Compiler Design

A type system is a set of rules that assigns types to expressions and variables to prevent type errors.

• Static typing: Types checked at compile time (e.g., C, Java, C++).
• Dynamic typing: Types checked at runtime (e.g., Python, JavaScript).
• Strong typing: No implicit, unsafe type conversions allowed.
• Weak typing: Implicit conversions allowed (e.g., C allows char to int).

Compiler Tasks:

• Type checking: Verify operations are applied to compatible types.
• Type inference: Deduce types without explicit annotations.
• Type coercion: Automatically convert one type to another when safe.

Data abstraction separates the interface (what a type does) from its implementation (how it does it).

Compiler Challenges:

• Layout computation: Determine size and field offsets of record/struct types in memory.
• Name mangling: Generate unique internal names for overloaded functions (crucial in C++).
• Separate compilation: Modules are compiled independently using only interface files (headers), requiring a linker to resolve final addresses.