1. really useful.. While it may look like cl.exe is doing all the work, cl.exe does the compiling and link.exe does the linking. To build a shared library, set BUILD_SHARED_LIBS=ON like this: cmake -DBUILD_SHARED_LIBS=ON <source-dir> Some generators (Visual Studio and XCode) support building multiple configurations of your projects in one build directory. This works faster as referencing the library project's directory using the add_subdirectory() command, as the exporting mechanism allows precisely selecting which targets to export. To compile this code, you must have g++, CMake, and libusb-1.0-dev installed on the machine. An object library compiles source files but does not archive or link their object files into a library. ; test: Directory for test. Now you can set INTERFACE properties on this only (since there is no built component). Aside from just going to the library folder and running CMake from there, you can actually do it from the project root - by setting --target option on build: $ rm -r ./* && cmake -DCMAKE_BUILD_TYPE=Debug .. $ cmake --build . Step by step, we will learn the basics of CMake as a build system, along with the CLion settings and actions for CMake projects. W orking with build systems is not the easiest task in the Software Engineering's world, this is especially true for C++ developers where there's not a "standard" of to use this or that. > mkdir build > cd build > cmake .. > cmake --build . 1: the find_library () command The idea here is to instruct CMake to search the system for the required library and then link it to the executable if found. Kitware also provides online and onsite CMake trainings. The source code of the sample project used below is available on GitHub. 1. This also serves as a basic project template for a modern CMake library build. Building a static library and executable which uses CUDA and C++ with CMake and the Makefile generator. CMake is a cross-platform software for building projects written in C, C++, Fortran, CUDA and so on. For internal use, we can just link against these libraries. On Linux run the binary from a terminal. This also means that you won't have any problems with visible symbols from any open source libraries that you linked statically. Why. Basic CMake project. Creates an Object Library. And then in your CMake script code you have: set (CMAKE_CXX_VISIBILITY_PRESET hidden) set (CMAKE_VISIBILITY_INLINES_HIDDEN 1) This will ensure that your shared library will contain only the MY_LIB_API symbols. cmake_minimum_required (VERSION 3.1) . This tutorial explains a relatively simple solution using CMake - the de-facto standard build tool - and git - the de-facto source code version control system. The main thing it's missing is handling dependencies. command is an abstraction for the necessary build/make call. Building complex projects is where CMake really shines CMake is a cross-platform Makefile generator! Florian Florian. It can do much more than that too (e.g., build MS Visual Studio solutions), but in this discussion I focus on the auto-generation of Makefiles for C/C++ projects. Directory structure: src: Directory for source code. The install rules are fairly straight forward. My previous post about CMake provided a simple CMakeLists.txt for a small, self-contained, project. Simple "Hello World" Project Simply put, CMake automatically generates the Makefiles for your project. answered Dec 13, 2015 at 19:38. So, in MathFunctions/CMakeLists.txt we need to create a SqrtLibrary that will conditionally be built and installed when USE_MYMATH is enabled. Object library is a very useful feature which is introduced in cmake 2.8.8. For all the compile options we can use cl and for all the linker options we can use link. This can be any valid CMake name, and the filename for the compiled library will be that value in your build directory. API: C++ 11 or newer, CMake 3.5+ Compiler: GCC, Clang or MSVC CMake automatically found and verified the C++ and CUDA compilers and generated a makefile project. It has a dependency on the list of package files, so that CMake knows it needs to rebuild the zip archive when those files change. cmake-shared-lib-tutorial. The CMake documentation is quite comprehensive but not suitable for a beginner. You can subscribe or request information by contacting us. A CMake script should avoid setting the CMAKE_BUILD_TYPE itself, as it's generally considered the users responsibility to do so. This command creates a new library target built from sources. ; src/main.cc is our main executable and src/math. Command Line (Out-of-Source, recommended) To keep your source code clean from any build artifacts you should do "out-of-source" builds. The solution is simple: When linking a shared library to your C application, you need to inform the GCC toolchain about the library you want to link. Yes it is. A subsequent build is likely to overwrite object files produced by the earlier configuration. When we run nmake, it looks for makefile in the current directory. The command name cmake_minimum_required is case insensitive, so the common practice is to use lower case. Here's the first line of every CMakeLists.txt, which is the required name of the file CMake looks for:. Firstly, the first parameter to add_library is the name of the library. Requirements. <build directory>\CMakeFiles\<target name>\<unique hash>\<source file name>.o. To configure the CMake project and generate a makefile, I used the command cmake -DCMAKE_CUDA_FLAGS="-arch=sm_30" . It is a little more complicated