C++ Compilation Overview

The Compilation Pipeline

Every C++ program goes through multiple transformation stages before becoming executable machine code. This overview shows the complete pipeline:

Compilation Stages

Each stage transforms your code closer to machine language:

1. Preprocessing

The preprocessor rewrites the source text before the compiler proper sees it:

• Macro expansion
• Include processing
• Conditional compilation
• Output: Expanded source (.i file)

2. Parsing & AST

The parser turns the token stream into an abstract syntax tree:

• Lexical analysis (tokenization)
• Syntax analysis (parsing)
• Build Abstract Syntax Tree
• Output: AST representation

3. Semantic Analysis

• Type checking
• Name resolution
• Template instantiation
• Output: Annotated AST

4. Optimization

The optimizer rewrites the intermediate representation:

• Code improvements
• Performance enhancements
• Size reductions
• Output: Optimized IR

5. Code Generation

• Target-specific assembly
• Register allocation
• Instruction selection
• Output: Assembly (.s file)

6. Assembly

• Convert to machine code
• Create object file
• Output: Object file (.o)

Quick Commands

# Complete compilation
g++ main.cpp -o program

# Stop after preprocessing
g++ -E main.cpp -o main.i

# Generate assembly
g++ -S main.cpp -o main.s

# Create object file only
g++ -c main.cpp -o main.o

# With optimization
g++ -O2 main.cpp -o program

Compilation Deep Dives

Explore each stage in detail:

• Preprocessor Directives - Macros and includes
• AST & Parsing - Code structure analysis
• Optimization Techniques - Performance improvements
• Object Files - Binary format and symbols

What's Next?

Related Topics

• Memory Management
• Templates & STL

Related concepts