CMAKE TARGET INSTALL
CMAKE TARGET SERIES

It is highly recommended to create a build directory before building a CMake project so that it doesn't pollute the rest of your project directory. Target_link_libraries(myawesomecli PRIVATE myawesomelib) We will use the add_executable command to create the executable target, and target_link_libraries to indicate what libraries we are using: add_executable(myawesomecli main.cpp) Now that we have a library, we want to use it in our commandline tool. Same thing for more information about targets, transitive usage requirements and the buildsystem in general, you can take a look at the documentation here. Other types of libraries exist but won't be covered in this article, refer to the documentation for an exhaustive list. This is done by calling add_library without sources and the INTERFACE keyword, for example add_library(myheaderonlylib INTERFACE). In the case of a header only library, you need to tell CMake that no compilation is required by creating an interface library. This means that when linking our myawesomelib, we will be able to include myawesomelib.h, and we will also be able to include it from myawesomelib.cpp. PUBLIC means it is both used by the target and propagated to its dependents.INTERFACE means the property will be propagated but not applied to the target, it is only used as part of the interface.

PRIVATE means there is no propagation and the property is only applied to the target.There are 3 keywords controlling the propagation:

Some of those properties are called transitive usage requirements and can be propagated from one target to another when a dependency is declared. In CMake, targets have a list of properties that are used when building, and you can populate those using various commands. You probably wonder what the PUBLIC parameter means. target_include_directories(myawesomelib PUBLIC include) Target properties and transitive usage requirements This is done with target_include_directories. Since we put our public headers in a different directory than the other source files, we'll need to tell the compiler where to find those. Note that we will be using the pitchfork convention for file layout. You can start by telling cmake what files are used to build the library. Let's say we want to create a project with a library, and a commandline interface application using it. Those can be created respectively using the commands add_executable, add_library and add_custom_target.ĭependencies between targets can then be defined to determine the build order and link commands. # This is a single line comment Targets The different types of targetsĪ target usually is an executable or a library, but can also be a custom target if your project needs to run some custom tools. 0 LANGUAGES C CXX) CommentsĬomments start with the character # and can be multiline ( bracket comments) if following the bracket_open syntax. This can be done easily with the project command: project(YOUR_PROJECT_NAME VERSION 0.1. Then, you'll want to specify the name, languages and version (needed for packaging purposes). Please do not use something older than 3.1, which dates back to 2014! cmake_minimum_required(VERSION 3.14) Project description In our case we choose CMake 3.14 as it is not too old and supports most recent features. This is important because CMake can have different behaviours based on its versions, which are named policies.ĭepending on the features you will be using, you might need to ask for more recent versions of CMake. The first thing you will need in it, is to specify the minimum version of CMake you will be using. CMake uses a file named CMakeLists.txt, and it is written in its own scripting language.

The CMakeLists.txt fileĪll build systems require some kind of entrypoint for the definition of the project.

CMAKE TARGET SERIES

This is the first article of a mini series related to build systems and continuous integration. We hope to answer this question so that the C++ community can thrive, and make it easier for everyone to integrate any library in a project. So while CMake is far from perfect, for now, it does the job.īut how does one write a good CMake project?

CMAKE TARGET INSTALL

It also requires no additional dependency such as Python which usually makes it a tiny bit easier to install for Continuous Integration on platforms such as Windows. We based this choice on the fact that most of the ecosystem is using CMake, so IDEs now have decent support for it, so do most libraries and major package managers. There are many (relatively) new (meta) buildsystems around lately such as build2 or meson. Cmake,tutorial,C++,buildsystem Why CMake?Īt siliceum, we decided to use CMake for our C++ based projects.

Cmake target