.. _doc_compiling_with_mono:

Compiling with Mono
===================

.. highlight:: shell

Requirements
------------

- Mono (the required version is listed here: :ref:`doc_c_sharp`)
- MSBuild
- pkg-config

Environment Variables
---------------------

By default, SCons will try to find Mono in the Windows Registry on Windows or via ``pkg-config`` on other platforms. You can specify a different installation directory by using the following environment variables for the respective ``bits`` option: ``MONO32_PREFIX`` and ``MONO64_PREFIX``.

The specified directory must contain the subdirectories ``bin``, ``include``, and ``lib``.

Enable Mono Module
--------------------

By default, the mono module is disabled for builds. To enable it you can pass the option ``module_mono_enabled=yes`` to your SCons command.

Generate The Glue
-------------------

The glue sources are the wrapper functions that will be called by the managed side. In order to generate them, first, you must build Godot with the options ``tools=yes`` and ``mono_glue=no``:

::

    scons p=<platform> tools=yes module_mono_enabled=yes mono_glue=no

After the build finishes, you need to run the compiled executable with the parameter ``--generate-mono-glue`` followed by the path to an output directory. This path must be ``modules/mono/glue`` in the Godot directory.

::

    godot --generate-mono-glue modules/mono/glue

This command will tell Godot to generate the file *modules/mono/glue/mono_glue.gen.cpp*. Once this file is generated, you can build Godot for all the desired targets without the need to repeat this process.

As always, ``godot`` refers to the compiled Godot binary, so if it isn't in your PATH, you need to give the full path to the executable, e.g. if it is located in the ``bin`` subfolder, it becomes ``bin/godot``.

Notes
^^^^^
-  **Do not** build normal binaries with ``mono_glue=no``. This option disables C# scripting and therefore must only be used for the temporary binary that will be used to generate the glue. Godot should print a message at startup warning you about this.
-  The glue sources must be regenerated every time the ClassDB API changes. If there is an API mismatch with the generated glue, Godot will print an error at startup.

Examples
--------

Example (Windows)
^^^^^^^^^^^^^^^^^
::

    # Build temporary binary
    scons p=windows tools=yes module_mono_enabled=yes mono_glue=no
    # Generate glue sources
    bin\godot.windows.tools.64.mono --generate-mono-glue modules/mono/glue

    ### Build binaries normally
    # Editor
    scons p=windows target=release_debug tools=yes module_mono_enabled=yes
    # Export templates
    scons p=windows target=debug tools=no module_mono_enabled=yes
    scons p=windows target=release tools=no module_mono_enabled=yes

Example (x11)
^^^^^^^^^^^^^
::

    # Build temporary binary
    scons p=x11 tools=yes module_mono_enabled=yes mono_glue=no
    # Generate glue sources
    bin/godot.x11.tools.64.mono --generate-mono-glue modules/mono/glue

    ### Build binaries normally
    # Editor
    scons p=x11 target=release_debug tools=yes module_mono_enabled=yes
    # Export templates
    scons p=x11 target=debug tools=no module_mono_enabled=yes
    scons p=x11 target=release tools=no module_mono_enabled=yes

If everything went well, apart from the normal output, SCons should have also built the *GodotSharpTools.dll* assembly and copied it together with the mono runtime shared library to the ``bin`` subdirectory.