Program Conversion Steps (Compiler)

1. Pre-Processor

• Takes High-Level Language (HLL) as input.
• Converts it into pure HLL (ready for compiler).

• Tasks:

  • File inclusion → adds header file content.
  • Macro replace → #define PI 3.14 → every PI becomes 3.14.
  • Small changes → e.g., i++ → i = i + 1.

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1. Compiler

• Converts pure HLL → Assembly Language.
• Checks errors (syntax, type mismatch, etc.).

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1. Assembler

• Converts Assembly code → Object code (binary form).

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1. Linker

• Combines many object files + libraries into one executable file.

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1. Loader

• Loads the executable file into main memory.
• Then CPU runs the program.

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Easy Flow:

High-Level Language → Pre-Processor → Compiler → Assembler → Linker → Loader → Execution

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