Add "Build System" section to godot-cpp docs.

Author: Ivorforce

tutorials/scripting/cpp/build_system.rst

@@ -0,0 +1,77 @@
+.. _doc_godot_cpp_build_system:
+
+Build System
+============
+
+`godot-cpp <https://github.com/godotengine/godot-cpp>`__ uses `SCons <https://scons.org>`__ as its build system.
+It is modeled after :ref:`Godot's build system <doc_compiling_index>`, and some commands available there are also
+available in godot-cpp projects.
+
+Getting Started
+---------------
+
+To build a godot-cpp project, it is generally sufficient to install `SCons <https://scons.org>`__, and simply run it
+in the project directory:
+
+    scons
+
+You may want to learn about available options:
+
+    scons --help
+
+To cleanly re-build your project, add ``--clean`` to your build command:
+
+    scons --clean
+
+You can find more information about common SCons arguments and build patterns in the
+`SCons User Guide <https://scons.org/doc/latest/HTML/scons-user/index.html>`__. Additional commands may be added by
+individual godot-cpp projects, so consult their individual documentations for more information on those.
+
+Configuring an IDE
+------------------
+
+Most IDEs can use a ``compile_commands.json`` file to understand a C++ project. You can generate it in godot-cpp with
+the following command:
+
+.. code-block:: shell
+
+   # Generate compile_commands.json while compiling
+   scons compiledb=yes
+
+   # Generate compile_commands.json without compiling
+   scons compiledb=yes compile_commands.json
+
+For more information, please check out the :ref:`IDE configuration guides <doc_configuring_an_ide>`.
+Although written for Godot engine contributors, they are largely applicable to godot-cpp projects as well.
+
+Loading your GDExtension in Godot
+---------------------------------
+
+Godot loads GDExtensions by finding :ref:`.gdextension <doc_gdextension_file>` files in the project directory.
+``.gdextension`` files are used to select and load a binary compatible with the current computer / operating system.
+
+The `godot-cpp-template <https://github.com/godotengine/godot-cpp-template>`__, as well as the
+:ref:`Getting Started section <doc_godot_cpp_getting_started>`, provide example ``.gdextension`` files for GDExtensions
+that are widely compatible to many different systems.
+
+Building for multiple platforms
+-------------------------------
+
+GDExtensions are expected to run on many different systems. Generally, a single computer is only capable of building
+for a few different platforms. For example, Windows users will be able to build for Windows, Android and Web,
+but not for macOS or Linux.
+
+To make your GDExtension as widely compatible as possible, we recommend setting up Continuous Integration (CI) to build
+your GDExtension on many different platforms. The
+`godot-cpp-template <https://github.com/godotengine/godot-cpp-template>`__ contains an example setup for a GitHub based
+CI workflow.
+
+CMake
+-----
+
+godot-cpp comes with a `CMakeLists.txt <https://github.com/godotengine/godot-cpp/blob/master/CMakeLists.txt>`__ file, to
+support users that prefer using `CMake <https://cmake.org>`__ over `SCons <https://scons.org>`__ for their build system.
+
+While actively supported, it is considered secondary to the SCons build system. This means it may lack some features
+that are provided for users using SCons. It is documented in godot-cpp's
+`cmake.rst <https://github.com/godotengine/godot-cpp/blob/master/doc/cmake.rst>`__ file.

tutorials/scripting/cpp/index.rst

@@ -14,4 +14,5 @@ the official C++ GDExtension bindings maintained as part of the Godot project.
 
    about_godot_cpp
    gdextension_cpp_example
+   build_system
    gdextension_docs_system