This technical content related to Unity’s Backend System like How unity compile the code? , How unity build code for different platforms?

Step-1: Convert Source code to Engine code

– We are writing the code in c# it’s called source code.

– Always source code converted into engine code through the compilation process.

– First, all the C# scripts compiled into CIL (Common Intermediate Language).

– All c# code is known as source code and CIL code known as Managed Code.
Managed Code: Managed code easily converted into different-different languages and able to prepare engine code.

– C# easily maintain managed code, so that it is also known as Mixed Programming Language.

Step-2: Types of Compilation

There are two types of the compilation process for c#,

  • AOT [Ahead Of Time]
  • JIT [Just In Time]

– Both compilation processes are starting compilation process depending on the target hardware like android, ios, play-station, etc.

1) AOT [Ahead Of Time] Compilation:

– Ahead Of Time compilation means compiling application during the build process.

– It’s also known as static compilation.

– All the IOS devices use the AOT compilation process because Ios doesn’t allow dynamic compilation.

2) JIT [Just In Time] Compilation:

– Just In Time compilation means compiling applications when running the application on the device.

– It’s also known as dynamic compilation.

Both the compilation process has its own back and forth, so which one is best it is a debatable topic because of both compilation capable of optimization and build code in a better way.
In Unity we can choose any of the compilation processes as per our requirement.

Step-3: Engine Code

– Compilation process build up engine code and finally, it will run on a device, But…

Complexity Level:

– Unity the engine is not developed in C#, it is developed in C++ like other software.

– So that here C++ engine code needs to communicate with C#’s engine code.

– Managed code integrated with “Manage Run-time”,

Manage Run-time is a security mechanism before run/compile process and throw an exception if any bug or error in managed code.

Step-4: Marshalling

– Managed Run-time code(C#) communicating with Unity Engine code (C++) it’s called Marshalling.

Step-5: Build Process

– After completion of marshalling, it will handle lots of complexity during converting code C# into C++ in backend for all the supported platforms like Android, IOS, Windows, Play-station, and many more.

– Finally engine code build up with security level and bug and exception free and ready to build on the device.