CMake is a tool used to build applications. This tutorial will cover the basics of CMake, and show you how to create simple applications using the tool. It will also cover more advanced implementations of the tool. The tutorial includes an example C++ application that you can use to practice the techniques learned. In addition to the basic use of CMake, this tutorial will also show you how to create cache files. The final part of this tutorial covers advanced CMake implementations.
Getting started with CMake
If you’re a developer who wants to build applications, then you’ve probably heard about CMake. This build tool can help you manage your dependency management and code. The tutorial below uses a simple C++ application as a case study. You’ll learn about its basic use and some more advanced implementations. You’ll also learn to use CMake to build applications with other languages, such as Java. If you’re new to CMake, you can start with a C++ application to learn how it works.
You can edit your CMake variables to customize your build. Some of the variables are cached, so you can change them when you need to. Others will display their current values. Once you’re happy with your choices, click Configure. Once you’ve finished setting up your project, you can click Generate to start building your program. After this, you’ll need to run a compilation test to ensure everything worked correctly.
A good place to get started is with the official CMake documentation. This easy-to-follow guide will introduce you to the many features of the CMake build system. It also contains many examples so that you can get started right away. You can also download the source code from the CMake repository. The official documentation also contains a helpful tutorial and CMake reference guide. The tutorial also contains a step-by-step practical exercise.
When you run CMake, you’ll see lots of output. It will list your output and the dependencies it finds. If there are any missing dependencies, CMake will display an error message. If the dependencies are optional, CMake won’t display them. However, you can still choose to install them if you want to build applications using CMake. This will make your project easier to maintain in the future.
You’ll need to create a build directory when building projects with CMake. This directory will store your compiler outputs and CMake cache. You can use different build directories for your source directory. This allows you to keep your source directory uncluttered. It’s recommended to keep your build directory separate from your source directory. You can skip this step if you don’t want to install your project.
You’re probably not interested in generating configurations with CMake unless you’re doing a very complex project, but some advanced features allow you to do so. One such feature is the ability to specify multiple build types and conditionally evaluate generator expressions based on the built configuration. This feature is particularly useful for multiple-configuration projects where the result will differ depending on the type of configuration.
To use CMake to generate configuration files, you should create a build configuration first. Then you can specify the variables you want to include. The value of the Build type must match the CMake_BUILD_TYPE variable. Once the configuration files are generated, you can then run the generated scripts. If you don’t use CMake, you’ll have to recompile your project after making certain changes. Some generated build scripts will detect these changes automatically, but others need you to recompile manually.
The CMake GUI allows you to run the configure step individually. Using the -D option, you can modify variables in the cache. This command will then create updated project files for you to use. You can also modify variables on the command line with the cmake command. It is important to note that the -D option will only modify the cache variables. So, before running the command line CMake, ensure you have all the required configurations.
The cmake command will generate configurations for the target environment. This command is the easiest way to generate configurations for the LLVM project. It will generate the files that your build tool will need. If you’re new to the LLVM project, you should start with the Getting Started with the LLVM System page. Alternatively, you can use the cmake-gui(1) command-line tool to browse and select generators.
You can use a generator expression to define different build configurations for each building type. When you build a project with cmake, the compiler will generate multiple build root directories. The configurations can be used for debugging and releasing environments. If you use cmake to build an application, define the target name in the command config. This way, the CMake command can evaluate the target name.
When setting variables in CMake, you must know the proper syntax. Usually, variable names start with all caps and are followed by the values. You can access a variable’s value using the $ symbol or the parent scope. The parent scope of a variable is the directory in which it is located. The following examples demonstrate how to use this technique. You can learn more about it in the CMake tutorial.
The cmake variable CMAKE_PREFIX_PATH specifies the path in which your executable will be installed. It must be in the deps/thirdParty folder. You can also use the -PATH keyword to specify the path to a library. This is useful if your executable will need to load a third-party library. Usually, the cmake command will recognize libraries installed on the system. However, if you set the CMAKE_PREFIX_PATH variable, cmake will install libraries that are not in the default path.
CMAKE_VERSION refers to the CMake version. It indicates the development and bug-fix level of a CMake build. It also defines the target platform for the CMake builds. This is useful when using CMake to build an application on different platforms. A wrong CMake code usually causes the error, so modify the file to avoid the error. It is also important to remember that you cannot use CMAKE_VERSION to change the C++ version.
To write a CMake script, you must know the syntax and scope. A CMake variable has scope, and a caller or function can overwrite it. Certain CMake commands and directives also create copies of their scope. You should also be aware that a CMake macro and include are two types of variables that share a single scope. You can use this to set properties for your target.
If you have a poorly written CMake project, you should use CONFIGURE_DEPENDS, which will automatically re-run CMake when you change the file. This will ensure that the generated build is a faithful implementation of the abstract build model. However, there are pathological projects that will require manual re-running of CMake. This is why setting variables in CMake tutorials is so important.
You might be interested in learning how to create a cache with CMake. A cache is a temporary file stored on your system that contains values that the CMake compiler needs to compile and run your application. These files do not appear to the user, but they are used to avoid compiling and running your application more than once. Because of the cache, the files you create should only contain values that change rarely. The following CMake tutorial will provide the steps to create a cache with your application.
The first step in creating a cache with CMake is to set up the project. To do this, you should create a binaries folder and select the generator that will generate the cache file. Once you’ve chosen a generator, you’ll see a list of all the cache variables. Notice that the new cache variables are highlighted in red. To remove the red highlights, click Configure. This will save your new cache files and configure them.
Next, you should set the values of your variables. The $ syntax allows you to set the values of variables in a list. For example, the list() command allows you to use lists in a CMake script. You can also use the list() command to access arbitrary elements in a list. In addition to using variables, you can use the list() command to create caches. The list() command is very useful for working with lists.
After you’ve set the values for the variables you’ll need, you can add them to your toolchain or presets. These variables will be used to customize the CMake build. By changing these values, you can set CMake’s default build settings. Once you’ve done that, you can make any necessary changes. Of course, if you don’t like what you’ve created, you can always remove the cache files.
Using the cache is an important part of CMake. CMake cache files contain information about where the compiler is located. This information is used to make your application run faster. In addition, you can use the cache if you need to access a specific file. Creating a cache for CMake is extremely simple and will save you time. However, it is important to note that caches can cause your application to fail or not compile properly.