A language processing system is a collection of tools and programs that work together to convert a source program written in a high-level language into an executable machine code that the computer can run.
1️⃣ Preprocessor
- Processes source code before compilation.
- Expands macros and includes header files.
- Output: Modified source code.
Example:
In C/C++, #include <stdio.h> is handled by the preprocessor.
2️⃣ Compiler
- Converts the modified high-level program to assembly language.
- Reports syntax and semantic errors.
- Output: Assembly code.
Think of it as the brain that understands your code and rewrites it in a closer-to-hardware form.
3️⃣ Assembler
- Translates the assembly code to relocatable machine code (object file).
- Output: .obj / .o file.
Assembly → Machine-level binary instructions
4️⃣ Linker
- Combines multiple object files and libraries.
- Resolves external symbols (e.g., functions from other files).
- Output: Final executable machine code.
It “links” your code together like puzzle pieces.
5️⃣ Loader
- Loads the executable into memory.
- Prepares the program for execution by assigning memory addresses.
This is the final step before your program runs.
Hybrid Compilation (Java Example):
- Java uses both compilation and interpretation.
- Java source code → Bytecode (via compiler)
- Bytecode → Executed by JVM (Java Virtual Machine)
Just-In-Time (JIT) Compilation:
- JVM can use a JIT compiler to convert bytecode into machine code at runtime for better performance.