Compile instructions (All Platforms)

4年前更新

    This generic guide covers the steps to build MuseScore that are the same on all platforms. See the platform-specific guides for details that only apply to your platform.

    Note to editors: Please do not duplicate information on this page in the specific guides. Where information is already given in multiple guides consider moving it to this page instead.

    Prerequisites

    Install Git and follow the steps in Git Workflow to get MuseScore's code repository on your machine.

    Install CMake, Qt, and the other depedencies (or you can try to compile without them and then install them as needed based on error messages you see in the terminal).

    All programs must be installed to a location mentioned in your PATH environment variable.

    Basic steps

    Once you have MuseScore's code and dependencies on your machine, the steps to compile are the same as for any CMake project. The following commands work on all platforms (Windows, macOS, Linux) and in all shells (Bash, PowerShell, CMD, etc.). Subsequent sections of this guide go into more detail about what the commands actually do.

    mkdir my_build_dir                              # 1. Create build directory
cd my_build_dir
cmake .. -DCMAKE_INSTALL_PREFIX=my_install_dir  # 2. Configure (Mac: add `-GXCode`)
cmake --build .                                 # 3. Build
cmake --build . --target install                # 4. Install (optional)

    These commands are likely to fail the first time you try. Pay attention to error messages displayed in the terminal output as they give clues about how to proceed.

    Note to developers: Please ensure that error messages include information about what the problem is and also how to fix it. This reduces the need for people to rely on a written tutorial.

    1. Create build directory

    mkdir my_build_dir
cd my_build_dir

    The build directory is where compiled code will go. You can name the build directory whatever you like.

    Tip: You can create multiple build directories for different configurations of the project (e.g. different platforms, compilers, git branches, or build types such as Release and Debug). This saves having to do a clean build every time you switch configuration.

    2. Configure

    cmake .. -G[generator] -D[option]=[value]  # configure

    During the configure step, CMake reads build rules from the top-level CMakeLists.txt and uses them to generate a native build system. This is just a new set of build rules that will work with whichever operating system, processor architecture, compiler toolchains, and IDE you happen to be using.

    Note: Build rules are also taken from other CMakeLists.txt and *.cmake files in subdirectories mentioned in the top-level file.

    CMake Generators

    By default, CMake tries to guess which native tool you want to build with. If you want it to generate code for a different tool then you can tell it to do so using the -G[generator] option at the configure stage. On macOS, only the XCode generator is currently supported, so you must use it as follows:

    cmake .. -GXCode -D[option]=[value]  # configure for XCode (only on macOS)

    On other platforms you can use any available generator, or you can leave out the -G option to make CMake use the default one.

    The CMake manual has a list of all generators and cmake --help will show the ones that are available on your system.

    CMake Variables

    You can pass options and variables to the configure step using the -D[variable]=[value] syntax. For example:

    cmake .. -DCMAKE_INSTALL_PREFIX=my_install_dir  # configure with variable

    This sets the CMake variable CMAKE_INSTALL_PREFIX to the value my_install_dir, which means that during the install step the compiled binary and accompanying resources (fonts, translations, templates, etc.) will be copied to a directory called my_install_dir inside your build directory.

    Built-in variables

    CMake's online documentation has a complete list of built-in variables. Here are some of the key ones:

    • CMAKE_INSTALL_PREFIX - directory to install the compiled program and accompanying resources.
      • The default locations are /usr/local on UNIX and C:/Program Files/${PROJECT_NAME} on Windows, but it's a good idea to use a relative path instead as this avoids the need for root/admin privileges during the install step.
    • CMAKE_BUILD_TYPE - whether to create a Release or a Debug build.
      • Developers usually set this to Debug because Release discards symbols necessary for debugging. Windows users might prefer RelWithDebug as this enables optimisations that increase performance while still retaining debug symbols.
    • CMAKE_MAKE_PROGRAM - full path to native build tool (or just the tool's name if it's in PATH).
      • You don't have to set this unless the tool has a non-standard name or location. MinGW users must set it to mingw32-make.exe.

    Project variables

    MuseScore defines it's own options and variables mostly in the top-level CMakeLists.txt. Examples:

    • BUILD_64 - Enable 64 bit builds.
      • Default is ON. Has no effect except with MSVC on Windows.
    • MSCORE_INSTALL_SUFFIX - string to append to the name of the mscore binary to prevent conflicts.
      • Has no effect except on Linux where MSCORE_INSTALL_SUFFIX=foo would give mscorefoo.
      • Default value is "" (i.e. the empty string) so binary is just called mscore.
      • Use values that start with -portable to enable AppImage builds on Linux.

    Project variables are set on the command line with the -D option in the same way as other CMake variables:

    cmake .. -DBUILD_64=OFF  # configure with option

    If you need to call CMake with lots of options then you could create a shell script or batch file to make it easy to run the same commands again in the future. You may notice that there are some scripts in repository root folder that do this already (see the Makefiles and msvc_build.bat). These are provided as a convenience, but it is better to avoid them and write your own if you can. CMake's purpose is to abstract the build process so that it is the same on all platforms. Providing a separate script for each platform undermines this purpose and discourages developers from learning how to use CMake properly.

    3. Build

    cmake --build .  -j[CPUs]

    During the build step, CMake runs the native build tool on the generated build system. This compiles the C++ code and creates the mscore binary.

    Note: You could run the native tool yourself by calling make, xcodebuild or MSBuild.exe directly, but then you'd have to learn how to use that tool and all the options it takes. Fortunately, CMake provides the handy --build option that calls the native tool for you with all the right options.

    Parallel builds

    CMake 3.12 and later versions have a -j[number] option to set the number of build jobs to launch in parallel. For the shortest build time, set the number equal to the number of CPU cores available on your machine. Alternatively, you can set the environment variable CMAKE_BUILD_PARALLEL_LEVEL.

    4. Install

    cmake --build . --target install

    During the install step, CMake again run the native build tool on the generated build system, but this time it specifically tells the tool to build the install target. The install target copies the compiled binaries and accompanying resources to the install directory specified in the configure step.

    If you attempt to install to a system folder such as /usr/local or C:\Program Files then you will need to run the install command as root/admin privileges. This means using sudo on Unix or running from an Administrator prompt on Windows.

    Note: CMake 3.15 and later versions have a dedicated --install option that does the same thing, but you can still use the old syntax if you prefer.

    cmake --install .  # install with CMake 3.15 or later

    Installing the project is optional. You can run the compiled mscore binary without installing it first but you won't be able to load the soundfont or templates untill you install.

    Subsequent builds

    You'd need to recompile the project whenever the code changes, but you don't have to go through all the steps from the beginning. You can usually get away with just running the build and install steps on subsequent builds. This applies even if you edit one of the CMakeLists.txt or *.cmake files; the build system will detect this during the build step and then rerun the configure step automatically.

    Incremental builds

    The build system CMake generates is clever enough to only recompile code files that have actually changed. This is known as an incremental build.

    Clean builds

    Occasionally it may be necessary to start again from scratch. This is known as a clean build. You have to do this if you want to use a different compiler, and you might find that it fixes other problems too.

    You can use either of the following commands from within the build directory to clean it:

    cmake --build . --target clean  # clean (i.e. delete compiled binaries)
cmake --build . --clean-first   # clean and then build

    Alternatively, you can simply create a new build directory and run the configure step from inside it. Make sure you delete any old build directories that you no longer need because they take up quite a lot of space.