today. The end result is that MathFunctions/CMakeLists.txt should look like: MathFunctions/CMakeLists.txt CMake Installation Head over to CMake download page and get a binary for your operating system, e.g. Rather than placing all of the source files in one directory, we can organize our project with one or more subdirectories. However, we also want to provide a public library for 3rd parties to use. {cc,h} is an internal library that used by src/main.cc.. We will start from the basic on how to build the project using c++(1) only and a simple Makefile.Then we define the build in CMakeLists.txt and using cmake(1) to generate complex Makefile for us. The cmake --build . You do this with linker flag: -l<library name>. cmake says it is mandatory and it will define convenient variables PROJECT_NAME, PROJECT_VERSION and PROJECT_DESCRIPTION (this latter variable necessitate cmake 3.9): project (mylib VERSION 1.0.1 DESCRIPTION "mylib description") Declare a new library target. In this article we're going to design a CMake build and find_package script that enables library users to easily choose and switch between the two library types. This feature allows us group a bunch of object files and pass them as src to add_library or add_executable. So I wrote this short CMake introduction as a distilled version of what I found out after working through the docs and . 37.5k 8 8 gold badges 124 124 silver badges 147 147 bronze badges. --target SomeLibrary Scanning dependencies of target SomeLibrary [ 50%] Building CXX object libraries/SomeLibrary . Follow edited May 23, 2017 at 11:46. The CMake Tutorial is now available as the CMake Tutorial Guide in the official documentation. For single-config generators switching the configuration requires re-running CMake. CMake Tutorial A Basic Starting Point (Step 1) Adding a Version Number and Configured Header File Specify the C++ Standard Build and Test Adding a Library (Step 2) Adding Usage Requirements for Library (Step 3) Installing and Testing (Step 4) Install Rules Testing Support Adding System Introspection (Step 5) Specify Compile Definition CMake is frequently used in compiling open-source and commercial projects. Sometimes you can forget something, if it wasn't used long time (or never on practice). Figure 1 shows the output. With STATIC, SHARED, and MODULE you can specify what kind of library to build. ). As you may have noticed this command is very similar to add_executable . On Linux, you can also install the packages from the distribution's package manager. STATIC libraries are archives of object files that are linked directly into other targets. nmake -f myfile option. add_library (<name> OBJECT [<source>.]) Basic CMake, part 2: libraries By Martin Hoeovsk Jun 2nd 2018 Tags: CMake, Tutorial, C++. But things are changing and efforts towards the development . Please avoid the use of file (GLOB . Now, since this is a tutorial, we are going to explicitly require that SqrtLibrary is built statically. This is provided from CMake to the source code through the TutorialConfig.h.in configured file by adding the following line to it: #cmakedefine USE_MYMATH Installing and Testing (Step 3) For the next step we will add install rules and testing support to our project. Since bar (shared) is linked against foo (static), both of bar and foo must be compiled with position independent code. Where the library name is the name of the shared library, minus the first lib part and minus the .so file extension. Windows, Linux, or Mac OS X. We add the controlling variable with its default value as an option (not a variable set command): This tutorial shows how to export a CMake library to a package and import it from a different project using the find_package() command. This tutorial shows you how to develop a basic shared library in the C programming language and how to generate its build environment with CMake. This tutorial will guide you through the process of creating and developing a simple CMake project. We define a custom command to create the zip file: it needs to invoke cmake -E tar to create an archive. It compiles projects with compilers like GCC, Clang, Intel, MS Visual C++. In this video we build a basic library with CMake.Here is a link to the source code.https://github.com/YansonTech/Introduction-to-libraries-with-CMake full CMake playlist: https://www.youtube.com/watch?v=nlKcXPUJGwA&list=PLalVdRk2RC6o5GHu618ARWh0VO0bFlif4repo: https://github.com/codetechandtutorials/OurLord. 1.cmake configuration 2. Let's mention a bit of CMake syntax. CMake knows bar is a shared library, and enables position independent code by default. We will use Visual Studio to create a basic library project for Raspberry Pi . We can specify a file using the . You should declare a project. If the resulting path is too long (exceeds the value of the CMAKE_OBJECT_PATH_MAX variable), CMake will try to shorten it to the following form: 1. Exercise 1 - Creating a Library To add a library in CMake, use the add_library () command and specify which source files should make up the library. cmake Tutorial => Libraries cmake Build Targets Libraries Example # To create an build target that creates an library, use the add_library command: add_library (my_lib lib.cpp) The CMake variable BUILD_SHARED_LIBS controls whenever to build an static ( OFF) or an shared ( ON) library, using for example cmake .. -DBUILD_SHARED_LIBS=ON. The code in this library is implemented using many of our internal libraries. 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