Understanding compilation

The process of translating high-level source code into runnable machine code for compiled languages like C and C++ is a multi-step pipeline that transforms human-readable instructions into a form the computer can execute directly. This process ensures that the logic, data structures, and operations defined in the source code are correctly interpreted and optimised for the CPU.

Each step in the compilation pipeline, from preprocessing and syntax analysis to code generation and linking, plays a crucial role in producing a reliable and efficient executable program.

Let's take a closer look at each of these steps to understand how source code becomes a running application.

Preprocessing

The source code files (e.g., .c or .cpp) are first handled by a preprocessor, a tool that prepares the code for compilation. One of its main tasks is to process directives that start with #, such as #include, which inserts the content of header files, and #define, which replaces macros with their corresponding values. This allows programmers to write modular, reusable code while keeping source files organised.