples that are out there. cmake has so many options and can be difficult to debug it is easy to create a lot of bloat.
About me: I am not a cmake fan boy. Build systems can be very complicated and
can leave developers spending way more time trying to compile than actually
doing good things. I use make and cmake regularly, and depending on the
project I will pick the solution that makes what I am trying to do easy.
.
├── benchmarks
│ ├── cmake_bench.cc
│ └── CMakeLists.txt
├── cmake
│ └── CPM.cmake
├── CMakeLists.txt
├── inc
│ └── cmk
│ └── cmake_proj.h
├── lib
│ ├── CMakeLists.txt
│ └── cmake_proj.cc
├── README.md
├── src
│ ├── CMakeLists.txt
│ └── cmake_src.cc
├── tests
│ ├── CMakeLists.txt
│ └── cmake_test.cc
└── third-party
├── benchmark-1.7.1.tar.gz
├── CMakeLists.txt
├── CMakeLists.txt.in
├── fftw-3.3.10.tar.gz
└── googletest-1.13.0.tar.gz
In some situations you may not have direct internet access, or in places where
internet access is heavily restricted. For these situations it is better to
bring your dependencies with you. I show how to carry those dependencies and
build them using CPM for cmake projects
and ExternalProject_Add for other projects, like fftw.
There are cases that sometimes arise where you may not want to use the system
level version of a library. In these cases you may consider wanting to build
your own version. I have ran across this numerous times with fftw. So rather
than trying to build and install one on the host, I show how you can build it
during configure time, and then you can link to it when you call
target_link_libraries for you executable by adding PkgConfig::fftw3
The hack a coworker showed me was to basically create a separate cmake project
third-party/CMakeLists.txt.in that is built during configuration time.
I include googletest and google benchmark so you can easily test and benchmark your software. These are also packaged internally as tar.gz files.
make test
or
ctest
will execute the tests, you can also add github runners to force running the tests on each commit or PR to master.
I show how to build a basic library and link against it with a src file. The code is really dumb, and provides no real utility other than to provide the user with an example of how they might go about building their own libraries.
It is setup to prefer to use clang vs gcc. You can omit the lines in the
cmake_template/CMakeLists.txt by commenting them out or removing them.
find_program(CMAKE_C_COMPILER NAMES $ENV{CC} clang gcc PATHS ENV PATH NO_DEFAULT_PATH)
find_program(CMAKE_CXX_COMPILER NAMES $ENV{CXX} clang++ g++ PATHS ENV PATH NO_DEFAULT_PATH)
mkdir build
cd build
cmake .. -GNinja
ninja
mkdir build
cd build
cmake ..
make -j`${nproc}`